FN Clarivate Analytics Web of Science VR 1.0 PT J AU Sittler, KL Parker, KL Gillingham, MP AF Sittler, Krista L. Parker, Katherine L. Gillingham, Michael P. TI Vegetation and prescribed fire: Implications for stone's sheep and elk SO JOURNAL OF WILDLIFE MANAGEMENT AB Fire is the dominant single natural disturbance influencing northern mountain and boreal landscapes. We evaluated fire-induced changes in forage resources for 2 focal ungulates, Stone's sheep (Ovis dalli stonei) and elk (Cervus canadensis), in northern British Columbia, Canada. We implemented 4 prescribed fires and monitored short-term vegetation (quantity and quality) and ungulate (Stone's sheep and elk) responses. We took measurements prior to burning, the year of burning, and 1 year after burning in treatment areas and adjacent unburned control areas in winter and summer at 2 scales. At a fine scale, we used vegetation transects and pellet counts; at the landscape scale, we used Landsat imagery for vegetation and aerial survey flights for animals. Following prescribed fire, shrub cover declined and burned communities increased in herbaceous cover. Plant species diversity also declined but increased to almost that of unburned areas by 1 year after burning. Burning increased quality of forage most (2-7 percentage points more digestibility and 0.3-6.3 percentage points more crude protein than unburned areas) in the summer of the burn. In winter, forage biomass and available digestible dry matter increased to pre-burn levels by 1 year after burning. Stone's sheep and elk always used burned areas more than unburned control areas in winter at both scales. Whereas elk used sites with higher forage quantity, Stone's sheep appeared to respond to forage quality at the fine scale. Ungulate grazing during the 2 years of this study did not alter forage quantity on burned or unburned sites, as determined from range exclosures. Based on our findings in this area, maximum benefits to elk would be achieved from large prescribed fires on south-aspect slopes that result in the greatest amounts of forage biomass. Smaller prescribed fires at high burn intensities on west-aspect slopes intermixed with rocky outcrops and talus scree (less frequented by elk) would most benefit Stone's sheep requirements for high-quality forage and escape terrain. (c) 2018 The Wildlife Society. SN 0022-541X EI 1937-2817 PD FEB PY 2019 VL 83 IS 2 BP 393 EP 409 DI 10.1002/jwmg.21591 UT WOS:000455486900015 ER PT J AU Olofsson, J Post, E AF Olofsson, Johan Post, Eric TI Effects of large herbivores on tundra vegetation in a changing climate, and implications for rewilding SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES AB In contrast to that of the Pleistocene epoch, between approximately 2.6 million and 10 000 years before present, the extant community of large herbivores in Arctic tundra is species-poor predominantly due to human extinctions. We here discuss how this species-poor herbivore guild influences tundra ecosystems, especially in relation to the rapidly changing climate. We show that present herbivore assemblages have large effects on tundra ecosystem composition and function and suggest that the effect on thermophilic species expected to invade the tundra in a warmer climate is especially strong, and that herbivores slow ecosystem responses to climate change. We focus on the ability of herbivores to drive transitions between different vegetation states. One such transition is between tundra and forest. A second vegetation transition discussed is between grasslands and moss-and shrub-dominated tundra. Contemporary studies show that herbivores can drive such state shifts and that a more diverse herbivore assemblage would have even higher potential to do so. We conclude that even though many large herbivores, and especially the megaherbivores, are extinct, there is a potential to reintroduce large herbivores in many arctic locations, and that doing so would potentially reduce some of the unwanted effects of a warmer climate. This article is part of the theme issue 'Trophic rewilding: consequences for ecosystems under global change'. OI Olofsson, Johan/0000-0002-6943-1218 SN 0962-8436 EI 1471-2970 PD DEC 5 PY 2018 VL 373 IS 1761 SI SI AR 20170437 DI 10.1098/rstb.2017.0437 UT WOS:000449344900005 PM 30348880 ER PT J AU Wegrzyn, MH Wietrzyk, P Lehmann-Konera, S Chmiel, S Cykowska-Marzencka, B Polkowska, Z AF Wegrzyn, Michal Hubert Wietrzyk, Paulina Lehmann-Konera, Sara Chmiel, Stanislaw Cykowska-Marzencka, Beata Polkowska, Zaneta TI Annual variability of heavy metal content in Svalbard reindeer faeces as a result of dietary preferences SO ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH AB During both winter and summer, Svalbard reindeer selectively feed on different types of vegetation that are not only a source of nutritional value, but also a place of heavy metal accumulation. In the present study, the content of cadmium, chromium, copper, iron, lead, nickel, manganese, and zinc in reindeer excrement was measured. The main aims were to determine the seasonal content of several heavy metals in Svalbard reindeer faeces, and to compare their values in terms of dietary preferences during the year. Summer and winter reindeer excrement was gathered along a designated linear transect running through Bolterdalen and the vegetation described on 1m(2) plots. All of the analysed heavy metals were detected in the reindeer faeces and this fact seems to be connected with the incomplete content of these elements in an animal's tissue after forage digestion. Analysis showed differences between summer and winter excrement in terms of concentrations of cadmium, chromium, iron, and nickel, but no differences were found for the other four elements analysed (manganese, lead, zinc, and copper). However, concentrations of heavy metals in faeces are rather low in comparison with both the levels in the vegetation that may be grazed by reindeer and in reindeer tissue. RI Wietrzyk-Pelka, Paulina/B-3506-2019 OI Wietrzyk-Pelka, Paulina/0000-0002-1324-2012; Wegrzyn, Michal/0000-0001-7638-4803 SN 0944-1344 EI 1614-7499 PD DEC PY 2018 VL 25 IS 36 SI SI BP 36693 EP 36701 DI 10.1007/s11356-018-3479-8 UT WOS:000452489500081 PM 30377969 ER PT J AU Hornberg, G Josefsson, T DeLuca, TH Higuera, PE Liedgren, L Ostlund, L Bergman, I AF Hornberg, G. Josefsson, T. DeLuca, T. H. Higuera, P. E. Liedgren, L. Ostlund, L. Bergman, I TI Anthropogenic use of fire led to degraded scots pine-lichen forest in northern Sweden SO ANTHROPOCENE AB Northern pine-lichen forests are generally regarded as natural ecosystems that, in the past, were repeatedly affected by wild fires. This paper presents and tests a new hypothesis that reindeer herders used recurrent fires to promote and sustain reindeer lichen-dominated ground vegetation, in order to maintain good winter-grazing grounds in Scots pine forests. We investigated vegetation and fire history in three pine-lichen forests along the Lulealven River in northernmost Sweden. Methods included analyses of pollen, spores, charcoal and soil nutrient capital, coupled with investigation of written historical sources and previous studies. Results suggest that recurrent, intermediate-interval fires started sometime between the 2nd and 8th centuries CE, i.e. at the same time that reindeer became semidomesticated in this region. Such fires continued until the 18th century, when introduction of active fire suppression reduced the occurrence of fire in the landscape. Repeated burning over this long period eventually depleted the soil-nutrient capital, especially nitrogen and phosphorous, thereby severely reducing productivity. In the early 20th century, foresters described such forests as degraded. Results of this study add a new dimension to understanding the genesis and history of many pine-lichen forests. They challenge the notion that reindeer herders have been reluctant, in the past, to use fire. Further studies are needed to evaluate whether a similar history can be ascribed to pine-lichen forests in other parts of northern Fennoscandia. (C) 2018 The Author(s). Published by Elsevier Ltd. OI DeLuca, Thomas Henry/0000-0003-1561-9597; Higuera, Philip/0000-0001-5396-9956 SN 2213-3054 PD DEC PY 2018 VL 24 BP 14 EP 29 DI 10.1016/j.ancene.2018.10.002 UT WOS:000452555800002 ER PT J AU Egelkraut, D Aronsson, KA Allard, A Akerholm, M Stark, S Olofsson, J AF Egelkraut, Dagmar Aronsson, Kjell-Ake Allard, Anna Akerholm, Marianne Stark, Sari Olofsson, Johan TI Multiple Feedbacks Contribute to a Centennial Legacy of Reindeer on Tundra Vegetation SO ECOSYSTEMS AB Historical contingency is the impact of past events, like the timing and order of species arrival, on community assembly, and can sometimes result in alternative stable states of ecological communities. Large herbivores, wild and domestic, can cause profound changes in the structure and functioning of plant communities and therefore probably influence historical contingency; however, little empirical data on the stability of such shifts or subsequent drivers of stability are available. We studied the centennial legacy of reindeer (Rangifer tarandus) pressure on arctic tundra vegetation by considering historical milking grounds (HMGs): graminoid- and forb-dominated patches amid shrub-dominated tundra, formed by historical Sami reindeer herding practices that ended approximately 100years ago. Our results show that the core areas of all studied HMGs remained strikingly stable, being hardly invaded by surrounding shrubs. Soil nitrogen concentrations were comparable to heavily grazed areas. However, the HMGs are slowly being reinvaded by vegetative growth of shrubs at the edges, and the rate of ingrowth increased with higher mineral N availability. Furthermore, our data indicate that several biotic feedbacks contribute to the stability of the HMGs: increased nutrient turnover supporting herbaceous vegetation, strong interspecific competition preventing invasion and herbivore damage to invading shrubs. In particular, voles and lemmings appear to be important, selectively damaging shrubs in the HMGs. We concluded that HMGs provide clear evidence for historical contingency of herbivore effects in arctic ecosystems. We showed that several biotic feedbacks can contribute to subsequent vegetation stability, but their relative importance will vary in time and space. SN 1432-9840 EI 1435-0629 PD DEC PY 2018 VL 21 IS 8 BP 1545 EP 1563 DI 10.1007/s10021-018-0239-z UT WOS:000450919700005 ER PT J AU Santalahti, M Sun, H Sietio, OM Koster, K Berninger, F Laurila, T Pumpanen, J Heinonsalo, J AF Santalahti, Minna Sun, Hui Sietio, Outi-Maaria Koster, Kajar Berninger, Frank Laurila, Tuomas Pumpanen, Jukka Heinonsalo, Jussi TI Reindeer grazing alter soil fungal community structure and litter decomposition related enzyme activities in boreal coniferous forests in Finnish Lapland SO APPLIED SOIL ECOLOGY AB Reindeer grazing in northern boreal zone affects forest floor vegetation heavily and alters the vegetation structure. However, the effect of grazing on soil fungal communities, which are intimately linked to plants, is not currently known. Therefore, our objectives were to investigate changes caused by reindeer grazing on soil fungal communities, litter decomposition rate and litter degrading extracellular enzyme activities. The study was conducted in four areas divided into grazed and non-grazed sites (all together 38 sample plots) in northern boreal forests in Finnish Lapland. Fungal communities were analyzed from humus with high-throughput sequencing technology (454-pyrosequencing), and litter mass loss and extracellular enzyme activities were analyzed after a one-year litterbag experiment. The results showed that grazing significantly affected the fungal community structure and the abundance of certain fungal genera and species. Grazing also decreased laccase and enhanced cellobiohydrolase I activities from the litterbags. Our study is one of the first to describe detailed fungal community composition in sites with long-term history of reindeer grazing and exclusion. Our results indicate that reindeer grazing alter fungal community structure and litter degradation related enzyme activities in the northern boreal forest soils. RI Koster, Kajar/C-8397-2012 OI Koster, Kajar/0000-0003-1988-5788; Santalahti, Minna E/0000-0002-3004-1714; Heinonsalo, Jussi/0000-0001-8516-1388 SN 0929-1393 EI 1873-0272 PD DEC PY 2018 VL 132 BP 74 EP 82 DI 10.1016/j.apsoil.2018.08.013 UT WOS:000447329300008 ER PT J AU Rasmus, S Kivinen, S Irannezhad, M AF Rasmus, Sirpa Kivinen, Sonja Irannezhad, Masoud TI Basal ice formation in snow cover in Northern Finland between 1948 and 2016 SO ENVIRONMENTAL RESEARCH LETTERS AB Basal ice formation in the terrestrial snow cover is a common phenomenon in northern circumpolar areas, onehaving significant impacts on ecosystems, vegetation, animals and human activities. There is limited knowledge on the spatial and temporal occurrence of basal ice formation because of the sparse observation network and challenges involved in detecting formation events. We present a unique dataset on the annual extent of ice formation events in northern Finland between 1948 and 2016 based on reindeer herders' descriptions of the cold season in their management reports. In extreme years, basal ice can form over wide geographical extents. In approximately half of the herding districts studied, it occurred more frequently in the period 1983-2016 than in the period 1948-1982. Furthermore, five out of seven of the most extensive basal ice formation events (90th percentile) occurred between 1991 and 2016. Themost commonly reported processes related to ice formation were thaw or rain-on-snow events followed by freezing of the snow cover. Years with extensive basal ice formation were often characterized by above-average October-December air temperatures, air temperature variations around 0 degrees C and relatively high precipitation. However, basal ice did not occur during all warm and wet early winters, and formation events were generally weakly linked to the large-scale atmospheric teleconnections. Another risk factor for reindeer grazing associated with warm and rainy earlywinters is the growth of mycotoxin-producing molds below the snow. Approximately 24% of all reported mold formation events co-occurred with basal ice formation. The prevalence and frequency of basal ice formation events can be assessed based on our results. Ourwork contributes to understanding long-term fluctuations and changes in snow and ice conditions and the impacts of this variability in circumpolar areas. SN 1748-9326 PD NOV PY 2018 VL 13 IS 11 AR 114009 DI 10.1088/1748-9326/aae541 UT WOS:000449184500004 ER PT J AU Sheremetev, IS Rozenfeld, SB AF Sheremetev, I. S. Rozenfeld, S. B. TI Landscape Changes during the Pleistocene-Holocene Transition and Range Dynamics of Large Herbivorous Mammals of Northern Asia SO ARID ECOSYSTEMS AB This work studies the effect of the reduction of steppe and tundra landscapes in Northern Asia during the Late Pleistocene and Holocene climatic changes on the ranges of large herbivorous mammals. The relationship between a complex of characteristics of herbivore species and their landscape was evaluated. It is found that not only the Mongolian gazelle, saiga, and musk ox, but also the snow sheep, the ancestors of domestic sheep and goats, and probably the Amur goral may reduced their ranges during the late Quaternary landscape changes. The widening of the range of the sika deer, as well as the range of the Siberian musk deer associated exclusively with forest landscapes, can be explained by a reduction of open landscapes. Any significant changes in the ranges of roe deer, red deer, reindeer, elk, wild boar, steppe bison, mammoth, woolly rhinoceros, and ancestral and probably related forms of domestic horse and cattle could not be directly caused by landscape changes 17000-7000 years ago, even if they coincide chronologically. SN 2079-0961 EI 2079-0988 PD OCT PY 2018 VL 8 IS 4 BP 245 EP 253 DI 10.1134/S207909611804011X UT WOS:000455518800002 ER PT J AU Morrissette-Boileau, C Boudreau, S Tremblay, JP Cote, SD AF Morrissette-Boileau, Clara Boudreau, Stephane Tremblay, Jean-Pierre Cote, Steeve D. TI Revisiting the role of migratory caribou in the control of shrub expansion in northern Nunavik (Quebec, Canada) SO POLAR BIOLOGY AB Widespread shrub expansion has been observed at the circumpolar scale in response to climate change. This phenomenon could be inhibited by large herbivores through selective browsing that reduces shrub growth. Our objective was to assess the dynamics of shrub species in the Deception Bay area, in Nunavik (Quebec, Canada), a region in the summer range of the Riviere-aux-Feuilles migratory caribou herd. We surveyed abundance and stem mortality of all shrub species along systematically located transects in a 54 km(2) area. Our results showed that shrubs covered 11.5% of the area, and were dominated by prostrate Betula glandulosa (8.7%). Stem mortality of established individuals was greater for Salix planifolia (45.6%) and Salix glauca (46.5%) than for B. glandulosa (9.3%). Using dendrochronological analysis, we determined the age structure of the two dominant erect shrub species in ten 10 m x 10 m plots. We recorded a high number of B. glandulosa and, to a lesser extent, of S. planifolia recruits (71.0 and 4.6 per 100 m(2), respectively) established after 1999, when the Riviere-aux-Feuilles herd was abundant. Thus, our results do not support the hypothesis that large herbivores counteracted the positive effects of climate change on shrub recruitment. However, since the structure of the recruits are prostrate rather than erect, as is usually observed with shrub expansion in the warming Arctic, it is likely that herbivory, and/or, the harsh climate, is constraining habitat change. SN 0722-4060 EI 1432-2056 PD SEP PY 2018 VL 41 IS 9 BP 1845 EP 1853 DI 10.1007/s00300-018-2325-2 UT WOS:000447600600016 ER PT J AU Ungerfeld, EM Leigh, MB Forster, RJ Barboza, PS AF Ungerfeld, Emilio M. Leigh, Mary Beth Forster, Robert J. Barboza, Perry S. TI Influence of Season and Diet on Fiber Digestion and Bacterial Community Structure in the Rumen of Muskoxen (Ovibos moschatus) SO MICROORGANISMS AB We studied the relationship between fiber digestion and the composition of the bacterial community in the rumen of muskoxen at the start and the end of the annual window of plant growth from spring to fall. Eight ruminally cannulated castrated males were fed brome hay or triticale straw (69.6% vs. 84.6% neutral detergent fiber, respectively) that were similar in fiber content to the sedges consumed by wild muskoxen (64.5 to 71.7% neutral detergent fiber). Muskoxen digested fiber from both forages faster and to a greater extent when straw rather than hay was consumed. Fiber digestion was therefore inducible by diet 4 in each season. We used 16S rRNA sequences from ruminal contents to study how season and diet affected the bacterial community and how the latter related to fiber digestion. We found that Bacteroidetes and Firmicutes accounted for 90% of the sequences at the level of Phylum, which is typical for the mammal gut microbiome. Using partial least square regressions, it was found that between 48% and 72% of the variation in fiber digestion was associated with 36-43 genera of bacteria. The main fibrolytic bacteria typical of domestic ruminants were generally not among the most important bacteria associated with fiber digestion in muskoxen. This reveals that muskoxen rely upon on a large suite of bacterial genera that are largely distinct from those used by other ruminants to digest the cell walls of plants that vary widely in both abundance and nutritional quality through the year. SN 2076-2607 PD SEP PY 2018 VL 6 IS 3 AR UNSP 89 DI 10.3390/microorganisms6030089 UT WOS:000446334200034 PM 30127327 ER PT J AU Vaieretti, MV Iamamoto, S Harguindeguy, NP Cingolani, AM AF Victoria Vaieretti, Maria Iamamoto, Sabrina Perez Harguindeguy, Natalia Maria Cingolani, Ana TI Livestock grazing affects microclimate conditions for decomposition process through changes in vegetation structure in mountain grasslands SO ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY AB It is often assumed that a change in litter quality is the main driver of alterations in the decomposition process when grazers modify vegetation structure. Soil microclimate is also modified, but this driver of decomposition has been far less studied than litter quality. We analyzed the relationships among vegetation structure, micro climate and decomposition in different mountain grassland types, across a fence-line separating paddocks with different grazing intensity. Along the fence, we selected nine pairs of contrasting grassland types including lawns and tall tussock grasslands, which are associated with high and low local grazing pressure, respectively. At each site (N = 18) we estimated growth form composition and vegetation height. During the growing season we recorded soil temperature, soil moisture and the photosynthetically active radiation. Within the same period, we measured the decomposition rate of two common litter substrates. We analyzed the relationships among those variables at the landscape and at the local scale. At the landscape scale we considered the variation across all sites (N = 18). At the local scale we considered each pair as a sample (N = 9) and the differences between both sides of the fence as the variables to correlate. Our results indicate that when short grasslands are released from grazing and tall grasslands became dominant, temperature and light at the soil level are reduced, while soil moisture tends to increase, enhancing decomposition. Furthermore, these results show that the microclimatic conditions effect can counteract the litter quality effect (reported in previous studies) on decomposition, resulting in increased decomposition rates when grazing is reduced. SN 1146-609X EI 1873-6238 PD AUG PY 2018 VL 91 BP 101 EP 107 DI 10.1016/j.actao.2018.07.002 UT WOS:000441487500014 ER PT J AU Egelkraut, D Kardol, P De Long, JR Olofsson, J AF Egelkraut, Dagmar Kardol, Paul De Long, Jonathan R. Olofsson, Johan TI The role of plant-soil feedbacks in stabilizing a reindeer-induced vegetation shift in subarctic tundra SO FUNCTIONAL ECOLOGY AB 1. Herbivory can drive vegetation into different states of productivity and community composition, and these changes may be stable over time due to historical contingency effects. Interactions with abiotic and biotic soil components can contribute to such long-term legacies in plant communities through stabilizing positive feedbacks. 2. We studied the role of plant-soil feedbacks in maintaining vegetation changes caused by historical (similar to 1350-1900 AD) reindeer herding in northern Sweden. These historical milking grounds (HMGs) consist of meadow plant communities formed in naturally nutrient-poor heath or naturally nutrient-rich shrub-dominated vegetation and are still clearly visible in the landscape, a century after active use ceased. 3. We selected two phytometer species: the forb Potentilla crantzii as representative of HMG vegetation, and the dwarf shrub Betula nana, as representative of control vegetation. We grew both species under glasshouse conditions on soils derived from replicated HMG and paired control plots, using live soils and sterilized (-radiation)-inoculated soils, to separate between biotic and abiotic soil effects. 4. A net negative plant-soil feedback for B.nana biomass in its home (i.e., control) soil and a net positive feedback for P.crantzii in its home (i.e., HMG) soil in heath habitat was partly driven by the soil biotic community. However, abiotic differences in mineral nitrogen (N) concentrations between control and HMG soils were a stronger driver of differences in plant growth. Positive feedbacks maintaining a high mineral nutrient availability are thus important, especially in nutrient-poor habitats. 5. The positive plant responses to higher soil mineral N concentrations, combined with positive biotic plant-soil feedbacks, might shift the competitive balance in favour of typical HMG plant species, thereby contributing to stability of HMG plant communities. Our data indicate that herbivore-driven changes in the interactions between plants and both biotic and abiotic components of the soil persist over long temporal scales. OI Olofsson, Johan/0000-0002-6943-1218; Kardol, Paul/0000-0001-7065-3435; De Long, Jonathan/0000-0002-7951-4818 SN 0269-8463 EI 1365-2435 PD AUG PY 2018 VL 32 IS 8 BP 1959 EP 1971 DI 10.1111/1365-2435.13113 UT WOS:000440651400006 ER PT J AU Fisher, JT Burton, AC AF Fisher, Jason T. Burton, A. Cole TI Wildlife winners and losers in an oil sands landscape SO FRONTIERS IN ECOLOGY AND THE ENVIRONMENT AB Energy development and consumption drive changes in global climate, landscapes, and biodiversity. The oil sands of western Canada are an epicenter of oil production, creating landscapes without current or historical analogs. Science and policy often focus on pipelines and species-at-risk declines, but we hypothesized that differential responses to anthropogenic disturbances shift the entire mammal community. Analysis of data collected from 3 years of camera trapping and species distribution models indicated that anthropogenic features best explained the distributions of the ten mammal species included in the study. Relative abundances of some mammals were positively correlated with anthropogenic feature density, and others were negatively correlated. Effect sizes were often larger than for natural features. Increasing anthropogenic spatial complexity, access to multiple habitats, and new forage sources favor generalist predators and browsers, to the detriment of specialists, likely altering ecological processes. This issue has far-reaching implications: as the oil sands landscape changes so too does its mammal community, serving as a bellwether of future change for energy landscapes worldwide. SN 1540-9295 EI 1540-9309 PD AUG PY 2018 VL 16 IS 6 BP 323 EP 328 DI 10.1002/fee.1807 UT WOS:000440409000006 ER PT J AU Bognounou, F Hulme, PE Oksanen, L Suominen, O Olofsson, J AF Bognounou, Fidele Hulme, Philip E. Oksanen, Lauri Suominen, Otso Olofsson, Johan TI Role of climate and herbivory on native and alien conifer seedling recruitment at and above the Fennoscandian tree line SO JOURNAL OF VEGETATION SCIENCE AB QuestionsWe investigated the importance of climate and herbivory on native and alien conifer colonization of the birch-dominated Fennoscandian tree line by addressing the following questions: (a) are tree line and tundra habitats similarly suitable for conifer seedling recruitment; (b) do ungulate and rodent herbivores differentially impact seedling recruitment; and (c) how does the role of habitat and herbivory on seedling recruitment vary across a marked climate gradient? LocationNorthern Fennoscandia, Sweden (Vassijaure and Paddus), and Norway (Joatka and Seiland). MethodsWe conducted an experiment to assess the emergence rate, survival probability and height development of Norway spruce (Picea abies), Scots pine (Pinus sylvestris) and Siberian larch (Larix sibirica) seedlings. Three experimental plots (i.e., open control, reindeer exclosure and complete vertebrate exclosure) were established in both tree line and tundra habitats at each of the four locations. Seeds of the three conifer species were sown in each plot in June 1999 during three consecutive years. The surviving seedlings were counted in August to September 1999, 2000, 2001, 2002 and 2007. The height of all seedlings was measured in 2007. ResultsOur study reveals that Norway spruce, Scots pine and Siberian larch can regenerate from seed at and above the current tree line in northern Fennoscandia. Their performance was generally higher above tree line in tundra than at tree line, but depended on species identity, climate aridity and mammal herbivory, particularly by rodents. These results suggest that the species composition and latitudinal limit of the tree line in the future might depend not only on direct effects of the future climate on the current tree line species, but also on the intensity of alien and native conifer introductions, as well as changes in herbivore populations. ConclusionIf sufficient seeds of Norway spruce, Scots pine and Siberian larch should reach the current tree line, their performances will increase with a warmer and wetter climate, and this effect will be markedly modulated by herbivores (particularly rodents). Further work is required to extend these results to determine the ability of these conifers to become tree line-forming species in the future. OI BOGNOUNOU, FIDELE/0000-0003-2809-6078; Olofsson, Johan/0000-0002-6943-1218 SN 1100-9233 EI 1654-1103 PD JUL PY 2018 VL 29 IS 4 BP 573 EP 584 DI 10.1111/jvs.12637 UT WOS:000443232400001 ER PT J AU Ohenoja, E Ruotsalainen, AL Vauras, J AF Ohenoja, Esteri Ruotsalainen, Anna Liisa Vauras, Jukka TI Mycological records from ISAM 9, Kevo, Finland SO MYCOSCIENCE CT 10th International Symposium on Arctic and Alpine Mycology (ISAM) CY AUG 29-SEP 03, 2016 CL Kanazawa, JAPAN SP Mycol Soc Japan AB ISAM 9 (International Symposium of Arctic-Alpine Mycology) was held in August 2012 at the Kevo Lapland Research Station in Utsjoki in northernmost Finnish Lapland. In addition to Utsjoki, some excursions were made in Finnmark, the northernmost part of Norway. Kevo station lies in the subarctic zone characterized by mountain birch (Betula pubescens var. czerepanovii), but the fells reach the arctic tundra zone. Ailegas fells at Utsjoki village and at Nuvvus lie on acid ground as does Skalluvaara, and all are under influence of reindeer grazing. The Gistuskaidi fell is highest and is characterized by the presence of more basic rocks; the vegetation also reflects some amount of maritime influence. The places visited on the Norwegian side belong to the Nesseby commune at the sea shore and Tana commune on the shore of the Tana River and along the road to Batsfjord where the tundra is maritime and mossy with calcareous spots. In all 123 taxa were found during the excursions, some of them not determined at species level. The reported fungal taxa belong to the Basidiomycota (115 taxa), Ascomycota (7 taxa), and Mycetozoa (1 taxon). (C) 2017 The Mycological Society of Japan. Published by Elsevier B.V. All rights reserved. SN 1340-3540 EI 1618-2545 PD JUL PY 2018 VL 59 IS 4 BP 263 EP 267 DI 10.1016/j.myc.2017.12.003 UT WOS:000437367100002 ER PT J AU Garnick, S Barboza, PS Walker, JW AF Garnick, Sarah Barboza, Perry S. Walker, John W. TI Assessment of Animal-Based Methods Used for Estimating and Monitoring Rangeland Herbivore Diet Composition SO RANGELAND ECOLOGY & MANAGEMENT AB Researchers and managers need effective tools for monitoring the use of forages by large herbivores. Since 2000, the number of herbivore diet studies has nearly doubled. In this review, we determine trends in the field; assess the utility of key techniques against five criteria ( cost, accuracy and precision, resolution, utility for long-term monitoring programs, and appropriateness for browsers and grazers); and make recommendations to give managers appropriate tools. Three techniques stand out: microhistology, near infrared reflectance spectroscopy, and deoxyribonucleic acid ( DNA) barcoding. Microhistology has a long history of use in rangelands and is often considered the gold standard for understanding diet composition, albeit at a high cost of labor. Near infrared reflectance spectroscopy can resolve the presence of target groups or species more quickly than microhistology, especially for grazers. DNA barcoding provides the greatest resolution of dietary items with less quantitative certainty than microhistology. The costs associated with DNA barcoding come primarily from technology and sequencing, while in microhistology they are associated with labor. Therefore, an improved, streamlined microhistology method could provide rangeland managers a rapid and cost-effective method for diet monitoring. Ultimately, the complex challenges facing rangeland managers today may require the use of more than one method to achieve acceptable resolution within actionable time frames. (C) 2018 The Authors. Published by Elsevier Inc. on behalf of The Society for Range Management. SN 1550-7424 EI 1551-5028 PD JUL PY 2018 VL 71 IS 4 BP 449 EP 457 DI 10.1016/j.rama.2018.03.003 UT WOS:000435480900007 ER PT J AU Rivals, F Alvarez-Lao, DJ AF Rivals, Florent Alvarez-Lao, Diego J. TI Ungulate dietary traits and plasticity in zones of ecological transition inferred from late Pleistocene assemblages at Jou Puerta and Rexidora in the Cantabrian Region of northern Spain SO PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY AB The diet and habitats of Late Pleistocene ungulate taxa were analyzed in the caves of Jou Puerta and Rexidora (Marine Isotope Stage, MIS 3), in the Cantabrian Region of northern Spain, a zone of ecological transition between mainland Europe and Central-Southern Iberia. The two ungulate assemblages, which are composed mainly by cold-adapted species, were analyzed through tooth mesowear and microwear. The Jou Puerta community is dominated by the leaf browsers while at Rexidora the dominant taxa are grazers that suggest an open landscape with availability of grass, but also with significant presence of trees and/or forbs. Our results suggest an open landscape with presence of arboreal plant taxa during the coldest events of the MIS3. Concerning dietary plasticity, the diets for the cold-adapted woolly rhino and the reindeer in populations that lived in the southwestern boundary of their Eurasian distribution fit within the plasticity observed for other populations during the Pleistocene. It is proposed here that diet was not a limiting factor for the populations that inhabited the limit of their known range of distribution in the Cantabrian Region. RI Rivals, Florent/B-7962-2014 OI Rivals, Florent/0000-0001-8074-9254; Alvarez Lao, Diego Jaime/0000-0002-9606-4548 SN 0031-0182 EI 1872-616X PD JUN 15 PY 2018 VL 499 BP 123 EP 130 DI 10.1016/j.palaeo.2018.03.024 UT WOS:000431157600011 ER PT J AU Dolant, C Montpetit, B Langlois, A Brucker, L Zolina, O Johnson, CA Royer, A Smith, P AF Dolant, C. Montpetit, B. Langlois, A. Brucker, L. Zolina, O. Johnson, C. A. Royer, A. Smith, P. TI Assessment of the Barren Ground Caribou Die-off During Winter 2015-2016 Using Passive Microwave Observations SO GEOPHYSICAL RESEARCH LETTERS AB In summer 2016, more than 50 Arctic Barren Ground caribous were found dead on Prince Charles Island (Nunavut, Canada), a species recently classified as threatened. Neither predator nor sign of diseases was observed and reported. The main hypothesis is that caribous were not able to access food due to a very dense snow surface, created by a strong storm system in spring. Using satellite microwave data, a significant increase in brightness temperature polarization ratio at 19 and 37GHz was observed in spring 2016 (60% higher than previous two winter seasons). Based on microwave radiative transfer simulations, such anomaly can be explained with a very dense snow surface. This is consistent with the succession of storms and strong winds highlighted in ERA-Interim over Prince Charles Island in spring 2016. Using several sources of data, this study shows that changes in snow conditions explain the caribou die-off due to restricted foraging. Plain Language Summary In this paper, it is discussed that the snow conditions could be caused by the massive die-off events of the caribou herd on Price Charles Island, Nunavut. Using ERA-Interim reanalysis data, it is possible to find the reason of surface snow condition changes. This change creates an anomaly in signal, in particularly using different parameters derived from passive microwave data (brightness temperature) from SSM/I and SSMI/S sensors. Moreover, modeling of brightness temperature using radiative transfer model in passive microwaves domain, allowed to determine new thresholds for high density layer detection, may have an ecological consequence (food do not accessible for several ungulates). OI dolant, caroline/0000-0002-4869-9952 SN 0094-8276 EI 1944-8007 PD MAY 28 PY 2018 VL 45 IS 10 BP 4908 EP 4916 DI 10.1029/2017GL076752 UT WOS:000435262000042 ER PT J AU Payette, S Delwaide, A AF Payette, Serge Delwaide, Ann TI Tamm review: The North-American lichen woodland SO FOREST ECOLOGY AND MANAGEMENT AB The lichen woodland (LW) is an open-crown subarctic forest distributed principally in North America where it extends from Newfoundland in Atlantic Canada to the Yukon and Alaska. It is the main tree ecosystem of the LW zone north of the closed-crown boreal forest zone, and south of the forest-tundra zone where its cover diminishes progressively toward the Arctic tree line. Growth and development of LWs are closely dependent on dry-mesic, nutrient-poor podzolic soil environments largely distributed on the Canadian Precambrian Shield. The sun exposed open structure and dominance of lichen species on the dry-mesic soils of LWs determine many of their functions. A diversified cryptogamic flora is thriving in LWs due to reduced competition from vascular plants unable to grow and survive on dry, nutrient-poor soils. Because of the reduced greenhouse effect caused by the open structure and dominance of pale-color lichen mats inducing a greater albedo, LWs exerts a negative microclimatic impact on the environment culminating in the reduction of the frost-free growth season and increase and intensity of frost events. A suite of common, often recurrent, sometime compounding, fine- and large-scale disturbances (including climate change) activates the successional dynamics of LWs and also their historical and present expansion and contraction across the boreal biome. Post-disturbance chronosequences induced by fire, wind and caribou trampling and grazing are producing similar seral communities converging toward the self maintenance of the LW ecosystem. Long-term succession in southernmost LW sites possibly converges toward the closing of tree canopy and recovery of closed-crown conifer forests (CCCF) in absence of fire. The creation of LW occurred repeatedly during the late Holocene, as well as its extirpation from the northernmost sites (forest tundra zone) with wildfire as the principal triggering mechanism. LWs are presently unable to transgress the tree line, except for minor advances in small confined sites. Current evidence of the dual distribution of LWs and CCCF in eastern Canada shows that the LW zone is expanding southward into the CCCF zone, where compound disturbances associated with epidemics followed by small to extensive fires are transforming dense forest stands to LWs, a process most likely independent of climate. In terms of ecosystem management, there are concerns about the maintenance of the southernmost LWs within the CCCF zone as poor carbon sinks. Projects involving LW plantation sites in the CCCF zone in eastern Canada are proposed to offset the increased emission of atmospheric gases and thus mitigate climate change. SN 0378-1127 EI 1872-7042 PD MAY 15 PY 2018 VL 417 BP 167 EP 183 DI 10.1016/j.foreco.2018.02.043 UT WOS:000430778900015 ER PT J AU Maliniemi, T Kapfer, J Saccone, P Skog, A Virtanen, R AF Maliniemi, Tuija Kapfer, Jutta Saccone, Patrick Skog, Anu Virtanen, Risto TI Long-term vegetation changes of treeless heath communities in northern Fennoscandia: Links to climate change trends and reindeer grazing SO JOURNAL OF VEGETATION SCIENCE AB QuestionIn recent decades, high-latitude climate has shown regionally variable trends towards warmer and moister conditions. These changes have been predicted to cause afforestation or shrubification of open tundra, increases of warmth-demanding southern species and plant groups favoured by increased moisture, and decline of species and habitats that are dependent on snow cover. In this study, we explore temporal changes in northern tundra upland plant communities along regional gradients and in local habitats. We ask how vegetation changes are linked with long-term trends in regional climate and grazing pressure. LocationNorthern Europe. MethodsIn 2013-2014, we resurveyed a total of 108 vegetation plots on wind-exposed and snow-protected tundra habitats in three subareas along a bioclimatic gradient from the northern boreal to the arctic zone. Vegetation plots were originally sampled in 1964-1967. We related observed vegetation changes to changes in temperature, precipitation and grazing pressure, which all showed regionally variable increases over the study period. ResultsWe found a significant increase of the evergreen dwarf shrub Empetrum nigrum subsp. hermaphroditum in snow-protected communities and a prominent decrease of lichens throughout the study area. No evidence for extensive tree or larger shrub (Betula spp., Salix spp. or Juniperus communis) encroachment despite climatic warming trends was found. Among studied communities, most pronounced changes in vegetation were observed in snow-protected boreal heaths on small isolated uplands, where community composition showed low resemblance to the original composition described decades ago. Changes in plant communities correlated with changes in summer and winter temperatures, summer precipitation and reindeer grazing pressure, yet correlations varied depending on region and habitat. ConclusionsNorthern tundra uplands vary in their resistance to on-going climate change and reindeer grazing. Isolated treeless heaths of boreal forest-tundra ecotone appear least resistant to climate change and have already shifted towards new community states. OI Virtanen, Risto/0000-0002-8295-8217; Kapfer, Jutta/0000-0002-8077-8917; Saccone, Patrick/0000-0001-8820-593X SN 1100-9233 EI 1654-1103 PD MAY PY 2018 VL 29 IS 3 BP 469 EP 479 DI 10.1111/jvs.12630 UT WOS:000438651900012 ER PT J AU Morrissette-Boileau, C Boudreau, S Tremblay, JP Cote, SD AF Morrissette-Boileau, Clara Boudreau, Stephane Tremblay, Jean-Pierre Cote, Steeve D. TI Simulated caribou browsing limits the effect of nutrient addition on the growth of Betula glandulosa, an expanding shrub species in Eastern Canada SO JOURNAL OF ECOLOGY AB Warmer summer temperatures and enhanced soil fertility increase shrub growth in tundra ecosystems, and these factors have likely contributed to shrub expansion at the circumpolar scale over the last decades. Conversely, large herbivores have the potential to counteract the positive impacts of climate change on shrub growth. Indeed, by stripping the leaves, herbivores have the potential to control the growth of shrub species and, consequently, limit their expansion. To disentangle the impacts of climate change and herbivory on Betula glandulosa Michx., we conducted a 5-year factorial experiment near Deception Bay, Nunavik, Canada, in which we simulated warmer temperatures, increased nitrogen availability and three caribou browsing intensities during the growing season. At the end of the experiment, we harvested the above-ground biomass of B. glandulosa and conducted dendrochronological analyses on stems. Fertilised plots under ambient temperature had 34% greater shrub biomass than plots assigned to the combined treatment of nitrogen addition and warmer temperatures. Browsing intensity had no effect on final biomass. Nitrogen addition increased radial growth (18%-33%; 3years out of 5). Overall, browsing had a cumulative negative impact on B. glandulosa radial growth during the 5-year experiment. While browsing had no effect in the first year of the experiment, moderate browsing (leaves stripped on 25% of available shoots) decreased radial growth by 27% at year 2, 32% at year 4 and 27% at year 5. Heavy browsing (leaves stripped on 75% of available shoots annually) decreased radial growth by c. 27% at year 2, 37% at year 3, 50% at year 4 and 48% at year 5. We did not observe significant interactions between browsing, temperature and nitrogen availability.Synthesis. Our results clearly showed that caribou browsing may limit the growth of B. glandulosa, and thus can potentially limit its expansion. Herbivory should thus be considered when predicting tundra vegetation changes in the Arctic, at least in areas with high herbivore densities. OI Tremblay, Jean-Pierre/0000-0003-0978-529X SN 0022-0477 EI 1365-2745 PD MAY PY 2018 VL 106 IS 3 BP 1256 EP 1265 DI 10.1111/1365-2745.12899 UT WOS:000430123800039 ER PT J AU Ylanne, H Olofsson, J Oksanen, L Stark, S AF Ylaenne, Henni Olofsson, Johan Oksanen, Lauri Stark, Sari TI Consequences of grazer-induced vegetation transitions on ecosystem carbon storage in the tundra SO FUNCTIONAL ECOLOGY AB 1. Large herbivores can control plant community composition and, under certain conditions, even induce vegetation shifts to alternative ecosystem states. As different plant assemblages maintain contrasting carbon (C) cycling patterns, herbivores have the potential to alter C sequestration at regional scales. Their influence is of particular interest in the Arctic tundra, where a large share of the world's soil C reservoir is stored. 2. We assessed the influence of grazing mammals on tundra vegetation and C stocks by resampling two sites located along pasture rotation fences in northern Norway. These fences have separated lightly grazed areas from heavily grazed areas (in close proximity to the fences) and moderately grazed areas (further away from the fences) for the past 50years. Fourteen years earlier, the lightly and moderately grazed areas were dominated by dwarf shrubs, whereas heavy grazing had promoted the establishment of graminoid-dominated vegetation. Since then, both reindeer densities and temperatures have increased, and more time has passed for transient dynamics to be expressed. We expected that the vegetation and C stocks would have changed under all grazing intensities, but not necessarily in the same way. 3. At the site where relative reindeer numbers and trampling intensity had increased the most, graminoid-dominated vegetation was now also found in the moderately grazed area. At the other site, the dominant vegetation types under all grazing intensities were the same as 14 years earlier. 4. We show that the heavily grazed, graminoid-dominated areas stored less C above-ground than the lightly grazed, shrub-dominated areas. Yet, the below-ground consequences of grazing-induced grassification varied between the sites: Grazing did not alter organic soil C stocks at the site where both evergreen and deciduous shrubs were abundant in the lightly grazed area, whereas heavy grazing increased organic soil C stocks at the site where the deciduous shrub Betula nana was dominant. 5. Our results indicate that, despite the negative impacts of grazers on above-ground C storage, their impact on below-ground C may even be positive. We suggest that the site-specific responses of organic soil C stocks to grazing could be explained by the differences in vegetation under light grazing. This would imply that the replacement of deciduous shrubs by graminoids, as a consequence of grazing could be beneficial for C sequestration in tundra soils. RI Stark, Sari/L-4440-2013 SN 0269-8463 EI 1365-2435 PD APR PY 2018 VL 32 IS 4 BP 1091 EP 1102 DI 10.1111/1365-2435.13029 UT WOS:000429323400023 ER PT J AU Rickbeil, GJM Hermosilla, T Coops, NC White, JC Wulder, MA Lantz, TC AF Rickbeil, Gregory J. M. Hermosilla, Txomin Coops, Nicholas C. White, Joanne C. Wulder, Michael A. Lantz, Trevor C. TI Changing northern vegetation conditions are influencing barren ground caribou (Rangifer tarandus groenlandicus) post-calving movement rates SO JOURNAL OF BIOGEOGRAPHY AB AimTo quantify changes in vegetation productivity over the past three decades across five barren ground caribou (Rangifer tarandus groenlandicus) herd ranges and assess how these changes are influencing caribou movement rates. LocationNorthwest Territories and Nunavut, Canada. MethodsAs an indicator of vegetation productivity, the enhanced vegetation index (EVI) was calculated on newly developed cloud-free, gap-free, Landsat surface reflectance image composites representing 1984-2012. Changes in EVI were assessed on a pixel basis using Theil-Sen's nonparametric regression and compared across herd ranges and land cover types using generalized least squares regression. Animal movement velocity was calculated from caribou telemetry data and generalized additive mixed models were used to link movement rates with vegetation productivity during the post-calving phase of the year (July and August). ResultsVegetation productivity increased across the five caribou herd ranges examined. The largest productivity increase occurred over the ranges of the most western herds, with the largest observed changes in grassland or shrub habitats. Caribou tended to move more slowly through tundra habitats with elevated levels of productivity to a point, while grasslands movement rates decreased linearly with increasing productivity. Movement velocities peaked at intermediate productivity levels in shrub habitats. Main conclusionsOver the three decades of collected data, barren ground caribou habitats have become more productive, which is consistent with other studies that have documented increases in Arctic vegetation productivity. The more western herds, whose ranges are also closest to the Arctic Ocean, experienced the largest increases in productivity. Finally, we demonstrate that barren ground caribou movement patterns will likely change as a result of changing vegetation productivity in complex manners depending on herd, habitat type and the magnitude of change in vegetation productivity. OI Hermosilla, Txomin/0000-0002-5445-0360; White, Joanne/0000-0003-4674-0373; Wulder, Michael/0000-0002-6942-1896 SN 0305-0270 EI 1365-2699 PD MAR PY 2018 VL 45 IS 3 BP 702 EP 712 DI 10.1111/jbi.13161 UT WOS:000426508900016 ER PT J AU Starr, L Seefeldt, S Zhang, MC Rowell, J AF Starr, Laura Seefeldt, Steven Zhang, Mingchu Rowell, Janice TI Sustainable livestock production in sub-arctic Alaska: Plant and soil responses to simulated intensively managed grazing SO AGRICULTURE ECOSYSTEMS & ENVIRONMENT AB Managing a robust pasture ecosystem and optimizing available forage under sub-arctic conditions in interior Alaska is a challenge. The region is characterized by a short growing season, slow residue decomposition rates and undeveloped soils that are vulnerable to compaction and erosion. The goal of this research was to examine the relative and combined role of grazing mechanisms; herbivory, trampling, and manure/urine deposition on forage yield and soil health in sub-arctic pastures within a simulated intensively managed rotational grazing (IMRG) framework. A full factorial experiment of muskox (Ovibos moschatus) manure/urine deposition (M), simulated trampling (T), and herbivory (forage clipping) (H), and control (C) mimicking IMRG timing and intensity, was conducted at the Robert G. White Large Animal Research Station, University of Alaska, Fairbanks. The simulations were conducted on 48-1 m(2) plots on hilltop and hill bottom pastures with different vegetation and soil types, over the 2014 and 2015 grazing seasons. The control represented a pasture absent of grazing and served as a comparison of the treatments to restorative rest of grazing land. Grazing treatments MH and MTH had a positive impact on forage yield, while T and MT had a negative impact compared to C (p < 0.05) in both pastures. Bare ground was reduced under all treatments in both locations compared to baseline measurements (p < 0.05) but was no different to control (p < 0.16). Differences were documented in soil parameters in both pastures with the hilltop pasture demonstrating the greatest change; MT had 93% more total water soluble nitrogen (N) and 287% more H3A extracted inorganic N than C (p < 0.05). In the hill bottom pasture, MTH had 28.5% more total water soluble N than C (p < 0.05). These findings suggest that trampling had a negative impact on forage yield if not combined with herbivory, while it had a positive impact on soil parameters if combined with manure. While grazing impact factors such as manure, trampling and herbivory have the potential to both benefit and harm pasture health, the study documented an improvement to both forage yield, and certain soil aspects of soil health and nutrients when applied in combination under the IMRG paradigm in the Alaskan sub-arctic. SN 0167-8809 EI 1873-2305 PD MAR 1 PY 2018 VL 255 BP 12 EP 19 DI 10.1016/j.agee.2017.12.015 UT WOS:000425578600002 ER PT J AU Koster, K Koster, E Berninger, F Heinonsalo, J Pumpanen, J AF Koster, Kajar Koster, Egle Berninger, Frank Heinonsalo, Jussi Pumpanen, Jukka TI Contrasting effects of reindeer grazing on CO2, CH4, and N2O fluxes originating from the northern boreal forest floor SO LAND DEGRADATION & DEVELOPMENT AB Reindeer (Rangifer tarandus L.) is considered to be an important mammalian herbivore, strongly influencing Arctic lichen-dominated ecosystems. There is no wide knowledge about the effect of reindeer on greenhouse gas (GHG) fluxes in northern boreal forests. Ground vegetation plays an important role in absorbing nitrogen (N) and carbon dioxide (CO2) from the atmosphere. Lately, it has also been found to be a significant source of nitrous oxide (N2O) and a small source of methane (CH4). We investigated the influence of reindeer grazing on field layer GHG (CO2, CH4, and N2O) fluxes, ground vegetation coverage and biomass, and soil physical properties (temperature and moisture) in a northern boreal forest. At our study site, the reindeer-induced replacement of lichen by mosses had contrasting effects on the GHG fluxes originating from the field layer. Field layer CO2 efflux was significantly higher in grazed areas. The field layer was a CH4 sink in all areas, but grazed areas absorbed more CH4 compared to non-grazed areas. Although total N2O fluxes remained around 0 in grazed areas, a small N2O sink occurred in non-grazed areas with lower moss biomass. Our results indicated that grazing by reindeer in northern boreal forests affects GHG fluxes from the forest field layer both positively and negatively, and these emissions largely depend on grazing-induced changes in vegetation composition. RI Koster, Kajar/C-8397-2012 OI Koster, Kajar/0000-0003-1988-5788; Heinonsalo, Jussi/0000-0001-8516-1388 SN 1085-3278 EI 1099-145X PD FEB PY 2018 VL 29 IS 2 BP 374 EP 381 DI 10.1002/ldr.2868 UT WOS:000425100700018 ER PT J AU Anderson, M Mclellan, BN Serrouya, R AF Anderson, Meghan Mclellan, Bruce N. Serrouya, Robert TI Moose Response to High-Elevation Forestry: Implications for Apparent Competition with Endangered Caribou SO JOURNAL OF WILDLIFE MANAGEMENT AB Habitat disturbance threatens woodland caribou (Rangifer tarandus caribou) by altering inter-tropic relationships, which causes predation rates to increase. Of particular concern is the increase in early seral vegetation in high-elevation caribou summer habitat created by the recent expansion of logging into these forests. Deep snow confines the relatively abundant moose (Alces alces) population to valleys during winter, but in summer they can move up slope, where their spatial overlap with caribou increases. Wolves (Canis lupus) follow moose, their primary prey, up slope and occasionally encounter and kill caribou. We tested the hypothesis that early seral vegetation in high-elevation cutblocks (i.e., logged areas) attracts moose into mountain caribou summer habitat, and thereby increases the spatial overlap between caribou, moose, and wolves. To test our hypothesis, we examined how moose selection for early seral vegetation changed with elevation, how moose used undisturbed habitat, and how the proportion of early seral vegetation at high elevations in a moose home range was related to the amount of time moose spent at high elevations. Moose selection for cutblocks increased with elevation; however, when moose were at high elevations they spent the majority of their time in old-growth forest where they were likely browsing on understory shrubs, and the area of high-elevation cutblocks in moose home ranges did not affect the amount of time moose spent at high elevations. When we further explored the relationship between the amount of early seral vegetation at high elevations and the amount of time moose spent at high elevations, we found moose spent more time at high elevations when total early seral vegetation (from natural sources and cutblocks) increased, but there was little evidence that either type, on their own, influenced moose to use higher elevations. We conclude that although moose select cutblocks, the influence of high-elevation cutblocks on moose was minor in our study. Our results and those of other studies suggests low-elevation logging in moose winter ranges has led to an increased number of moose, and likely has a greater effect on moose distribution than logging at higher elevations. These insights can help guide management of apparent competition between moose and caribou. (C) 2017 The Wildlife Society. SN 0022-541X EI 1937-2817 PD FEB PY 2018 VL 82 IS 2 BP 299 EP 309 DI 10.1002/jwmg.21380 UT WOS:000423417700007 ER PT J AU Dolant, C Langlois, A Brucker, L Royer, A Roy, A Montpetit, B AF Dolant, Caroline Langlois, A. Brucker, L. Royer, A. Roy, A. Montpetit, B. TI Meteorological inventory of rain-on-snow events in the Canadian Arctic Archipelago and satellite detection assessment using passive microwave data SO PHYSICAL GEOGRAPHY CT 75th Eastern Snow Conference (ESC) CY JUN 05-08, 2018 CL NOAA Ctr Weather & Climate Predict, Climate Predict Ctr, College Park, MD HO NOAA Ctr Weather & Climate Predict, Climate Predict Ctr AB The spatial and temporal distributions of rain-on-snow (ROS) events across the Canadian Arctic Archipelago (CAA) remain poorly understood owing to their sporadic nature in time and space. This situation motivated the development of remote sensing detection algorithms. This paper uses a large meteorological dataset across the CAA to adapt an existing ROS-detection algorithm developed in a previous study by our group. Results highlight the spatial distribution and evolution of ROS occurrences reported since 1985 at 14 weather stations across the CAA. Results show that >600 ROS events were inventoried since 1985, for which >70% were classified as pure rain (liquid form) and 30% as mixed precipitation(solid/liquid). Of the pure rain events, 75% occurred during spring, 14% during fall, 8% during summer and <1% during winter. Such events can have significant impacts on ungulate grazing conditions through the creation of ice layers, causing serious problems for caribou calf survival, especially during the migration period. This paper introduces an adaptation for larger scale Arctic application of a detection algorithm (sensitivity analysis on the detection threshold) with an error of similar to 5%. The validation, however, remains limited due to a short study period and limited number of sites. SN 0272-3646 EI 1930-0557 PY 2018 VL 39 IS 5 BP 428 EP 444 DI 10.1080/02723646.2017.1400339 UT WOS:000452182900004 ER PT J AU Scornavacca, D Cotza, A Lovari, S Ferretti, F AF Scornavacca, Davide Cotza, Antonella Lovari, Sandro Ferretti, Francesco TI Suckling behaviour and allonursing in the Apennine chamois SO ETHOLOGY ECOLOGY & EVOLUTION AB Maternal cares and, in particular, suckling behaviour, are fundamental for early growth and survival of offspring ungulates. In turn, factors influencing maternal cares can have important effects at individual and population levels, with consequences at both short and long temporal scales. We assessed monthly variation of behavioural indices of suckling and nursing, as well as occurrence of allosuckling, in a mountain-dwelling ungulate, the Apennine chamois Rupicapra pyrenaica ornata, on summer-early autumn 2013-2014. Not surprisingly, duration of suckling events and frequency of suckling solicitations by kids, decreased throughout months, whereas the proportion of grazing kids increased from July to October, indicating a growing reliance on pasture. Conversely, the probability of suckling success kept stable from July to October, suggesting a constant willingness of females to allow kids to suckle. Of all suckling events, 63% involved more than one kid, indicating allosuckling. On average, multiple suckles were shorter than those involving one kid and occurred in all months with the same proportion.Our results suggest the occurrence of high levels of maternal cares in a gregarious herbivore, with frequent allosuckling and apparent willingness of females to nurse offspring throughout summer-autumn. These results suggest that the mother's role does not terminate with weaning. OI Ferretti, Francesco/0000-0002-0414-1615; LOVARI, Sandro/0000-0002-9945-0268 SN 0394-9370 EI 1828-7131 PY 2018 VL 30 IS 5 BP 385 EP 398 DI 10.1080/03949370.2017.1423115 UT WOS:000439730300001 ER PT J AU Croitor, R Obada, T AF Croitor, Roman Obada, Theodor TI On the presence of Late Pleistocene wapiti, Cervus canadensis Erxleben, 1777 (Cervidae, iklantinalia) in the Palaeolithic site Climauti II (Moldova) SO CONTRIBUTIONS TO ZOOLOGY AB This article reports antler remains from the Late Paleolithic site of Climauti II (Republic of Moldova) confirming the presence of wapiti Cervus canadensis in the Late Pleistocene of Western Eurasia. The occurrence of wapiti in the East Carpathian area by 20 ky BP coincides with the local extinction of Megaloceros giganteus, Crocutaspelaea, and Ursus spelaeus, and substitution of local forest reindeer with grazing tundra-steppe Rangifer tarandus constantini. We here provide an overview of paleontological data and opinions on the presence of Cervus canadensis in Europe, a discussion on the taxonomic status and systematic position of the extinct deer Cervus elaphus palmidactyloceros, and propose a dispersal model for wapiti in Europe during the Late Pleistocene. OI Croitor, Roman/0000-0003-4224-1251 SN 1383-4517 EI 1875-9866 PY 2018 VL 87 IS 1 BP 1 EP 10 UT WOS:000438186200001 ER PT J AU Mizin, IA Sipko, TP Davydov, AV Gruzdev, AR AF Mizin, Ivan A. Sipko, Taras P. Davydov, Andrey V. Gruzdev, Alexander R. TI THE WILD REINDEER (RANGIFER TARANDUS: CERVIDAE, MAMMALIA) ON THE ARCTIC ISLANDS OF RUSSIA: A REVIEW SO NATURE CONSERVATION RESEARCH AB The article presents summary data on the wild reindeer's (Rangifer tarandus) distribution on islands in the Russian Arctic. It discusses the abundance, diet, and general state of knowledge about the species in remote areas, especially on Novaya Zemlya and Wrangel Island. Brief data are provided about domestic reindeer grazing on the Arctic islands. Literature data are complemented with research findings in recent years. A negative trend is demonstrated in the wild reindeer abundance; also the need for studying isolated populations is emphasised. SN 2500-008X PY 2018 VL 3 IS 3 BP 1 EP 14 DI 10.24189/ncr.2018.040 UT WOS:000437909800001 ER PT J AU Barboza, PS Van Someren, LL Gustine, DD Bret-Harte, MS AF Barboza, Perry S. Van Someren, Lindsay L. Gustine, David D. Bret-Harte, M. Syndonia TI The nitrogen window for arctic herbivores: plant phenology and protein gain of migratory caribou (Rangifer tarandus) SO ECOSPHERE AB Terrestrial plants are often limited by nitrogen (N) in arctic systems, but constraints of N supply on herbivores are typically considered secondary to those of energy. We tested the hypothesis that forage N is more limiting than energy for arctic caribou by collecting key forages (three species of graminoids, three species of woody browse, and one genus of forb) over three summers in the migratory range of the Central Arctic Herd in Alaska from the Brooks Range to the Coastal Plain on the Arctic Ocean. We combined in vitro digestion and detergent extraction to measure fiber, digestible energy, and usable fractions of N in forages (n = 771). Digestible energy content fell below the minimum threshold value of 9kJ/g for one single forage group: graminoids, and only beyond 64-75d from parturition (6 June), whereas all forages fell below the minimum threshold value for digestible N (1% of dry matter) before female caribou would have weaned their calves at 100d from parturition. The window for digestible N was shortest for browse, which fell below 1% at 30-41d from parturition, whereas digestible N contents of graminoids were adequate until 46-57d from parturition. The low quality of browse as a source of N was also apparent from concentrations of available N (i.e., the N not bound to fiber) that were <1% at 72-80d from parturition. The Coastal Plain may be favored by female caribou because available and digestible concentrations of N are not only greater than those on the Brooks Range, the window of usable N on the Coastal Plain extends the period of protein gain for females and their calves by 17d. Conversely, inland areas with greater biomass and densities of digestible N than the Coastal Plain may be more favorable for large male caribou that begin gaining protein from spring to breed in autumn. Our study provides evidence that phenological windows for protein gain in caribou are both spatially and temporally dynamic and likely to affect the distribution and growth of the population. SN 2150-8925 PD JAN PY 2018 VL 9 IS 1 AR e02073 DI 10.1002/ecs2.2073 UT WOS:000425731000021 ER PT J AU Grogan, P Zamin, TJ AF Grogan, Paul Zamin, Tara J. TI Growth responses of the common arctic graminoid Eriophorum vaginatum to simulated grazing are independent of soil nitrogen availability SO OECOLOGIA AB Plant compensatory growth responses to herbivory are mediated by soil fertility and can have significant feedbacks that affect overall ecosystem nutrient cycling. The sedge Eriophorum vaginatum is the dominant graminoid in arctic mesic tundra, and is heavily consumed by caribou. Here, we compare the principal compensatory growth models in explaining the impact of a single episode of simulated caribou grazing at two clipping intensities on E. vaginatum total growing season shoot production, nitrogen concentrations, and nitrogen pools, over two successive years across a soil nitrogen fertilisation gradient. The clipping treatments had no effect on shoot production in the growing season when they were applied, but substantially reduced growth in the following year. Surprisingly, these reductions were consistent across all levels of soil nitrogen availability. The Limiting Resource Model can best explain this legacy effect on production because it predicts alternate compensatory growth responses depending on whether or not the herbivory affects availability of the resource that most limits plant growth. Accordingly, our results suggest that shoot compensatory growth in the year after the clipping was limited by some resource other than nitrogen-probably internal carbohydrate reserves or soil phosphorus. The clipping treatments initially enhanced shoot nitrogen concentrations and pools, but shoot nitrogen pools had decreased by the end of the second year due to the legacy effect of reduced shoot production. Finally, inflorescence removal substantially stimulated new shoot production in both years. Together, our results suggest that herbivory can significantly enhance temporal and local spatial heterogeneity in graminoid growth and nitrogen cycling. SN 0029-8549 EI 1432-1939 PD JAN PY 2018 VL 186 IS 1 BP 151 EP 162 DI 10.1007/s00442-017-3990-5 UT WOS:000419477800016 PM 29098420 ER PT J AU Barthelemy, H Stark, S Michelsen, A Olofsson, J AF Barthelemy, Helene Stark, Sari Michelsen, Anders Olofsson, Johan TI Urine is an important nitrogen source for plants irrespective of vegetation composition in an Arctic tundra: Insights from a N-15-enriched urea tracer experiment SO JOURNAL OF ECOLOGY AB 1. Mammalian herbivores can strongly influence nitrogen (N) cycling and herbivore urine could be a central component of the N cycle in grazed ecosystems. Despite its potential role for ecosystem productivity and functioning, the fate of N derived from urine has rarely been investigated in grazed ecosystems. 2. This study explored the fate of N-15-enriched urea in tundra sites that have been either lightly or intensively grazed by reindeer for more than 50years. We followed the fate of the N-15 applied to the plant canopy, at 2weeks and 1year after tracer addition, in the different ecosystem N pools. 3. N-15-urea was rapidly incorporated in cryptogams and in above-ground parts of vascular plants, while the soil microbial pool and plant roots sequestered only a marginal proportion. Furthermore, the litter layer constituted a large sink for the N-15-urea, at least in the short term, indicating a high biological activity in the litter layer and high immobilization in the first phases of organic matter decomposition. 4. Mosses and lichens still constituted the largest sink for the N-15-urea 1year after tracer addition at both levels of grazing intensity demonstrating their large ability to capture and retain N from urine. Despite large fundamental differences in their traits, deciduous and evergreen shrubs were just as efficient as graminoids in taking up the N-15-urea. The total recovery of N-15-urea was lower in the intensively grazed sites, suggesting that reindeer reduce ecosystem N retention. 5. Synthesis. The rapid incorporation of the applied N-15-urea indicates that arctic plants can take advantage of a pulse of incoming N from urine. In addition, N-15 values of all taxa in the heavily grazed sites converged towards the N-15 values for urine, bringing further evidence that urine is an important N source for plants in grazed tundra ecosystems. RI Stark, Sari/L-4440-2013 OI Michelsen, Anders/0000-0002-9541-8658 SN 0022-0477 EI 1365-2745 PD JAN PY 2018 VL 106 IS 1 BP 367 EP 378 DI 10.1111/1365-2745.12820 UT WOS:000417839700031 ER PT J AU Handeland, K Vikoren, T Josefsen, TD Madslien, K Valdecanas, B Uhlig, S AF Handeland, Kjell Vikoren, Turid Josefsen, Terje D. Madslien, Knut Valdecanas, Belinda Uhlig, Silvio TI Yew (Taxus) intoxication in free-ranging cervids SO PLOS ONE AB Wild ruminants, including deer species (cervids) have incorrectly been regarded as refractory to yew (Taxus) intoxication. This assumption has been based upon anecdotal observations of individual deer browsing on yew over time without apparent adverse effect. A single case of yew intoxication was reported in a free-ranging Norwegian moose (Alces alces) in 2008. The current report describes five additional cases of yew toxicosis in moose, seven in roe deer (Capreolus capreolus) and two in reindeer (Rangifer tarandus tarandus), all in Norway. The animals were found dead during the winter, close to or within gardens containing yew plants showing signs of browsing. Gross findings included lung congestion and edema, thoracic and pericardial effusion, bilateral heart dilatation, epi-and endocardial hemorrhage, and enlarged (congested) spleen. Yew plant remnants were detected in the rumen of all animals with the exception of a single moose. Histology revealed multifocal acute myocardial degeneration and necrosis with hemorrhage in roe deer, but not in the two other species. A qualitative high performance liquid chromatography-ion trap mass spectrometry analysis was used to tentatively identify five major Taxus alkaloids (taxines) in crude yew extracts and in heart and liver samples from the moose cases. All five major taxines were detected with good signal/noise ratio in tissue samples from the four moose with visible ruminal yew content, whereas lower levels of taxines were detected in the moose without visible ruminal yew content. Possible differences in interspecies tolerance to taxines and role of individual protective adaptation are discussed. SN 1932-6203 PD DEC 27 PY 2017 VL 12 IS 12 AR e0188961 DI 10.1371/journal.pone.0188961 UT WOS:000419006200013 PM 29281648 ER PT J AU Brathen, KA Ravolainen, VT Stien, A Tveraa, T Ims, RA AF Brathen, Kari Anne Ravolainen, Virve Tuulia Stien, Audun Tveraa, Torkild Ims, Rolf A. TI Rangifer management controls a climate-sensitive tundra state transition SO ECOLOGICAL APPLICATIONS AB Rangifer (caribou/reindeer) management has been suggested to mitigate the temperature-driven transition of Arctic tundra into a shrubland state, yet how this happens is uncertain. Here we study this much focused ecosystem state transition in riparian areas, where palatable willows (Salix) are dominant tall shrubs and highly responsive to climate change. For the state transition to take place, small life stages must become tall and abundant. Therefore we predicted that the performance of small life stages (potential recruits) of the tall shrubs were instrumental to the focal transition, where Rangifer managed at high population density would keep the small-stage shrubs in a "browse trap" independent of summer temperature. We used a large-scale quasi-experimental study design that included real management units that spanned a wide range of Rangifer population densities and summer temperatures in order to assess the relative importance of these two driving variables. Ground surveys provided data on density and height of the small shrub life stages, while the distributional limit (shrubline) of established shrublands (the tall shrub life stage) was derived from aerial photographs. Where Rangifer densities were above a threshold of approximately 5 animals/km(2), we found, in accordance with the expectation of a "browse trap," that the small life stages of shrubs in grasslands were at low height and low abundance. At Rangifer densities below this threshold, the small life stages of shrubs were taller and more abundant indicating Rangifer were no longer in control of the grassland state. For the established shrubland state, we found that the shrubline was at a 100-m lower elevation in the management units where Rangifer had been browsing in summer as opposed to the migratory ranges with no browsing in summer. In both seasonal ranges, the shrubline increased 100 m per 1 degrees C increment in temperature. Our study supports the proposal that Rangifer management within a sustainable range of animal densities can mitigate the much-focused transition from grassland to shrubland in a warming Arctic. OI Stien, Audun/0000-0001-8046-7337; Brathen, Kari Anne/0000-0003-0942-1074 SN 1051-0761 EI 1939-5582 PD DEC PY 2017 VL 27 IS 8 BP 2416 EP 2427 DI 10.1002/eap.1618 UT WOS:000416862700013 ER PT J AU Thompson, DP Barboza, PS AF Thompson, D. P. Barboza, P. S. TI Seasonal energy and protein requirements for Siberian reindeer (Rangifer tarandus) SO JOURNAL OF MAMMALOGY AB During summer and early autumn, reindeer and caribou (Rangifer tarandus) must exceed daily maintenance requirements for protein and energy to replenish body reserves for winter survival and reproduction. We estimated the maintenance requirements and the incremental costs of mass gain of captive female Siberian reindeer (R. t. tarandus) during summer and autumn by a mass balance approach. Intake (88 versus 56 g kg(-0.75) day(-1)) and digestibility (89% versus 81%) of dry matter were greater in summer than in autumn on the same diet. Body mass increased over the summer and remained stable into autumn. At zero mass gain, reindeer required 911 kJ kg(-0.75) day(-1) digestible energy and 1.12 g kg(-0.75) day(-1) digestible nitrogen (N). Requirements of N were affected by endogenous losses of N in the feces that were 72-82% of total fecal N. During summer, reindeer would need to consume forage containing more than 9.5 +/- 0.4 (SE) kJ g(-1) digestible energy and 1.17 +/- 0.4 (SE) % digestible N to gain body mass at intakes of 98 g kg(-0.75) day(-1). Reindeer could use a mix of graminoids and browse to meet energy demands and gain fat (6-18 kJ g(-1)) but may not be able to maintain or gain body protein in late summer as forages senesce and N contents decline below 1% of dry matter. SN 0022-2372 EI 1545-1542 PD DEC 1 PY 2017 VL 98 IS 6 BP 1558 EP 1567 DI 10.1093/jmammal/gyx132 UT WOS:000417241500005 ER PT J AU Xafis, A Nagel, D Bastl, K AF Xafis, Alexandros Nagel, Doris Bastl, Katharina TI Which tooth to sample? A methodological study of the utility of premolar/non-carnassial teeth in the microwear analysis of mammals SO PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY AB Low magnification dental microwear constitutes one of the most important proxies on the ecology and evolution of diet in mammals. Numerous studies have been established on the reconstruction of dietary ecology of even toed and carnivorous taxa. To date, these studies have used the second permanent molars or carnassials exclusively, for ungulates or carnivores, respectively. In this study, for the first time, premolars and non-carnassials of artiodactyls and carnivores, respectively, were used. Tooth samples from nine artiodactyl and eight carnivore taxa, covering the largest dietary spectrum possible, were evaluated and the microwear signal of the premolars/non-carnassials compared with known data of the second permanent molars and carnassials. The results reveal an almost identical statistical microwear signal of the premolars and molars for artiodactyls and the non-carnassials and carnassials for carnivores. Based on the even-toed taxa, new expanded morphospaces for both browsers and grazers are depicted on an average scratches versus average pits scatterplot. Additionally, dietary tendencies were delineated for the carnivore taxa with low or high counts of small and large pits for specific preferences such as a meat/bone, frugivorous or mixed carnivore diets in non-carnassial tooth positions as well. Lastly, low scratch and low large pit score plots for the ungulate and carnivore taxa, respectively, reveal an even clearer separation between the main dietary categories. OI Bastl, Katharina/0000-0002-8200-9708 SN 0031-0182 EI 1872-616X PD DEC 1 PY 2017 VL 487 BP 229 EP 240 DI 10.1016/j.palaeo.2017.09.003 UT WOS:000414881100019 ER PT J AU Sitters, J te Beest, M Cherif, M Giesler, R Olofsson, J AF Sitters, Judith te Beest, Mariska Cherif, Mehdi Giesler, Reiner Olofsson, Johan TI Interactive Effects Between Reindeer and Habitat Fertility Drive Soil Nutrient Availabilities in Arctic Tundra SO ECOSYSTEMS AB Herbivores impact nutrient availability and cycling, and the net effect of herbivory on soil nutrients is generally assumed to be positive in nutrient-rich environments and negative in nutrient-poor ones. This is, however, far from a uniform pattern, and there is a recognized need to investigate any interactive effects of herbivory and habitat fertility (i.e., plant C/N ratios) on soil nutrient availabilities. We determined long-term effects of reindeer on soil extractable nitrogen (N) and phosphorus (P) and their net mineralization rates along a fertility gradient of plant carbon (C) to N and P ratios in arctic tundra. Our results showed that reindeer had a positive effect on soil N in the more nutrient-poor sites and a negative effect on soil P in the more nutrient-rich sites, which contrasts from the general consensus. The increase in N availability was linked to a decrease in plant and litter C/N ratios, suggesting that a shift in vegetation composition toward more graminoids favors higher N cycling. Soil P availability was not as closely linked to the vegetation and is likely regulated more by herbivore-induced changes in soil physical and chemical properties. The changes in soil extractable N and P resulted in higher soil N/P ratios, suggesting that reindeer could drive the vegetation toward P-limitation. This research highlights the importance of including both the elements N and P and conducting studies along environmental gradients in order to better understand the interactive effects of herbivory and habitat fertility on nutrient cycling and primary production. OI Sitters, Judith/0000-0003-2926-5339; Cherif, Mehdi/0000-0003-0107-9374 SN 1432-9840 EI 1435-0629 PD NOV PY 2017 VL 20 IS 7 BP 1266 EP 1277 DI 10.1007/s10021-017-0108-1 UT WOS:000414175600003 ER PT J AU Barthelemy, H Stark, S Kytoviita, MM Olofsson, J AF Barthelemy, Helene Stark, Sari Kytoviita, Minna-Maarit Olofsson, Johan TI Grazing decreases N partitioning among coexisting plant species SO FUNCTIONAL ECOLOGY AB 1. Herbivores play a key role in shaping ecosystem structure and functions by influencing plant and microbial community composition and nutrient cycling. 2. This study investigated the long-term effects of herbivores on plant resource acquisition. We explored differences in the natural delta N-15 signatures in plant, microbial and soil N pools, and examined mycorrhizal colonization in two tundra sites that have been either lightly or heavily grazed by reindeer for more than 50 years. The study examined changes in nutrient acquisition in five common tundra plants with contrasting traits and mycorrhiza status; the mycorrhizal dwarf shrubs, Betula nana, Vaccinium myrtillus and Empetrum hermaphroditum; a mycorrhizal grass, Deschampsia flexuosa, and a non-mycorrhizal sedge, Carex bigelowii. 3. There were large variations in delta N-15 among coexisting plant species in the lightly grazed sites. This variation was dramatically reduced in the heavily grazed sites. At an individual species level, delta N-15 was higher in E. hermaphroditum and lower in C. bigelowii in the heavily grazed sites. Mycorrhizal colonization in B. nana and E. hermaphroditum roots were also lower in the heavily grazed sites. The delta N-15 signatures of the total soil N pool and of the microbial N pools were higher in the heavily grazed sites. 4. Since the strong delta N-15 differentiation among plant species has been interpreted as a result of plants with different mycorrhizal types using different sources of soil nitrogen, we suggest that the lower variation in delta N-15 in heavily grazed sites indicates a lower niche differentiation in nitrogen uptake among plants. Reduced mycorrhizamediated nitrogen uptake by some of the species, a shift towards a more mineral nutrition due to higher nutrient turnover, and uptake of labile nitrogen from dung and urine in the heavily grazed sites could all contribute to the changes in plant delta N-15. 5. We conclude that herbivores have the potential to influence plant nutrient uptake and provide the first data suggesting that herbivores decrease nutrient partitioning on the basis of chemical N forms among plant species. Reduced niche complementarity among species is potentially important for estimates of the effects of -herbivory on plant nutrient availability and species coexistence. RI Stark, Sari/L-4440-2013 SN 0269-8463 EI 1365-2435 PD NOV PY 2017 VL 31 IS 11 BP 2051 EP 2060 DI 10.1111/1365-2435.12917 UT WOS:000414248100003 ER PT J AU Vowles, T Gunnarsson, B Molau, U Hickler, T Klemedtsson, L Bjork, RG AF Vowles, Tage Gunnarsson, Bengt Molau, Ulf Hickler, Thomas Klemedtsson, Leif Bjork, Robert G. TI Expansion of deciduous tall shrubs but not evergreen dwarf shrubs inhibited by reindeer in Scandes mountain range SO JOURNAL OF ECOLOGY AB 1. One of the most palpable effects of warming in Arctic ecosystems is shrub expansion above the tree line. However, previous studies have found that reindeer can influence plant community responses to warming and inhibit shrubification of the tundra. 2. We revisited grazed (ambient) and ungrazed study plots (exclosures), at the southern as well as the northern limits of the Swedish alpine region, to study long-term grazing effects and vegetation changes in response to increasing temperatures between 1995 and 2011, in two vegetation types (shrub heath and mountain birch forest). 3. In the field layer at the shrub heath sites, evergreen dwarf shrubs had increased in cover from 26% to 49% but were unaffected by grazing. Deciduous dwarf and tall shrubs also showed significant, though smaller, increases over time. At the birch forest sites, the increase was similar for evergreen dwarf shrubs (20-48%) but deciduous tall shrubs did not show the same consistent increase over time as in the shrub heath. 4. The cover and height of the shrub layer were significantly greater in exclosures at the shrub heath sites, but no significant treatment effects were found on species richness or diversity. 5. July soil temperatures and growing season thawing degree days (TDD) were higher in exclosures at all but one site, and there was a significant negative correlation between mean shrub layer height and soil TDD at the shrub heath sites. 6. Synthesis. This study shows that shrub expansion is occurring rapidly in the Scandes mountain range, both above and below the tree line. Tall, deciduous shrubs had benefitted significantly from grazing exclosure, both in terms of cover and height, which in turn lowered summer soil temperatures. However, the overriding vegetation shift across our sites was the striking increase in evergreen dwarf shrubs, which were not influenced by grazing. As the effects of an increase in evergreen dwarf shrubs and more recalcitrant plant litter may to some degree counteract some of the effects of an increase in deciduous tall shrubs, herbivore influence on shrub interactions is potentially of great importance for shaping arctic shrub expansion and its associated ecosystem effects. OI Bjork, Robert/0000-0001-7346-666X SN 0022-0477 EI 1365-2745 PD NOV PY 2017 VL 105 IS 6 SI SI BP 1547 EP 1561 DI 10.1111/1365-2745.12753 UT WOS:000413341700009 PM 29200500 ER PT J AU Tsegaye, D Colman, JE Eftestol, S Flydal, K Rothe, G Rapp, K AF Tsegaye, Diress Colman, Jonathan E. Eftestol, Sindre Flydal, Kjetil Rothe, Gunnlaug Rapp, Kare TI Reindeer spatial use before, during and after construction of a wind farm SO APPLIED ANIMAL BEHAVIOUR SCIENCE AB The Fakken Wind farm (WF) was built in 2010-12 on the Fakken peninsula on the south-east corner of the island of Vannoy. Field and GPS sampling was conducted to test the interaction between reindeer spatial use and the WF with associated infrastructure for the period 2007-2015. "Before data" for both direct observations and GPS-positions confirmed that the site where the WF was built was an important winter grazing area for reindeer. Testing data from before, during and after construction of the WF showed that the overall use on the island and for the WE area did not change during the study period. The reindeer density did not vary significantly among the periods, both for the WF and power line areas. We found no avoidance responses on reindeer spatial use towards the WF during the operation periods for direct observation data. However, we found some significant changes in reindeer area use that may be related to disturbance from human activities for the calving period during construction in WF zone 1 and road zone 1 (GPS-data), and for the power line area during construction in summer and autumn (direct observational data). Our study site represents an area where coexistence of reindeer husbandry and wind energy development is possible, with negligible effects on reindeer spatial use during and after WF development. We recommend that new WFs should be built close to existing infrastructure and limit an increase in human accessibility to remote areas where reindeer are less accustomed to human activity. SN 0168-1591 EI 1872-9045 PD OCT PY 2017 VL 195 BP 103 EP 111 DI 10.1016/j.applanim.2017.05.023 UT WOS:000412259000015 ER PT J AU Pekkarinen, AJ Kumpula, J Tahvonen, O AF Pekkarinen, Antti-Juhani Kumpula, Jouko Tahvonen, Olli TI Parameterization and validation of an ungulate-pasture model SO ECOLOGY AND EVOLUTION AB Ungulate grazing and trampling strongly affect pastures and ecosystems throughout the world. Ecological population models are used for studying these systems and determining the guidelines for sustainable and economically viable management. However, the effect of trampling and other resource wastage is either not taken into account or quantified with data in earlier models. Also, the ability of models to describe the herbivore impact on pastures is usually not validated. We used a detailed model and data to study the level of winter- and summertime lichen wastage by reindeer and the effects of wastage on population sizes and management. We also validated the model with respect to its ability of predicting changes in lichen biomass and compared the actual management in herding districts with model results. The modeling efficiency value (0.75) and visual comparison between the model predictions and data showed that the model was able to describe the changes in lichen pastures caused by reindeer grazing and trampling. At the current lichen biomass levels in the northernmost Finland, the lichen wastage varied from 0 to 1 times the lichen intake during winter and from 6 to 10 times the intake during summer. With a higher value for wastage, reindeer numbers and net revenues were lower in the economically optimal solutions. Higher wastage also favored the use of supplementary feeding in the optimal steady state. Actual reindeer numbers in the districts were higher than in the optimal steady-state solutions for the model in 18 herding districts out of 20. Synthesis and applications. We show that a complex model can be used for analyzing ungulate-pasture dynamics and sustainable management if the model is parameterized and validated for the system. Wastage levels caused by trampling and other causes should be quantified with data as they strongly affect the results and management recommendations. Summertime lichen wastage caused by reindeer is higher than expected, which suggests that seasonal pasture rotation should be used to prevent the heavy trampling of winter lichen pastures during summer. In the present situation, reindeer numbers in northernmost Finland are in most cases higher than in the management solutions given by the model. OI Pekkarinen, Antti-Juhani/0000-0002-1993-6429 SN 2045-7758 PD OCT PY 2017 VL 7 IS 20 BP 8282 EP 8302 DI 10.1002/ece3.3358 UT WOS:000413308700011 PM 29075449 ER PT J AU Dearing, MD Kohl, KD AF Dearing, M. Denise Kohl, Kevin D. TI Beyond Fermentation: Other Important Services Provided to Endothermic Herbivores by their Gut Microbiota SO INTEGRATIVE AND COMPARATIVE BIOLOGY AB For decades, comparative biologists have recognized the importance of microbial partners in facilitating herbivory as a successful feeding strategy. Most of this success is attributed to the ability of gut microbes to digest recalcitrant dietary fiber and provides usable nutrients to their hosts. Gut microbes can also provide numerous other functions, such as vitamin synthesis, nitrogen recycling, and the detoxification of plant secondary compounds. Here, we review these microbial functions in herbivorous mammals and birds, highlighting studies that utilize recently developed metagenomic techniques. Several of these studies emphasize that microbial services are the product of interactions and exchanges within a complex microbial community, rather than the product of an individual member. Additionally, a number of these microbial functions are interdependent. For example, levels of dietary nitrogen or plant toxins can influence fiber digestibility. Further studies into the variety of microbial services provided to herbivorous hosts, and how these services might interact will broaden our understanding of host-microbe interactions. SN 1540-7063 EI 1557-7023 PD OCT PY 2017 VL 57 IS 4 BP 723 EP 731 DI 10.1093/icb/icx020 UT WOS:000412708600006 PM 28662572 ER PT J AU Skonhoft, A Johannesen, AB Olaussen, JO AF Skonhoft, Anders Johannesen, Anne Borge Olaussen, Jon Olaf TI On the tragedy of the commons: When predation and livestock loss may improve the economic lot of herders SO AMBIO AB This paper studies the practice of semi-domestic reindeer (Rangifer t. tarandus) herding in Finnmark county in northern Norway. In this area, the Saami reindeer herders compete for space and grazing areas and keep large herds, while at the same time, the reindeer population is heavily exposed to carnivore predation by the lynx (Lynx lynx), the wolverine (Gulo gulo), and the golden eagle (Aquila chrysaetos). It is demonstrated that predation actually may improve the economic lot of livestock holders in this unmanaged local common setting. There are ecological as well as economic reasons as to why this happens. The ecological reason is that predation compensates for natural mortality; that is, increased predation reduces natural mortality, indicating that the net loss due to predation actually may be quite small. When predation reduces livestock density, the feeding conditions of the animals will improve, resulting in increased livestock weight and higher per animal slaughter value. At the same time, a smaller stock reduces the operating costs of the herders. SN 0044-7447 EI 1654-7209 PD OCT PY 2017 VL 46 IS 6 BP 644 EP 654 DI 10.1007/s13280-017-0910-1 UT WOS:000410711600003 PM 28361495 ER PT J AU Laiho, R Penttila, T Fritze, H AF Laiho, Raija Penttila, Timo Fritze, Hannu TI Reindeer droppings may increase methane production potential in subarctic wetlands SO SOIL BIOLOGY & BIOCHEMISTRY AB Reindeer (Rangifer tarandus) herding is a major land-use form in northern Eurasian peatlands, especially subarctic fens. Nevertheless, the impacts of reindeer grazing on the functioning of peatland ecosystems remain virtually unexplored. Here we show with a laboratory incubation study that reindeer droppings may stimulate methane production in peat soils, a phenomenon that should be quantified at field scale and taken into account when analyzing the greenhouse gas exchange of northern peatlands. This is a globally important topic, since these peatlands hold potential for contributing notably to atmospheric carbon gas concentrations. (C) 2017 Elsevier Ltd. All rights reserved. RI Laiho, Raija/C-2920-2008 OI Laiho, Raija/0000-0001-7767-8520; Penttila, Timo/0000-0002-0710-4131 SN 0038-0717 PD OCT PY 2017 VL 113 BP 260 EP 262 DI 10.1016/j.soilbio.2017.06.017 UT WOS:000407536200028 ER PT J AU Horstkotte, T Utsi, TA Larsson-Blind, A Burgess, P Johansen, B Kayhko, J Oksanen, L Forbes, BC AF Horstkotte, T. Utsi, T. Aa. Larsson-Blind, A. Burgess, P. Johansen, B. Kayhko, J. Oksanen, L. Forbes, B. C. TI Human-animal agency in reindeer management: Sami herders' perspectives on vegetation dynamics under climate change SO ECOSPHERE AB Many primary livelihoods in Arctic and sub-Arctic regions experience accelerating effects of environmental change. The often close connection between indigenous peoples and their respective territories allows them to make detailed observations of how these changes transform the landscapes where they practice their daily activities. Here, we report Sami reindeer herders' observations based on their long-term inhabitance and use of contrasting pastoral landscapes in northern Fennoscandia. In particular, we focus on the capacity for various herd management regimes to prevent a potential transformation of open tundra vegetation to shrubland or woodland. Sami herders did not confirm a substantial, rapid, or large-scale transformation of treeless tundra areas into shrub-and/or woodlands. However, where they observe encroachment of open tundra landscapes, a range of factors was deemed responsible. These included abiotic conditions, anthropogenic influences, and the direct and indirect effects of reindeer. The advance of the mountain birch tree line was in some cases associated with reduced or discontinued grazing and firewood cutting, depending on the seasonal significance of these particular areas. Where the tree line has risen in elevation and/or latitude, herding practices have by necessity adapted to these changes. Exploiting the capacity of reindeer impacts on vegetation as a conservation tool offers time-tested adaptive strategies of ecosystem management to counteract a potential encroachment of the tundra by woody plants. However, novel solutions in environmental governance involve difficult trade-offs for ecologically sustainable, economically viable, and socially desirable management strategies. RI Forbes, Bruce/L-4431-2013 OI Forbes, Bruce/0000-0002-4593-5083 SN 2150-8925 PD SEP PY 2017 VL 8 IS 9 AR e01931 DI 10.1002/ecs2.1931 UT WOS:000410627100012 ER PT J AU Yu, Q Epstein, H Engstrom, R Walker, D AF Yu, Qin Epstein, Howard Engstrom, Ryan Walker, Donald TI Circumpolar arctic tundra biomass and productivity dynamics in response to projected climate change and herbivory SO GLOBAL CHANGE BIOLOGY AB Satellite remote sensing data have indicated a general 'greening' trend in the arctic tundra biome. However, the observed changes based on remote sensing are the result of multiple environmental drivers, and the effects of individual controls such as warming, herbivory, and other disturbances on changes in vegetation biomass, community structure, and ecosystem function remain unclear. We apply ArcVeg, an arctic tundra vegetation dynamics model, to estimate potential changes in vegetation biomass and net primary production (NPP) at the plant community and functional type levels. ArcVeg is driven by soil nitrogen output from the Terrestrial Ecosystem Model, existing densities of Rangifer populations, and projected summer temperature changes by the NCAR CCSM4.0 general circulation model across the Arctic. We quantified the changes in aboveground biomass and NPP resulting from (i) observed herbivory only; (ii) projected climate change only; and (iii) coupled effects of projected climate change and herbivory. We evaluated model outputs of the absolute and relative differences in biomass and NPP by country, bioclimate subzone, and floristic province. Estimated potential biomass increases resulting from temperature increase only are approximately 5% greater than the biomass modeled due to coupled warming and herbivory. Such potential increases are greater in areas currently occupied by large or dense Rangifer herds such as the Nenets-occupied regions in Russia (27% greater vegetation increase without herbivores). In addition, herbivory modulates shifts in plant community structure caused by warming. Plant functional types such as shrubs and mosses were affected to a greater degree than other functional types by either warming or herbivory or coupled effects of the two. OI Yu, Qin/0000-0002-6693-7299 SN 1354-1013 EI 1365-2486 PD SEP PY 2017 VL 23 IS 9 BP 3895 EP 3907 DI 10.1111/gcb.13632 UT WOS:000406812100038 PM 28276177 ER PT J AU Heggenes, J Odland, A Chevalier, T Ahlberg, J Berg, A Larsson, H Bjerketvedt, DK AF Heggenes, Jan Odland, Arvid Chevalier, Tomas Ahlberg, Jorgen Berg, Amanda Larsson, Hakan Bjerketvedt, Dag K. TI Herbivore grazing-or trampling? Trampling effects by a large ungulate in cold high-latitude ecosystems SO ECOLOGY AND EVOLUTION AB Mammalian herbivores have important top-down effects on ecological processes and landscapes by generating vegetation changes through grazing and trampling. For free-ranging herbivores on large landscapes, trampling is an important ecological factor. However, whereas grazing is widely studied, low-intensity trampling is rarely studied and quantified. The cold-adapted northern tundra reindeer (Rangifer tarandus) is a wide-ranging keystone herbivore in large open alpine and Arctic ecosystems. Reindeer may largely subsist on different species of slow-growing ground lichens, particularly in winter. Lichen grows in dry, snow-poor habitats with frost. Their varying elasticity makes them suitable for studying trampling. In replicated factorial experiments, high-resolution 3D laser scanning was used to quantify lichen volume loss from trampling by a reindeer hoof. Losses were substantial, that is, about 0.3 dm(3) per imprint in dry thick lichen, but depended on type of lichen mat and humidity. Immediate trampling volume loss was about twice as high in dry, compared to humid thin (2-3 cm), lichen mats and about three times as high in dry vs. humid thick (6-8 cm) lichen mats, There was no significant difference in volume loss between 100% and 50% wetted lichen. Regained volume with time was insignificant for dry lichen, whereas 50% humid lichen regained substantial volumes, and 100% humid lichen regained almost all lost volume, and mostly within 10-20 min. Reindeer trampling may have from near none to devastating effects on exposed lichen forage. During a normal week of foraging, daily moving 5 km across dry 6-to 8-cm-thick continuous lichen mats, one adult reindeer may trample a lichen volume corresponding to about a year's supply of lichen. However, the lichen humidity appears to be an important factor for trampling loss, in addition to the extent of reindeer movement. OI Ahlberg, Jorgen/0000-0002-6763-5487 SN 2045-7758 PD AUG PY 2017 VL 7 IS 16 BP 6423 EP 6431 DI 10.1002/ece3.3130 UT WOS:000409528000033 PM 28861245 ER PT J AU Hupp, JW Ward, DH Hogrefe, KR Sedinger, JS Martin, PD Stickney, AA Obritschkewitsch, T AF Hupp, Jerry W. Ward, David H. Hogrefe, Kyle R. Sedinger, James S. Martin, Philip D. Stickney, Alice A. Obritschkewitsch, Tim TI Growth of Black Brant and Lesser Snow Goose Goslings in Northern Alaska SO JOURNAL OF WILDLIFE MANAGEMENT AB Gosling body mass can affect first year survival, recruitment, adult body size, and future fecundity of geese, and can serve as an indicator of forage availability and quality on brood-rearing areas. From 2012-2014 we measured body mass of 76 black brant (Branta bernicla nigricans) and 268 lesser snow goose (Chen caerulescens caerulescens) goslings of known age on the Colville River Delta (CRD) of northern Alaska to determine if there was evidence of density-dependent declines in gosling growth following recent population increases of those species and sympatric greater white-fronted geese (Anser albifrons frontalis). We contrasted contemporary body mass of brant goslings and forage biomass in brood-rearing habitats that were shared by all species, with measures obtained on, and near the CRD in the 1990s, prior to the establishment of snow goose nesting colonies in the area. Body mass of brant goslings recaptured between 25 and 32 days of age had not changed over the past 2 decades, despite an influx of snow geese, and increases in populations of brant and white-fronted geese. At 30 days of age, body mass of brant goslings on the CRD was 100-400 g heavier than for brant goslings of the same age on the Yukon-Kuskokwim Delta (YKD), Alaska. Contemporary biomass of grazed Carex subspathacea on CRD brood-rearing areas was comparable to the 1990s and was 2-4 times greater than for the same plant community on the YKD. Historical data on growth of snow goose goslings were not available for the CRD. However, average body mass of 34-day-old snow goose goslings was > 230 g heavier than for conspecifics of the same age in the Hudson Bay region. We conclude that the establishment of nesting snow geese on the CRD has not negatively affected brant gosling growth, and that recent population increases of all species have likely not been constrained by forage availability on brood-rearing areas. Barring demographic changes elsewhere in their annual cycles, we predict that goose populations will continue to increase in northern Alaska. However, snow geese are increasingmore rapidly than brant in the region. Because the black brant population has periodically been below conservation objectives, the effects of the increasing number of snow geese on forage biomass and growth of brant goslings in northern Alaska should be monitored. (C) 2017 The Wildlife Society. SN 0022-541X EI 1937-2817 PD JUL PY 2017 VL 81 IS 5 BP 846 EP 857 DI 10.1002/jwmg.21246 UT WOS:000404132300010 ER PT J AU Skarin, A Alam, M AF Skarin, Anna Alam, Moudud TI Reindeer habitat use in relation to two small wind farms, during preconstruction, construction, and operation SO ECOLOGY AND EVOLUTION AB Worldwide there is a rush toward wind power development and its associated infrastructure. In Fennoscandia, large-scale wind farms comprising several hundred windmills are currently built in important grazing ranges used for Sami reindeer husbandry. In this study, reindeer habitat use was assessed using reindeer fecal pellet group counts in relation to two relatively small wind farms, with 8 and 10 turbines, respectively. In 2009, 1,315 15-m(2) plots were established and pellet groups were counted and cleaned from the plots. This was repeated once a year in May, during preconstruction, construction, and operation of the wind farms, covering 6years (2009-2014) of reindeer habitat use in the area. We modeled the presence/absence of any pellets in a plot at both the local (wind farm site) and regional (reindeer calving to autumn range) scale with a hierarchical logistic regression, where spatial correlation was accounted for via random effects, using vegetation type, and the interaction between distance to wind turbine and time period as predictor variables. Our results revealed an absolute reduction in pellet groups by 66% and 86% around each wind farm, respectively, at local scale and by 61% at regional scale during the operation phase compared to the preconstruction phase. At the regional, scale habitat use declined close to the turbines in the same comparison. However, at the local scale, we observed increased habitat use close to the wind turbines at one of the wind farms during the operation phase. This may be explained by continued use of an important migration route close to the wind farm. The reduced use at the regional scale nevertheless suggests that there may be an overall avoidance of both wind farms during operation, but further studies of reindeer movement and behavior are needed to gain a better understanding of the mechanisms behind this suggested avoidance. OI Alam, Moudud/0000-0002-3183-3756; Skarin, Anna/0000-0003-3221-1024 SN 2045-7758 PD JUN PY 2017 VL 7 IS 11 BP 3870 EP 3882 DI 10.1002/ece3.2941 UT WOS:000403273000024 PM 28616184 ER PT J AU Guillemot, T Bichet, V Gauthier, E Zocatelli, R Massa, C Richard, H AF Guillemot, Typhaine Bichet, Vincent Gauthier, Emilie Zocatelli, Renata Massa, Charly Richard, Herve TI Environmental responses of past and recent agropastoral activities on south Greenlandic ecosystems through molecular biomarkers SO HOLOCENE AB Paleoenvironmental studies previously performed on Lake Igaliku revealed two agropastoral phases in south Greenland: the Norse settlement from AD 986 to ca. AD 1450 and the recent installation of sheep farmers, since the 1920s. To improve the knowledge of the timing and magnitude of the Greenlandic agropastoral activities, a lipid inventory was realized and compared with biological and geochemical data. During the 12th century, a major increase in deoxycholic acid (DOC) and coprophilous fungal spores revealed a maximum of herbivores. Synchronously, a minimum of the n-C-29/n-C-31 alkane ratio and tree and shrub pollen and a maximum of triterpenyl acetates showed a reduction in the tree and shrub cover, because of grazing activities. Lupanone, produced by angiosperms, appeared simultaneously in the molecular content, probably revealing an introduction of plant species by the Norse, as it has been the case for Rumex spp. No major erosion was recorded by trimethyl-tetrahydrocrysenes (TTHCs) and titanium (Ti) fluxes. No massive algal production, identified by the n-C-17/total n-alkane ratio and mesotrophic diatoms, was either revealed. After the Norse abandon (around AD 1450), a return of the vegetation to quasi-pristine conditions was observed in the molecular content. Finally, a re-introduction of sheep in the 1920s provoked major impacts between the 1970s and the 1990s. A major decrease in the n-C-29/n-C-31 alkane ratio and tree and shrub pollen associated with maxima of triterpenyl acetates, TTHCs, Ti fluxes, and mesotrophic diatoms highlighted a reduction in the tree and shrub cover, a strong soil mobilization, and algal blooms, probably linking to the recent mechanized creation of hay fields and the massive use of fertilizers. In this study, molecular biomarkers revealed two periods of major impacts: the 12th century and between the 1970s and the 1990s, separated by centuries without agropastoral practices, allowing a quasi-resilience of the vegetation. SN 0959-6836 EI 1477-0911 PD JUN PY 2017 VL 27 IS 6 BP 783 EP 795 DI 10.1177/0959683616675811 UT WOS:000402888300001 ER PT J AU Fauchald, P Park, T Tommervik, H Myneni, R Hausner, VH AF Fauchald, Per Park, Taejin Tommervik, Hans Myneni, Ranga Hausner, Vera Helene TI Arctic greening from warming promotes declines in caribou populations SO SCIENCE ADVANCES AB The migratory tundra caribou herds in North America follow decadal population cycles, and browsing from abundant caribou could be expected to counteract the current climate-driven expansion of shrubs in the circumpolar tundra biome. We demonstrate that the sea ice cover in the Arctic Ocean has provided a strong signal for climate-induced changes on the adjacent caribou summer ranges, outperforming other climate indices in explaining the caribou-plant dynamics. We found no evidence of a negative effect of caribou abundance on vegetation biomass. On the contrary, we found a strong bottom-up effect in which a warmer climate related to diminishing sea ice has increased the plant biomass on the summer pastures, along with a paradoxical decline in caribou populations. This result suggests that this climate-induced greening has been accompanied by a deterioration of pasture quality. The shrub expansion in Arctic North America involves plant species with strong antibrowsing defenses. Our resultsmight therefore be an early signal of a climate-driven shift in the caribou-plant interaction from a system with low plant biomass modulated by cyclic caribou populations to a system dominated by nonedible shrubs and diminishing herds of migratory caribou. RI Myneni, Ranga/F-5129-2012 OI Myneni, Ranga/0000-0002-0234-6393 SN 2375-2548 PD APR PY 2017 VL 3 IS 4 AR e1601365 DI 10.1126/sciadv.1601365 UT WOS:000401954800006 PM 28508037 ER PT J AU Bogdanov, VD Golovatin, MG AF Bogdanov, V. D. Golovatin, M. G. TI Anthrax in Yamal: An ecological view on traditional reindeer husbandry SO RUSSIAN JOURNAL OF ECOLOGY AB The critical situation with traditional reindeer husbandry in the Yamal district of the Yamalo- Nenets Autonomous Area, indicated by an anthrax epizootic, is analyzed from an ecological viewpoint. The phenomenon of epizootic is regarded as an ecosystemic homeostatic mechanism operating to prevent excess population growth and maintain ecosystem integrity. The shutdown of this mechanism by means of vaccination, with the proportion of reindeer removed from slaughter remaining low, has resulted in an increased grazing load of rangelands and their consequent severe degradation. These events have been aggravated due to change in the type of ownership in reindeer husbandry during the reforms of the 1990s. The ecological situation is classified as critical, posing a real hazard to this particular ethnic form of economy. It is concluded that the period of extensive/expansive development of Yamal reindeer husbandry has come to an end. Sociopsychological attitudes of the Nenets, acquired when biological resources were abundant, contradict with the principles of ecosystem existence and functioning in the period of resource depletion. The maintenance of reindeer husbandry in the traditional form requires increasing material, labor, and financial investments, but positive results are unlikely to be obtained because of ecological constraints. SN 1067-4136 EI 1608-3334 PD MAR PY 2017 VL 48 IS 2 BP 95 EP 100 DI 10.1134/S1067413617020059 UT WOS:000401746800001 ER PT J AU Vowles, T Lovehav, C Molau, U Bjork, RG AF Vowles, Tage Lovehav, Cajsa Molau, Ulf Bjork, Robert G. TI Contrasting impacts of reindeer grazing in two tundra grasslands SO ENVIRONMENTAL RESEARCH LETTERS AB Plant communities in Arctic and alpine areas are changing due to higher temperatures and longer vegetation periods and it is uncertain how this will affect plant-herbivore dynamics. For instance, relatively fast-growing, deciduous shrub species that are the most responsive to warming may also be the most targeted by herbivores such as reindeer, giving less palatable evergreen shrubs the chance to expand. Using herbivore exclosures, we have studied how two grasslands with contrasting nutrient and moisture regimes, a dry, nutrient-poor alpine grass heath and a wet, productive low herb meadow, changed between 1995 and 2012, in grazed and ungrazed conditions. At the grass heath, evergreen low shrub abundance had more than doubled, regardless of grazer treatment, whereas at the low herb meadow, evergreen shrubs had increased only outside exclosures while deciduous tall shrubs and forbs were significantly more abundant inside exclosures. Deciduous tall shrubs were also significantly taller in exclosures. These contrasting findings suggest that the impact of herbivores is to a great deal determined by their influence on competitive interactions between plant species, and therefore depends on the underlying composition of the plant community. Consequently, as the balance in these competitive interactions is shifting due to climate warming, we conclude that the potential of herbivory to influence this balance is considerable yet highly site dependent. OI Bjork, Robert/0000-0001-7346-666X SN 1748-9326 PD MAR PY 2017 VL 12 IS 3 AR 034018 DI 10.1088/1748-9326/aa62af UT WOS:000397606500001 ER PT J AU Langlois, A Johnson, CA Montpetit, B Royer, A Blukacz-Richards, EA Neave, E Dolant, C Roy, A Arhonditsis, G Kim, DK Kaluskar, S Brucker, L AF Langlois, A. Johnson, C. -A. Montpetit, B. Royer, A. Blukacz-Richards, E. A. Neave, E. Dolant, C. Roy, A. Arhonditsis, G. Kim, D. -K. Kaluskar, S. Brucker, L. TI Detection of rain-on-snow (ROS) events and ice layer formation using passive microwave radiometry: A context for Peary caribou habitat in the Canadian Arctic SO REMOTE SENSING OF ENVIRONMENT AB Over the past four decades, amplified warming in the Arctic has led to numerous consequences. Of particular relevance, negative anomalies of snow and sea ice cover, glacier retreat, and the extended melt of Greenland combined with increasing temperature at double the rate of the rest of the planet have been observed in the Arctic. Several studies have suggested that another response to the current arctic warming could be an increase in rain-on-snow (ROS) events followed by subsequent freezing and the creation of ice layers. We use recently developed detection algorithms of ROS and ice events using passive microwave retrieval approaches to examine the spatial and temporal trends in rain-on-snow and ice layer creation for 18 islands across the Canadian Arctic Archipelago (CAA) over the last two decades. Results show that both icing and ROS event occurrence tripled between the periods of 1979-1995 and 1996-2011, with very active years in winters 1993-1994,1998-1999 and 2002-2003. The areas with the most combined occurrences are the Boothia Peninsula and Axel Heiberg, Cornwallis, Banks and Victoria Islands. We then compare the rain-on-snow and icing events to Peary caribou estimates to test whether the algorithms can detect weather events associated with population declines. There has been an important reduction in population numbers of Peary caribou, the northernmost caribou population in Canada, over the last three generations. The major hypothesis for the decline is that severe weather events lead to more difficult winter grazing conditions. The comparison with the Peary caribou population estimates suggest that caribou numbers decrease with increased occurrence of ROS and icing events, where 3-4 ROS events and 12 icing events in one winter season are sufficient to have a negative impact on Peary caribou. Crown Copyright (C) 2016 Published by Elsevier Inc. All rights reserved. RI Arhonditsis, George/C-6980-2009; Brucker, Ludovic/A-8029-2010 OI Brucker, Ludovic/0000-0001-7102-8084; Arhonditsis, George/0000-0001-5359-8737 SN 0034-4257 EI 1879-0704 PD FEB PY 2017 VL 189 BP 84 EP 95 DI 10.1016/j.rse.2016.11.006 UT WOS:000393005400007 ER PT J AU Koster, K Koster, E Kulmala, L Berninger, F Pumpanen, J AF Koster, Kajar Koster, Egle Kulmala, Liisa Berninger, Frank Pumpanen, Jukka TI Are the climatic factors combined with reindeer grazing affecting the soil CO2 emissions in subarctic boreal pine forest? SO CATENA AB In this work, we investigated how the reindeer grazing in subarctic boreal Scots pine forests and climate (air temperature and the amount of precipitation) affects soil temperature, soil water content, and ultimately the CO2 efflux from forest soils. The study was carried out in years 2013 and 2014, where 2013 was an extremely dry year (especially the summer), while 2014 was a "normal" year. Our work showed that in subarctic mature pine forests, soil temperatures were higher, and soil water content was fluctuating more on grazed areas compared to non grazed areas in both years. On both years, the soil water content on the grazed area was higher in June and the situation changed in the second half of July when the moisture content in the non-grazed area remained higher. There was a negative correlation between soil water content and soil temperature. The soil CO2 effluxes were mostly affected by the year of measurement, time of measurement (different months through growing season), soil temperature and also by the management (grazed or non-grazed) resulting in higher CO2 emissions on the grazed areas. Soil moisture content was not affecting the soil CO2 efflux. The average soil CO2 efflux values were significantly higher in the year 2014 compared to the year 2013 mainly due to differences in soil temperature at the beginning of season. (C) 2016 Elsevier B.V. All rights reserved. RI Pumpanen, Jukka/B-1254-2012; Koster, Kajar/C-8397-2012 OI Pumpanen, Jukka/0000-0003-4879-3663; Koster, Kajar/0000-0003-1988-5788; Kulmala, Liisa/0000-0003-1775-8240 SN 0341-8162 EI 1872-6887 PD FEB PY 2017 VL 149 SI SI BP 616 EP 622 DI 10.1016/j.catena.2016.06.011 PN 2 UT WOS:000390733900011 ER PT J AU Karlsen, SR Tommervik, H Johansen, B Riseth, JA AF Karlsen, Stein Rune Tommervik, Hans Johansen, Bernt Riseth, Jan Age TI Future forest distribution on Finnmarksvidda, North Norway SO CLIMATE RESEARCH AB Finnmarksvidda is Norway's largest mountain plateau, located in the Arctic/alpineboreal transition area. The area is also a central winter grazing area for the reindeer herds of the indigenous Sami people. This study develops a bioclimatic-based model to simulate future potential vegetation, with a focus on forest types. The model utilizes a bioclimatic study in the region, where vegetation types have been grouped according to minimum summer temperature demands. This is then used as a base for modelling of future vegetation. Due to the flat landscape of Finnmarksvidda, the model shows that a 1 degrees C increase in summer temperatures will potentially lead to an increase of forested areas by 4485 km(2), which is a 70% increase from the current 6900 km(2) to a simulated 11 706 km(2). This in turn will lead to a reduction of Arctic-alpine heaths from 4440 km(2) today to potentially only 670 km(2). Such changes will have consequences for the reindeer grazing system, as the predicted changes will lead to a decrease in the vegetation types that have high winter grazing accessibility for reindeer, from 2386 km(2) today to potentially only 377 km(2). On the other hand, vegetation types with medium accessibility will experience an increase, from 2857 to 3366 km(2). OI Riseth, Jan Age/0000-0002-4607-5927 SN 0936-577X EI 1616-1572 PY 2017 VL 73 IS 1-2 BP 125 EP 133 DI 10.3354/cr01459 UT WOS:000408250000012 ER PT J AU Loginov, VG Ignatyeva, MN Balashenko, VV AF Loginov, V. G. Ignatyeva, M. N. Balashenko, V. V. TI Harm to the Resources of Traditional Nature Management and Its Economic Evaluation SO EKONOMIKA REGIONA-ECONOMY OF REGION AB The Yamal region occupies the fifth part of the Yamal-Nenets Autonomous District. Therefore it is one of the territories where traditional natural resource management is mainly developing. Its key branches are reindeer herding and fisheries. The major problems in the development of industries are due to an active industrial and transport exploitation of the tundra zone; the situation in reindeer husbandry caused by pasture overgrazing because of uncontrolled increase in livestock; poaching fish. Two following anthropogenic factors have a negative impact on soil and vegetation in the Yamal region: reindeer herding as the main traditional form of natural resource management of Small Indigenous People of the North (SIPN) and the intensive industryrelated development of the territory (geological exploration, industry, transport, construction). Since grazing is practiced throughout the whole Yamal Peninsula, which is not occupied by industrial zones, it is the most widespread form of natural resource use and the leading factor of anthropogenic impact on Yamal's natural territorial complexes. The primary reason for the decline in fish resources is the violation of the ecosystemic reproduction of fish resources due to their excessive catch. One of the main reasons of this is poaching. In turn, the annual increase of surplus catch is caused by the population growth, including SIPN, and the growing density of the road network providing the access to fishing grounds. The article offers the guidelines for economic damage assessment determined by the harm to the pasture resources. The authors justify the amount of compensation that repairs losses arising from their damage, which takes into account the decline in the productivity of land and the period of restoration of the economic and biological potential of pastures for the corresponding periods of years (compensation for economic damage). The economic damage assessment of the fish resources supposes taking into account the decline in their economic value. It involves the use of a refined population-biological approach while the detailed calculation. In addition, we give an example of the guidelines' approbation. OI Ignat'eva, Margarita/0000-0001-9014-905X SN 2072-6414 EI 2411-1406 PY 2017 VL 13 IS 2 BP 396 EP 409 DI 10.17059/2017-2-6 UT WOS:000403655000006 ER PT J AU Stempniewicz, L AF Stempniewicz, Lech TI Polar bears observed climbing steep slopes to graze on scurvy grass in Svalbard SO POLAR RESEARCH AB It is well known that polar bears feed on vegetation. Here, I report novel observations of polar bears grazing on polar scurvy grass (Cochlearia groenlandica) at the foot of a large seabird colony on a cliff on Spitsbergen, Svalbard, in the summers of 2005, 2006, 2009, 2014 and 2015. Why they choose such energy-costly climbing to feed on plants is not clear. One possibility is that they may be suffering from vitamin C deficiency and are searching for this particular plant, which has a high level of this vitamin. Another, but not exclusive reason, is that vegetation containing scurvy grass is abundant enough to be efficiently grazed by such unspecialized plant-eaters as polar bears only on such relatively inaccessible, steep slopes below seabird colonies. Most of the lowland and gently sloping tundra areas in Svalbard are overgrazed by geese and reindeer, the populations of which have increased considerably as a consequence of climate amelioration. Large seabird colonies are known to attract animals from different trophic levels, but this is the first description of their attractiveness to polar bears as grazing areas. OI Stempniewicz, Lech/0000-0001-9405-7320 SN 0800-0395 EI 1751-8369 PY 2017 VL 36 AR 1326453 DI 10.1080/17518369.2017.1326453 UT WOS:000403369000001 ER PT J AU Ouellet, F Langlois, A Blukacz-Richards, EA Johnson, CA Royer, A Neave, E Larter, NC AF Ouellet, F. Langlois, A. Blukacz-Richards, E. A. Johnson, C. A. Royer, A. Neave, E. Larter, N. C. TI Spatialization of the SNOWPACK snow model for the Canadian Arctic to assess Peary caribou winter grazing conditions SO PHYSICAL GEOGRAPHY AB Peary caribou is the northernmost designatable unit for caribou species, and its population has declined by about 70% over the last three generations. The Committee on the Status of Endangered Wildlife in Canada identified difficult grazing conditions through the snow cover as being the most significant factor contributing to this decline. This study focuses on a spatially explicit assessment tool using snow model simulations (Swiss SNOWPACK model driven in an off-line mode by spatialized meteorological forcing data generated by the Canadian Regional Climate Model) to characterize snow conditions for Peary caribou grazing in the Canadian Arctic. The life cycle of Peary caribou has been subdivided into three critical periods: summer foraging and fall breeding (July-October), winter foraging (NovemberMarch), and spring calving (April-June). Winter snow conditions are analyzed and snow simulations compared to Peary caribou island counts to identify a snow parameter that could potentially act as a proxy for grazing conditions and explain fluctuations in Peary caribou numbers. This analysis concludes that caribou counts are affected by simulated snow density values > 300 kg m(-3). A software tool mapping possibly favorable and unfavorable grazing conditions based on snow is proposed at a regional scale across the Canadian Arctic Archipelago. Specific output examples are given to show the utility of the tool, mapping pixels with cumulative snow thickness above densities of 300 kg m(-3), where cumulative seasonal thicknesses > 7000 cm are considered unfavorable. SN 0272-3646 EI 1930-0557 PY 2017 VL 38 IS 2 BP 143 EP 158 DI 10.1080/02723646.2016.1274200 UT WOS:000396756200004 ER PT J AU Bignon-lau, O Catz, N Berlioz, E Veiberg, V Strand, O Merceron, G AF Bignon-lau, Olivier Catz, Natacha Berlioz, Emilie Veiberg, Vebjorn Strand, Olav Merceron, Gildas TI Dental microwear textural analyses to track feeding ecology of reindeer: a comparison of two contrasting populations in Norway SO MAMMAL RESEARCH AB Using dental microwear textural analysis, we aim to explore variations in feeding habits within and between wild reindeer populations (Rangifer tarandus) in Norway. Specimens from the two wild reindeer areas of Knutsho and Hardangervidda were hunted between late August and the end of September 2014, and found to share very similar topological and ecological characteristics (continental alpine tundra). Despite the homogenisation of plant resources at the end of the snow-free period, dental microwear textural analysis on cheek teeth indicates differences in feeding behaviors between the two populations, in that reindeer from Knutsho might display a more "grazing" signal than the ones from Hardangervidda. Such differences in dental microwear textures reflect the differences in feeding habits that could be linked with differences in population density of reindeer. The Knutsho reindeer density is lower than at Hardangervidda, where primary food resources like grasses, sedges, and lichens are less abundant. Analyses also show the differences in gender for the population of Knutsho, but more studies are necessary for the clearest interpretation of data. Our results emphasize the need to explore local variations at a monthly time frame in order to better assess the versatility of dental microwear textures before applying this kind of analysis to either extant or extinct multi-population scales. OI Merceron, Gildas/0000-0001-5777-7126 SN 2199-2401 EI 2199-241X PD JAN PY 2017 VL 62 IS 1 BP 111 EP 120 DI 10.1007/s13364-016-0304-y UT WOS:000392323900010 ER PT J AU te Beest, M Sitters, J Menard, CB Olofsson, J AF te Beest, Mariska Sitters, Judith Menard, Cecile B. Olofsson, Johan TI Reindeer grazing increases summer albedo by reducing shrub abundance in Arctic tundra SO ENVIRONMENTAL RESEARCH LETTERS AB Previous studies have shown that climate warming is causing shrub cover to increase at high latitudes. Increased shrub cover generally lowers surface albedo, which results in higher energy absorption and further warming. In parts of Fennoscandia, herbivory is known to control vegetation height and abundance, and thus preventing this positive feedback. Here, we combine field measurements of albedo, herbivory and vegetation characteristics in four topographically-defined vegetation types of varying shrub height and abundance with land surface modeling (JULES) to investigate if reindeer grazing can influence the energy balance of an arctic tundra. We find that when reindeer reduces shrub height and abundance, summer albedo increases in both Betula nana-dominated heath vegetation and Salix glauca-dominated willow depressions. Model results reveal associated lower net radiation, and latent and sensible heat fluxes in heavily-grazed sites in all shrub-dominated vegetation types. Our results also suggest that the structural shift from graminoid to shrub tundra drives the difference in summer albedo, rather than shifts from dwarf-shrub to tall-shrub tundra. Reindeer has thus a potential cooling effect on climate by increasing summer albedo and decreasing net radiation, which highlights the importance of mammalian herbivores for the earth system beyond their local grazing impacts. However, the strong effects of reindeer on albedo are probably restricted to areas with high reindeer densities, since a dramatic vegetation change is essential. The importance of these processes across the whole range of reindeer densities found in the arctic tundra needs to be further evaluated. RI Menard, Cecile/F-7860-2014 OI Menard, Cecile/0000-0003-2166-9523; Sitters, Judith/0000-0003-2926-5339 SN 1748-9326 PD DEC PY 2016 VL 11 IS 12 AR 125013 DI 10.1088/1748-9326/aa5128 UT WOS:000391723000001 ER PT J AU Wegrzyn, M Wietrzyk, P Lisowska, M Klimek, B Nicia, P AF Wegrzyn, Michal Wietrzyk, Paulina Lisowska, Maja Klimek, Beata Nicia, Pawel TI What influences heavy metals accumulation in arctic lichen Cetrariella delisei in Svalbard? SO POLAR SCIENCE AB The main aim of this study was to identify variations in heavy metal concentrations in Cetrariella delisei along a transect from a High Arctic glacier forehead to the shoreline as well as determine the main environmental factors influencing the deposition of heavy metals in arctic lichens. The macrolichen Cetrariella delisei appears to be an interesting alternative to those lichen species used in the past (e.g. Flavocetraria nivalis, Cladonia sp.) for heavy metal biomonitoring purposes in the Arctic: it is widely distributed, easy to identify and reluctantly grazed by reindeer. Fieldwork was conducted in the summer of 2012 in the Kaffioyra Plain, Oskar II Land, NW Spitsbergen. C. delisei and soil samples were collected from 5 localities. Concentrations of Cr, Mn, Ni, Cu, Zn, Pb, and Cd were measured in each sample. A bioaccumulation factor (BAF) was calculated for all the analyzed elements. The BAFs for Cu, Mn, and Ni showed a relatively low accumulation level in lichen thalli. On the other hand, the BAFs for Cr, Pb, and Zn, revealed an increased accumulation level in C. delisei. The Cd content in lichen is almost equal to its level in the soil. The statistical analyses covered three environmental factors: soil pH, substrate type and distance from the shoreline. The data were examined using the Kruskal-Wallis test, canonical correspondence analysis and a permutation test. The results show that distance from the shoreline had the greatest influence on the majority of the heavy metal concentrations in the lichen thalli and the soil. However, the level of Mn accumulated in the soil is determined by its source in the glacier. Moreover, the soil pH had the greatest effect on the Cd accumulated in the soil and the Mn accumulated in the lichen thalli. (C) 2016 Elsevier B.V. and NIPR. All rights reserved. RI Wietrzyk-Pelka, Paulina/B-3506-2019; Wietrzyk, Paulina/M-9724-2015 OI Wietrzyk-Pelka, Paulina/0000-0002-1324-2012; Wietrzyk, Paulina/0000-0002-1324-2012; Wegrzyn, Michal/0000-0001-7638-4803 SN 1873-9652 EI 1876-4428 PD DEC PY 2016 VL 10 IS 4 BP 532 EP 540 DI 10.1016/j.polar.2016.10.002 UT WOS:000388510000008 ER PT J AU Risvoll, C Fedreheim, GE Galafassi, D AF Risvoll, Camilla Fedreheim, Gunn Elin Galafassi, Diego TI Trade-offs in pastoral governance in Norway: Challenges for biodiversity and adaptation SO PASTORALISM-RESEARCH POLICY AND PRACTICE AB Norway is committed to the two-fold policy objective of preserving biodiversity and maintaining traditional local livelihoods. This creates management dilemmas with the potential to undermine the legitimacy of both national and international policies. In this article, we take a social-ecological perspective to highlight how these two policy objectives are linked and interdependent and, therefore, subjected to complex dynamics between institutions and ecosystems. We use a case study in northern Norway to discuss trade-offs in the implementation of the two-fold conservation objectives. Based on interviews, a focus group meeting with 16 reindeer herders and stakeholders and participant observations during a grazing committee meeting, we identified that ecological dynamics between carnivores, sheep and grassland patterns are central to this trade-off. We demonstrate how current governance instruments in carnivore management do not address the spatial dynamics of carnivores leading to a perceived conflict between environmentalist groups and farmers around questions of carnivore protection and sheep killings by carnivores. Fragmentation in the multi-layered governance system prevents ongoing dialogue among various actors, thereby enhancing antagonisms while reducing the likelihood of the emergence and implementation of adaptation measures and practices. OI Galafassi, Diego/0000-0003-3572-9275 SN 2041-7136 PD DEC PY 2016 VL 6 IS 1 AR UNSP 4 DI 10.1186/s13570-016-0051-3 UT WOS:000372500700004 ER PT J AU Miles, VV Esau, I AF Miles, Victoria V. Esau, Igor TI Spatial heterogeneity of greening and browning between and within bioclimatic zones in northern West Siberia SO ENVIRONMENTAL RESEARCH LETTERS AB Studies of the normalized difference vegetation index (NDVI) have found broad changes in vegetation productivity in high northern latitudes in the past decades, including increases in NDVI ('greening') in tundra regions and decreases ('browning') in forest regions. The causes of these changes are not well understood but have been attributed to a variety of factors. We use Moderate Resolution Imaging Spectrometer (MODIS) satellite data for 2000-2014 and focus on northern West Siberia-a hot spot of extensive landcover change due to rapid resource development, geomorphic change, climate change and reindeer grazing. The region is relatively little-studied in terms of vegetation productivity patterns and trends. This study examines changes between and within bioclimatic sub-zones and reveals differences between forest and treeless areas and differences in productivity even down to the tree species level. Our results show that only 18% of the total northern West Siberia area had statistically significant changes in productivity, with 8.4% increasing (greening) and 9.6% decreasing (browning). We find spatial heterogeneity in the trends, and contrasting trends both between and within bioclimatic zones. A key finding is the identification of contrasting trends for different species within the same bioclimatic zone. Browning is most prominent in areas of denser tree coverage, and particularly in evergreen coniferous forest with dark (Picea abie, Picea obovata) or light (Pinus sylvestris) evergreen and evergreen-majority mixed forests. In contrast, low density deciduous needle-leaf forest dominated by larch (Larix sibirica), shows a significant increase in productivity, even while neighboring different species show productivity decrease. These results underscore the complexity of the patterns of variability and trends in vegetation productivity, and suggest the need for spatially and thematically detailed studies to better understand the response of different northern forest types and species to climate and environmental change. SN 1748-9326 PD NOV PY 2016 VL 11 IS 11 AR 115002 DI 10.1088/1748-9326/11/11/115002 UT WOS:000387358000001 ER PT J AU Tyler, NJC Gregorini, P Forchhammer, MC Stokkan, KA van Oort, BEH Hazlerigg, DG AF Tyler, Nicholas J. C. Gregorini, Pablo Forchhammer, Mads C. Stokkan, Karl-Arne van Oort, Bob E. H. Hazlerigg, David G. TI Behavioral Timing without Clockwork: Photoperiod-Dependent Trade-Off between Predation Hazard and Energy Balance in an Arctic Ungulate SO JOURNAL OF BIOLOGICAL RHYTHMS AB Occurrence of 24-h rhythms in species apparently lacking functional molecular clockwork indicates that strong circadian mechanisms are not essential prerequisites of robust timing, and that rhythmical patterns may arise instead as passive responses to periodically changing environmental stimuli. Thus, in a new synthesis of grazing in a ruminant (MINDY), crepuscular peaks of activity emerge from interactions between internal and external stimuli that influence motivation to feed, and the influence of the light/dark cycle is mediated through the effect of low nocturnal levels of food intake on gastric function. Drawing on risk allocation theory, we hypothesized that the timing of behavior in ruminants is influenced by the independent effects of light on motivation to feed and perceived risk of predation. We predicted that the antithetical relationship between these 2 drivers would vary with photoperiod, resulting in a systematic shift in the phase of activity relative to the solar cycle across the year. This prediction was formalized in a model in which phase of activity emerges from a photoperiod-dependent trade-off between food and safety. We tested this model using data on the temporal pattern of activity in reindeer/caribou Rangifer tarandus free-living at natural mountain pasture in sub-Arctic Norway. The resulting nonlinear relationship between the phasing of crepuscular activity and photoperiod, consistent with the model, suggests a mechanism for behavioral timing that is independent of the core circadian system. We anticipate that such timing depends on integration of metabolic feedback from the digestive system and the activity of the glucocorticoid axis which modulates the behavioral responses of the animal to environmental hazard. The hypothalamus is the obvious neural substrate to achieve this integration. RI publicationpage, cmec/B-4405-2017; Gregorini, Pablo/N-1588-2014 OI Gregorini, Pablo/0000-0002-7084-5223 SN 0748-7304 EI 1552-4531 PD OCT PY 2016 VL 31 IS 5 BP 522 EP 533 DI 10.1177/0748730416662778 UT WOS:000383436700009 PM 27634928 ER PT J AU Larter, NC Macdonald, CR Elkin, BT Wang, X Harms, NJ Gamberg, M Muir, DCG AF Larter, N. C. Macdonald, C. R. Elkin, B. T. Wang, X. Harms, N. J. Gamberg, M. Muir, D. C. G. TI Cadmium and other elements in tissues from four ungulate species from the Mackenzie Mountain region of the Northwest Territories, Canada SO ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY AB Tissue samples from four ungulate species from the south Mackenzie Mountain region of the Northwest Territories (NT), Canada, were analysed for stable and radioactive elements and N-15 and C-13 stable isotopes. Elevated Cd concentrations in moose (Alces americanus) kidney have been observed in the region and are a health care concern for consumers of traditional foods. This study examined the factors associated with, and potential renal effects from, the accumulation of cadmium, and interactions with other elements in four sympatric ungulate species. Mean renal Cd concentration was highest in moose (48.3 mg/kg ww), followed by mountain caribou (Rangifer tarandus caribou) (13.9 mg/kg ww) and mountain goat (Oreamnos americanus) (5.78 mg/kg ww). No local sources of Cd were evident and the elevated levels in moose are considered to be natural in origin. Conversely, total Hg concentration was significantly higher in mountain caribou kidney (021 mg/kg ww) than in moose (0.011 mg/kg ww). Cs-134 (t(1/2)=2.1 y) in mountain goat and Dall's sheep (Ovis dalli) muscle is evidence of deposition from the Fukushima reactor accident in 2011. Cs-137 (t(1/2)=30.2 y) in all four ungulates is primarily a remnant of the nuclear weapons tests of the 1960s. The levels of both nuclides are low and the risk to the animals and people consuming them is negligible. Stable isotope delta N-15 and delta C-13 signatures in muscle showed a separation between the mountain caribou, with a lichen-dominated diet, and moose, which browse shrubs and forbs. Isotope signatures for mountain goat and Dall's sheep showed generalist feeding patterns. Differences in elemental and radionuclide levels between species were attributed to relative levels of metal accumulation in the different food items in the diets of the respective species. Kidneys from each species showed minor histological changes in the proximal tubule and glomerulus, although glomerular changes were rare and all changes were rare in mountain goat kidney. Kidney function was not expected to be affected in any species. Provisional Monthly Intake recommendations from the WHO indicate that Cd in moose organs will continue to be a public health care concern. However, traditional foods continue to be an important nutritional component of northern diets, particularly in consideration of the shift towards store-bought food. (C) 2016 Published by Elsevier Inc. SN 0147-6513 EI 1090-2414 PD OCT PY 2016 VL 132 BP 9 EP 17 DI 10.1016/j.ecoenv.2016.05.018 UT WOS:000380867200002 PM 27240258 ER PT J AU Rivals, F Lister, AM AF Rivals, Florent Lister, Adrian M. TI Dietary flexibility and niche partitioning of large herbivores through the Pleistocene of Britain SO QUATERNARY SCIENCE REVIEWS AB Tooth wear analysis techniques (mesowear and microwear) are employed to analyze dietary traits in proboscideans, perissodactyls and artiodactyls from 33 Pleistocene localities in Britain. The objectives of this study are to examine the variability in each taxon, to track dietary shifts through time, and to investigate resource partitioning among species. The integration of mesowear and microwear results first allowed us to examine dietary variability. We identified differences in variability among species, from more stenotopic species such as Capreolus capreolus to more eurytopic species such as Megaloceros giganteus and Cervus elaphus. Broad dietary shifts at the community level are seen between climatic phases, and are the result of species turnover as well as dietary shifts in the more flexible species. The species present at each locality are generally spread over a large part of the dietary spectrum, and resource partitioning was identified at most of these localities. Mixed feeders always coexist with at least one of the two strict dietary groups, grazers or browsers. Finally, for some species, a discrepancy is observed between meso- and microwear signals and may imply that individuals tended to die at a time of year when their normal food was in short supply. (C) 2016 Elsevier Ltd. All rights reserved. RI Rivals, Florent/B-7962-2014 OI Rivals, Florent/0000-0001-8074-9254 SN 0277-3791 PD AUG 15 PY 2016 VL 146 BP 116 EP 133 DI 10.1016/j.quascirev.2016.06.007 UT WOS:000381234000007 ER PT J AU Vowles, T Molau, U Lindstein, L Molau, M Bjork, RG AF Vowles, Tage Molau, Ulf Lindstein, Lars Molau, Mathias Bjork, Robert G. TI The impact of shrub browsing by mountain hare and reindeer in subarctic Sweden SO PLANT ECOLOGY & DIVERSITY AB Background: Climate warming has been causing an increase in tall shrub cover around the Arctic, however, mammalian herbivory has been shown to inhibit shrub expansion. Though the effect of reindeer (Rangifer tarandus) and many other mammals has been widely studied in this context, the role of the mountain hare (Lepus timidus) in subarctic Scandinavia remains unknown.Aims: To quantify browsing from mountain hare and reindeer on tall shrubs in different vegetation types and to investigate differences in shrub preference between the two.Methods: In the summers of 2013 and 2014, we counted signs of browsing by hare and reindeer on tall shrub species in 31 study plots at three alpine locations in the Scandes range, Sweden.Results: Hare browsing was significantly more frequent than that by reindeer in two (dry-mesic heath and dry meadow) out of seven vegetation types studied. Reindeer browsing was significantly higher in the low herb meadow and Langfjallet shrub heath. Two shrub species, Betula nana and Salix hastata, were significantly more browsed by hare, while reindeer browsing was significantly higher on S. phylicifolia and S. lapponum.Conclusions: Our results show that mountain hares can cause extensive damage to tall shrubs in the subarctic and may have a stronger impact on shrub communities than previously recognised. OI Bjork, Robert/0000-0001-7346-666X SN 1755-0874 EI 1755-1668 PD AUG PY 2016 VL 9 IS 4 BP 421 EP 428 DI 10.1080/17550874.2016.1264017 UT WOS:000395073700010 ER PT J AU Damgaard, C Raundrup, K Aastrup, P Langen, PL Feilberg, J Nabe-Nielsen, J AF Damgaard, Christian Raundrup, Katrine Aastrup, Peter Langen, Peter L. Feilberg, Jon Nabe-Nielsen, Jacob TI Arctic resilience: no evidence of vegetation change in response to grazing and climate changes in South Greenland SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Recent studies suggest that climate changes may have a strong impact on the vegetation composition in Arctic ecosystems, causing increasing dominance of woody species. Evidence from short-term studies on the effects of herbivory indicates that this effect may be counteracted by grazing, but it has not yet been studied whether the effect is persistent and general. Here, we present the results from a large-scale, long-term study of the effects of sheep grazing and climate on the relative dominance of woody plants, graminoids, and forbs. The study is based on exdosures established from 1984 onward across a climatic gradient in South Greenland. The relative cover of the three plant functional types was modeled in a state-space model. There was no significant overall change in the relative cover of the three groups, although such changes occurred intermittently on some sites. This suggests that the relative dominance of the plant functional types is resilient to the impacts of grazing and climate changes in the tundra of South Greenland in line with other studies from sites where summer temperatures have not increased. RI Damgaard, Christian/G-2441-2010 OI Damgaard, Christian/0000-0003-3932-4312; Aastrup, Peter/0000-0003-4258-3358; Nabe-Nielsen, Jacob/0000-0002-0716-9525 SN 1523-0430 EI 1938-4246 PD AUG PY 2016 VL 48 IS 3 BP 531 EP 549 DI 10.1657/AAAR0016-005 UT WOS:000382800700007 ER PT J AU den Herder, M Helle, S Niemela, P Henttonen, H Helle, T AF den Herder, Michael Helle, Samuli Niemela, Pekka Henttonen, Heikki Helle, Timo TI Large herbivore grazing limits small-mammal densities in Finnish Lapland SO ANNALES ZOOLOGICI FENNICI AB Grazing by large mammals can affect small-mammal populations by modifying the ground-layer vegetation, which provides them with food and shelter. The aim of this study was to investigate the impact of semi-domesticated reindeer grazing on small-mammal abundance in boreal forests/subarctic tundra ecosystems in a large-scale exclosure experiment in northernmost Finnish Lapland. In our experiment spanning four years, reindeer grazing affected the abundance of arvicoline voles, which were less abundant in grazed areas. This was probably due to a reduction in the abundance and height of bilberry, an important forage plant for both voles and reindeer. Changes in ground-layer vegetation affected the general condition of bank voles, which had significantly lower body mass in grazed areas. The abundance of insectivorous shrews was also reduced by grazing, probably due to a reduction in ground-dwelling invertebrates as an indirect effect of changes in the composition of ground-layer vegetation. A grazing-induced reduction in small mammal abundance can have far reaching ecological consequences for small-mammal population dynamics as well as mammalian and avian predators depending on small mammals as food. SN 0003-455X EI 1797-2450 PD AUG PY 2016 VL 53 IS 3-4 BP 154 EP 164 UT WOS:000381902000003 ER PT J AU Fortin, MAN Sirois, L St-Laurent, MH AF Fortin, Marie-Audrey Nadeau Sirois, Luc St-Laurent, Martin-Hugues TI Extensive forest management contributes to maintain suitable habitat characteristics for the endangered Atlantic-Gaspesie caribou SO CANADIAN JOURNAL OF FOREST RESEARCH AB Extensive forest management aims at minimizing differences between managed and natural forests and at contributing to the conservation of endangered species such as the Atlantic-Gaspesie caribou. The decline of this isolated population was exacerbated by intensive forest practices, as the over-representation of regenerating forests supports high densities of bears and coyotes. These predators select such stands for the high availability of berries and browse suitable to alternative prey, especially moose. Our objective was to verify whether extensive treatments can provide suitable habitat characteristics for caribou. We compared the impacts of different intensive and extensive treatments on habitat attributes known to be selected by caribou, moose, and their predators. We sampled 291 sites in seven treatments and in mature coniferous forests (as the control). A partial canonical correspondence analysis highlighted which treatments maintain habitat attributes that are comparable with those found in mature forests, including some characteristics suitable for caribou such as a substantial biomass of arboreal lichen and a lower availability of resources for predators. Although being more suitable than the three intensive treatments tested, none of the four extensive treatments we studied provided similar habitat conditions to mature forest. Favouring extensive treatments could nevertheless be a relevant conservation compromise at the forest stand level, but their utility remains uncertain under the maximum sustainable yield paradigm as they impact a larger area. SN 0045-5067 EI 1208-6037 PD JUL PY 2016 VL 46 IS 7 BP 933 EP 942 DI 10.1139/cjfr-2016-0038 UT WOS:000378783800005 ER PT J AU Pape, R Loffler, J AF Pape, R. Loeffler, J. TI Spatial patterns of alpine phytomass, primary productivity, and related calorific resources SO ECOSPHERE AB There is an obvious need for a better understanding of the drivers of local spatial heterogeneity in alpine phytomass. Facing challenges in scaling relations with data available either at biome-scale or at plot-scale we wanted to disentangle the driving forces behind spatial patterns of phytomass, productivity, and energy content in alpine reindeer pastures. Our hypothesis was that we would find a set of environmental variables that explain the patterns of fodder resources, thereafter facilitating a spatial upscaling of plot-based data to the broad-scale range of the reindeer pastures. Based on a nested stratified random design, we used univariate and multivariate statistical analyses to relate fodder resources to environmental data along fine-scaled micro-topographical gradients which were embedded in broad-scaled gradients of grazing intensities and climatic conditions throughout Norway. We found that the spatial heterogeneity of resources was not sufficiently explained by our comprehensive set of commonly available environmental variables. This reveals that micro-spatial patterns of energetic fodder resources for reindeer in alpine landscapes are miscalculated by common approaches and that the functionalities behind these micro-spatial patterns are not yet fully understood. Hence, our results suggest that broad-scale models cannot account for the functionality in alpine environments, highlighting that resolution, scale, and the functional context are crucial aspects in understanding broad-scale resource patterns of reindeer pastures. SN 2150-8925 PD JUN PY 2016 VL 7 IS 6 AR e01347 DI 10.1002/ecs2.1347 UT WOS:000378523100018 ER PT J AU Aniano, L Ungerfeld, R AF Aniano, Lucia Ungerfeld, Rodolfo TI Time budget of socially high and low ranked pampas deer (Ozotoceros bezoarticus) females SO NORTH-WESTERN JOURNAL OF ZOOLOGY AB Several ruminant species present variations in their time budget related to social rank. Our aim was to describe the budget time pattern of pampas deer females (Ozotoceros bezoarticus, Linnaeus, 1758), an endangered species, classified in CITES Appendix 1, and to determinate if it differs according to their social rank. This study took place in a population kept in semicaptivity in Maldonado, Uruguay, with 28 females housed in six breeding groups constituted of one stag and three-six hinds and their fawns. Success index (SI) for each female was calculated recording the agonistic behavior during feeding with ration. Females were considered as high-ranked (HR) when their SI was >= 0.5 and low-ranked (LR) at SI < 0.5. The behavior of each female was recorded using instantaneous scan sampling every 15 minutes for eight hours over three days. Except for running, all activities showed differences according to the time of the day (P <= 0.03). In 34.6 +/- 7.2% (mean +/- SEM) of the recording time females were observed lying, and 58.4 +/- 7.5% of this time as standing. Grazing was the most frequent feeding activity (40.5 +/- 7.0%), being more frequent in early morning hours and late in the afternoon. HR females were observed lying more frequently (37.7 +/- 1.9 vs 31.6 +/- 1.9%; P=0.03) and walking less frequently (5.1 +/- 0.8 vs 7.3 +/- 0.8%, P=0.05; respectively) than LR females. We concluded that pampas deer females present a well defined diurnal activity rhythm, with two activity peaks, one early in the morning and a second one late in the afternoon, which are slightly influenced by their social rank, as HR females were observed to spend less time walking than LR. SN 1584-9074 EI 1842-6441 PD JUN PY 2016 VL 12 IS 1 BP 58 EP 64 AR e151704 UT WOS:000378415600008 ER PT J AU Mannisto, M Ganzert, L Tiirola, M Haggblom, MM Stark, S AF Mannisto, Minna Ganzert, Lars Tiirola, Marja Haggblom, Max M. Stark, Sari TI Do shifts in life strategies explain microbial community responses to increasing nitrogen in tundra soil? SO SOIL BIOLOGY & BIOCHEMISTRY AB Subarctic tundra soils store large quantities of the global organic carbon (C) pool as the decomposition of plant litter and soil organic matter is limited by low temperatures and limiting nutrients. Mechanisms that drive organic matter decomposition are still poorly understood due to our limited knowledge of microbial communities and their responses to changing conditions. In subarctic tundra large grazers, in particular reindeer, exert a strong effect on vegetation and nutrient availability causing drastic nutrient pulses in the soils located along the migratory routes. Here we studied the effect of increased nitrogen (N) availability on microbial community structure and activities by laboratory incubations of soil collected from two sites with contrasting grazing intensities. We hypothesized that heavily grazed soil experiencing nutrient pulses harbor more copiotrophic taxa that are able to respond positively to increases in available N leading to increased enzyme activities and respiration. Contrary to our hypothesis, there were only minor differences in the microbial community composition between the lightly and heavily grazed soils. N amendment shifted the bacterial community composition drastically, but the changes were similar at both grazing intensities. The relative abundance of diverse Actinobacteria and Rhodanobacter-affiliated Gammaproteobacteria increased in the N amended microcosms, while the abundance of Acidobacteria, Alphaproteobacteria, Deltaproteobacteria, Verrucomicrobia and Bacteroidetes decreased. Contrary to our hypotheses, increased N availability decreased respiration and microbial biomass at both grazing intensities, while increased N availability had little influence on the extracellular enzyme activities. We propose that similar to what has been reported in other systems, elevated N availability suppressed microbial respiration and biomass by favoring copiotrophic species with faster growth rates and with limited capabilities to decompose recalcitrant organic matter. Similar responses in soils from contrasting vegetation types, soil organic matter (SOM) quality and N availabilities in response to grazing intensity indicate that nutrient pulses may have a strong direct impact on the microbial communities. Responses detected using laboratory incubations are likely amplified in the field where the direct effect of increased N availability is combined with increase in labile C through changes in plant production and species composition. (C) 2016 Elsevier Ltd. All rights reserved. RI Stark, Sari/L-4440-2013; Haggblom, Max/E-7597-2010 OI Haggblom, Max/0000-0001-6307-7863 SN 0038-0717 PD MAY PY 2016 VL 96 BP 216 EP 228 DI 10.1016/j.soilbio.2016.02.012 UT WOS:000378462500026 ER PT J AU Rasmus, S Kivinen, S Bavay, M Heiskanen, J AF Rasmus, Sirpa Kivinen, Sonja Bavay, Mathias Heiskanen, Janne TI Local and regional variability in snow conditions in northern Finland: A reindeer herding perspective SO AMBIO AB Weather station measurements were used to force the SNOWPACK snow model and combined with reindeer herders' experiences to study the local and regional variations in snow conditions in a Finnish reindeer herding area for the 1981-2010 period. Winter conditions varied significantly between the four selected herding districts and between open and forest environments within the districts. The highest snow depths and densities, the thicknesses of ground ice, and the lengths of snow cover period were generally found in the northernmost districts. The snow depths showed the strongest regional coherence, whereas the thicknesses of ground ice were weakly correlated among the districts. The local variation in snow depths was higher than the regional variation and limits for rare or exceptional events varied notably between different districts and environments. The results highlight that forests diversify snow and foraging conditions, e.g., ground ice rarely forms simultaneously in different environments. Sufficient and diverse forest pastures are important during the critical winter season if reindeer herding is pursued on natural grazing grounds also in the future. SN 0044-7447 EI 1654-7209 PD MAY PY 2016 VL 45 IS 4 BP 398 EP 414 DI 10.1007/s13280-015-0762-5 UT WOS:000373744900002 PM 26754168 ER PT J AU Sandstrom, P Cory, N Svensson, J Hedenas, H Jougda, L Borchert, N AF Sandstrom, Per Cory, Neil Svensson, Johan Hedenas, Henrik Jougda, Leif Borchert, Nanna TI On the decline of ground lichen forests in the Swedish boreal landscape: Implications for reindeer husbandry and sustainable forest management SO AMBIO AB Lichens are a bottleneck resource for circumpolar populations of reindeer, and as such, for reindeer husbandry as an indigenous Sami land-use tradition in northern Sweden. This study uses ground lichen data and forest information collected within the Swedish National Forest Inventory since 1953, on the scale of northern Sweden. We found a 71 % decline in the area of lichen-abundant forests over the last 60 years. A decline was observed in all regions and age classes and especially coincided with a decrease of > 60 year old, open pine forests, which was the primary explanatory factor in our model. The effects of reindeer numbers were inconclusive in explaining the decrease in lichen-abundant forest. The role that forestry has played in causing this decline can be debated, but forestry can have a significant role in reversing the trend and improving ground lichen conditions. SN 0044-7447 EI 1654-7209 PD MAY PY 2016 VL 45 IS 4 BP 415 EP 429 DI 10.1007/s13280-015-0759-0 UT WOS:000373744900003 PM 26754169 ER PT J AU Horstkotte, T Lind, T Moen, J AF Horstkotte, Tim Lind, Torgny Moen, Jon TI Quantifying the Implications of Different Land Users' Priorities in the Management of Boreal Multiple-Use Forests SO ENVIRONMENTAL MANAGEMENT AB In the management of natural resources, conflicting interests and objectives among different stakeholders often need to be considered. Here, we examine how two contrasting management scenarios of boreal forests in northern Sweden differ in their consequences on forest structural composition and the economic gains at harvest. Management strategies prioritize either (i) forest characteristics that promote grazing resources for reindeer herded by the indigenous Sami, or (ii) timber production as practiced in Sweden today. When prioritizing reindeer grazing, forest stands develop a higher abundance of older age classes with larger trees and lower stem density, which reduces harvest and revenue levels by approximately 20 % over a 100-year period. The differences between these strategies illustrate the complexity in finding a trade-off for coexistence between industrial land users and other livelihoods that share the same landscape. Political support and institutional solutions are necessary to initiate changes in policy in finding such trade-offs in the management of environmental resources and thereby influence the optimal distribution of costs and benefits between different actors. SN 0364-152X EI 1432-1009 PD APR PY 2016 VL 57 IS 4 BP 770 EP 783 DI 10.1007/s00267-015-0643-5 UT WOS:000372432100003 PM 26645074 ER PT J AU Tolvanen, A Kangas, K AF Tolvanen, Anne Kangas, Katja TI Tourism, biodiversity and protected areas - Review from northern Fennoscandia SO JOURNAL OF ENVIRONMENTAL MANAGEMENT AB Tourist numbers in northern Fennoscandia outweigh those in other northern boreal - arctic regions, which creates a specific need to evaluate the impacts of tourism. This review 1) identifies patterns and trends in the vegetation and wildlife of northern Fennoscandian terrestrial ecosystems as a consequence of tourism and recreation, 2) discusses the implications of findings in terms of the intensity, area and magnitude of impacts, changing climate and management needs under increasing tourist pressure, and 3) identifies research gaps. The reviewed studies show negative environmental and biodiversity impacts that are most pronounced near tourist resorts. The most sensitive plants, birds and mammals decline or disappear from the disturbed sites, and the species composition shifts from 'wild' species to cultural and human associated species. There is little research on the spread of alien species, but the few examples show that alien species can be promoted by tourism activities. Impacts of the use of motorized vehicles have not been widely studied either, despite the extensive track network which can cause disturbance to wildlife. The integrated impacts of tourism and climate change on the vegetation and wildlife was not addressed directly in any of the reviewed studies. In addition, little research has been done on carrying out restoration at tourist areas. Scientific research on these topics is needed to prevent, minimize or restore the most negative ecological impacts of tourism and recreation. (C) 2015 Elsevier Ltd. All rights reserved. RI Tolvanen, Anne/I-5873-2015 OI Tolvanen, Anne/0000-0002-5304-7510 SN 0301-4797 EI 1095-8630 PD MAR 15 PY 2016 VL 169 BP 58 EP 66 DI 10.1016/j.jenvman.2015.12.011 UT WOS:000370909500007 PM 26720330 ER PT J AU Ricca, MA Miles, AK Van Vuren, DH Eviner, VT AF Ricca, Mark A. Miles, A. Keith Van Vuren, Dirk H. Eviner, Valerie T. TI Impacts of introduced Rangifer on ecosystem processes of maritime tundra on subarctic islands SO ECOSPHERE AB Introductions of mammalian herbivores to remote islands without predators provide a natural experiment to ask how temporal and spatial variation in herbivory intensity alter feedbacks between plant and soil processes. We investigated ecosystem effects resulting from introductions of Rangifer tarandus (hereafter "Rangifer") to native mammalian predator- and herbivore-free islands in the Aleutian archipelago of Alaska. We hypothesized that the maritime tundra of these islands would experience either: (1) accelerated ecosystem processes mediated by positive feedbacks between increased graminoid production and rapid nitrogen cycling; or (2) decelerated processes mediated by herbivory that stimulated shrub domination and lowered soil fertility. We measured summer plant and soil properties across three islands representing a chronosequence of elapsed time post-Rangifer introduction (Atka: -100yr; Adak: -50; Kagalaska: -0), with distinct stages of irruptive population dynamics of Rangifer nested within each island (Atka: irruption, K-overshoot, decline, K-re-equilibration; Adak: irruption, K-overshoot; Kagalaska: initial introduction). We also measured Rangifer spatial use within islands (indexed by pellet group counts) to determine how ecosystem processes responded to spatial variation in herbivory. Vegetation community response to herbivory varied with temporal and spatial scale. When comparing temporal effects using the island chronosequence, increased time since herbivore introduction led to more graminoids and fewer dwarf-shrubs, lichens, and mosses. Slow-growing Cladonia lichens that are highly preferred winter forage were decimated on both long-term Rangifer-occupied islands. In addition, linear relations between more concentrated Rangifer spatial use and reductions in graminoid and forb biomass within islands added spatial heterogeneity to long-term patterns identified by the chronosequence. These results support, in part, the hypothesis that Rangifer population persistence on islands is facilitated by successful exploitation of graminoid biomass as winter forage after palatable lichens are decimated. However, the shift from shrubs to graminoids was expected to enhance rates of nitrogen cycling, yet rates of net N-mineralization, NH4+ pools, and soil delta N-15 declined markedly along the chronosequence and were weakly associated with spatial use within islands. Overall plant and soil patterns were disrupted but responded differently to intermediate (50 yr) and long-term (100 yr) herbivory, and were correlated with distinct stages of irruptive population dynamics. OI Eviner, Valerie/0000-0001-5530-9417 SN 2150-8925 PD MAR PY 2016 VL 7 IS 3 AR e01219 DI 10.1002/ecs2.1219 UT WOS:000374896800003 ER PT J AU Neethling, J Hoffman, LC Muller, M AF Neethling, J. Hoffman, L. C. Muller, M. TI Factors influencing the flavour of game meat: A review SO MEAT SCIENCE AB Flavour is a very important attribute contributing to the sensory quality of meat and meat products. Although the sensory quality of meat includes orthonasal and retronasal aroma, taste, as well as appearance, juiciness and other textural attributes, the focus of this review is primarily on flavour. The influence of species, age, gender, muscle anatomical location, diet, harvesting conditions, ageing of meat, packaging and storage, as well as cooking method on the flavour of game meat are discussed. Very little research is available on the factors influencing the flavour of the meat derived from wild and free-living game species. The aim of this literature review is thus to discuss the key ante- and post-mortem factors that influence the flavour of game meat, with specific focus on wild and free-living South African game species. (C) 2015 Elsevier Ltd. All rights reserved. OI Hoffman, Louwrens/0000-0003-2736-1933 SN 0309-1740 EI 1873-4138 PD MAR PY 2016 VL 113 BP 139 EP 153 DI 10.1016/j.meatsci.2015.11.022 UT WOS:000368949400020 PM 26658009 ER PT J AU Zielinska, S Kidawa, D Stempniewicz, L Los, M Los, JM AF Zielinska, Sylwia Kidawa, Dorota Stempniewicz, Lech Los, Marcin Los, Joanna M. TI New Insights into the Microbiota of the Svalbard Reindeer Rangifer tarandus platyrhynchus SO FRONTIERS IN MICROBIOLOGY AB Svalbard reindeer (Rangifer tarandus platyrhynchus) is a non-migratory subspecies of reindeer inhabiting the high-arctic archipelago of Svalbard. In contrast to other Rangifer tarandus subspecies, Svalbard reindeer graze exclusively on natural sources of food and have no chance of ingestion of any crops. We report the use of a non-invasive method for analysis of fecal microbiome by means of sequencing the 16S rDNA extracted from the fecal microbiota of R. tarandus platyrhynchus from a small, isolated population in Hornsund, South Spitsbergen National Park. Analyses of all samples showed that 99% of the total reads were represented by Bacteria. Taxonomy-based analysis showed that fecal bacterial communities consisted of 14 phyla. The most abundant phyla across the population were Firmicutes and Bacteroidetes, and those phyla jointly accounted for more than 95% of total bacterial sequences (ranging between 90.14 and 98.19%). Specifically, Firrnicutes comprised 56.53% (42.98-63.64%) and Bacteroidetes comprised 39.17% (34.56-47.16%) of the total reads. The remaining 5% of the population reads comprised of Tenericutes, Cyanobacteria, TM7, Actinobacteria, Proteobacteria, Verrucomicrobia, Elusimicrobia, Planctomycetes, Fibrobacteres, Spirochaetes, Chloroflexi, and Deferribacteres. Differences in the fecal bacteria composition between particular reindeer were not statistically significant which may reflect the restricted location and similar diet of all members of the local population. OI Stempniewicz, Lech/0000-0001-9405-7320 SN 1664-302X PD FEB 23 PY 2016 VL 7 AR 170 DI 10.3389/fmicb.2016.00170 UT WOS:000370596900001 PM 26941714 ER PT S AU Alekseyev, A Vitebsky, P AF Alekseyev, Afanasy Vitebsky, Piers GP SGEM TI RESPECT FOR THE NATURE & FEEDING LANDSCAPE. THE SCIENTIFIC BASES OF USE OF THE REINDEER PASTURE IN TAIGA-MOUNTAINOUS ZONE OF YAKUTIA SO SGEM 2016, BK 3: ANTHROPOLOGY, ARCHAEOLOGY, HISTORY & PHILOSOPHY CONFERENCE PROCEEDINGS, VOL II SE International Multidisciplinary Scientific Conferences on Social Sciences and Arts CT 3rd International Multidisciplinary Scientific Conference on Social Sciences and Arts, SGEM 2016 CY AUG 24-30, 2016 CL Albena, BULGARIA SP Bulgarian Acad Sci, Acad Sci Czech Republ, Latvian Acad Sci, Polish Acad Sci, Russian Acad Sci, Serbian Acad Sci & Arts, Slovak Acad Sci, Natl Acad Sci Ukraine, Natl Acad Sci Armenia, Sci Council Japan, World Acad Sci, European Acad Sci, Arts & Letters, Acad Fine Arts Zagreb Croatia, Croatian Acad Sci & Arts, Acad Sci Moldova, Montenegrin Acad Sci & Arts, Georgian Acad Sci, Acad Fine Arts & Design Bratislava, Russian Acad Arts, Turkish Acad Sci, Bulgarian Cultural Inst Vienna AB Prior to the reindeer state-farm foundation in the 1960s there was no scientific approach to the use of reindeer pastures not only in a mountain-taiga zone, but also all over Yakutia. The number of reindeers in the collective herd was small - only 300-500 animals. They all year migrated in traditional places of one kind or another. Thus nomads maintained the ecological balance in the first years of Soviet power until the foundation the large reindeer farms. In connection with the increase in the number of livestock herds of reindeer in Yakutia it was necessary to use reindeer pastures on a scientific basis. Since then the scientists have begun to study deer grazing in a mountain and taiga zone of Yakutia. Of course, reindeer grazing has a huge impact on the vegetation of pastures. The scale of the impact of deer grazing on vegetation depends on the daily and seasonal grazing areas per one deer. Therefore, the scale of the impact on the pastures are considered the best in the summer season, which clearly emerges every kilometer concrete used, and shows the load on pastures. SN 2367-5659 BN 978-619-7105-77-3 PY 2016 BP 3 EP 9 UT WOS:000395727400001 ER PT S AU Klokov, K Khrushchev, S AF Klokov, Konstantin Khrushchev, Sergei GP SGEM TI COMPARATIVE ETHNO-ECOLOGICAL EVALUATION OF THE SUSTAINABILITY OF TRADITIONAL REINDEER HERDING ON KOLA AND YAMAL PENINSULAS SO SGEM 2016, BK 3: ANTHROPOLOGY, ARCHAEOLOGY, HISTORY & PHILOSOPHY CONFERENCE PROCEEDINGS, VOL II SE International Multidisciplinary Scientific Conferences on Social Sciences and Arts CT 3rd International Multidisciplinary Scientific Conference on Social Sciences and Arts, SGEM 2016 CY AUG 24-30, 2016 CL Albena, BULGARIA SP Bulgarian Acad Sci, Acad Sci Czech Republ, Latvian Acad Sci, Polish Acad Sci, Russian Acad Sci, Serbian Acad Sci & Arts, Slovak Acad Sci, Natl Acad Sci Ukraine, Natl Acad Sci Armenia, Sci Council Japan, World Acad Sci, European Acad Sci, Arts & Letters, Acad Fine Arts Zagreb Croatia, Croatian Acad Sci & Arts, Acad Sci Moldova, Montenegrin Acad Sci & Arts, Georgian Acad Sci, Acad Fine Arts & Design Bratislava, Russian Acad Arts, Turkish Acad Sci, Bulgarian Cultural Inst Vienna AB The target of the investigation was the comparative analysis of conditions determining the dynamics and sustainability of reindeer herding in two Arctic regions Kola and Yamal peninsulas based on the authors' field studies (2010-2014) and official statistic data. In the 1960s the reindeer stock on Kola and Yamal was commeasurable (74,200 and 103,100 in 1961), however, for the next half a century the difference increased. In 2014 in these regions there were, correspondingly, 54,900 and 293,600 of reindeer. We tried to clear out what it is connected with. Although reindeer husbandries on Kola and Yamal peninsulas have much in common (big herds, long summer-winter migrations from North to South, orientation on meat production), they have also a number of important differences. On Yamal nomadic Nenets herders migrate with their families all year round. Herds are controlled and managed continuously. The majority of reindeer are owned by nomadic families. On Kola peninsula herders' families live in settlements. The reindeer's grazing system is a combination of the Nenets herd management with the Saamies tradition of free (nonrestricted) summer pasturing. As distinct from Yamal, fences are used here. 90% of reindeer are publicly owned, and only 10% belong to herdsmen. The main threat to reindeer herding on Yamal is the lack of pastures and their exhaustion caused by overgrazing and land transfer for the needs of gas extraction industry. Besides, Yamal is crossed with pipe-lines and railways, which are a serious problem for migrating herds. In some winters, when ice crust was formed, dozens thousand reindeer died because of the lack of pasture reserves. On Kola peninsula the main pasture range is located away from industrial areas. However, poaching and disturbance of reindeer by snowmobiles are really serious problems here. Another, even more important problem is recruiting young herdsmen. The results of the study allowed to reveal three main reasons for the differences between the trends in Yamal and Kola reindeer herding. The first advantage of Yamal reindeer herding is a kind of symbiosis of private reindeer owners with municipal reindeer herding enterprises, the second one is the Nenets cultural tradition, according to which reindeer number is the main social measure of welfare, and the third one is 1000 nomadic herders' families which preserve herding traditions and have many children who on growing become reindeer herders. RI Klokov, Konstantin/M-5929-2015 OI Klokov, Konstantin/0000-0002-6149-5778 SN 2367-5659 BN 978-619-7105-77-3 PY 2016 BP 31 EP 38 UT WOS:000395727400005 ER PT S AU Almabekova, O Vasilyeva, Z Bagdasarian, I AF Almabekova, Olga Vasilyeva, Zoya Bagdasarian, Irina GP SGEM TI SILENCE IN A UNIVERSITY CLASSROOM: BETWEEN REFLECTION AND COMMUNICATION SO SGEM 2016, BK 1: PSYCHOLOGY AND PSYCHIATRY, SOCIOLOGY AND HEALTHCARE, EDUCATION CONFERENCE PROCEEDINGS, VOL I SE International Multidisciplinary Scientific Conferences on Social Sciences and Arts CT 3rd International Multidisciplinary Scientific Conference on Social Sciences and Arts, SGEM 2016 CY AUG 24-30, 2016 CL Albena, BULGARIA SP Bulgarian Acad Sci, Acad Sci Czech Republ, Latvian Acad Sci, Polish Acad Sci, Russian Acad Sci, Serbian Acad Sci & Arts, Slovak Acad Sci, Natl Acad Sci Ukraine, Natl Acad Sci Armenia, Sci Council Japan, World Acad Sci, European Acad Sci Arts & Letters, Acad Fine Arts Zagreb Croatia, Croatian Acad Sci & Arts, Acad Sci Moldova, Montenegrin Acad Sci & Arts, Georgian Acad Sci, Acad Fine Arts & Design Bratislava, Russian Acad Arts, Turkish Acad Sci, Bulgarian Cultural Inst Vienna AB Prior to the reindeer state-farm foundation in the 1960s there was no scientific approach to the use of reindeer pastures not only in a mountain-taiga zone, but also all over Yakutia. The number of reindeer s in the collective herd was small - only 300-500 animals. They all year migrated in traditional places of one kind or another. Thus nomads maintained the ecological balance in the first years of Soviet power until the foundation the large reindeer farms. In connection with the increase in the number of livestock herds of reindeer in Yakutia it was necessary to use reindeer pastures on a scientific basis. Since then, the scientists have begun to study deer grazing in a mountain and taiga zone of Yakutia. Of course, reindeer grazing has a huge impact on the vegetation of pastures. The scale of the impact of deer grazing on vegetation depends on the daily and seasonal grazing areas per one deer. Therefore, the scale of the impact on the pastures are considered the best in the summer season, which clearly emerges every kilometer concrete used, and shows the load on pastures. SN 2367-5659 BN 978-619-7105-70-4 PY 2016 BP 1039 EP 1046 UT WOS:000395620400132 ER PT J AU Berg, S Valinger, E Lind, T Suominen, T Tuomasjukka, D AF Berg, Staffan Valinger, Erik Lind, Torgny Suominen, Tommi Tuomasjukka, Diana TI Comparison of co-existing forestry and reindeer husbandry value chains in northern Sweden SO SILVA FENNICA AB Forestry in Mala, northern Sweden, coexists with other land uses. Reindeer husbandry is in the area for centuries and requires large areas of grazing land. Competing land uses may threaten the Mala Sami village. The aim of the study was to evaluate increased consideration in forest management towards 1) reindeer husbandry, 2) nature and 3) a combination of the two. These scenarios were compared with forest management as it was in 2009. Results indicate that all three scenarios lead to a decrease in annual harvesting volumes of 0.2 to 0.4 million m(3). Forest industry dominated the economic viability in the area. Forest management adapted to the needs of reindeer husbandry resulted in less potential for yearly harvest, employment and profits from forest industry. On the other hand, it led to an increase in growing stock and consequently the potential for carbon sequestration over time. Indeed the increased sequestration would compensate for all fossil emissions of carbon from the Forest Wood Chain (FWC). The nature scenario had minor effects on economic result and on the emissions of fossil carbon. The combined scenario gave a reduced economic performance for the FWC. A scenario based on forest management accommodating the needs of reindeer husbandry gave the best economic result for the reindeer chain, due to high survival rate of the reindeer. However the economic importance of reindeer husbandry in the region was small compared to the FWC. Results from scenario analysis could serve as a platform for mutual understanding between stakeholders. SN 0037-5330 EI 2242-4075 PY 2016 VL 50 IS 1 AR 1384 UT WOS:000368411200003 ER PT J AU Brathen, KA Lortie, C AF Brathen, Kari Anne Lortie, Christopher TI A portfolio effect of shrub canopy height on species richness in both stressful and competitive environments SO FUNCTIONAL ECOLOGY AB 1. Facilitating effects of benefactor plants on plant species richness have been commonly tested in stressful habitats because competitive effects are assumed to predominate in more productive habitats. Here, we examine this assumption by testing whether benefactor plants can nonetheless be facilitating in competitive environments. 2. We provide a conceptual framework describing how a trait of benefactor plants, canopy height of shrubs, can have a portfolio of facilitative effects on species richness in more competitive environments, and we provide an empirical assessment of this portfolio effect in tundra plant communities. 3. Across tundra plant communities representing an extensive gradient in aboveground live biomass ranging from 11 to above 800 grams per m(2), we found that species richness exhibited a humped-back relationship. Increasing canopy height of shrubs to a maximum height of what defines the dwarf shrub tundra, that is 40 cm, consistently and significantly increased species richness along the entire biomass gradient tested. 4. The positive effect of shrub canopy height was not confounded with herbivore intensity, competitive interference or abiotic factors such as bedrock-weathered mineral availability, moisture availability or temperature. However, we cannot rule out that the general presence of large mammalian herbivory may have been central to the positive effect of shrub canopy height in reducing herbivore impacts on species richness. 5. In this study, conceptual and empirical evidence support that increasing canopy height of shrubs facilitates species richness regardless of relative abiotic stress levels within tundra ecosystems. We propose that positive interactions can play an important ecological role in systems where competitive effects are observed or assumed. For tundra plant communities where climate change is currently causing encroachment of shrub species, the effects of increasing canopy height may have unprecedented effects on plant species richness. RI lortie, christopher/F-6241-2014 OI lortie, christopher/0000-0002-4291-7023; Brathen, Kari Anne/0000-0003-0942-1074 SN 0269-8463 EI 1365-2435 PD JAN PY 2016 VL 30 IS 1 BP 60 EP 69 DI 10.1111/1365-2435.12458 UT WOS:000367855900007 ER PT J AU Krivoshapkina, EA Prokopieva, SM AF Krivoshapkina, Ekaterina Afanas'evna Prokopieva, Svetlana Mitrophanovna TI Ethno-Cultural Concept 'Reindeer Breeding' in the Even Language SO RUPKATHA JOURNAL ON INTERDISCIPLINARY STUDIES IN HUMANITIES AB The paper reveals ethno-cultural value of the concept 'reindeer breeding' in denotation formation of the Even language. The work is aimed at an analysis of the ethno-cultural concept of 'reindeer breeding' in Even. The investigation is based on lexical units reflecting reindeer characteristics, traditional ways of locational orientation, calendar selected from lexicographic sources of the Even language. The concept 'reindeer breeding' has not been subject of special investigation although this very layer of lexical and phraseological units reflects ethno-cultural specifics of the Even language. The analyzed lexical units are subdivided into three groups: 1) vocational vocabulary reflecting general denotations of reindeer, gender-age related reindeer denotations, reindeer color, viscera, reindeer diseases, movements and actions of reindeer, grazing and feeding land, reindeer character and habits; 2) spatial vocabulary (oikonyms, hydronyms, oronyms, toponyms); 3) temporal vocabulary. The study is of complex character; to reveal specific ethnic-cultural features of the linguistic picture of the world we used the inductive-deductive method. The semantic analysis of lexical units involved dictionary definitions of the concept'reindeer breeding'. Using the component analysis, lexical units were separated into smallest meaningful parts. The research results are of interest for further investigation of other layers of the Even language. SN 0975-2935 PY 2016 VL 8 IS 3 SI SI BP 13 EP 23 DI 10.21659/rupkatha.v8n3.03 UT WOS:000437045400003 ER PT J AU Christie, KS Bryant, JP Gough, L Ravolainen, VT Ruess, RW Tape, KD AF Christie, Katie S. Bryant, John P. Gough, Laura Ravolainen, Virve T. Ruess, Roger W. Tape, Ken D. TI The Role of Vertebrate Herbivores in Regulating Shrub Expansion in the Arctic: A Synthesis SO BIOSCIENCE AB Shrubs are expanding in Arctic ecosystems, and herbivores may be influencing this expansion by reducing the growth of preferred forage species. We synthesized new and published data to evaluate the relative influence of climate and vertebrate herbivory on different shrub species and groups. Variation in chemistry across shrub species translates to a strong preference for (and damage to) palatable deciduous shrubs compared with evergreen shrubs when herbivores are at low densities, but differences in palatability matter less when herbivores are at high densities and/or food limited. Long-term observational and experimental studies indicate that herbivores moderate the expansion of fast-growing deciduous shrubs such as willows (Salix spp.), although moal research is needed to address the relative strength of climate and herbivory at larger scales. Well-defended shrubs such as Siberian alder (Alnus viridis) and resinous dwarf birch (Betula nana exilis) are generally not preferred by herbivores and may therefore outpace the expansion of more palatable species. SN 0006-3568 EI 1525-3244 PD DEC PY 2015 VL 65 IS 12 BP 1123 EP 1133 DI 10.1093/biosci/biv137 UT WOS:000365829200004 ER PT J AU Stark, S Vaisanen, M Ylanne, H Julkunen-Tiitto, R Martz, F AF Stark, S. Vaisanen, M. Ylanne, H. Julkunen-Tiitto, R. Martz, F. TI Decreased phenolic defence in dwarf birch (Betula nana) after warming in subarctic tundra SO POLAR BIOLOGY AB Dwarf birch (Betula nana L.), a dominant deciduous dwarf shrub in many tundra ecosystems, is predicted to increase substantially in abundance due to climate warming. Potential warming-induced changes in the concentrations of phenolic compounds in B. nana leaves could influence the susceptibility of B. nana to environmental stresses; however, only a few studies have investigated the effects of climate warming on the phenolic defence in B. nana. We analysed the responses of phenolic concentrations and amounts in B. nana leaves to factorial treatments of warming and fertilization for 2 years in a subarctic tundra heath. Warming induced a strong decrease in total phenolics, including both flavonols (i.e. quercetin and myricetin derivatives, important defence compounds against oxidative stress) and hydrolysable tannins (HTs, important defence compounds against herbivory). Fertilization exerted weaker effects on phenolic concentrations while significantly increasing the leaf area. Our data indicate that climate warming may decrease the level of phenolic defence in B. nana leaves. Given the important role of these compounds in the plant defence, this phenomenon could potentially increase the susceptibility of B. nana to biotic stresses such as herbivory. RI Martz, Francoise/C-6354-2017; Stark, Sari/L-4440-2013 SN 0722-4060 EI 1432-2056 PD DEC PY 2015 VL 38 IS 12 BP 1993 EP 2005 DI 10.1007/s00300-015-1758-0 UT WOS:000365791300004 ER PT J AU Jung, TS Stotyn, SA Czetwertynski, SM AF Jung, Thomas S. Stotyn, Shannon A. Czetwertynski, Sophie M. TI Dietary overlap and potential competition in a dynamic ungulate community in Northwestern Canada SO JOURNAL OF WILDLIFE MANAGEMENT AB The potential for interspecific competition for food resources is a key consideration when newly introduced ungulates occupy a shared range with resident native species. Management plans in Yukon, Canada, for reintroduced bison (Bison bison) and introduced elk (Cervus canadensis) called for an assessment of competition for food resources between these species and resident populations of caribou (Rangifer tarandus), thinhorn sheep (Ovis dalli), and moose (Alces americanus). To assess potential competition among ungulates, we examined dietary overlap of 7 ungulate species in southwestern Yukon, Canada. We compared diet composition at the forage class level and composite diet indices (diversity, evenness, and niche breadth) among species found at 2 elevation classes (high [1,200m ASL] and low [<1,200m ASL]) during summer and winter, using data derived from microhistological analyses of feces. Composite indices and percent of key forage classes in diets differed among ungulates during summer and winter and at both high and low elevations. Potential dietary overlap for most species pairs was low to moderate (0.07-0.60). However, for bison and thinhorn sheep at high elevations, and bison and semi-feral horses (Equus ferus caballus) at low elevations, it was high (0.82-0.97) during both summer and winter, indicating potential for food competition. Dietary overlap between species appeared to be based primarily on morphophysiological classification (i.e., browser-intermediate-grazer), rather than body size. Bison, horses, and sheep were all grazers. Intermediate species, such as introduced elk, had only moderate dietary overlap with several species. We concluded that the potential for competition for food resources based on dietary overlap between bison and sheep and bison and horses may be high in our study area, depending on forage availability, but for all other species pairs in our study area the potential for forage competition is low to moderate. (c) 2015 The Wildlife Society. OI Jung, Thomas S./0000-0003-2681-6852 SN 0022-541X EI 1937-2817 PD NOV PY 2015 VL 79 IS 8 BP 1277 EP 1285 DI 10.1002/jwmg.946 UT WOS:000363418200008 ER PT J AU Ylanne, H Stark, S Tolvanen, A AF Ylanne, Henni Stark, Sari Tolvanen, Anne TI Vegetation shift from deciduous to evergreen dwarf shrubs in response to selective herbivory offsets carbon losses: evidence from 19years of warming and simulated herbivory in the subarctic tundra SO GLOBAL CHANGE BIOLOGY AB Selective herbivory of palatable plant species provides a competitive advantage for unpalatable plant species, which often have slow growth rates and produce slowly decomposable litter. We hypothesized that through a shift in the vegetation community from palatable, deciduous dwarf shrubs to unpalatable, evergreen dwarf shrubs, selective herbivory may counteract the increased shrub abundance that is otherwise found in tundra ecosystems, in turn interacting with the responses of ecosystem carbon (C) stocks and CO2 balance to climatic warming. We tested this hypothesis in a 19-year field experiment with factorial treatments of warming and simulated herbivory on the dominant deciduous dwarf shrub Vacciniummyrtillus. Warming was associated with a significantly increased vegetation abundance, with the strongest effect on deciduous dwarf shrubs, resulting in greater rates of both gross ecosystem production (GEP) and ecosystem respiration (ER) as well as increased C stocks. Simulated herbivory increased the abundance of evergreen dwarf shrubs, most importantly Empetrum nigrum ssp. hermaphroditum, which led to a recent shift in the dominant vegetation from deciduous to evergreen dwarf shrubs. Simulated herbivory caused no effect on GEP and ER or the total ecosystem C stocks, indicating that the vegetation shift counteracted the herbivore-induced C loss from the system. A larger proportion of the total ecosystem C stock was found aboveground, rather than belowground, in plots treated with simulated herbivory. We conclude that by providing a competitive advantage to unpalatable plant species with slow growth rates and long life spans, selective herbivory may promote aboveground C stocks in a warming tundra ecosystem and, through this mechanism, counteract C losses that result from plant biomass consumption. RI Stark, Sari/L-4440-2013; Tolvanen, Anne/I-5873-2015 OI Tolvanen, Anne/0000-0002-5304-7510 SN 1354-1013 EI 1365-2486 PD OCT PY 2015 VL 21 IS 10 BP 3696 EP 3711 DI 10.1111/gcb.12964 UT WOS:000360994500012 PM 25950664 ER PT J AU Skarin, A Nellemann, C Ronnegard, L Sandstrom, P Lundqvist, H AF Skarin, Anna Nellemann, Christian Ronnegard, Lars Sandstrom, Per Lundqvist, Henrik TI Wind farm construction impacts reindeer migration and movement corridors SO LANDSCAPE ECOLOGY AB Over the last decade, we have seen a massive increase in the construction of wind farms in northern Fennoscandia. Wind farms comprising hundreds of wind turbines are being built, with little knowledge of the possible cumulative adverse effects on the habitat use and migration of semi-domesticated free-ranging reindeer. We assessed how reindeer responded to wind farm construction in an already fragmented landscape, with specific reference to the effects on use of movement corridors and reindeer habitat selection. We used GPS-data from reindeer during calving and post-calving in the MalAyen reindeer herding community in Sweden. We analysed data from the pre-development years compared to the construction years of two relatively small wind farms. During construction of the wind farms, use of original migration routes and movement corridors within 2 km of development declined by 76 %. This decline in use corresponded to an increase in activity of the reindeer measured by increased step lengths within 0-5 km. The step length was highest nearest the development and declining with distance, as animals moved towards migration corridors and turned around or were observed in holding patterns while not crossing. During construction, reindeer avoided the wind farms at both regional and landscape scale of selection. The combined construction activities associated with even a few wind turbines combined with power lines and roads in or close to central movement corridors caused a reduction in the use of such corridors and grazing habitat and increased the fragmentation of the reindeer calving ranges. OI Ronnegard, Lars/0000-0002-1057-5401; Skarin, Anna/0000-0003-3221-1024 SN 0921-2973 EI 1572-9761 PD OCT PY 2015 VL 30 IS 8 BP 1527 EP 1540 DI 10.1007/s10980-015-0210-8 UT WOS:000360673200013 ER PT J AU Vaisanen, M Sjogerstern, S Large, D Drage, T Stark, S AF Vaisanen, Maria Sjogerstern, Sofie Large, David Drage, Trevor Stark, Sari TI Long-term reindeer grazing limits warming-induced increases in CO2 released by tundra heath soil: potential role of soil C quality SO ENVIRONMENTAL RESEARCH LETTERS AB The current climate warming in the Arctic may increase the microbial degradation of vast pools of soil carbon (C); however, the temperature sensitivity of decomposition is often highly dependent on the quality of accumulated soil C. Grazing by reindeer (Rangifer tarandus L.) substantially affects the dominant vegetation and often increases graminoids in relation to dwarf shrubs in ecosystems, but the effect of this vegetation shift on the soil C quality has not been previously investigated. We analyzed the soil C quality and rate of microbially mediated CO2 release at different temperatures in long-term laboratory incubations using soils from lightly grazed dwarf shrub-dominated and heavily grazed graminoid-dominated tundra ecosystem. The soil C quality was characterized by solid-state cross-polarization magic angle spinning (CPMAS C-13 NMR) spectroscopy, which showed a higher relative proportion of carbohydrate Cunder light grazing and higher relative proportion of aliphatic not-O-substituted C under heavy grazing. Initial measurements showed lower temperature sensitivity of the CO2 release in soils under light grazing compared with soil under heavy grazing, but the overall CO2 release rate and its temperature sensitivity increased under light grazing as the soil incubation progressed. At the end of incubation, significantly more carbohydrate Chad been lost in soils under light grazing compared with heavy grazing. These findings indicate that there may be a link between the grazer-induced effects on soil C quality and the potential of soils to release CO2 to atmosphere. We suggest that vegetation shifts induced by grazing could influence the proportion of accumulated soil C that is vulnerable to microbial degradation under warming climate. RI Stark, Sari/L-4440-2013 OI Large, David John/0000-0003-0559-8526 SN 1748-9326 PD SEP PY 2015 VL 10 IS 9 AR 094020 DI 10.1088/1748-9326/10/9/094020 UT WOS:000367141000023 ER PT J AU Kivinen, S AF Kivinen, Sonja TI Many a little makes a mickle: Cumulative land cover changes and traditional land use in the Kyro reindeer herding district, northern Finland SO APPLIED GEOGRAPHY AB Traditional land use systems are threatened by land use intensification and resulting land cover transitions in northern areas. This article examines cumulative land cover changes and their impacts on reindeer grazing grounds in the Kyro reindeer herding district in northern Finland. Land cover transitions were studied using Landsat TM and OLI images and topographic maps. The results showed that the herding district has experienced notable land cover changes during the past decades, and most of these changes were directly related to forestry. The proportion of continuous coniferous forests of the total forest cover declined from 92% to 78% between 1987 and 2013. Approximately one third of the forests outside current conservation areas were disturbed by forest management by 2013, and remaining forests were notably more fragmented than forests within conservation areas. The extent of the road and path networks expanded considerably between 1960s and 2010 as a result of increasing logging and tourism. Accumulation of disturbances gradually results in loss of key resources and declined quality of the landscape mosaic from the reindeer herding perspective, which can pose a serious threat to long-term sustainability of the livelihood. Rapid land cover changes in non-protected areas highlight an increasingly important role of conservation areas in maintaining resources for reindeer husbandry in the face of intensifying land use. Sustainable management of resources outside conservation areas requires careful participatory planning and efficient cumulative impact assessment of different land use activities. (C) 2015 Elsevier Ltd. All rights reserved. SN 0143-6228 EI 1873-7730 PD SEP PY 2015 VL 63 BP 204 EP 211 DI 10.1016/j.apgeog.2015.06.013 UT WOS:000362059700019 ER PT J AU Kaarlejarvi, E Hoset, KS Olofsson, J AF Kaarlejarvi, Elina Hoset, Katrine S. Olofsson, Johan TI Mammalian herbivores confer resilience of Arctic shrub-dominated ecosystems to changing climate SO GLOBAL CHANGE BIOLOGY AB Climate change is resulting in a rapid expansion of shrubs in the Arctic. This expansion has been shown to be reinforced by positive feedbacks, and it could thus set the ecosystem on a trajectory toward an alternate, more productive regime. Herbivores, on the other hand, are known to counteract the effects of simultaneous climate warming on shrub biomass. However, little is known about the impact of herbivores on resilience of these ecosystems, that is, the capacity of a system to absorb disturbance and still remain in the same regime, retaining the same function, structure, and feedbacks. Here, we investigated how herbivores affect resilience of shrub-dominated systems to warming by studying the change of shrub biomass after a cessation of long-term experimental warming in a forest-tundra ecotone. As predicted, warming increased the biomass of shrubs, and in the absence of herbivores, shrub biomass in tundra continued to increase 4 years after cessation of the artificial warming, indicating that positive effects of warming on plant growth may persist even over a subsequent colder period. Herbivores contributed to the resilience of these systems by returning them back to the original low-biomass regime in both forest and tundra habitats. These results support the prediction that higher shrub biomass triggers positive feedbacks on soil processes and microclimate, which enable maintaining the rapid shrub growth even in colder climates. Furthermore, the results show that in our system, herbivores facilitate the resilience of shrub-dominated ecosystems to climate warming. RI Hoset, Katrine S./A-5090-2010 OI Hoset, Katrine S./0000-0002-1371-012X SN 1354-1013 EI 1365-2486 PD SEP PY 2015 VL 21 IS 9 BP 3379 EP 3388 DI 10.1111/gcb.12970 UT WOS:000360998400018 PM 25967156 ER PT J AU Eckerberg, K Bjarstig, T Zachrisson, A AF Eckerberg, Katarina Bjarstig, Therese Zachrisson, Anna TI Incentives for Collaborative Governance: Top-Down and Bottom-Up Initiatives in the Swedish Mountain Region SO MOUNTAIN RESEARCH AND DEVELOPMENT AB Governance collaborations between public and private partners are increasingly used to promote sustainable mountain development, yet information is limited on their nature and precise extent. This article analyzes collaboration on environment and natural resource management in Swedish mountain communities to critically assess the kinds of issues these efforts address, how they evolve, who leads them, and what functional patterns they exhibit based on Margerum's (2008) typology of action, organizational, and policy collaboration. Based on official documents, interviews, and the records of 245 collaborative projects, we explore the role of the state, how perceptions of policy failure may inspire collaboration, and the opportunities that European Union funds have created. Bottom-up collaborations, most of which are relatively recent, usually have an action and sometimes an organizational function. Top-down collaborations, however, are usually organizational or policy oriented. Our findings suggest that top-down and bottom-up collaborations are complementary in situations with considerable conflict over time and where public policies have partly failed, such as for nature protection and reindeer grazing. In less contested areas, such as rural development, improving tracks and access, recreation, and fishing, there is more bottom-up, action-oriented collaboration. State support, especially in the form of funding, is central to explaining the emergence of bottom-up action collaboration. Our findings show that the state both initiates and coordinates policy networks and retains a great deal of power over the nature and functioning of collaborative governance. A practical consequence is that there is great overlap-aggravated by sectorized approaches-that creates a heavy workload for some regional partners. SN 0276-4741 EI 1994-7151 PD AUG PY 2015 VL 35 IS 3 BP 289 EP 298 DI 10.1659/MRD-JOURNAL-D-14-00068.1 UT WOS:000361557100008 ER PT J AU Koster, K Berninger, F Koster, E Pumpanen, J AF Koster, Kajar Berninger, Frank Koster, Egle Pumpanen, Jukka TI Influences of reindeer grazing on above- and belowground biomass and soil carbon dynamics SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Reindeer (Rangifer tarandus L.) are the most important large mammalian herbivores in Lapland, strongly affecting the dynamics of vegetation by grazing and trampling, and this is likely in turn to have consequences for the soil processes. We have investigated the changes occurring in above-and belowground biomasses, and soil C dynamics (CO2 efflux, soil C content, soil microbial biomass) among areas grazed and not grazed by reindeer. Our study areas are located in the northern boreal subarctic coniferous forest (undisturbed Scots pine [Pinus sylvestris L.] forests that are naturally lichen-dominated). Our study showed that grazing by reindeer decreased the biomass and cover of lichens in the area significantly. Also the tree regeneration was affected by grazing, as we had much less tree regeneration in the grazed areas. In subarctic mature pine forest, grazing did not affect the soil temperature or the soil moisture. We found no statistically significant effect of grazing on the soil CO2 efflux, soil C stock, and the soil microbial C biomass. Soil microbial N biomass was significantly lower in the grazed areas compared to the non-grazed areas. Our results indicate that in the northern boreal subarctic coniferous forests, grazing by reindeer can be considered as "C neutral." RI Koster, Kajar/C-8397-2012; Pumpanen, Jukka/B-1254-2012; Berninger, Frank/A-8891-2010 OI Koster, Kajar/0000-0003-1988-5788; Pumpanen, Jukka/0000-0003-4879-3663; Berninger, Frank/0000-0001-7718-1661 SN 1523-0430 EI 1938-4246 PD AUG PY 2015 VL 47 IS 3 BP 495 EP 503 DI 10.1657/AAAR0014-062 UT WOS:000359679000007 ER PT J AU Hempson, GP Illius, AW Hendricks, HH Bond, WJ Vetter, S AF Hempson, G. P. Illius, A. W. Hendricks, H. H. Bond, W. J. Vetter, S. TI Herbivore population regulation and resource heterogeneity in a stochastic environment SO ECOLOGY AB Large-mammal herbivore populations are subject to the interaction of internal density-dependent processes and external environmental stochasticity. We disentangle these processes by linking consumer population dynamics, in a highly stochastic environment, to the availability of their key forage resource via effects on body condition and subsequent fecundity and mortality rates. Body condition and demographic rate data were obtained by monitoring 500 tagged female goats in the Richtersveld National Park, South Africa, over a three-year period. Identifying the key resource and pathway to density dependence for a population allows environmental stochasticity to be partitioned into that which has strong feedbacks to population stability, and that which does not. Our data reveal a density-dependent seasonal decline in goat body condition in response to concomitant density-dependent depletion of the dry-season forage resource. The loss in body condition reduced density-dependent pregnancy rates, litter sizes, and pre-weaning survival. Survival was lowest following the most severe dry season and for juveniles. Adult survival in the late-dry season depended on body condition in the mid-dry season. Population growth was determined by the length of the dry season and the population size in the previous year. The RNP goat population is thereby dynamically coupled primarily to its dry-season forage resource. Extreme environmental variability thus does not decouple consumer resource dynamics, in contrast to the views of nonequilibrium protagonists. OI Hempson, Gareth/0000-0001-8055-4895; Bond, William/0000-0002-3441-2084; Vetter, Susanne/0000-0002-2063-5615 SN 0012-9658 EI 1939-9170 PD AUG PY 2015 VL 96 IS 8 BP 2170 EP 2180 DI 10.1890/14-1501.1 UT WOS:000358454500015 PM 26405742 ER PT J AU Barthelemy, H Stark, S Olofsson, J AF Barthelemy, Helene Stark, Sari Olofsson, Johan TI Strong Responses of Subarctic Plant Communities to Long-Term Reindeer Feces Manipulation SO ECOSYSTEMS AB Deposition of feces is a key mechanism by which herbivores influence soil nutrient cycling and plant production, but the knowledge about its importance for plant production and community structure is still rudimental since experimental evidence is scarce. We thus performed a 7-year long reindeer feces manipulation experiment in two tundra vegetation types with contrasting nutrient availability and analyzed effects on plant community composition and soil nutrient availability. Despite feces being fairly nutrient poor, feces manipulation had strong effect on both the nutrient-poor heath and the nutrient-rich meadow. The strongest effect was detected when feces were added at high density, with a substantial increase in total vascular plant productivity and graminoids in the two communities. Doubling natural deposition of reindeer feces enhanced primary production and the growth of deciduous shrubs in the heath. By contrast, removal of feces decreased only the production of graminoids and deciduous shrubs in the heath. Although the response to feces addition was faster in the nutrient-rich meadow, after 7 years it was more pronounced in the nutrient-poor heath. The effect of feces manipulation on soil nutrient availability was low and temporarily variable. Our study provides experimental evidence for a central role of herbivore feces in regulating primary production when herbivores are abundant enough. Deposition of feces alone does, however, not cause dramatic vegetation shifts; to drive unproductive heath to a productive grass dominated state, herbivore trampling, and grazing are probably also needed. RI Stark, Sari/L-4440-2013 SN 1432-9840 EI 1435-0629 PD AUG PY 2015 VL 18 IS 5 BP 740 EP 751 DI 10.1007/s10021-015-9856-y UT WOS:000358089100002 ER PT J AU Herfindal, I Tremblay, JP Hester, AJ Lande, US Wam, HK AF Herfindal, Ivar Tremblay, Jean-Pierre Hester, Alison J. Lande, Unni Stobet Wam, Hilde Karine TI Associational relationships at multiple spatial scales affect forest damage by moose SO FOREST ECOLOGY AND MANAGEMENT AB Increasing abundance of large herbivores combined with changes in forestry practices has led to increased forest damage in many temperate and boreal forest areas. The role of alternative forage as a driver for browsing pressure on tree species important for forestry has received increased attention. However, actions to reduce damage through altering forage abundance must be carried out at spatial scales that correspond to the behavioural processes that generate the browsing pattern. We used a multi-scaled dataset on browse abundance and utilisation in Southern Norway to assess how pine browsing damage was related to abundance and quality of browse measured at different spatial scales. Pine trees had a lower probability to be browsed at high pine abundance at all spatial scales. However, the abundance and quality of alternative browse was negatively related to pine browsing (i.e. associational resistance) at several spatial scales, with the highest explanatory power at the largest spatial scale. Management actions to reduce pine browsing by moose should focus on facilitating high abundance of both pine and alternative high-quality browse, and should be carried out at sufficiently large spatial scales (moose home range scale or larger). (C) 2015 Elsevier B.V. All rights reserved. RI Herfindal, Ivar/A-4609-2015 OI Herfindal, Ivar/0000-0002-5860-9252 SN 0378-1127 EI 1872-7042 PD JUL 15 PY 2015 VL 348 BP 97 EP 107 DI 10.1016/j.foreco.2015.03.045 UT WOS:000355353300010 ER PT J AU Rickbeil, GJM Coops, NC Adamczewski, J AF Rickbeil, Gregory J. M. Coops, Nicholas C. Adamczewski, Jan TI The grazing impacts of four barren ground caribou herds (Rangifer tarandus groenlandicus) on their summer ranges: An application of archived remotely sensed vegetation productivity data SO REMOTE SENSING OF ENVIRONMENT AB Barren ground caribou (Rangifer tarandus groenlandicus) herds experience significant fluctuations in abundance through time. A proposed hypothesis for these fluctuations involves the overgrazing of vegetation on herd summer ranges at high herd densities resulting in a reduction in available forage. Semi-domesticated reindeer (Rangifer tarandus) herds in Scandinavia negatively affect vegetation productivity at high herd densities and exclosure experiments have indicated that overgrazing may also affect barren ground caribou herds. However, overgrazing of summer range vegetation has yet to be tested at the landscape level or related to herd densities for barren ground caribou herds. Accordingly, the question examined in this study was does barren ground caribou herd density have an effect on summer range vegetation productivity? To answer this question, summer home ranges for four herds in the Northwest Territories and Nunavut, Canada, were delineated using caribou telemetry data. Yearly overall productivity and vegetation seasonality (the change between the maximum and minimum productivity throughout the year) metrics were calculated by year using Moderate Resolution Imaging Spectroradiometer and Advanced Very High Resolution Radiometer data and related to herd densities. Overall vegetation productivity was negatively related to herd density, indicating that some summer range degradation may have occurred at high densities. Conversely, and contrary to our expectations, vegetation seasonality was positively related to herd density. The Bathurst herd, which experienced densities more than three times those of the other herds examined, had the least negative association with overall productivity. Given the negative relationship detected between each herd's densities and overall vegetation productivity, it is likely that some summer range degradation occurred as herd densities increased. Considering the results of the Bathurst herd however, it is difficult to conclude that overgrazing has been a major factor governing herd abundance in the herds examined here. This study demonstrated the utility of archived remotely sensed productivity data and how productivity indices can be useful tools for providing information on large mammal grazing impacts. (C) 2015 Elsevier Inc. All rights reserved. RI Coops, Nicholas/J-1543-2012 OI Coops, Nicholas/0000-0002-0151-9037 SN 0034-4257 EI 1879-0704 PD JUL PY 2015 VL 164 BP 314 EP 323 DI 10.1016/j.rse.2015.04.006 UT WOS:000356554600025 ER PT J AU Stark, S Mannisto, MK Eskelinen, A AF Stark, Sari Mannisto, Minna K. Eskelinen, Anu TI When do grazers accelerate or decelerate soil carbon and nitrogen cycling in tundra? A test of theory on grazing effects in fertile and infertile habitats SO OIKOS AB It is generally predicted that grazers enhance soil microbial activity and nutrient availability and promote soil bacteria in fertile ecosystems, but retard microbial activity and nutrient availability and promote soil fungi in infertile ecosystems. We tested these predictions in tundra by comparing grazing effects between fertile and infertile habitats and with/without nutrient manipulation by fertilization. Grazing decreased soil N content in fertile and in fertilized plots in infertile habitats while increased it in infertile tundra habitats, which directly opposed our prediction. We conclude that this unpredicted outcome probably resulted from nutrient transport between habitats. Also contrasting with our hypothesis, grazing increased fungal rather than bacterial abundance in fertilized plots at both habitats. In support with predictions, grazing increased microbial activity for soil C decomposition in fertile but decreased it in infertile habitats. The effect of grazing on soil C decomposition followed same patterns as grazer-induced changes in the activity of beta-glucosidase, which is an extracellular enzyme synthesized by soil microorganisms for degrading soil cellulose. We suggest that the theoretical framework on grazer-soil interactions should incorporate microbial potential for extracellular enzyme production ('microscale' grazer effects) and nutrient translocation by grazers among habitats ('macroscale' grazer effects) as important mechanisms by which grazers influence soil processes and nutrient availability for plants at contrasting levels of habitat fertility. RI Stark, Sari/L-4440-2013 SN 0030-1299 EI 1600-0706 PD MAY PY 2015 VL 124 IS 5 BP 593 EP 602 DI 10.1111/oik.01355 UT WOS:000356010300007 ER PT J AU Stark, S Mannisto, MK Ganzert, L Tiirola, M Haggblom, MM AF Stark, Sari Mannisto, Minna K. Ganzert, Lars Tiirola, Marja Haeggblom, Max M. TI Grazing intensity in subarctic tundra affects the temperature adaptation of soil microbial communities SO SOIL BIOLOGY & BIOCHEMISTRY AB Grazing by large ungulates, such as reindeer (Rangifer tarandus L.), in subarctic tundra exerts a considerable effect on the soil microclimate. Because of higher insulation by the aboveground vegetation in light versus heavily grazed areas, soil temperatures during the growing season are considerably higher under heavy grazing. Here, we hypothesized that these grazer-induced changes in soil microclimate affect the temperature sensitivity of soil microbial activity. To test this hypothesis, we conducted soil incubations at different temperatures (4 degrees C, 9 degrees C and 14 degrees C) for six weeks using soils from sites with contrasting long-term grazing intensities. Microbial respiration at low temperature (4 degrees C) was significantly higher in soils under light grazing than in soils under heavy grazing; however, grazing intensity did not affect respiration rates at 9 degrees C and 14 degrees C. In soils under light grazing, post-incubation beta-glucosidase (BG) activity at 4 degrees C was higher in soils that had been incubated at 4 degrees C than in soils incubated at 14 degrees C, suggesting functional adaptation of the soil microbial community to low temperature. Similar adaptation was not detected in soils under heavy grazing. Ion Torrent sequencing of bacterial 16S rRNA genes showed major differences in the bacterial community composition in soils incubated at different temperatures. Overall, our results indicate that tundra soil microorganisms may be more cold-adapted under low than high grazing intensity. Due to this difference in temperature adaptation, the consequences of climate warming on soil microbial processes may be dependent on the grazing intensity. (C) 2015 Elsevier Ltd. All rights reserved. RI Stark, Sari/L-4440-2013; Haggblom, Max/E-7597-2010 OI Haggblom, Max/0000-0001-6307-7863 SN 0038-0717 PD MAY PY 2015 VL 84 BP 147 EP 157 DI 10.1016/j.soilbio.2015.02.023 UT WOS:000353087600015 ER PT J AU Bartzke, GS May, R Solberg, EJ Rolandsen, CM Roskaft, E AF Bartzke, G. S. May, R. Solberg, E. J. Rolandsen, C. M. Roskaft, E. TI Differential barrier and corridor effects of power lines, roads and rivers on moose (Alces alces) movements SO ECOSPHERE AB Building new power lines is required to satisfy increasing demands for the transmission of electricity, and at the same time the road network is expanding. To provide guidelines for the routing of new power lines and roads, it is essential to test whether linear features deter or attract movements of animals in different landscape settings. Using GPS relocation data from 151 moose (Alces alces L.) in central Norway, we tested for barrier and corridor effects of roads, power lines and rivers and accounted for forest cover, the topographical orientation of linear features and the placement of other nearby linear features. We predicted step selection probabilities for different movement options at varying distances from linear features and linear feature combinations. Barrier and corridor effects of linear features altered moose movements, although effects were minor compared to the effects of topography and forest cover. Moose did not avoid crossing power lines, unless the placement of power lines along contour lines impeded movements across them. In contrast, moose avoided crossing of roads and rivers in forests. Moose more likely moved along linear features when getting closer to linear features. Barrier and corridor effects were higher for road/river combinations compared to single linear features. Likewise, the barrier and corridor effects were higher for road/power line combinations, but not power line/river combinations compared to single linear features, when moose were close to the edge of those features. The inconsistent pattern could be due to the low sample size. We found indications of higher disturbance potential of roads compared to power lines and rivers. Managing vegetation in power line rights-of-way to provide abundant browse could counteract possible disturbance, while wildlife overpasses could mitigate road fragmentation effects. SN 2150-8925 PD APR PY 2015 VL 6 IS 4 AR 67 DI 10.1890/ES14-00278.1 UT WOS:000354777300022 ER PT J AU Kivinen, S Rasmus, S AF Kivinen, Sonja Rasmus, Sirpa TI Observed cold season changes in a Fennoscandian fell area over the past three decades SO AMBIO AB We studied trends and variability in snow and climate characteristics in 1978-2012 in the Varriotunturit fell area, northern Finland. Cold season changes were examined using long-term observational data on snow depths, meteorological data, large-scale climate indices, and reindeer herders' experiences with difficult snow conditions. Snow depths declined, and temperatures increased significantly over the study period, with the largest changes observed in October-December and in April. Snow depths decreased particularly in forests at lower altitudes but not in treeless areas at higher altitudes. Interannual variability (but not the trends) in snow depths could be partially linked to large-scale climate indices. A majority of difficult reindeer grazing conditions were related to deep snow in the winter or spring. Our observations suggest that shortened duration of snow cover may facilitate reindeer grazing, whereas potentially more frequent formation of ice layers and mold growth on pastures in the future is disadvantageous for reindeer husbandry. SN 0044-7447 EI 1654-7209 PD APR PY 2015 VL 44 IS 3 BP 214 EP 225 DI 10.1007/s13280-014-0541-8 UT WOS:000351293600006 PM 25001240 ER PT J AU Gundersen, V Mehmetoglu, M Vistad, OI Andersen, O AF Gundersen, Vegard Mehmetoglu, Mehmet Vistad, Odd Inge Andersen, Oddgeir TI Linking visitor motivation with attitude towards management restrictions on use in a national park SO JOURNAL OF OUTDOOR RECREATION AND TOURISM-RESEARCH PLANNING AND MANAGEMENT AB The increasing demand for visiting wilderness areas often requires management actions that both conserve the natural resources and ensure a high quality visitor experience. Many of the alpine national parks in southern Norway hold the last remaining populations of wild reindeer (Rangifer tarandus tarandus) in Europe. Therefore management needs more effective tools to reduce or remove recreational impact on wild reindeer populations. Management actions should also consult research-based knowledge on visitors. Therefore, this study explores the link between visitor motivations and their attitudes towards management actions on track-related (trail, path, trampling, track) and area-related (zoning, legal restrictions) use. The results show that two of the visitor motivations (i.e. hiking and place attachment) affect visitors' attitudes towards management restrictions on use significantly. For instance, those visiting the national park for hiking are more positive to area-related restrictions while individuals attached to the place are more positive to track-related restrictions. Practical and theoretical implications are also discussed. (C) 2015 Elsevier Ltd. All rights reserved. SN 2213-0780 EI 2213-0799 PD APR PY 2015 VL 9 BP 77 EP 86 DI 10.1016/j.jort.2015.04.004 UT WOS:000218649100009 ER PT J AU Vuojala-Magga, T Turunen, MT AF Vuojala-Magga, Terhi Turunen, Minna T. TI Sami reindeer herders' perspective on herbivory of subarctic mountain birch forests by geometrid moths and reindeer: a case study from northernmost Finland SO SPRINGERPLUS AB Introduction: Geometrid moths and semi-domesticated reindeer are both herbivores which feed on birch leaves in the subarctic mountain birch forests in northern Fennoscandia. The caterpillars of autumnal and winter moths have episodic outbreaks, which can occasionally lead to extensive defoliation of birch forests. Earlier studies have shown that reindeer have a negative effect on the regeneration of defoliated birches by grazing and browsing their seedlings and sprouts. Case description: We interviewed 15 reindeer herders in the Kaldoaivi and Paistunturi herding co-operative in northernmost Finland in order to analyse their past, present and future views on the behaviour of moths and the growth of mountain birches. We investigate the behaviour of the two herbivores by combining the indigenous knowledge (IK) of Sami herders with the results of relevant studies in biology and anthropology, applying niche construction theory (NCT) in doing so. Discussion and evaluation: In the first stage, the niche constructors (moths, reindeer, herders, mountain birch and other organisms) are looked upon as "equal constructors" of a shared niche. As changes unfold in their niche, their role changes from that of constructor to key constructor. The role and importance of niche constructors were different when nomadic pasture rotation was used than they are today under the herding co-operative system. Niche construction faced its most radical and permanent negative changes during the border closures that took place over the latter half of the 19th century. The large-scale nomadic life among the Sami herders, who migrated between Finland and Norway, came to an end. This phase was followed by stationary herding, which diminished the possibilities of reindeer to look for various environmental affordances. Difficult snow conditions or birch defoliation caused by moth outbreaks made the situation worse than before. Eventually reindeer became key constructors, together with moth larvae, leading to negative ecological inheritance that forced herders to use new, adaptive herding practices. Conclusions: Both the scientific data and the IK of herders highlight the roles of reindeer and herders as continuous key constructors of the focal niche, one which stands to be modified in more heterogenic ways than earlier due to global warming and hence will result in new ecological inheritance. RI Turunen, Minna/L-4442-2013; Vuojala-Magga, Terhi/L-4456-2013 OI Vuojala-Magga, Terhi/0000-0002-2750-2946 SN 2193-1801 PD MAR 20 PY 2015 VL 4 AR 134 DI 10.1186/s40064-015-0921-y UT WOS:000359195000001 PM 25825690 ER PT J AU Drucker, DG Vercoutere, C Chiotti, L Nespoulet, R Crepin, L Conard, NJ Munzel, SC Higham, T van der Plicht, J Laznickova-Galetova, M Bocherens, H AF Drucker, Dorothee G. Vercoutere, Carole Chiotti, Laurent Nespoulet, Roland Crepin, Laurent Conard, Nicholas J. Muenzel, Susanne C. Higham, Thomas van der Plicht, Johannes Laznickova-Galetova, Martina Bocherens, Herve TI Tracking possible decline of woolly mammoth during the Gravettian in Dordogne (France) and the Ach Valley (Germany) using multi-isotope tracking (C-13, C-14, N-15, S-34, O-18) SO QUATERNARY INTERNATIONAL AB The woolly mammoth (Mammuthus primigenius) was an emblematic and key species of the so-called mammoth steppe ecosystem between ca. 110,000 and 12,000 years ago. Its contribution to human subsistence during the Gravettian period as source of raw material was documented in southwestern France and southwestern Germany, with some evidence of active hunting in the latter region. However, decreasing genetic diversity and increasing indications of nutritional stress point to a likely decline of this megaherbivore. The specificity of the ecological niche occupied by the woolly mammoth is clearly reflected by their collagen C-13 and N-15 abundances (delta C-13(coll) and delta N-15(coll)), measured on skeletal remains of the typical mammoth steppe. The abundances of carbon-13 in mammoth collagen are comparable to those of other grazers like horse (Equus sp.), while the nitrogen-15 abundances are significantly higher (about 3 parts per thousand) than in the other herbivores, either horse or reindeer (Rangifer tarandus). During the Aurignacian and Gravettian occupation at Geissenklosterle in the Ach Valley (Germany), the mammoths had the expected stable isotope signature, but the nitrogen-15 of horses showed an unexpected overlap with those of the mammoth. This unusual pattern was already occurring during the Aurignacian, while the oxygen-18 abundances in bone phosphate (delta O-18(bp)) of horse and reindeer were unchanged between Aurignacian and Gravettian periods, which rules out significant change in environmental and climatic conditions. Thus, we hypothesize that during the Aurignacian and Gravettian, the ecological niche of mammoth was intact but not occupied intensively by mammoths due to a decline in their population. This decline could be tentatively explained by human pressure through hunting. In Dordogne (France), decreasing horse and reindeer delta N-15(coll) values coeval to decreasing horse delta O-18(bp) values between the Aurignacian and the Early Gravettian periods reflected a clear change in the environment, while no contrast in delta N-15(coll) values was observed between the Early and Final Gravettian at the Abri Pataud. The mammoth of Dordogne yielded slightly higher delta N-15(coll) values than expected, probably as a consequence of the nursing effect since all the analyzed samples were ivory instead of bone. The direct dating and sulphur-34 measurement on the ivory of the Early Gravettian at Pataud showed that almost all of them were of contemporaneous and local origin. Significant contrasts in delta S-34(coll) values were found between the Dordogne and the Ach Valley for the same herbivores species, which confirms the potential of sulphur-34 in collagen as a mobility tracker. (C) 2014 Elsevier Ltd and INQUA. All rights reserved. RI Drucker, Dorothee/E-8900-2011; Bocherens, Herve/F-3580-2011; van der Plicht, Johannes/B-9994-2013 OI Drucker, Dorothee/0000-0003-0854-4371; Bocherens, Herve/0000-0002-0494-0126; SN 1040-6182 EI 1873-4553 PD MAR 2 PY 2015 VL 359 BP 304 EP 317 DI 10.1016/j.quaint.2014.11.028 UT WOS:000350997500024 ER PT J AU Bocherens, H Hofman-Kaminska, E Drucker, DG Schmolcke, U Kowalczyk, R AF Bocherens, Herve Hofman-Kaminska, Emilia Drucker, Dorothee G. Schmoelcke, Ulrich Kowalczyk, Rafal TI European Bison as a Refugee Species? Evidence from Isotopic Data on Early Holocene Bison and Other Large Herbivores in Northern Europe SO PLOS ONE AB According to the refugee species concept, increasing replacement of open steppe by forest cover after the last glacial period and human pressure had together forced European bison (Bison bonasus)-the largest extant terrestrial mammal of Europe-into forests as a refuge habitat. The consequent decreased fitness and population density led to the gradual extinction of the species. Understanding the pre-refugee ecology of the species may help its conservation management and ensure its long time survival. In view of this, we investigated the abundance of stable isotopes (delta C-13 and delta N-15) in radiocarbon dated skeletal remains of European bison and other large herbivores-aurochs (Bos primigenius), moose (Alces alces), and reindeer (Rangifer tarandus)-from the Early Holocene of northern Europe to reconstruct their dietary habits and pattern of habitat use in conditions of low human influence. Carbon and nitrogen isotopic compositions in collagen of the ungulate species in northern central Europe during the Early Holocene showed significant differences in the habitat use and the diet of these herbivores. The values of the delta C-13 and delta N-15 isotopes reflected the use of open habitats by bison, with their diet intermediate between that of aurochs (grazer) and of moose (browser). Our results show that, despite the partial overlap in carbon and nitrogen isotopic values of some species, Early Holocene large ungulates avoided competition by selection of different habitats or different food sources within similar environments. Although Early Holocene bison and Late Pleistocene steppe bison utilized open habitats, their diets were significantly different, as reflected by their delta N-15 values. Additional isotopic analyses show that modern populations of European bison utilize much more forested habitats than Early Holocene bison, which supports the refugee status of the species. RI Drucker, Dorothee/E-8900-2011; Bocherens, Herve/F-3580-2011 OI Drucker, Dorothee/0000-0003-0854-4371; Bocherens, Herve/0000-0002-0494-0126 SN 1932-6203 PD FEB 11 PY 2015 VL 10 IS 2 AR UNSP e0115090 DI 10.1371/journal.pone.0115090 UT WOS:000349545300004 PM 25671634 ER PT J AU Bock, N Anderson, OR AF Bock, Nicholas Anderson, O. Roger TI Eukaryotic Microbial Communities Associated with Rock-dwelling Foliose Lichens: A Functional Morphological and Microecological Analysis SO ACTA PROTOZOOLOGICA AB Lichens are widely recognized as important examples of a fungal-algal or fungal-cyanophyte symbiosis; and in some cases they are a major food source for some animal grazers such as caribou (Rangifer tarandus), especially in the Arctic during winter. However, relatively little is known about the ecology of their co-associated bacterial and protistan communities. This is one of the first reports of an analysis of microbial communities associated with rock-dwelling foliose lichens (Flavoparmelia sp.), including a more detailed analysis of the microbial communities associated with segments of the shield-like, radially arranged lobes. Samples were taken from lichens on granite boulders beneath an oak and maple tree stand on the Lamont-Doherty Earth Observatory Campus, Palisades, N.Y. The bacteria and protist members of the lichen associated microbial communities are comparable to recently reported associations for foliose lichens growing on tree bark at the same locale, including the presence of large myxomycete plasmodial amebas, heterotrophic nanoflagellates, and naked and testate amebas. To obtain evidence of possible differences in the microecology of different portions of each radial lobe, three segments of the radial lobe in the shield-like lichen were sampled: 1) inner, more mature, central segment; 2) middle section linking the central and peripheral segments; and 3) outer, peripheral, usually broader, less closely attached segment. The mean densities (number/g) and biomasses (mu g/g) of bacteria and heterotrophic nanoflagellates were highest in the older central segment and lowest in the peripheral segment of the radial lobes, especially when expressed on moist weight basis. Large myxomycete plasmodial amebas were typically located in the outermost segment of the radial lobe. The proportion of vannellid amebas (Vannella spp. and Cochliopodium spp.) were significantly more abundant in the samples of the inner lobes compared to non-vannellid amebas that were more prevalent in the outer lobes. The outer segment of the thallus lobe was typically more spongiose and absorbed more water per unit weight (based on a wet/dry-weight ratio) than the innermost segment. In general, patterns of densities and taxonomic composition of bacteria and eukaryotic microbes intergraded from the inner most segment to the outer part of each lobe - indicating a possible microecological gradient, coincident with the age-related and morphological radial gradations of the lobe. Overall, the evidence shows that the radial variation in the morphology and age-related variables of the three lobe segments may affect the microenvironment of the lobe segments and hence influence the organization of the microbial communities within each segment. SN 0065-1583 EI 1689-0027 PY 2015 VL 54 IS 4 BP 265 EP 273 DI 10.4467/16890027AP.15.021.3535 UT WOS:000364713600001 ER PT J AU Grilli, D Egea, V Lama, SP Carcano, D Allegretti, L Escudero, MS Arenas, GN AF Grilli, Diego Egea, Vanina Paez Lama, Sebastian Carcano, Diego Allegretti, Liliana Sosa Escudero, Miguel Nora Arenas, Graciela TI Degradation and utilization of hemicellulose from species forage by Pseudobutyrivibrio ruminis and Pseudobutyrivibrio xylanivorans SO REVISTA DE LA FACULTAD DE CIENCIAS AGRARIAS AB This study was performed to determine the degradation and utilization of hemicellulose from intact forages by two strains (P. xylanivorans 2 and P. ruminis 153) isolated from rumen of Creole goats. Fermentations by pure culture were run to completion by using alfalfa hay and native forages selected by goats grazing. Degradation was defined as the solubilization of 80% ethanol-insoluble pentose, whereas utilization was defined as a loss in total pentose. The nutritional components measured from intact forages were cutin, neutral detergent fiber, acid detergent fiber, acid detergent lignin, hemicellulose, cellulose, crude protein and starch. A. lampa showed the maximum degradation value and utilization of hemicellulose, and M. ephedroides and G. decorticans were the native forage species with the smallest value of degradation, in comparison with alfalfa hay. The correlation coefficient between acid detergent lignin and percentage of degradation and utilization of hemicellulose, suggests that lignin affects hemicellulolytic activity of P. xylanivorans. These results provide a framework to try to modify the activity of ruminal hemicellulolytic environment by incorporating P. xylanivorans as probiotic strain. SN 1853-8665 PY 2015 VL 47 IS 2 BP 231 EP 243 UT WOS:000364322700018 ER PT J AU Bernes, C Brathen, KA Forbes, BC Speed, JDM Moen, J AF Bernes, Claes Brathen, Kari Anne Forbes, Bruce C. Speed, James D. M. Moen, Jon TI What are the impacts of reindeer/caribou (Rangifer tarandus L.) on arctic and alpine vegetation? A systematic review SO ENVIRONMENTAL EVIDENCE AB Background: The reindeer (or caribou, Rangifer tarandus L.) has a natural range extending over much of Eurasia's and North America's arctic, alpine and boreal zones, yet its impact on vegetation is still unclear. This lack of a common understanding hampers both the management of wild and semi-domesticated reindeer populations and the preservation of biodiversity. To achieve a common platform, we have undertaken a systematic review of published studies that compare vegetation at sites with different reindeer densities. Besides biodiversity, we focused on effects on major plant growth forms. Methods: Searches for literature were made using online publication databases, search engines, specialist websites and bibliographies of literature reviews. Search terms were developed in English, Finnish, Norwegian, Russian and Swedish. Identified articles were screened for relevance based on titles, abstracts and full text using inclusion criteria set out in an a priori protocol. Relevant articles were then subject to critical appraisal of susceptibility to bias. Data on outcomes such as abundance, biomass, cover and species richness of vegetation were extracted together with metadata on site properties and other potential effect modifiers. Results: Our searches identified more than 6,000 articles. After screening for relevance, 100 of them remained. Critical appraisal excluded 60 articles, leaving 40 articles with 41 independent studies. Almost two thirds of these studies had been conducted in Fennoscandia. Meta-analysis could be made of data from 31 of the studies. Overall, effects of reindeer on species richness of vascular plants depended on temperature, ranging from negative at low temperature to positive at high temperature. Effects on forbs, graminoids, woody species, and bryophytes were weak or non-significant, whereas the effect on lichens was negative. However, many individual studies showed clear positive or negative effects, but the available information was insufficient to explain this context dependence. Conclusions: We see two pressing matters emerging from our study. First, there is a lack of research with which to build a circumpolar understanding of grazing effects, which calls for more studies using a common protocol to quantify reindeer impacts. Secondly, the highly context-dependent outcomes suggest that research and management have to consider local conditions. For instance, predictions of what a management decision would mean for the effects of reindeer on vegetation will have to take the variation of vegetation types and dominant growth forms, productivity, and grazing history into account. Policy and management have to go hand-in-hand with research in individual cases if the dynamics between plants, animals, and humans are to be sufficiently understood. OI Speed, James D. M./0000-0002-0633-5595; Brathen, Kari Anne/0000-0003-0942-1074 SN 2047-2382 PY 2015 VL 4 IS 1 AR 4 DI 10.1186/s13750-014-0030-3 UT WOS:000449406700004 ER PT J AU Mattisson, J Odden, J Linnell, JDC AF Mattisson, J. Odden, J. Linnell, J. D. C. TI A catch-22 conflict: Access to semi-domestic reindeer modulates Eurasian lynx depredation on domestic sheep SO BIOLOGICAL CONSERVATION AB Conserving large carnivores in multi-use landscape is a global challenge. In northern Norway the presence of Eurasian lynx (Lynx lynx) conflicts greatly with the current ways of keeping free-grazing, unguarded livestock in large carnivore habitat. In contrast to most other places in Europe, livestock (sheep Ovis aries, reindeer Rangifer tarandus) are the only ungulate prey available for lynx in this area. The relative preference by lynx for these two domestic species will strongly influence depredation pressure for the respective species. We examined predation patterns on domestic sheep in summer from 17 GPS-collared lynx that had access to both free ranging sheep and reindeer. During 1115 lynx monitoring days, we documented 47 sheep and 274 reindeer killed by lynx. Most lynx individuals selected reindeer over sheep and the probability for a kill to be a sheep increased at low reindeer densities combined with high sheep densities. Kill rates on sheep were several times lower than for reindeer and were not related to density of livestock. General avoidance and low kill rates on sheep by most lynx generated low predation pressure on sheep within the reindeer husbandry, similar to what has been observed in areas of high roe deer densities. However, even a small shift of herd location within the designated summer grazing areas for reindeer could potentially cause a significant increase in depredation on sheep locally. This is one of several studies demonstrating that the density of alternative prey can modulate kill rates on livestock, which is important to include in spatially explicit risk models of large carnivore depredation on livestock. (C) 2014 The Authors. Published by Elsevier Ltd. OI Linnell, John D C/0000-0002-8370-5633; Mattisson, Jenny/0000-0001-6032-5307 SN 0006-3207 EI 1873-2917 PD NOV PY 2014 VL 179 BP 116 EP 122 DI 10.1016/j.biocon.2014.09.004 UT WOS:000345475500013 ER PT J AU Ahman, B Svensson, K Ronnegard, L AF Ahman, Birgitta Svensson, Kristin Ronnegard, Lars TI High Female Mortality Resulting in Herd Collapse in Free-Ranging Domesticated Reindeer (Rangifer tarandus tarandus) in Sweden SO PLOS ONE AB Reindeer herding in Sweden is a form of pastoralism practised by the indigenous Sami population. The economy is mainly based on meat production. Herd size is generally regulated by harvest in order not to overuse grazing ranges and keep a productive herd. Nonetheless, herd growth and room for harvest is currently small in many areas. Negative herd growth and low harvest rate were observed in one of two herds in a reindeer herding community in Central Sweden. The herds (A and B) used the same ranges from April until the autumn gathering in October-December, but were separated on different ranges over winter. Analyses of capture-recapture for 723 adult female reindeer over five years (2007-2012) revealed high annual losses (7.1% and 18.4%, for herd A and B respectively). A continuing decline in the total reindeer number in herd B demonstrated an inability to maintain the herd size in spite of a very small harvest. An estimated breakpoint for when herd size cannot be kept stable confirmed that the observed female mortality rate in herd B represented a state of herd collapse. Lower calving success in herd B compared to A indicated differences in winter foraging conditions. However, we found only minor differences in animal body condition between the herds in autumn. We found no evidence that a lower autumn body mass generally increased the risk for a female of dying from one autumn to the next. We conclude that the prime driver of the on-going collapse of herd B is not high animal density or poor body condition. Accidents or disease seem unlikely as major causes of mortality. Predation, primarily by lynx and wolverine, appears to be the most plausible reason for the high female mortality and state of collapse in the studied reindeer herding community. OI Ronnegard, Lars/0000-0002-1057-5401 SN 1932-6203 PD OCT 30 PY 2014 VL 9 IS 10 AR e111509 DI 10.1371/journal.pone.0111509 UT WOS:000346765000066 PM 25356591 ER PT J AU Davidson, RK Kutz, SJ Madslien, K Hoberg, E Handeland, K AF Davidson, Rebecca K. Kutz, Susan J. Madslien, Knut Hoberg, Eric Handeland, Kjell TI Gastrointestinal parasites in an isolated Norwegian population of wild red deer (Cervus elaphus) SO ACTA VETERINARIA SCANDINAVICA AB Background: Thirteen red deer (Cervus elaphus), culled from the isolated population at the Mongstad Oil Refinery, Norway, were investigated for gastrointestinal helminths. These animals, enclosed by the refinery fence, do not have contact with other ruminants and have a high population density considering the available browsing area (1 km(2)) within the refinery site (3 km(2)). The population was estimated to be 110-130 at the time of culling. Results: The helminth fauna among these sampled red deer was enumerated and species were identified based on morphology. Ostertagia leptospicularis/O. kolchida was detected in 83% [CI 55 - 95%], Spiculopteragia spiculoptera/S. mathevossiani in 92% [CI 65 - 99%] and Trichostrongylus axei in 42%, [CI 19 - 68%] of the abomasa examined. Characterisation of the intestinal parasite fauna revealed Capillaria bovis, Cooperia oncophora, Oesophagostomum venulosum, Trichuris globulosa and tapeworm fragments (presumed anoplocephalids) in seven individuals. Only one calf had an infection with more than one intestinal helminth (tapeworm fragment and Trichuris globulosa). The remaining six deer had single species intestinal infections. No significant age related trends were seen, with the exception of higher intensity of infection of T. axei in yearlings relative to other age classes. Assessment of abomasal parasite burden and body condition revealed no significant trends. In calves, statistically non-significant correlation was seen between increased parasite burden and decreased slaughter weight, whilst the opposite was seen in adults with the heaviest adults exhibiting the higher burdens. Given the small sample size the trends that were seen need further investigation. The parasite burden was aggregated with three adult red deer harbouring 75% of the total abomasal parasite count. Conclusion: This isolated population was parasitised by a reduced subset of gastrointestinal nematodes typical of this cervid across an extensive geographic range in Eurasia. The intensity and abundance of abomasal nematodes was higher in this isolated population than reported in similar studies of red deer populations across Europe. SN 0044-605X EI 1751-0147 PD OCT 8 PY 2014 VL 56 AR 59 DI 10.1186/s13028-014-0059-x UT WOS:000343177200001 PM 25294401 ER PT J AU Horstkotte, T Sandstrom, C Moen, J AF Horstkotte, Tim Sandstrom, Camilla Moen, Jon TI Exploring the Multiple Use of Boreal Landscapes in Northern Sweden: The Importance of Social-Ecological Diversity for Mobility and Flexibility SO HUMAN ECOLOGY AB Landscapes undergo changes in structure and function at multiple temporal and spatial levels. As a consequence of natural and anthropogenic drivers, these changes affect options for land use. We describe winter land use by reindeer husbandry in the boreal forest in Northern Sweden. The landscape changes in its suitability for husbandry practices due to environmental stochasticity and transformations due to other forms of land use. This creates structures that can either (i) promote flexibility in the form of mobility or (ii) create fragmentation that restricts adaptation to changes. As these drivers are interdependent in their influence on land use practices by reindeer herders, different choices regarding husbandry strategies have to be made within a season and between years. To allow such choices and ensure pastoral resilience to change, boreal forests should be regulated to provide continuity of grazing resources at multiple temporal and spatial levels. SN 0300-7839 EI 1572-9915 PD OCT PY 2014 VL 42 IS 5 BP 671 EP 682 DI 10.1007/s10745-014-9687-z UT WOS:000343723700002 ER PT J AU Tveraa, T Stien, A Broseth, H Yoccoz, NG AF Tveraa, Torkild Stien, Audun Broseth, Henrik Yoccoz, Nigel G. TI The role of predation and food limitation on claims for compensation, reindeer demography and population dynamics SO JOURNAL OF APPLIED ECOLOGY AB 1. A major challenge in biodiversity conservation is to facilitate viable populations of large apex predators in ecosystems where they were recently driven to ecological extinction due to resource conflict with humans. 2. Monetary compensation for losses of livestock due to predation is currently a key instrument to encourage human-carnivore coexistence. However, a lack of quantitative estimates of livestock losses due to predation leads to disagreement over the practice of compensation payments. This disagreement sustains the human-carnivore conflict. 3. The level of depredation on year-round, free-ranging, semi-domestic reindeer by large carnivores in Fennoscandia has been widely debated over several decades. In Norway, the reindeer herders claim that lynx and wolverine cause losses of tens of thousands of animals annually and cause negative population growth in herds. Conversely, previous research has suggested that monetary predator compensation can result in positive population growth in the husbandry, with cascading negative effects of high grazer densities on the biodiversity in tundra ecosystems. 4. We utilized a long-term, large-scale data set to estimate the relative importance of lynx and wolverine predation and density-dependent and climatic food limitation on claims for losses, recruitment and population growth rates in Norwegian reindeer husbandry. 5. Claims of losses increased with increasing predator densities, but with no detectable effect on population growth rates. Density-dependent and climatic effects on claims of losses, recruitment and population growth rates were much stronger than the effects of variation in lynx and wolverine densities. 6. Synthesis and applications. Our analysis provides a quantitative basis for predator compensation and estimation of the costs of reintroducing lynx and wolverine in areas with free-ranging semi-domestic reindeer. We outline a potential path for conflict management which involves adaptive monitoring programmes, open access to data, herder involvement and development of management strategy evaluation (MSE) models to disentangle complex responses including multiple stakeholders and individual harvester decisions. OI Tveraa, Torkild/0000-0002-7501-3696; Yoccoz, Nigel/0000-0003-2192-1039; Broseth, Henrik/0000-0003-3795-891X; Stien, Audun/0000-0001-8046-7337 SN 0021-8901 EI 1365-2664 PD OCT PY 2014 VL 51 IS 5 BP 1264 EP 1272 DI 10.1111/1365-2664.12322 UT WOS:000342851300016 PM 25558085 ER PT J AU Handeland, K Tengs, T Kokotovic, B Vikoren, T Ayling, RD Bergsjo, B Sigurdardottir, OG Bretten, T AF Handeland, Kjell Tengs, Torstein Kokotovic, Branko Vikoren, Turid Ayling, Roger D. Bergsjo, Bjarne Sigurdardottir, Olof G. Bretten, Tord TI Mycoplasma ovipneumoniae - A Primary Cause of Severe Pneumonia Epizootics in the Norwegian Muskox (Ovibos moschatus) Population SO PLOS ONE AB The Norwegian muskox (Ovibos moschatus) population lives on the high mountain plateau of Dovre and originates from animals introduced from Greenland. In the late summers of 2006 and 2012, severe outbreaks of pneumonia with mortality rates of 25-30% occurred. During the 2012 epidemic high quality samples from culled sick animals were obtained for microbiological and pathological examinations. High throughput sequencing (pyrosequencing) of pneumonic lung tissue revealed high concentrations of Mycoplasma ovipneumoniae in all six animals examined by this method and Pasteurella multocida subsp. multocida in four animals, whereas no virus sequences could be identified. Mycoplasma ovipneumoniae and P. multocida multocida were also isolated by culture. Using real time PCR on lung swabs, M. ovipneumoniae was detected in all of the 19 pneumonic lungs examined. Gross pathological examination revealed heavy consolidations primarily in the cranial parts of the lungs and it also identified one case of otitis media. Histologically, lung lesions were characterized as acute to subacute mixed exudative and moderately proliferative bronchoalveolar pneumonia. Immunohistochemical (IHC) examination revealed high load of M. ovipneumoniae antigens within lung lesions, with particularly intensive staining in the neutrophils. Similar IHC finding were observed in archived lung tissue blocks from animals examined during the 2006 epidemic. An M. ovipneumoniae specific ELISA was applied on bio-banked muskox sera from stray muskoxen killed in the period 2004-2013 and sick muskoxen culled, as well as sera from wild reindeer (Rangifer tarandus tarandus) on Dovre and muskoxen from Greenland. Serology and mycoplasma culturing was also carried out on sheep that had been on pasture in the muskox area during the outbreak in 2012. Our findings indicated separate introductions of M. ovipneumoniae infection in 2006 and 2012 from infected co-grazing sheep. Salt licks shared by the two species were a possible route of transmitting infection. RI Ayling, Roger/C-7567-2011; APHA, Staff publications/E-6082-2010 SN 1932-6203 PD SEP 8 PY 2014 VL 9 IS 9 AR e106116 DI 10.1371/journal.pone.0106116 UT WOS:000341304700023 PM 25198695 ER PT J AU Lemdahl, G Buckland, PI Mortensen, MF AF Lemdahl, Geoffrey Buckland, Philip I. Mortensen, Morten Fischer TI Lateglacial insect assemblages from the Palaeolithic site Slotseng: New evidence concerning climate and environment in SW Denmark SO QUATERNARY INTERNATIONAL AB The Slotseng site represents Paleolithic settlements of the Havelte phase of the Hamburgian culture (c. 15 to 14 cal ka BP). The Lateglacial sediment stratigraphy of an adjacent kettle hole was studied in a multidisciplinary project, including the analysis of pollen, macroscopic plant remains, vertebrate bones, and insect remains. In this article the results from the insect analysis are presented. Twelve samples were analysed from a monolith, which chronologically spans from ca. 15,500 to 13,600 cal BP. 108 taxa of Coleoptera and 15 taxa of Trichoptera, Hemiptera, Megaloptera, Diptera and Hymenoptera were recorded. The beetle assemblages indicate an open heath environment with shrub and herb vegetation during this period, with only minor changes during the stadials and interstadials. This is in good agreement with the interpretations based on pollen and plant macrofossil analyses. The presence of dung beetles indicates that reindeer herds grazed in the vicinity of the site. A number of finds of the carrion beetle Thanatophilus dispar suggest that fish may have been a complementary food resource for the hunters at Slotseng. MCR reconstructions indicate arctic/subarctic climate conditions during the periods GS-2a (Pre-Bolling) and GI-1d (Older Dryas) with mean summer temperatures similar to 9-13 degrees C and mean winter temperatures similar to-3 to -20 degrees C. During the interstadials GI-1e (Bolling) and GI-1c (Allerod 1) mean summer temperatures were similar to 14-16 degrees C, but mean winter temperatures remained similar to those during the colder periods. The reconstructed environments and living conditions for the Paleolithic hunters show striking similarities with contemporaneous conditions reconstructed for Magdalenian/Azilian sites at Lake Neuchatel, Switzerland. (C) 2014 Elsevier Ltd and INQUA. All rights reserved. SN 1040-6182 EI 1873-4553 PD AUG 18 PY 2014 VL 341 BP 172 EP 183 DI 10.1016/j.quaint.2014.01.050 UT WOS:000340905800014 ER PT J AU Boan, JJ Malcolm, JR McLaren, BE AF Boan, Julee J. Malcolm, Jay R. McLaren, Brian E. TI Forest overstorey and age as habitat? Detecting the indirect and direct effects of predators in defining habitat in a harvested boreal landscape SO FOREST ECOLOGY AND MANAGEMENT AB Given the importance of wildlife habitat protection in meeting land use management objectives, criteria for "habitat" identification are surprisingly amorphous. For example, while much current habitat modeling has tended to avoid the term "niche modeling", niche assumptions are implicit - meaning the presence of predators and competitors is essential to whether or not a species uses, or will use, an area. In this paper, we examine environmental variables associated with woodland caribou (Rangifer tarandus caribou) presence in the boreal forests of northwestern Ontario, Canada. Based on winter aerial surveys conducted in 2010-2013, we used logistic regression to identify important habitat characteristics (and/or their surrogates) and structural equation modeling (SEM) to explore causal and indirect caribou habitat relationships, at broad and fine scales. The best-fit regression model (>10,000 ha) to explain caribou presence, at the broad scale, included the presence of moose (Alces alces), wolves (Canis lupus), logging roads and primary roads, and all top models included wolves. In contrast, at the fine scale (<1000 ha), older, conifer forest was included in all of the top models of caribou presence. Using SEM, at broad scales, we found significant effects of increases in logging road density resulting in a direct increase in wolf presence, and indirectly in a decrease in caribou presence. However, at fine scales, we found significant direct positive effects between moose browse and moose presence, with indirect negative effects on caribou presence. We provide evidence that, at broad scales, habitat identification that includes logging roads and wolves provides a better measure of suitability of an area for caribou occupation than does forest cover alone. We suggest modeling of present or future habitat for woodland caribou will only be marginally effective if additional covariates of predation risk are not inclusive to the quantification of habitat supply. (C) 2014 Elsevier B.V. All rights reserved. SN 0378-1127 EI 1872-7042 PD AUG 15 PY 2014 VL 326 BP 101 EP 108 DI 10.1016/j.foreco.2014.03.052 UT WOS:000339129700010 ER PT J AU Biuw, M Jepsen, JU Cohen, J Ahonen, SH Tejesvi, M Aikio, S Wali, PR Vindstad, OPL Markkola, A Niemela, P Ims, RA AF Biuw, Martin Jepsen, Jane U. Cohen, Juval Ahonen, Saija H. Tejesvi, Mysore Aikio, Sami Wali, Piippa R. Vindstad, Ole Petter L. Markkola, Annamari Niemela, Pekka Ims, Rolf A. TI Long-term Impacts of Contrasting Management of Large Ungulates in the Arctic Tundra-Forest Ecotone: Ecosystem Structure and Climate Feedback SO ECOSYSTEMS AB The arctic forest-tundra ecotone (FTE) represents a major transition zone between contrasting ecosystems, which can be strongly affected by climatic and biotic factors. Expected northward expansion and encroachment on arctic tundra in response to climate warming may be counteracted by natural and anthropogenic processes such as defoliating insect outbreaks and grazing/browsing regimes. Such natural and anthropogenic changes in land cover can substantially affect FTE dynamics, alter ground albedo (index of the amount of solar energy reflected back into the atmosphere) and provide important feedbacks into the climate system. We took advantage of a naturally occurring contrast between reindeer grazing regimes in a border region between northern Finland and Norway which was recently defoliated by an outbreak of the geometrid moth. We examined ecosystem-wide contrasts between potentially year-round (but mainly summer) grazed (YRG) regions in Finland and mainly winter grazed (WG) regions in Norway. We also used a remotely sensed vegetation index and albedo to quantify effects on local energy balance and potential climate feedbacks. Although differences in soil characteristics and ground vegetation cover were small, we found dramatic differences in the tree layer component of the ecosystem. Regeneration of mountain birch stands appears to have been severely hampered in the YRG regime, by limiting regeneration from basal shoots and reestablishment of individual trees from saplings. This has led to a more open forest structure and a significant 5% increase in spring albedo in the summer grazed compared to the winter grazed regions. This supports recent suggestions that ecosystem processes in the Arctic can significantly influence the climate system, and that such processes must be taken into account when developing climate change scenarios and adaptation strategies. RI Tejesvi, Mysore/M-7928-2015 OI Tejesvi, Mysore/0000-0002-6176-0981; Wali, Piippa/0000-0002-2484-7455; Ahonen, Saija/0000-0003-3313-784X; Cohen, Juval/0000-0001-6396-1536 SN 1432-9840 EI 1435-0629 PD AUG PY 2014 VL 17 IS 5 BP 890 EP 905 DI 10.1007/s10021-014-9767-3 UT WOS:000339418400011 ER PT J AU Stark, S Vaisanen, M AF Stark, Sari Vaisanen, Maria TI Insensitivity of Soil Microbial Activity to Temporal Variation in Soil N in Subarctic Tundra: Evidence from Responses to Large Migratory Grazers SO ECOSYSTEMS AB Large migratory grazers commonly influence soil processes in tundra ecosystems. However, the extent to which grazing effects are limited to intensive grazing periods associated with migration has not previously been investigated. We analyzed seasonal patterns in soil nitrogen (N), microbial respiration and extracellular enzyme activities (EEAs) in a lightly grazed tundra and a heavily grazed tundra that has been subjected to intensive grazing during reindeer (Rangifer tarandus L.) migration for the past 50 years. We hypothesized that due to the fertilizing effect of the reindeer, microbial respiration and EEAs related to microbial C acquisition should be higher in heavily grazed areas compared to lightly grazed areas and that the effects of grazing should be strongest during reindeer migration. Reindeer migration caused a dramatic peak in soil N availability, but in contrast to our predictions, the effect of grazing was more or less constant over the growing season and the seasonal patterns of microbial activities and microbial N were strikingly uniform between the lightly and heavily grazed areas. Microbial respiration and the EEAs of beta-glucosidase, acid-phosphatase, and leucine-aminopeptidase were higher, whereas that of N-acetylglucosamidase was lower in the heavily grazed area. Experimental fertilization had no effect on EEAs related to C acquisition at either level of grazing intensity. Our findings suggest that soil microbial activities were independent of grazing-induced temporal variation in soil N availability. Instead, the effect of grazing on soil microbial activities appeared to be mediated by substrate availability for soil microorganisms. Following a shift in the dominant vegetation in response to grazing from dwarf shrubs to graminoids, the effect of grazing on soil processes is no longer sensitive to temporal grazing patterns; rather, grazers exert a consistent positive effect on the soil microbial potential for soil C decomposition. RI Stark, Sari/L-4440-2013 SN 1432-9840 EI 1435-0629 PD AUG PY 2014 VL 17 IS 5 BP 906 EP 917 DI 10.1007/s10021-014-9768-2 UT WOS:000339418400012 ER PT J AU Vaisanen, M Ylanne, H Kaarlejarvi, E Sjogersten, S Olofsson, J Crout, N Stark, S AF Vaisanen, Maria Ylanne, Henni Kaarlejarvi, Elina Sjoegersten, Sofie Olofsson, Johan Crout, Neil Stark, Sari TI Consequences of warming on tundra carbon balance determined by reindeer grazing history SO NATURE CLIMATE CHANGE AB Arctic tundra currently stores half of the global soil carbon (C) stock(1). Climate warming in the Arctic may lead to accelerated CO2 release through enhanced decomposition and turn Arctic ecosystems from a net C sink into a net C source, if warming enhances decomposition more than plant photosynthesis(2). A large portion of the circumpolar Arctic is grazed by reindeer/caribou, and grazing causes important vegetation shifts in the long-term. Using a unique experimental set-up, where areas experiencing more than 50 years of either light (LG) or heavy (HG) grazing were warmed and/or fertilized, we show that under ambient conditions areas under LG were a 70% stronger C sink than HG areas. Although warming decreased the C sink by 38% under LG, it had no effect under HG. Grazing history will thus be an important determinant in the response of ecosystem C balance to climate warming, which at present is not taken into account in climate change models. RI Stark, Sari/L-4440-2013; Crout, Neil/A-1369-2011 OI Crout, Neil/0000-0001-7394-5070 SN 1758-678X EI 1758-6798 PD MAY PY 2014 VL 4 IS 5 BP 384 EP 388 DI 10.1038/NCLIMATE2147 UT WOS:000335403500028 ER PT J AU Plante, S Champagne, E Ropars, P Boudreau, S Levesque, E Tremblay, B Tremblay, JP AF Plante, Sabrina Champagne, Emilie Ropars, Pascale Boudreau, Stephane Levesque, Esther Tremblay, Benoit Tremblay, Jean-Pierre TI Shrub cover in northern Nunavik: can herbivores limit shrub expansion? SO POLAR BIOLOGY AB Recent climate changes have increased the primary productivity of many Arctic and subarctic regions. Erected shrub has been shown to increase in abundance over the last decades in northern regions in response to warmer climate. At the same time, caribou herds are declining throughout the circumboreal regions. Based on observation of heavy browsing on shrubs at Deception Bay (Nunavik, Canada), we hypothesized that the densification of shrubs observed in nearby locations did not occur at our study site despite of observed warming because of a recent peak of the RiviSre-aux-Feuilles caribou herd. To assess shrub cover changes, we compared a 1972 mosaic of aerial photos to a 2010 satellite image over a 5 km(2) area, divided into 56 grids of 100 30 m x 30 m cells. Most cells (n = 4,502) did not show any changes in the cover of shrubs but those who did were as likely to increase as to decrease. The relative cover of shrubs in cells who changed was not higher in 2010 (6.1 +/- A 0.2 %) than in 1972 (7.3 +/- A 0.4 %). More than 70 % of birch and willow had more than 50 % of their shoot browsed, suggesting that caribou may limit shrub expansion at this site. We cannot rule out that abiotic factors also contribute to the inertia in shrub cover. Increases in shrub abundance reported in Nunavik and elsewhere were located closer to the tree line or in discontinuous permafrost, whereas our site is characterized by herbaceous arctic tundra, continuous permafrost and relatively low annual precipitation. OI Champagne, Emilie/0000-0003-1550-2735 SN 0722-4060 EI 1432-2056 PD MAY PY 2014 VL 37 IS 5 BP 611 EP 619 DI 10.1007/s00300-014-1461-6 UT WOS:000334172600002 ER PT J AU Newton, EJ Pond, BA Brown, GS Abraham, KF Schaefer, JA AF Newton, Erica J. Pond, Bruce A. Brown, Glen S. Abraham, Kenneth F. Schaefer, James A. TI Remote sensing reveals long-term effects of caribou on tundra vegetation SO POLAR BIOLOGY AB Declining use and abandonment of traditional ranges by migratory caribou (Rangifer tarandus) have often been related to density-dependent depletion of summer forage. The Pen Islands caribou herd (R. t. caribou), Ontario and Manitoba, Canada, numbered in the thousands on its traditional summer tundra range during the 1980s, but then declined in that region. We postulated that increased caribou abundance over three decades negatively affected phytomass, given that under the exploitation ecosystem hypothesis (EEH), grazers limit the amount of primary production if few predators are present. We tested this prediction using the Normalized Difference Vegetation Index (NDVI), as a proxy for phytomass available to caribou. We lagged caribou abundance in the explanatory model by the number of years (4-7) between peak caribou abundance and minimum NDVI. NDVI was negatively related to caribou abundance lagged by 6 years, and growing degree days explained much of the annual variation in NDVI. Precipitation was not an important predictor in the model. Our study is the first to apply NDVI to support the EEH for caribou. We propose that this method could be used over broad scales to shed light on limiting factors for migratory caribou across the circumpolar North. OI Newton, Erica/0000-0002-6532-9478 SN 0722-4060 EI 1432-2056 PD MAY PY 2014 VL 37 IS 5 BP 715 EP 725 DI 10.1007/s00300-014-1472-3 UT WOS:000334172600012 ER PT J AU Thompson, DP Barboza, PS AF Thompson, D. P. Barboza, P. S. TI Nutritional implications of increased shrub cover for caribou (Rangifer tarandus) in the Arctic SO CANADIAN JOURNAL OF ZOOLOGY AB Shrubs are increasing in the annual range of arctic caribou (Rangifer tarandus (L., 1758)), but it is unknown how much summer browse caribou could consume. We measured instantaneous intakes of resin birch (Betula glandulosa Michx.) and feltleaf willow (Salix alaxensis (Andersson) Coville) by caribou during summer. Daily intake of a formulated diet without toxins was measured during the same period to monitor appetite. Caribou appetite increased from 64.1 to 86.7 g DM.kg(-0.75).day(-1) as animals gained body mass from 96.8 to 113.5 kg. We estimated that caribou required 645 kJ.kg(-0.75).day(-1) of digestible energy to maintain body mass and 1113 kJ.kg(-0.75).day(-1) to gain body mass for autumn reproduction. Caribou had the same bite mass (9.7 mg.bite(-1).kg(-0.75)) and instantaneous intake rate (0.17 g DM.min(-1).kg(-0.75)) on both forages; however, birch contained more phenols (3.3% vs. 1.5%) and less available protein (6.2% vs. 10.2%) than willow. A 100 kg female caribou would need to consume 2.4-8.7 kg of fresh browse, requiring 3.1-8.5 h.day(-1) of eating time to meet daily energy requirements. Birch is unlikely to provide enough nitrogen for maintenance of body protein. Therefore, caribou may depend on abundance and diversity of plants to offset toxin loads and low protein intake from shrubs during summer. SN 0008-4301 EI 1480-3283 PD APR PY 2014 VL 92 IS 4 BP 339 EP 351 DI 10.1139/cjz-2013-0265 UT WOS:000344953600008 ER PT J AU Francini, G Liiri, M Mannisto, M Stark, S Kytoviita, MM AF Francini, Gaia Liiri, Mira Mannisto, Minna Stark, Sari Kytoviita, Minna-Maarit TI Response to reindeer grazing removal depends on soil characteristics in low Arctic meadows SO APPLIED SOIL ECOLOGY AB In Arctic tundra, grazing is expected to exert a positive influence on microbial activity thus enhancing nutrient cycling and promoting the presence of high productive graminoids. We investigated the changes occurring in two low Arctic meadow sites after 10 years exclusion from grazing. We compared plant, soil fauna and microbial community composition, extracellular enzymes activities, and soil nutrients in ungrazed and adjacent grazed area in two low Arctic meadows. The two closely located experimental sites were both dominated by the common grass Deschampsia flexuosa which covered more than 50% of the meadows. Plant community was affected significantly by site and grazing, but the effect of grazing was stronger in the site that was more nutrient rich. Grazing decreased litter abundance in both sites, but did not influence the amount of total plant biomass. Grazing had a negative effect on some species of Collembola (e.g. Isotomiella minor) and Enchytraeidae were reduced by 40% by grazing. Also the site itself contributed in shaping the microarthropod community. Microbial community structure was not affected by grazing. In the nutrient rich site grazing also significantly decreased some extracellular enzyme activities. Our results showed that grazing had a strong effect on plant and microarthropod community structure, but the effects were very dependent on local characteristics. (C) 2013 Elsevier B.V. All rights reserved. RI Stark, Sari/L-4440-2013 OI Kytoviita, Minna-Maarit/0000-0002-8928-6951 SN 0929-1393 EI 1873-0272 PD APR PY 2014 VL 76 BP 14 EP 25 DI 10.1016/j.apsoil.2013.12.003 UT WOS:000334008900003 ER PT J AU Kumpula, J Kurkilahti, M Helle, T Colpaert, A AF Kumpula, Jouko Kurkilahti, Mika Helle, Timo Colpaert, Alfred TI Both reindeer management and several other land use factors explain the reduction in ground lichens (Cladonia spp.) in pastures grazed by semi-domesticated reindeer in Finland SO REGIONAL ENVIRONMENTAL CHANGE AB Roles of intensive reindeer grazing and several additional land use factors in the reduction in ground lichens (Cladonia spp.) in pastures grazed by the semi-domesticated reindeer have been argued in Finland. Our analysis showed that several factors and processes explain the standing biomass of lichens (during 2005-2008) and the recent changes in this biomass (after 1995-1996) on lichen pastures located in the 20 northernmost herding districts in Finland. The higher the long-term reindeer densities on the lichen pastures the lower was the lichen biomass. The lichen biomass was also strongly affected by the grazing system; the lowest biomass values of lichens were measured in all grazing areas that were used in the snow-free seasons. The lichen biomass in pine forests less than 80 years old and in all mountain type lichen pastures was lower than that in mature and old pine forests. The lichen biomass also decreased as the proportion of arboreal lichen pastures within a district decreased and the proportion of human infrastructure increased. The aerial drift of heavy metals from the Kola Peninsula appeared to reduce lichens in a small north-eastern part of the study area. Increases in summer precipitation and winter temperatures increased the amount of lichens, but increases in summer temperatures and winter precipitation had the opposite effect. Reindeer densities, grazing system, pasture type and the previous abiotic factors were also associated with the reduction in lichen biomass between the inventories. We conclude that several local, regional and even global factors and processes affect the state of reindeer pastures in large and complex grazing ecosystems. Therefore, more comprehensive research and management strategies for the entire reindeer herding environment are needed. SN 1436-3798 EI 1436-378X PD APR PY 2014 VL 14 IS 2 SI SI BP 541 EP 559 DI 10.1007/s10113-013-0508-5 UT WOS:000333267700010 ER PT J AU Freschet, GT Ostlund, L Kichenin, E Wardle, DA AF Freschet, Gregoire T. Ostlund, Lars Kichenin, Emilie Wardle, David A. TI Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment SO ECOLOGY AB Human activities that involve land-use change often cause major transformations to community and ecosystem properties both aboveground and belowground, and when land use is abandoned, these modifications can persist for extended periods. However, the mechanisms responsible for rapid recovery vs. long-term maintenance of ecosystem changes following abandonment remain poorly understood. Here, we examined the long-term ecological effects of two remote former settlements, regularly visited for similar to 300 years by reindeer-herding Sami and abandoned similar to 100 years ago, within an old-growth boreal forest that is considered one of the most pristine regions in northern Scandinavia. These human legacies were assessed through measurements of abiotic and biotic soil properties and vegetation characteristics at the settlement sites and at varying distances from them. Low-intensity land use by Sami is characterized by the transfer of organic matter towards the settlements by humans and reindeer herds, compaction of soil through trampling, disappearance of understory vegetation, and selective cutting of pine trees for fuel and construction. As a consequence, we found a shift towards early successional plant species and a threefold increase in soil microbial activity and nutrient availability close to the settlements relative to away from them. These changes in soil fertility and vegetation contributed to 83% greater total vegetation productivity, 35% greater plant biomass, and 23% and 16% greater concentrations of foliar N and P nearer the settlements, leading to a greater quantity and quality of litter inputs. Because decomposer activity was also 40% greater towards the settlements, soil organic matter cycling and nutrient availability were further increased, leading to likely positive feedbacks between the aboveground and belowground components resulting from historic land use. Although not all of the activities typical of Sami have left visible residual traces on the ecosystem after 100 years, their low-intensity but long-term land use at settlement sites has triggered a rejuvenation of the ecosystem that is still present. Our data demonstrates that aboveground-belowground interactions strongly control ecosystem responses to historical human land use and that medium- to long-term consequences of even low-intensity human activities must be better accounted for if we are to predict and manage ecosystems succession following land-use abandonment. RI Wardle, David/F-6031-2011 OI Wardle, David/0000-0002-0476-7335; Ostlund, Lars/0000-0002-7902-3672 SN 0012-9658 EI 1939-9170 PD APR PY 2014 VL 95 IS 4 BP 963 EP 977 DI 10.1890/13-0824.1 UT WOS:000334573500001 PM 24933815 ER PT J AU Porter, KM DePerno, CS Krings, A Krachey, M Braham, R AF Porter, Kimberly M. DePerno, Christopher S. Krings, Alexander Krachey, Matthew Braham, Richard TI Vegetative Impact of Feral Horses, Feral Pigs, and White-tailed Deer on the Currituck National Wildlife Refuge, North Carolina SO CASTANEA AB The Currituck National Wildlife Refuge (CNWR) in North Carolina is inhabited by feral horses (Equus caballus), feral pigs (Sus scrofa), and white-tailed deer (Odocoileus virginianus). The impact of these species on the vegetation of CNWR is unknown. To assess impact, we created two replicate exclosure plots within maritime forests, brackish marshes, and maritime grasslands. An electric fence divided each habitat into two sections: including or excluding horses. On each side of the electric fence within each habitat, we sampled three different 5 x 5 m plots (i.e., 36 plots). The first was a fenced exclosure 3 m high, the second a fenced exclosure raised 1 in above the ground and extended to 3 m, and the third, a control, was not fenced. Within plots, we created two 1 m transects, and randomly selected and tagged grasses, forbs, shrubs, and trees. We measured the distances from base to tip of herbs and from branching point to terminal bud in shrubs. We used a linear model to analyze plant growth rate. We used a length ratio adjusted by the number of days as the response variable. Out of 1,105 tagged plants, we detected 87 disturbances; 80 where horses were present and 7 where horses were excluded. Overall, horses were responsible for 84% of disturbances. Most disturbances occurred in brackish marshes on Schoenoplectus pungens. We detected a significant effect of exclosure treatment on plant growth rate where horses were present (p = 0.035), but not where they were excluded (p = 0.32). SN 0008-7475 EI 1938-4386 PD MAR PY 2014 VL 79 IS 1 BP 8 EP 17 DI 10.2179/13-037 UT WOS:000334976100002 ER PT J AU Bryant, JP Joly, K Chapin, FS DeAngelis, DL Kielland, K AF Bryant, John P. Joly, Kyle Chapin, F. Stuart, III DeAngelis, Donald L. Kielland, Knut TI Can antibrowsing defense regulate the spread of woody vegetation in arctic tundra? SO ECOGRAPHY AB Global climate warming is projected to promote the increase of woody plants, especially shrubs, in arctic tundra. Many factors may affect the extent of this increase, including browsing by mammals. We hypothesize that across the Arctic the effect of browsing will vary because of regional variation in antibrowsing chemical defense. Using birch (Betula) as a case study, we propose that browsing is unlikely to retard birch expansion in the region extending eastward from the Lena River in central Siberia across Beringia and the continental tundra of central and eastern Canada where the more effectively defended resin birches predominate. Browsing is more likely to retard birch expansion in tundra west of the Lena to Fennoscandia, Iceland, Greenland and South Baffin Island where the less effectively defended non-resin birches predominate. Evidence from the literature supports this hypothesis. We further suggest that the effect of warming on the supply of plant-available nitrogen will not significantly change either this pan-Arctic pattern of variation in antibrowsing defense or the resultant effect that browsing has on birch expansion in tundra. However, within central and east Beringia warming-caused increases in plant-available nitrogen combined with wildfire could initiate amplifying feedback loops that could accelerate shrubification of tundra by the more effectively defended resin birches. This accelerated shrubification of tundra by resin birch, if extensive, could reduce the food supply of caribou causing population declines. We conclude with a brief discussion of modeling methods that show promise in projecting invasion of tundra by woody plants. OI Chapin III, F Stuart/0000-0002-2558-9910 SN 0906-7590 EI 1600-0587 PD MAR PY 2014 VL 37 IS 3 BP 204 EP 211 DI 10.1111/j.1600-0587.2013.00436.x UT WOS:000332149100002 ER PT J AU Ravolainen, VT Brathen, KA Yoccoz, NG Nguyen, JK Ims, RA AF Ravolainen, Virve T. Brathen, Kari Anne Yoccoz, Nigel G. Nguyen, Julie K. Ims, Rolf A. TI Complementary impacts of small rodents and semi-domesticated ungulates limit tall shrub expansion in the tundra SO JOURNAL OF APPLIED ECOLOGY AB While shrubs appear to be expanding in Arctic tundra due to climatic warming, patches of tall shrubs in riparian habitats are most likely to colonize new areas. Shrub recruits outside established patches represent the forefront of area expansion, but their dynamics may be sensitive to the action of several herbivore species. The empirical evidence for how different-sized herbivores affect recruits of tall shrubs is lacking. Moreover, although management and natural population dynamics of herbivores happens at landscape and regional scales, field research on herbivore impacts on shrubs seldom covers these scales. Reindeer management and different rodent population dynamics result in regional variation in herbivore abundances in arctic Norway. We conducted an herbivore exclusion experiment, covering three low-arctic river catchments with contrasting herbivore abundances. We assessed the impacts of small rodents and reindeer on growth, and survival of willow Salix spp. recruits after 3years of herbivore exclusion. As expected, the Salix recruits increased in sizes and had lower mortality when released from herbivores. Both types of herbivores had strong impacts on size and survival of Salix recruits. Spatially contrasting results were consistent with regional differences in the abundance of reindeer and rodents; herbivore impacts on shrubs were found when at least one type of herbivore was abundant. However, the impact was not independent of herbivore species. While both browsing from reindeer and rodents pruned the recruits and prevented them from escaping the field layer, the rodents also inflicted substantial mortality and thus thinned the stand of recruits.Synthesis and applications. Sympatric populations of rodents and reindeer have strongly complementary impacts on shrub recruits and may limit the expansion potential of tall shrubs even in the most productive habitats of arctic tundra. The spatial correspondence between shrub recruits performance and herbivore abundances, found after a short time period, suggests that the extent of tall shrub expansion in tundra is contingent on current variation and future trends in herbivore populations. In areas where humans control large herbivore populations, management may opt to counteract climate-driven shrub expansion also in habitats that are most prone to such expansion. Sympatric populations of rodents and reindeer have strongly complementary impacts on shrub recruits and may limit the expansion potential of tall shrubs even in the most productive habitats of arctic tundra. The spatial correspondence between shrub recruits performance and herbivore abundances, found after a short time period, suggests that the extent of tall shrub expansion in tundra is contingent on current variation and future trends in herbivore populations. In areas where humans control large herbivore populations, management may opt to counteract climate-driven shrub expansion also in habitats that are most prone to such expansion. RI Yoccoz, Nigel/C-8561-2014 OI Yoccoz, Nigel/0000-0003-2192-1039; Brathen, Kari Anne/0000-0003-0942-1074 SN 0021-8901 EI 1365-2664 PD FEB PY 2014 VL 51 IS 1 BP 234 EP 241 DI 10.1111/1365-2664.12180 UT WOS:000329846500025 ER PT J AU Tettamanti, F Viblanc, VA AF Tettamanti, Federico Viblanc, Vincent A. TI Influences of Mating Group Composition on the Behavioral Time-Budget of Male and Female Alpine Ibex (Capra ibex) during the Rut SO PLOS ONE AB During the rut, polygynous ungulates gather in mixed groups of individuals of different sex and age. Group social composition, which may vary on a daily basis, is likely to have strong influences on individual's time-budget, with emerging properties at the group-level. To date, few studies have considered the influence of group composition on male and female behavioral time budget in mating groups. Focusing on a wild population of Alpine ibex, we investigated the influence of group composition (adult sex ratio, the proportion of dominant to subordinate males, and group size) on three behavioral axes obtained by Principal Components Analysis, describing male and female group time-budget. For both sexes, the first behavioral axis discerned a trade-off between grazing and standing/vigilance behavior. In females, group vigilance behavior increased with increasingly male-biased sex ratio, whereas in males, the effect of adult sex ratio on standing/vigilance behavior depended on the relative proportion of dominant males in the mating group. The second axis characterized courtship and male-male agonistic behavior in males, and moving and male-directed agonistic behavior in females. Mating group composition did not substantially influence this axis in males. However, moving and male-directed agonistic behavior increased at highly biased sex ratios (quadratic effect) in females. Finally, the third axis highlighted a trade-off between moving and lying behavior in males, and distinguished moving and female-female agonistic behavior from lying behavior in females. For males, those behaviors were influenced by a complex interaction between group size and adult sex ratio, whereas in females, moving and female-female agonistic behaviors increased in a quadratic fashion at highly biased sex ratios, and also increased with increasing group size. Our results reveal complex behavioral trade-offs depending on group composition in the Alpine ibex, and emphasize the importance of social factors in influencing behavioral time-budgets of wild ungulates during the rut. RI Viblanc, Vincent/A-7455-2014 OI Viblanc, Vincent/0000-0002-4953-659X SN 1932-6203 PD JAN 8 PY 2014 VL 9 IS 1 AR e86004 DI 10.1371/journal.pone.0086004 UT WOS:000329862500268 PM 24416453 ER PT J AU Akujarvi, A Hallikainen, V Hypponen, M Mattila, E Mikkola, K Rautio, P AF Akujarvi, Anu Hallikainen, Ville Hypponen, Mikko Mattila, Eero Mikkola, Kari Rautio, Pasi TI Effects of reindeer grazing and forestry on ground lichens in Finnish Lapland SO SILVA FENNICA AB Reindeer husbandry and forestry are practiced in the same areas in northern Fennoscandia. Reindeer pastures have largely deteriorated. We aimed to quantify the separate and combined effects of reindeer grazing and forestry on the amount of ground lichens. To do this, we mapped and inventoried all larger enclosures (49) in Finnish Lapland where forest management practices were similar in both sides of the fence. The average time since fencing was 43 years. We recorded the cover and estimated dry biomass of ground lichens, as well as parameters describing forest stand characteristics. The effect of reindeer grazing on both the cover and estimated dry biomass of lichens was clear: in the ungrazed (fenced) sites, the lichen cover (35.8%) was on average 5.3-fold and the dry biomass (1929 kg ha(-1)) 14.8-fold compared with the corresponding estimates in the grazed sites (6.8% and 130 kg ha(-1)). The effect of forestry on lichens was smaller. In the grazed stands the cover and biomass of lichens were higher in the mature stands compared to the younger stand development classes, whereas in the ungrazed stands there were no significant differences between the development classes. Both reindeer grazing and forestry affect the cover and biomass of ground lichens. The influence of reindeer grazing is, however, much heavier than that of forestry. The decrease of not only the biomass, but also the lichen cover, is alarming. The decrease of lichen cover may hinder the recovery of reindeer pastures, which in the long run endangers the sustainability of reindeer husbandry. RI Hallikainen, Ville/E-8766-2013; Rautio, Pasi/A-6595-2013 OI Hallikainen, Ville/0000-0001-5384-8265; Rautio, Pasi/0000-0003-0559-7531 SN 0037-5330 EI 2242-4075 PY 2014 VL 48 IS 3 AR 1153 DI 10.14214/sf.1153 UT WOS:000343873600007 ER PT J AU Mayer, R Erschbamer, B AF Mayer, Roland Erschbamer, Brigitta TI Ongoing changes at the long-term monitoring sites of Gurgler Kamm Biosphere Reserve, Tyrol, Austria SO ECO MONT-JOURNAL ON PROTECTED MOUNTAIN AREAS RESEARCH AB By means of a long-term monitoring project, species diversity and abundance were analysed at 16 sites along an altitudinal gradient from 1 960 m to 2 830 m in Gurgler Kamm Biosphere Reserve (LTER site of the platform Tyrolean Alps; Obergurgl, Otztal). A total of 108 permanent plots of 1 m(2) were established. The main aim was to observe effects of time in untreated sites and impacts of grazing exclusion on species number and frequency of functional groups in different subalpine and alpine plant communities. Grazing exclusion led to decreases in species numbers. Significant positive grazing effects were detected for dwarf shrubs and legumes in the subalpine zone and for herbs in the upper alpine zone. Within the untreated sites, species numbers and frequencies changed significantly with time, involving almost all functional groups. The lichen heath was the most stable community. Here, only graminoids showed an increasing trend. All in all, the intermediate disturbance hypothesis was found to be valid also for high altitudes. A continuation of the traditional grazing regime is therefore suggested for the entire Gurgler Kamm Biosphere Reserve. SN 2073-106X EI 2073-1558 PD JAN PY 2014 VL 6 IS 1 BP 5 EP 14 DI 10.1553/ecomont-6-1s5 UT WOS:000344488000002 ER PT S AU Muuttoranta, K Maki-Tanila, A AF Muuttoranta, K. Maki-Tanila, A. BE Kuipers, A Rozstalnyy, A Keane, G TI Reindeer production in Finland - integration of traditional and new technologies SO CATTLE HUSBANDRY IN EASTERN EUROPE AND CHINA: STRUCTURE, DEVELOPMENT PATHS AND OPTIMISATION SE EAAP European Association for Animal Production Publication CT 3rd Workshop on Eastern Europe held at the 63rd EAAP Annual Meeting CY AUG 27-31, 2012 CL Bratislava, SLOVAKIA SP European Federat Anim Sci, FAO, Lifelong Learning Programme AB Reindeer is a semi-domesticated species that mostly lives free in nature and utilises the natural grazing area in northern marginal regions. Traditional herding originated from hunting and developed in Finland into an organised way of life with a special social structure of herder co-operatives (herding units). The Reindeer Herders' Association is an umbrella organisation for the co-operatives to promote common policies in reindeer husbandry. In Finland there are now about 4,600 reindeer owners. The number has recently decreased while the mean herd size has increased. Reindeer feed on a wide range of plants. In summer they eat wild plants. In the autumn they eat mushrooms and in winter lichens are an important source of feed. The winter pastures have degraded because of overgrazing and competing land uses (such as mining, forestry, peat harvesting, and tourism). Consequently, supplemental winter feeding is a common practice guaranteeing better survival. The main product from reindeer is meat. Reindeer meat is healthy, lean, and tasty, and the small amount produced ensures a prestige image. Marketing and direct sales yield higher prices, although with some fluctuations. The economic condition of the herders has room for improvement, although high monetary return is not the primary driving force keeping herders in this traditional system. The reindeer herders receive relatively small subsidies (18%) compared to the gross return of Finnish agricultural production. The herders like their work and consider it as an independent, traditional and nature-based occupation that supports their cultural heritage. The reindeer are gathered together twice a year, for ear-marking the new born calves and for culling the animals for slaughter. Despite the traditions of the special livelihood, the herders are willing to adopt new technology to ease the work. The herders know the importance of selective breeding and have decades ago changed the focus in the slaughter regime of calves to have lower grazing pressure in the winter and to improve the meat quality. Predation is considered among the single most serious threat to this livelihood. The predation pressure is highest in the eastern part of the reindeer herding area and hinders the possibilities for efficient management. SN 0071-2477 BN 978-90-8686-785-1; 978-90-8686-232-0 PY 2014 IS 135 BP 231 EP 250 DI 10.3920/978-90-8686-785-1_19 UT WOS:000343552200019 ER PT J AU Taylor, LA Muller, DWH Schwitzer, C Kaisers, TM Codron, D Schulz, E Clauss, M AF Taylor, Lucy A. Mueller, Dennis W. H. Schwitzer, Christoph Kaisers, Thomas M. Codron, Daryl Schulz, Ellen Clauss, Marcus TI Tooth wear in captive rhinoceroses (Diceros, Rhinoceros, Ceratotherium: Perissodactyla) differs from that of free-ranging conspecifics SO CONTRIBUTIONS TO ZOOLOGY AB Tooth wear can affect body condition, reproductive success and life expectancy. Poor dental health is frequently reported in the zoo literature, and abrasion-dominated tooth wear, which is typical for grazers, has been reported in captive browsing ruminants. The aim of this study was to test if a similar effect is evident in captive rhinoceros species. Dental casts of maxillary cheek teeth of museum specimens of captive black (Diceros bicornis; browser), greater one-horned (Rhinoceros unicorn is; intermediate feeder) and white rhinoceroses (Ceratotherium simum; grazer) were analysed using the recently developed extended mesowear method for rhinoceroses. Captive D. bicornis exhibited significantly more abrasion-dominated tooth wear than their free-ranging conspecifics (p<0.001), whereas captive C. simum exhibited significantly less abrasion-dominated tooth wear, particularly in the posterior cusp of the second molar (p=0.005). In R. unicornis, fewer differences were exhibited between free-ranging and captive animals, but tooth wear was highly variable in this species. In both free-ranging and captive D. bicornis, anterior cusps were significantly more abrasion-dominated than posterior cusps (p<0.05), which indicates morphological differences between cusps that may represent functional adaptations. By contrast, tooth wear gradients between free-ranging and captive animals differed, which indicates ingesta-specific influences responsible for inter-tooth wear differences. Captive D. bicornis exhibited more homogenous tooth wear than their free-ranging conspecifics, which may be caused by an increase in the absolute dietary abrasiveness and a decrease in relative environmental abrasiveness compared to their freer-anging conspecifics. The opposite occurred in C. simum. The results of this study suggest that diets fed to captive browsers are too abrasive, which could result in the premature loss of tooth functionality, leading to reduced food acquisition and processing ability and, consequently, malnourishment. RI Codron, Daryl/B-8867-2008; Clauss, Marcus/A-4710-2008 OI Codron, Daryl/0000-0001-5223-9513; Clauss, Marcus/0000-0003-3841-6207; Kaiser, Thomas/0000-0002-8154-1751; Schulz-Kornas, Ellen/0000-0003-1657-8256 SN 1383-4517 EI 1875-9866 PY 2014 VL 83 IS 2 BP 107 EP 117 UT WOS:000337708700002 ER PT J AU Falldorf, T Strand, O Panzacchi, M Tommervik, H AF Falldorf, Tobias Strand, Olav Panzacchi, Manuela Tommervik, Hans TI Estimating lichen volume and reindeer winter pasture quality from Landsat imagery SO REMOTE SENSING OF ENVIRONMENT AB Reindeer and caribou are keystone species in the circumpolar region, and rely on lichens as their main winter forage to survive in some of the most extreme environments on Earth. Lichen mats, however, can be heavily overgrazed at high deer densities, triggering area abandonment or population declines. Although the species' management and conservation require precise information on the quality of winter grazing areas, no reliable and cost-efficient methods are available to date to measure lichen volume across wide and remote areas. We developed a new Lichen Volume Estimator, LVE, using remote sensing and field measurements. We used a Landsat TM land cover mask to separate lichen heath communities from other vegetation types and, therein, we predicted lichen volume from a two dimensional Gaussian regression model using two indexes: the Normalized Difference Lichen Index, NDLI (Band 5 - Band 4/ Band 5 + Band 4), and the Normalized Difference Moisture Index, NDMI (Band 4 - Band 5 / Band 4 + Band 5). The model was parameterized using 202 ground measurements equally distributed across a gradient ranging from 0 to 80 lichen dm(3)/m(2) (R-2 = 0.74 between predicted and observed ground measurements), and was validated with a ten-fold cross validation procedure (R-2 = 0.67), which also showed a high parameter stability. The LW can be a valuable tool to predict the quality of winter pastures for reindeer and caribou and, thus, help to improve the species' management and conservation. (C) 2013 The Authors. Published by Elsevier Inc All rights reserved. SN 0034-4257 EI 1879-0704 PD JAN PY 2014 VL 140 BP 573 EP 579 DI 10.1016/j.rse.2013.09.027 UT WOS:000329766200046 ER PT J AU Bates, MR Champness, C Haggart, A Macphail, RI Parfitt, SA Schwenninger, JL AF Bates, Martin R. Champness, Carl Haggart, Andrew Macphail, Richard I. Parfitt, Simon A. Schwenninger, Jean-Luc TI Early Devensian sediments and palaeovenvironmental evidence from the excavations at the Royal Oak Portal Paddington, West London, UK SO PROCEEDINGS OF THE GEOLOGISTS ASSOCIATION AB This paper discusses the results of the investigation of Pleistocene sediments at the Royal Oak Portal CROP) site on the new Crossrail scheme near Paddington Station, London. The site was sampled and recorded in May 2011 by archaeologists from Oxford Archaeology commissioned by Crossrail Ltd. The investigation revealed a sedimentary sequence associated with cool climate waterlain deposition towards the edge of the River Westbourne floodplain. During excavation an assemblage of around 100 identifiable large mammal bones was recovered, dating to the Late Pleistocene. The major concentration of bones, from bison and reindeer, was located and excavated from a shallow sequence of sediments. Analysis of the bones indicates that they represent a natural death assemblage, scavenged and subsequently disarticulated, transported by water, exposed and further dispersed and broken by trampling. The site is of regional and national importance because the assemblage derives from a well-constrained geological context, with associated dating evidence suggesting accumulation during the later parts of Marine Isotope Stage (MIS) 5 and continuing within MIS 4. The site is also of significance because it is one of a growing number of recently discovered sites away from the main fluvial archive for the British Middle and Upper Pleistocene. These sites have the potential to add significantly to our understanding of parts of the Pleistocene record that remain difficult to document through the investigation of the more active systems associated with major rivers such as the Thames, Severn or Trent. (C) 2013 The Geologists' Association. Published by Elsevier Ltd. All rights reserved. SN 0016-7878 PD JAN PY 2014 VL 125 IS 1 BP 41 EP 55 DI 10.1016/j.pgeola.2013.06.001 UT WOS:000329952300005 ER PT J AU Koster, E Koster, K Aurela, M Laurila, T Berninger, F Lohila, A Pumpanen, J AF Koster, Egle Koster, Kajar Aurela, Mika Laurila, Tuomas Berninger, Frank Lohila, Annalea Pumpanen, Jukka TI Impact of reindeer herding on vegetation biomass and soil carbon content: a case study from Sodankyla, Finland SO BOREAL ENVIRONMENT RESEARCH AB Factors that strongly affects the dynamics of ground vegetation in northern boreal forests are grazing and trampling by reindeers. Cladina stellaris, which is the main species of lichen in northern areas, is also an important food source for reindeer. The population of reindeer is high, and it has a considerable influence on the boreal forest ecosystems. In this study, we describe the reindeer herding effects on above- and below-ground vegetation and on soil carbon (C) content. We compared the changes on both sides of a fence that has excluded reindeer from one area for the last 50 years. As expected, in the grazed area there were significantly smaller amounts of lichens and other vegetation. Total above-ground biomass as well as that of trees was higher in the area where no reindeer grazing occurred. In the ungrazed area, the tree-diameter distribution was strongly skewed towards thinner trees. There was no significant effect of reindeer grazing on the soil C content. RI Pumpanen, Jukka/B-1254-2012; Aurela, Mika/L-4724-2014; Lohila, Annalea/C-7307-2014; Koster, Kajar/C-8397-2012 OI Pumpanen, Jukka/0000-0003-4879-3663; Lohila, Annalea/0000-0003-3541-672X; Koster, Kajar/0000-0003-1988-5788; Berninger, Frank/0000-0001-7718-1661 SN 1239-6095 EI 1797-2469 PD DEC 18 PY 2013 VL 18 SU A SI SI BP 35 EP 42 UT WOS:000329020200005 ER PT J AU Jaakkola, LM Heiskanen, MM Lensu, AM Kuitunen, MT AF Jaakkola, Lotta M. Heiskanen, Miia M. Lensu, Anssi M. Kuitunen, Markku T. TI Consequences of forest landscape changes for the availability of winter pastures to reindeer (Rangifer tarandus tarandus) from 1953 to 2003 in Kuusamo, northeast Finland SO BOREAL ENVIRONMENT RESEARCH AB Using aerial photographs, we examined the changes in the forest matrix from 1953 to 2003 in the Oulanka National Park and commercial forests in the northern part of the municipality of Kuusamo. The changes concerned the potential winter grazing grounds available to the existing reindeer population. The main changes in the commercial forests took place between 1953 and 1977, during which time the mean forest-patch size shrank by 65%, and the number of patches increased by 78%. From 1953 to 2003, the total area of epiphytic lichens and ground-lichen pastures decreased by 48.6%. The area of ground-lichen pastures decreased by 20%, and the area of common hair grass pastures doubled. The forest matrix transition in the commercial forests changed not only the spatial configuration and areas of different pasture patches, but also the grazing pressure at the remaining pasture sites. In the national park, the changes in grazing pressure were related only to the changes in numbers of reindeer. In general, the conditions of reindeer pastures are a result of interaction between different land-use components. SN 1239-6095 EI 1797-2469 PD DEC 2 PY 2013 VL 18 IS 6 BP 459 EP 472 UT WOS:000327807000003 ER PT J AU Vaisanen, M Martz, F Kaarlejarvi, E Julkunen-Tiitto, R Stark, S AF Vaisanen, Maria Martz, Francoise Kaarlejarvi, Elina Julkunen-Tiitto, Riitta Stark, Sari TI Phenolic Responses of Mountain Crowberry (Empetrum nigrum ssp hermaphroditum) to Global Climate Change are Compound Specific and Depend on Grazing by Reindeer (Rangifer tarandus) SO JOURNAL OF CHEMICAL ECOLOGY AB Mountain crowberry (Empetrum nigrum ssp. hermaphroditum) is a keystone species in northern ecosystems and exerts important ecosystem-level effects through high concentrations of phenolic metabolites. It has not been investigated how crowberry phenolics will respond to global climate change. In the tundra, grazing by reindeer (Rangifer tarandus) affects vegetation and soil nutrient availability, but almost nothing is known about the interactions between grazing and global climate change on plant phenolics. We performed a factorial warming and fertilization experiment in a tundra ecosystem under light grazing and heavy grazing and analyzed individual foliar phenolics and crowberry abundance. Crowberry was more abundant under light grazing than heavy grazing. Although phenolic concentrations did not differ between grazing intensities, responses of crowberry abundance and phenolic concentrations to warming varied significantly depending on grazing intensity. Under light grazing, warming increased crowberry abundance and the concentration of stilbenes, but decreased e.g., the concentrations of flavonols, condensed tannins, and batatasin-III, resulting in no change in total phenolics. Under heavy grazing, warming did not affect crowberry abundance, and induced a weak but consistent decrease among the different phenolic compound groups, resulting in a net decrease in total phenolics. Our results show that the different phenolic compound groups may show varying or even opposing responses to warming in the tundra at different levels of grazing intensity. Even when plant phenolic concentrations do not directly respond to grazing, grazers may have a key control over plant responses to changes in the abiotic environment, reflecting multiple adaptive purposes of plant phenolics and complex interactions between the biotic and the abiotic factors. RI Martz, Francoise/C-6354-2017; Stark, Sari/L-4440-2013 SN 0098-0331 EI 1573-1561 PD DEC PY 2013 VL 39 IS 11-12 BP 1390 EP 1399 DI 10.1007/s10886-013-0367-z UT WOS:000328202100005 PM 24287946 ER PT J AU Jorgensen, RH Meilby, H Kollmann, J AF Jorgensen, Rasmus H. Meilby, Henrik Kollmann, Johannes TI Shrub Expansion in SW Greenland under Modest Regional Warming: Disentangling Effects of Human Disturbance and Grazing SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Shrub expansion has been observed widely in tundra areas across the Arctic. This phenomenon has been partially attributed to increasing temperatures over the past century. However, relationships among shrub expansion, grazing, and human disturbance have been studied little. SW Greenland is a subarctic to low-arctic region with a long and complex land-use history and only modest temperature increases over the past 50 years (0.2 degrees C decade(-1)), but changes in shrub cover have not previously been studied in this region. We compiled historical photographs of vegetation in SW Greenland (1898-1974) and repeated the photos in 2010 and 2011. Sixty-four photo pairs were cropped into 133 smaller units and classified by aspect, substrate stability, muskoxen grazing, and human disturbance. The photo material was evaluated by 22 experts with respect to changes in shrub cover, revealing a general increase across the whole data set, and in a subset including only undisturbed sites. Shrub cover increased most on E and SE slopes, in sites with stable substrate, and in areas characterized by human disturbance and without muskoxen grazing. The general shrub cover increase could be caused mainly by changed land-use intensity, but effects of the moderately increased temperatures cannot be ruled out. RI Kollmann, Johannes/B-4255-2012; Meilby, Henrik/E-1404-2015 OI Kollmann, Johannes/0000-0002-4990-3636; Meilby, Henrik/0000-0002-3770-3880 SN 1523-0430 EI 1938-4246 PD NOV PY 2013 VL 45 IS 4 BP 515 EP 525 DI 10.1657/1938-4246-45.4.515 UT WOS:000329533400008 ER PT J AU Lindwall, F Vowels, T Ekblad, A Bjork, RG AF Lindwall, Frida Vowels, Tage Ekblad, Alf Bjork, Robert G. TI Reindeer grazing has contrasting effect on species traits in Vaccinium vitis-idaea L. and Bistorta vivipara (L.) Gray SO ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY AB That reindeer grazing can have large effects on plant communities is well known, but how reindeer grazing affects plant traits and plant carbon (C) and nitrogen (N) allocation has not been studied to the same extent. This study was conducted in a sub-arctic dry heath in northern Sweden. 17-year-old reindeer exclosures were used to test whether reindeer grazing affects the C:N ratio (a plant quality index), and the delta C-13 and delta N-15 (indicators of changes in C and N dynamics) as well as the C and N content of above- and below ground parts of the evergreen dwarf shrub Vaccinium vitis-idaea L. and the perennial forb Bistorta vivipara (L) Gray. A lower C:N ratio was found in B. vivipara compared to V. vitis-idaea suggesting a higher grazing pressure on that species. We found that grazing reduced the total C content, by 26%, and increased the delta N-15, by 1 parts per thousand, in the leaves of B. vivipara, while no changes were observed in V. vitis-idaea. Fine roots of B. vivipara had higher delta C-13 (1 parts per thousand) and delta N-15 (2.5 parts per thousand) than the leaves, while such differences were not found in V. vitis-idaea. The results also highlight the importance of analysing both above- and belowground plant parts when interpreting natural variations in delta C-13 and delta N-15. (C) 2013 The Authors. Published by Elsevier Masson SAS. All rights reserved. OI Bjork, Robert/0000-0001-7346-666X SN 1146-609X EI 1873-6238 PD NOV PY 2013 VL 53 BP 33 EP 37 DI 10.1016/j.actao.2013.08.006 UT WOS:000327806600004 ER PT J AU Ophof, AA Oldeboer, KW Kumpula, J AF Ophof, A. A. Oldeboer, K. W. Kumpula, J. TI Intake and chemical composition of winter and spring forage plants consumed by semi-domesticated reindeer (Rangifer tarandus tarandus) in Northern Finland SO ANIMAL FEED SCIENCE AND TECHNOLOGY AB Reindeer diets are highly influenced by seasonal availability of forage plants and their nutritive value. This study investigated the use and chemical composition of winter and spring forage plants consumed by semi-domesticated reindeer (Rangifer tarandus tarandus) grazing on natural pastures in Northern Finland. Reindeer diet composition was determined by microhistological analysis of faeces collected during winter and spring. Terrestrial lichen species (mainly Cladonia sp.) dominated the winter and spring diet of reindeer, as well as various dwarf shrub species. A seasonal shift occurred in the diet, with proportion of lichen which corresponded with an increase in graminoids as spring progressed, reflecting reindeer adaptations to seasonal fluctuations of forage quality and availability. Chemical composition of forage plants showed that terrestrial lichen had high levels of hemicellulose, while arboreal lichen had relatively high nitrogen levels. In contrast, new growth of birch leaf, graminoids and dwarf shrub had high levels of crude protein, ether extract and minerals. The observed diet composition and its chemical content reflect high seasonal variability in the availability and intake of nutrients to which reindeer have adapted. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved. SN 0377-8401 EI 1873-2216 PD OCT 25 PY 2013 VL 185 IS 3-4 BP 190 EP 195 DI 10.1016/j.anifeedsci.2013.08.005 UT WOS:000326061500010 ER PT J AU Kaarlejarvi, E Eskelinen, A Olofsson, J AF Kaarlejarvi, Elina Eskelinen, Anu Olofsson, Johan TI Herbivory prevents positive responses of lowland plants to warmer and more fertile conditions at high altitudes SO FUNCTIONAL ECOLOGY AB Warm-adapted low elevation plants are expected to exhibit considerable range shifts to higher altitudes and latitudes as a result of climate warming and increased nutrient loads. However, empirical studies show that the magnitude and direction of plant responses are highly species- and site-specific, suggesting that several additional drivers interact with warmer climate. We experimentally tested the interactive effects of climate warming, mammalian herbivory and soil fertility on low elevation plants. Seedlings of three warm-adapted lowland forbs (Epilobium angustifolium, Silene dioica and Solidago virgaurea) were transplanted to an open tundra site with native mountain tundra vegetation, and the effects of full factorial combinations of herbivore exclosures, warming and fertilization on transplant survival, growth and flowering were studied for two growing seasons. We also investigated the response of native vegetation biomass to the same treatments and compared it with the responses of transplanted lowland forbs. Effects of both warming and fertilization on the transplanted lowland forbs strongly hinged on herbivore exclusion, resulting in 2-13-fold increase in biomass in warmed and fertilized plots without herbivores compared with warmed and fertilized plots with herbivores present, the magnitude depending on the species. While warm-adapted transplants benefited from warming, the native tundra plant community biomass did not respond to warming treatment. Our results show that grazing limits the growth of transplants under warmer and more productive conditions, indicating that the expansion of lowland plant species to higher altitudes with warming may be hampered by mammalian herbivory. Furthermore, our results also suggest that migration of warm-adapted species into lightly grazed high-altitude tundra ecosystems might transform these communities to be more responsive to warmer climate and nutrient loads. Studies that do not consider species' upward shifts from lower altitudes might thus have underestimated vegetation responses to global warming, as well as the potential of herbivory to influence these responses. SN 0269-8463 EI 1365-2435 PD OCT PY 2013 VL 27 IS 5 BP 1244 EP 1253 DI 10.1111/1365-2435.12113 UT WOS:000325366500016 ER PT J AU Metcalfe, JZ Longstaffe, FJ Hodgins, G AF Metcalfe, Jessica Z. Longstaffe, Fred J. Hodgins, Greg TI Proboscideans and paleoenvironments of the Pleistocene Great Lakes: landscape, vegetation, and stable isotopes SO QUATERNARY SCIENCE REVIEWS AB In this study, we review the history of proboscideans in the Great Lakes region (Ontario and western New York) in the context of local glacial and vegetational histories. Further, we investigate mammoth (Mammuthus) and mastodon (Mammut) environmental niche partitioning using stable isotope analysis of bone and dentin collagen (delta C-13(col), delta N-15(col)) and structural carbonate in tooth enamel bioapatite (delta C-13(sc), delta O-18(sc)), and demonstrate that stable isotopes can be used to identify non-locals among museum specimens with no contextual records. New radiocarbon dates suggest that Ontario mastodons lived in tundra-like environments as well as their more common spruce forest habitat. Local Ontario/New York mammoths and mastodons consumed 100% C-3-plant diets and drank low-O-18 waters, consistent with colder-than-modern climates and proximity to glacial meltwater sources. Mammoths and mastodons occupied distinct environmental niches, characterized by different oxygen- and nitrogen-isotope compositions and geographical locations. This suggests that direct competition for resources was not a major factor in their local extinction. We suggest that both mammoths and mastodons obtained water from sources formed primarily from precipitation rather than glacial meltwater. We describe how high delta N-15 values in mammoths could have been caused by a combination of preferences for dry environments, consumption of low-nutrient forage (particularly stems and stalks), coprophagy, geophagy, and dung fertilization. We argue that low delta N-15 values in mastodons could have been caused by consumption of trees and shrubs (including nitrogen-fixing taxa) and a preference for recently deglaciated landscapes and/or spruce environments. Finally, we raise the possibility that mastodons contributed to the spruce-pine transition by browsing directly on spruce trees. (c) 2013 Elsevier Ltd. All rights reserved. SN 0277-3791 PD SEP 15 PY 2013 VL 76 BP 102 EP 113 DI 10.1016/j.quascirev.2013.07.004 UT WOS:000324449200009 ER PT J AU Olofsson, J te Beest, M Ericson, L AF Olofsson, Johan te Beest, Mariska Ericson, Lars TI Complex biotic interactions drive long-term vegetation dynamics in a subarctic ecosystem SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES AB Predicting impacts of global warming requires understanding of the extent to which plant biomass and production are controlled by bottom-up and top-down drivers. By annually monitoring community composition in grazed control plots and herbivore-free exclosures at an Arctic location for 15 years, we detected multiple biotic interactions. Regular rodent cycles acted as pulses driving synchronous fluctuations in the biomass of field-layer vegetation; reindeer influenced the biomass of taller shrubs, and the abundance of plant pathogenic fungi increased when densities of their host plants increased in exclosures. Two outbreaks of geometrid moths occurred during the study period, with contrasting effects on the field layer: one in 2004 had marginal effects, while one in 2012 severely reduced biomass in the control plots and eliminated biomass that had accumulated over 15 years in the exclosures. The latter was followed by a dramatic decline of the dominant understory dwarf-shrub Empetrum hermaphroditum, driven by an interaction between moth herbivory on top buds and leaves, and increased disease severity of a pathogenic fungus. We show that the climate has important direct and indirect effects on all these biotic interactions. We conclude that long time series are essential to identify key biotic interactions in ecosystems, since their importance will be influenced by climatic conditions, and that manipulative treatments are needed in order to obtain the mechanistic understanding needed for robust predictions of future ecosystem changes and their feedback effects. SN 0962-8436 EI 1471-2970 PD AUG 19 PY 2013 VL 368 IS 1624 AR UNSP 20120486 DI 10.1098/rstb.2012.0486 UT WOS:000321565600008 PM 23836791 ER PT J AU Jacks, G Slejkovec, Z Morth, M Bhattacharya, P AF Jacks, Gunnar Slejkovec, Zdenka Morth, Magnus Bhattacharya, Prosun TI Redox-cycling of arsenic along the water pathways in sulfidic metasediment areas in northern Sweden SO APPLIED GEOCHEMISTRY AB Arsenic has emerged as a problem element in groundwater. The most common mechanism of mobilising As from the solid phase into water is through the reductive dissolution of ferric oxyhydroxides. This investigation was made in northern Sweden where metasediments containing pyrite, pyrrhotite and arsenopyrite underlay about 4000 km(2). The overlying till contains as much as up to 100 mg kg (1) As. Speciation of the dissolved As shows that arsenite dominates largely over arsenate. The Fe oxyhydroxides formed may contain up to 0.5% As. Sandy sediments may contain 100-500 mg kg (1). Arsenic and Fe are closely correlated. The cycling of As in water, flora and fauna in wetlands has been studied. Ferric reduction occurs in wetlands and groundwater rich in Fe, and As is found to be discharging into ditches, brooks and streams. Wetland trees and plants show a moderately elevated content of As with a few species showing above 2 mg kg (1), the permissible level in fodder for domestic animals. The only plants having a high content of As are Equisetum species showing up to 26 mg kg (1). These plants make up a small fraction of the food of wild, grazing and browsing animals, for example moose and reindeer, and does not seem to constitute an environmental risk. However, the animals could be exposed to considerable amounts of As by drinking water from springs in wetlands. In the fauna, an elevated As content has so far been found in a limited number of benthic macroinvertebrate samples (1.23-42.1 mg kg (1) dry weight), in which inorganic As species (arsenate) predominate in the extractable fraction (62-82%) with lower amounts of arsenite, mono-and dimethylarsenic acid. Some samples also contained arsenobetaine, trimethylarsine oxide and tetramethylarsonium ion. To the authors' knowledge, this is the first report on As speciation in benthic macroinvertebrates. Fish species from polluted streams (pike and brown trout) had normal As levels (0.57-1.84 mg kg (1) dry weight), mainly present in a form of arsenobetaine (brown trout) or arsenobetaine and dimethylarsinic acid (pike). As both fish species also contained minor amounts of arsenite and arsenate, it is estimated that there is no serious health risk to potential consumers. (C) 2013 Elsevier Ltd. All rights reserved. RI Bhattacharya, Prosun/B-1564-2010 OI Bhattacharya, Prosun/0000-0003-4350-9950 SN 0883-2927 PD AUG PY 2013 VL 35 BP 35 EP 43 DI 10.1016/j.apgeochem.2013.05.002 UT WOS:000322065800005 ER PT J AU Cohen, J Pulliainen, J Menard, CB Johansen, B Oksanen, L Luojus, K Ikonen, J AF Cohen, Juval y Pulliainen, Jouni Menard, Cecile B. Johansen, Bernt Oksanen, Lauri Luojus, Kari Ikonen, Jaakko TI Effect of reindeer grazing on snowmelt, albedo and energy balance based on satellite data analyses SO REMOTE SENSING OF ENVIRONMENT AB Surface albedo has a major influence on the energy balance of the Earth. The albedo difference between snow-covered and snow-free tundra is high. Earlier studies have shown that taller and denser vegetation causes earlier snowmelt, and that shrub height and abundance, as well as the total biomass in summer reindeer pastures are lower than in winter pastures. Therefore, reindeer summer grazing could eventually delay the snowmelt and decrease the absorbed solar energy on the ground. The effect of reindeer summer grazing on the vegetation, snowmelt timing, surface albedo and ground heating is investigated in this study by comparing summer and non-summer pastures in the northern tundra areas of Fennoscandia. A comparison of vegetation types, NDVI, fractional snow cover and albedo between the Finnish year-round (including summer) pastures and the Norwegian non-summer (winter or spring/autumn) pastures is performed. Other factors influencing the snowmelt, such as surface air temperature, ground elevation and incoming solar radiation are taken into account. Information about the vegetation on the ground is based on a vegetation map compiled from Landsat TM/ETM + satellite data and ancillary map information. The NDVI, snowmelt and albedo analyses are performed using multi-temporal remote sensing data such as GlobSnow SE and MODIS based NDVI, snow and albedo products. The results here support previous studies and indicate that vegetation in the summer pastures is shorter and sparser and that snowmelt there occurs later than in the more densely vegetated, non-summer pastures. More shrubs protruding above the snowpack and earlier snowmelt on the Norwegian side lower the albedo during the snowmelt season. This causes higher solar energy absorption of up to 6 W/m(2) in the snowmelt season and contributes up to 0.5 W/m(2) to the yearly energy balance. Therefore this study suggests that summer reindeer herding can be used to delay snowmelt, increase surface albedo and to decrease the ground heating in the snowmelt season. (C) 2013 Elsevier Inc. All rights reserved. RI Menard, Cecile/F-7860-2014 OI Menard, Cecile/0000-0003-2166-9523; Cohen, Juval/0000-0001-6396-1536 SN 0034-4257 PD AUG PY 2013 VL 135 BP 107 EP 117 DI 10.1016/j.rse.2013.03.029 UT WOS:000320419100009 ER PT J AU Mann, DH Groves, P Kunz, ML Reanier, RE Gaglioti, BV AF Mann, Daniel H. Groves, Pamela Kunz, Michael L. Reanier, Richard E. Gaglioti, Benjamin V. TI Ice-age megafauna in Arctic Alaska: extinction, invasion, survival SO QUATERNARY SCIENCE REVIEWS AB Radical restructuring of the terrestrial, large mammal fauna living in arctic Alaska occurred between 14,000 and 10,000 years ago at the end of the last ice age. Steppe bison, horse, and woolly mammoth became extinct, moose and humans invaded, while muskox and caribou persisted. The ice age megafauna was more diverse in species and possibly contained 6x more individual animals than live in the region today. Megafaunal biomass during the last ice age may have been 30x greater than present. Horse was the dominant species in terms of number of individuals. Lions, short-faced bears, wolves, and possibly grizzly bears comprised the predator/scavenger guild. The youngest mammoth so far discovered lived ca 13,800 years ago, while horses and bison persisted on the North Slope until at least 12,500 years ago during the Younger Dryas cold interval. The first people arrived on the North Slope ca 13,500 years ago. Bone-isotope measurements and foot-loading characteristics suggest megafaunal niches were segregated along a moisture gradient, with the surviving species (muskox and caribou) utilizing the warmer and moister portions of the vegetation mosaic. As the ice age ended, the moisture gradient shifted and eliminated habitats utilized by the dryland, grazing species (bison, horse, mammoth). The proximate cause for this change was regional paludification, the spread of organic soil horizons and peat. End-Pleistocene extinctions in arctic Alaska represent local, not global extinctions since the megafaunal species lost there persisted to later times elsewhere. Hunting seems unlikely as the cause of these extinctions, but it cannot be ruled out as the final blow to megafaunal populations that were already functionally extinct by the time humans arrived in the region. (C) 2013 Elsevier Ltd. All rights reserved. SN 0277-3791 PD JUN 15 PY 2013 VL 70 BP 91 EP 108 DI 10.1016/j.quascirev.2013.03.015 UT WOS:000320746300007 ER PT J AU Ravolainen, VT Brathen, KA Ims, RA Yoccoz, NG Soininen, EM AF Ravolainen, Virve T. Brathen, Kari A. Ims, Rolf A. Yoccoz, Nigel G. Soininen, Eeva M. TI Shrub patch configuration at the landscape scale is related to diversity of adjacent herbaceous vegetation SO PLANT ECOLOGY & DIVERSITY AB Background: Patterns of shrub patches reflect the long-term effects of several environmental drivers; the same drivers may also affect adjacent herbaceous vegetation. The identity of such drivers may be indicated by associating patterns of shrubs and adjacent vegetation. However, such associations have rarely been examined. Aim: Assess the hypothesis that configuration of shrub patches is related to the diversity of adjacent herbaceous vegetation, through the impact of variation in herbivory and/or growing conditions. Methods: Multivariate analyses of the relationship between patch configuration of tall shrubs and diversity of adjacent herbaceous vegetation, across two tundra river catchments in Norway. Results: Configuration of shrub patches was clearly related to and diversity of adjacent herbaceous vegetation, independent of concurrent herbivore abundance (estimated from faeces during the study), or growing conditions. Highly-shredded shrub patches (i.e. fragmented patches with high edge density) were associated with grazing-tolerant species and low species richness. Conversely, little-shredded tall shrub patches were associated with grazing-sensitive shrub saplings. This indicates change in herbivory on a timescale longer than that covered by our faeces data. Conclusions: Consistent co-variation of shrub and herbaceous patches in tall shrub tundra supports the hypothesis of impacts of a shared driver. Interpretation of this co-variation points to long-term influence of herbivory as the shared driver. RI Yoccoz, Nigel/C-8561-2014 OI Yoccoz, Nigel/0000-0003-2192-1039; Brathen, Kari Anne/0000-0003-0942-1074 SN 1755-0874 EI 1755-1668 PD JUN 1 PY 2013 VL 6 IS 2 BP 257 EP 268 DI 10.1080/17550874.2013.773104 UT WOS:000320018100009 ER PT J AU Henden, JA Yoccoz, NG Ims, RA Langeland, K AF Henden, John-Andre Yoccoz, Nigel G. Ims, Rolf A. Langeland, Knut TI How Spatial Variation in Areal Extent and Configuration of Labile Vegetation States Affect the Riparian Bird Community in Arctic Tundra SO PLOS ONE AB The Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by large herbivores and growing human activity. Thickets of tall shrubs represent a conspicuous vegetation state in northern and temperate ecosystems, where it serves important ecological functions, including habitat for wildlife. Thickets are however labile, as tall shrubs respond rapidly to both abiotic and biotic environmental drivers. Our aim was to assess how large-scale spatial variation in willow thicket areal extent, configuration and habitat structure affected bird abundance, occupancy rates and species richness so as to provide an empirical basis for predicting the outcome of environmental change for riparian tundra bird communities. Based on a 4-year count data series, obtained through a large-scale study design in low arctic tundra in northern Norway, statistical hierarchical community models were deployed to assess relations between habitat configuration and bird species occupancy and community richness. We found that species abundance, occupancy and richness were greatly affected by willow areal extent and configuration, habitat features likely to be affected by intense ungulate browsing as well as climate warming. In sum, total species richness was maximized in large and tall willow patches of small to intermediate degree of fragmentation. These community effects were mainly driven by responses in the occupancy rates of species depending on tall willows for foraging and breeding, while species favouring other vegetation states were not affected. In light of the predicted climate driven willow shrub encroachment in riparian tundra habitats, our study predicts that many bird species would increase in abundance, and that the bird community as a whole could become enriched. Conversely, in tundra regions where overabundance of large herbivores leads to decreased areal extent, reduced height and increased fragmentation of willow thickets, bird community richness and species-specific abundance are likely to be significantly reduced. RI Yoccoz, Nigel/C-8561-2014 OI Yoccoz, Nigel/0000-0003-2192-1039; Henden, John-Andre/0000-0002-8825-1167 SN 1932-6203 PD MAY 14 PY 2013 VL 8 IS 5 AR e63312 DI 10.1371/journal.pone.0063312 UT WOS:000319107400049 PM 23691020 ER PT J AU Zamin, TJ Grogan, P AF Zamin, Tara J. Grogan, Paul TI Caribou exclusion during a population low increases deciduous and evergreen shrub species biomass and nitrogen pools in low Arctic tundra SO JOURNAL OF ECOLOGY AB Increased shrub growth has been observed across the Arctic with recent climate warming trends, whilst many populations of caribou and reindeer (Rangifer) have been in decline. Paradoxically, our current understanding of the impacts of caribou and reindeer in altering trajectories of Arctic vegetation change is almost entirely dependent on studies with relatively high density semi-domesticated herds in Fennoscandia. With many wild herd populations across the Arctic presently at much lower densities, it is important to understand the impact of low intensity browsing on shrub biomass and the soil nutrient pools that fuel it. We used exclosures that have been in place for 5years in mesic birch hummock tundra in the central Canadian low Arctic to investigate the impact of caribou exclusion on tundra shrub biomass, tissue chemistry and plant and soil nitrogen (N) pools. Over the study period, the migratory tundra caribou herd in the region declined from 25% to 7% of its previous population maximum. Caribou exclusion significantly enhanced the above-ground biomass components of one deciduous shrub (Betula glandulosa) and two evergreen shrubs (Vaccinium vitis-idaea and Rhododendron subarcticum). In particular, exclusion doubled B.glandulosa leaf biomass and increased V.vitis-idaea old leaf biomass 1.7 times, with the strongest effects in evergreens present in tissues > 1year old, indicating a legacy of browsing from the earlier years of the experiment when the caribou population was higher. Meanwhile, Vaccinium uliginosum biomass and overall vascular plant diversity tended to decline with exclusion. Caribou exclusion increased B.glandulosa leaf N pools by 0.15gNm2 (equivalent to 12% of the total vascular plant community annual N requirement for apical growth). Altogether exclusion did not alter total above-ground N pools, but rather led to a redistribution of shoot biomass and N, enhancing spatial variability in a key growth-limiting resource for tundra plants. Synthesis. Excluding caribou during a population low resulted in ecologically significant changes in the distribution of plant above-ground biomass and nitrogen, further increasing the dominance of the three most abundant shrubs. These findings demonstrate that, despite uncertainty in herd recovery, Rangifer browsing impacts to both deciduous and evergreen shrub species should be considered for more robust projections of Arctic vegetation change. OI Zamin, Tara/0000-0002-0991-6651 SN 0022-0477 PD MAY PY 2013 VL 101 IS 3 BP 671 EP 683 DI 10.1111/1365-2745.12082 UT WOS:000318186800013 ER PT J AU Horstkotte, T Roturier, S AF Horstkotte, Tim Roturier, Samuel TI Does forest stand structure impact the dynamics of snow on winter grazing grounds of reindeer (Rangifer t. tarandus)? SO FOREST ECOLOGY AND MANAGEMENT AB The landscape in boreal Sweden is dominated by even-aged, single-layered forest monocultures and clear cuts. Few forest stands with a more complex, multi-layered structure remain as landscape elements. We studied the impact that different forest management regimes have on snow conditions and the metamorphosis of snow, and discuss how these factors may affect suitability for reindeer grazing. Over two winters, we recorded the development of snow depth and hardness in clear cuts and two different forest types, and their changes with weather events. In the forests, the dynamics of snow characteristics were analyzed in relation to stand structure and at the level of individual trees. There were no clear differences in snow characteristics between single-layered and multi-layered stands, although snow hardness was more variable in the latter. In single-layered stands, snow depth and hardness were spatially uniformly distributed in relation to stand characteristics. Contrastingly, the complex structure of multi-layered stands did influence snow depth significantly. However, hardness was highly heterogeneous in these stands. Due to the absence of tree effects, clear cuts had deeper but softer snow than forested stands, although hardness increased towards spring. Weather affected the metamorphosis of the snow blanket. The magnitude of the effects depended on both timing and severity of discrete weather events and forest structure, but generally weather had a greater influence on snow cover characteristics than forest structure per se. In their interaction with weather, different forest structures affect the snow and thus suitability as winter grazing area for reindeer. Reindeer herders, therefore, require diversity in the landscape in order to respond to such weather variations and their impact on grazing conditions. (C) 2012 Elsevier B.V. All rights reserved. SN 0378-1127 PD MAR 1 PY 2013 VL 291 BP 162 EP 171 DI 10.1016/j.foreco.2012.10.044 UT WOS:000316827500017 ER PT J AU Vikhamar-Schuler, D Hanssen-Bauer, I Schuler, TV Mathiesen, SD Lehning, M AF Vikhamar-Schuler, D. Hanssen-Bauer, I. Schuler, T. V. Mathiesen, S. D. Lehning, M. TI Use of a multilayer snow model to assess grazing conditions for reindeer SO ANNALS OF GLACIOLOGY AB High-density snow layers deteriorate grazing conditions for reindeer during winter. We compare two different methods for identifying past winters with difficult grazing conditions for reindeer in Kautokeino, northern Norway. A long-term climate analysis based on monthly values of precipitation and temperature (1900-2011) demonstrated that the reported winters were difficult to identify systematically. The processes leading to hard layers or ground-ice layers occur on daily, not monthly, timescales, and whether or not specific conditions are problematic depends on the development throughout the winter, not just on single values. To better analyse the weather conditions and development over time that favour the formation of high-density snow layers, we apply the multilayer model SNOWPACK over the period 1956-2010. We simulate the evolution of the snowpack by forcing the model with 6 hour interval meteorological data. The model output was analysed by summing up the vertical extent of the simulated high-density snow layers (>350 kg m(-3)) for each winter. These results were compared with historical records of difficult winter grazing conditions reported in the period 1956-2010. In particular, the heavy losses of reindeer during the catastrophic 1967/68 winter were caused by the occurrence of ground ice together with long snow-cover duration. This unfavourable coincidence is well reproduced by our model results, together with eight of the ten reported difficult winters. RI Schuler, Thomas/G-4781-2015 OI Schuler, Thomas/0000-0003-0972-3929 SN 0260-3055 PY 2013 VL 54 IS 62 BP 214 EP 226 DI 10.3189/2013AoG62A306 PN 2 UT WOS:000322047100012 ER PT J AU Soininen, EM Brathen, KA Jusdado, JGH Reidinger, S Hartley, SE AF Soininen, Eeva M. Brathen, Kari Anne Jusdado, Juan German Herranz Reidinger, Stefan Hartley, Susan E. TI More than herbivory: levels of silica-based defences in grasses vary with plant species, genotype and location SO OIKOS AB Silica defences in grasses have recently been suggested to be a potential driver of vole population dynamics. However, the ability of grasses to induce silica in response to herbivory has not been tested in northern ecosystems where small rodents are important herbivores. We conducted a large-scale field experiment in subarctic tundra using three river catchments differing in herbivore densities, and examined the effects of small rodent and/or reindeer exclusion on leaf silica levels in five grass species (Avenella flexuosa, Anthoxanthum nipponicum, Calamagrostis phragmitoides, Deschampsia cespitosa and Phleum alpinum). We also conducted a greenhouse experiment using three of these species (A. flexuosa, A. nipponicum and D. cespitosa) and Festuca ovina to determine whether intraspecific genotypic variation affects baseline silica concentrations and the capacity to induce silica in response to simulated grazing. Baseline leaf silica concentrations and silica induction varied with plant species in both experiments, with catchment in the field experiment and with genotype in the greenhouse experiment. These findings show that the allocation to silica defences in grasses is highly variable, and suggest that the combined effects of grazing pressure, plant species and intraspecific genotypic differences are likely to determine the circumstances under which silica induction may be an optimal defence strategy. A better understanding of the interplay between grazing and other factors influencing silica induction is necessary to interpret the role of silica in plant-herbivore interactions. OI Soininen, Eeva/0000-0003-4280-8350; Brathen, Kari Anne/0000-0003-0942-1074 SN 0030-1299 PD JAN PY 2013 VL 122 IS 1 BP 30 EP 41 DI 10.1111/j.1600-0706.2012.20689.x UT WOS:000313748800003 ER PT J AU Wegrzyn, M Lisowska, M Nicia, P AF Wegrzyn, Michal Lisowska, Maja Nicia, Pawel TI The value of the terricolous lichen Cetrariella delisei in the biomonitoring of heavy-metal levels in Svalbard SO POLISH POLAR RESEARCH AB The aim of this study was to identify a suitable lichen species for the long-term monitoring of heavy-metal atmospheric pollution in Svalbard. Cladonia and Cetraria s.l. species that have been widely used until now for assessing heavy-metal deposition in the Arctic are in decline over extensive areas of Svalbard, mainly due to climate change and over-grazing by reindeer. Cetrariella delisei, rarely used for biomonitoring, is still common and widespread in this area. Levels of Cr, Ni, Fe, Cu, Pb, Zn, Cd and Mn were measured in three lichen species: Cetrariella delisei, Cladonia uncialis, Flavocetraria nivalis and in a moss Racomitrium lanuginosum from Sorkapp Land, South Spitsbergen. The results imply that Cetrariella delisei can be safely compared to Cladonia uncialis for identifying the levels of heavy metals, but direct comparison between Cetrariella delisei and other species studied is more difficult owing to differences in levels of heavy metals even in samples from the same site. OI Wegrzyn, Michal/0000-0001-7638-4803 SN 0138-0338 EI 2081-8262 PY 2013 VL 34 IS 4 BP 375 EP 382 DI 10.2478/popore-2013-0022 UT WOS:000328442800003 ER PT J AU Champagne, E Tremblay, JP Cote, SD AF Champagne, Emilie Tremblay, Jean-Pierre Cote, Steeve D. TI Tolerance of an Expanding Subarctic Shrub, Betula glandulosa, to Simulated Caribou Browsing SO PLOS ONE AB Densification of the shrub layer has been reported in many subarctic regions, raising questions about the implication for large herbivores and their resources. Shrubs can tolerate browsing and their level of tolerance could be affected by browsing and soils productivity, eventually modifying resource availability for the caribou. Our objective was to assess the compensatory growth potential of a subarctic shrub, Betula glandulosa Michx., in relation with caribou browsing and nutriment availability for the plants. We used a simulated browsing (0, 25 and 75% of available shoots) and nitrogen-fertilisation (0 and 10 g m 22) experiment to test two main hypotheses linking tolerance to resource availability, the Compensatory Continuum Hypothesis and the Growth Rate Hypothesis as well as the predictions from the Limiting Resource Model. We seek to explicitly integrate the relative browsing pressure in our predictions since the amount of tissues removed could affect the capacity of long-lived plants to compensate. Birches fully compensated for moderate browsing with an overall leaf biomass similar to unbrowsed birches but undercompensated under heavy browsing pressure. The main mechanism explaining compensation appears to be the conversion of short shoots into long shoots. The leaf area increased under heavy browsing pressure but only led to undercompensation. Fertilisation for two consecutive years did not influence the response of birch, thus we conclude that our results support the LRM hypothesis of equal tolerance under both high and low nitrogen availability. Our results highlight that the potential for compensatory growth in dwarf birch is surpassed under heavy browsing pressure independently of the fertilisation regime. In the context of the worldwide decline in caribou herds, the reduction in browsing pressure could act synergistically with global climate change to promote the current shrub expansion reported in subarctic regions. Citation: Champagne E, Tremblay J-P, Cote SD (2012) Tolerance of an Expanding Subarctic Shrub, Betula glandulosa, to Simulated Caribou Browsing. PLoS ONE 7(12): e51940. doi: 10.1371/journal.pone.0051940 OI Champagne, Emilie/0000-0003-1550-2735 SN 1932-6203 PD DEC 13 PY 2012 VL 7 IS 12 AR e51940 DI 10.1371/journal.pone.0051940 UT WOS:000312386600050 PM 23272191 ER PT J AU Sokolov, V Ehrich, D Yoccoz, NG Sokolov, A Lecomte, N AF Sokolov, Vasiliy Ehrich, Dorothee Yoccoz, Nigel G. Sokolov, Alexander Lecomte, Nicolas TI Bird Communities of the Arctic Shrub Tundra of Yamal: Habitat Specialists and Generalists SO PLOS ONE AB Background: The ratio of habitat generalists to specialists in birds has been suggested as a good indicator of ecosystem changes due to e. g. climate change and other anthropogenic perturbations. Most studies focusing on this functional component of biodiversity originate, however, from temperate regions. The Eurasian Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by domestic reindeer and growing human activity. Methodology/Principal Findings: Here we monitored bird communities in a tundra landscape harbouring shrub and open habitats in order to analyse bird habitat relationships and quantify habitat specialization. We used ordination methods to analyse habitat associations and estimated the proportions of specialists in each of the main habitats. Correspondence Analysis identified three main bird communities, inhabiting upland, lowland and dense willow shrubs. We documented a stable structure of communities despite large multiannual variations of bird density (from 90 to 175 pairs/km(2)). Willow shrub thickets were a hotspot for bird density, but not for species richness. The thickets hosted many specialized species whose main distribution area was south of the tundra. Conclusion/Significance: If current arctic changes result in a shrubification of the landscape as many studies suggested, we would expect an increase in the overall bird abundance together with an increase of local specialists, since they are associated with willow thickets. The majority of these species have a southern origin and their increase in abundance would represent a strengthening of the boreal component in the southern tundra, perhaps at the expense of species typical of the subarctic zone, which appear to be generalists within this zone. RI Sokolov, Vasiliy/B-3657-2013; Sokolov, Aleksandr/P-3421-2017; Ehrich, Dorothee/F-6492-2015; Yoccoz, Nigel/C-8561-2014 OI Sokolov, Vasiliy/0000-0002-0115-3151; Sokolov, Aleksandr/0000-0002-1521-3856; Ehrich, Dorothee/0000-0002-3028-9488; Yoccoz, Nigel/0000-0003-2192-1039 SN 1932-6203 PD DEC 11 PY 2012 VL 7 IS 12 AR e50335 DI 10.1371/journal.pone.0050335 UT WOS:000312290800016 PM 23239978 ER PT J AU Kaarlejarvi, E Baxter, R Hofgaard, A Hytteborn, H Khitun, O Molau, U Sjogersten, S Wookey, P Olofsson, J AF Kaarlejarvi, Elina Baxter, Robert Hofgaard, Annika Hytteborn, Hakan Khitun, Olga Molau, Ulf Sjoegersten, Sofie Wookey, Philip Olofsson, Johan TI Effects of Warming on Shrub Abundance and Chemistry Drive Ecosystem-Level Changes in a Forest-Tundra Ecotone SO ECOSYSTEMS AB Tundra vegetation is responding rapidly to on-going climate warming. The changes in plant abundance and chemistry might have cascading effects on tundra food webs, but an integrated understanding of how the responses vary between habitats and across environmental gradients is lacking. We assessed responses in plant abundance and plant chemistry to warmer climate, both at species and community levels, in two different habitats. We used a long-term and multisite warming (OTC) experiment in the Scandinavian forest-tundra ecotone to investigate (i) changes in plant community composition and (ii) responses in foliar nitrogen, phosphorus, and carbon-based secondary compound concentrations in two dominant evergreen dwarf-shrubs (Empetrum hermaphroditum and Vaccinium vitis-idaea) and two deciduous shrubs (Vaccinium myrtillus and Betula nana). We found that initial plant community composition, and the functional traits of these plants, will determine the responsiveness of the community composition, and thus community traits, to experimental warming. Although changes in plant chemistry within species were minor, alterations in plant community composition drive changes in community-level nutrient concentrations. In view of projected climate change, our results suggest that plant abundance will increase in the future, but nutrient concentrations in the tundra field layer vegetation will decrease. These effects are large enough to have knock-on consequences for major ecosystem processes like herbivory and nutrient cycling. The reduced food quality could lead to weaker trophic cascades and weaker top down control of plant community biomass and composition in the future. However, the opposite effects in forest indicate that these changes might be obscured by advancing treeline forests. RI Khitun, Olga/J-6169-2013; Baxter, Robert/C-7688-2012 OI Baxter, Robert/0000-0002-7504-6797; Wookey, Philip/0000-0001-5957-6424 SN 1432-9840 PD DEC PY 2012 VL 15 IS 8 BP 1219 EP 1233 DI 10.1007/s10021-012-9580-9 UT WOS:000312143300001 ER PT J AU Blix, AS Ness, J Lian, H Callaghan, TV AF Blix, Arnoldus Schytte Ness, John Lian, Hans Callaghan, Terry V. TI Experimental reduction of food quality is not compensated with increased food intake in high-arctic muskoxen (Ovibos moschatus) SO BRITISH JOURNAL OF NUTRITION AB A total of four barren adult female muskoxen (Ovibos moschatus) were used over a period of 2 years for the purpose of the present study. During the first year, the natural changes in appetite (ad libitum intake of standard pelleted reindeer feed) and body mass were determined in two of the animals. During the second year, the effect of reduced food quality on ad libitum food intake was tested in all four animals in July when the appetite had been found to be at a high. We found that the experimentally reduced food quality was not compensated with increased food intake in these large high-Arctic herbivores. SN 0007-1145 PD OCT 28 PY 2012 VL 108 IS 8 BP 1337 EP 1340 DI 10.1017/S0007114511007379 UT WOS:000310015300001 PM 22293221 ER PT J AU Pajunen, A Virtanen, R Roininen, H AF Pajunen, Adela Virtanen, Risto Roininen, Heikki TI Browsing-mediated shrub canopy changes drive composition and species richness in forest-tundra ecosystems SO OIKOS AB Changes in climate and in browsing pressure are expected to alter the abundance of tundra shrubs thereby influencing the composition and species richness of plant communities. We investigated the associations between browsing, tundra shrub canopies and their understory vegetation by utilizing a long-term (1013 seasons) experiment controlling reindeer and ptarmigan herbivory in the subarctic forest tundra ecotone in northwestern Fennoscandia. In this area, there has also been a consistent increase in the yearly thermal sum and precipitation during the study period. The cover of shrubs increased 2.87.8 fold in exclosures and these contrasted with browsed control areas creating a sharp gradient of canopy cover of tundra shrubs across a variety of vegetation types. Browsing exclusions caused significant shifts in more productive vegetation types, whereas little or no shift occurred in low-productive tundra communities. The increased deciduous shrub cover was associated with significant losses of understory plant species and shifts in functional composition, the latter being clearest in the most productive plant community types. The total cover of understory vegetation decreased along with increasing shrub cover, while the cover of litter showed the opposite response. The cover of cryptogams decreased along with increasing shrub cover, while the cover of forbs was favoured by a shrub cover. Increasing shrub cover decreased species richness of understory vegetation, which was mainly due to the decrease in the cryptogam species. The effects were consistent across different types of forest tundra vegetation indicating that shrub increase may have broad impacts on arctic vegetation diversity. Deciduous shrub cover is strongly regulated by reindeer browsing pressure and altered browsing pressure may result in a profound shrub expansion over the next one or two decades. Results suggest that the impact of an increase in shrubs on tundra plant richness is strong and browsing pressure effectively counteracts the effects of climate warming-driven shrub expansion and hence maintains species richness. RI Virtanen, Risto/G-1810-2010 OI Virtanen, Risto/0000-0002-8295-8217 SN 0030-1299 PD OCT PY 2012 VL 121 IS 10 BP 1544 EP 1552 DI 10.1111/j.1600-0706.2011.20115.x UT WOS:000308634600005 ER PT J AU Nystrom, M Holmgren, J Olsson, H AF Nystrom, Mattias Holmgren, Johan Olsson, Hakan TI Prediction of tree biomass in the forest-tundra ecotone using airborne laser scanning SO REMOTE SENSING OF ENVIRONMENT AB The effect of ongoing climate change on sub-arctic and alpine forests has led to increased interest in monitoring potential changes in the forest-tundra ecotone. In addition to climate change, insect damage, browsing pressure by herbivores such as moose and reindeer, as well as anthropogenic impacts will contribute to changes in the forest-tundra ecotone. These changes are difficult to monitor with manual methods because of the complex mosaic pattern of the ecotone. In this study, the possibility to predict maximum tree height, above ground tree biomass and canopy cover with airborne laser scanning (ALS) was therefore tested at a forest-tundra ecotone site near Abisko in northern Sweden (Lat. N 68 degrees 20', Long. E 19 degrees 01', 420-700 m a.s.l.). The forest in the area is dominated by mountain birch (Betula pubescens ssp. czerepanovii), which has highly irregular stem and canopy forms. Predictions from two different laser data acquisitions were compared. The first laser data set had 6.1 points m(-2) and was obtained in 2008 with a TopEye MKII scanner carried by a helicopter flown at 500 m a.g.l. The second laser data set had 1.4 points m(-2) and was obtained in 2010 with an Optech ALTM Gemini scanner carried by a fixed-wing aircraft flown at 1740 m a.g.l. Linear regression models were developed for the predictions using data from 73 sample plots with ten meter radius surveyed in 2009 and 2010. The relative RMSEs obtained for the TopEye and Optech data after leave-one-out cross-validation were, respectively, 8.8% and 9.5% for maximum tree height; 18.7% and 21.2% for above ground tree biomass; and, 16.8% and 18.7% for vertical canopy cover on plot level. The results were clearly improved by introducing a new procedure to compensate for unevenly distributed laser points. In conclusion, ALS has strong potential as a data source to map mountain birch biomass in the forest-tundra ecotone, even when using sparse point density ALS data. (C) 2012 Elsevier Inc. All right; reserved. RI Holmgren, Johan/E-7878-2016 OI Holmgren, Johan/0000-0002-7112-8015 SN 0034-4257 EI 1879-0704 PD AUG PY 2012 VL 123 BP 271 EP 279 DI 10.1016/j.rse.2012.03.008 UT WOS:000309496000024 ER PT J AU Zamin, TJ Grogan, P AF Zamin, Tara J. Grogan, Paul TI Birch shrub growth in the low Arctic: the relative importance of experimental warming, enhanced nutrient availability, snow depth and caribou exclusion SO ENVIRONMENTAL RESEARCH LETTERS AB Deciduous shrub growth has increased across the Arctic simultaneously with recent climate warming trends. The reduction in albedo associated with shrub-induced 'greening' of the tundra is predicted to cause significant positive feedbacks to regional warming. Enhanced soil fertility arising from climate change is expected to be the primary mechanism driving shrub responses, yet our overall understanding of the relative importance of soil nitrogen ( N) and phosphorus ( P) availability and the significance of other ecological drivers is constrained by experiments with varying treatments, sites, and durations. We investigated dwarf birch apical stem growth responses to a wide range of ecological factors ( enhanced summer temperatures, deepened snow, caribou exclusion, factorial high level nitrogen and phosphorus additions, and low level nitrogen additions) after six years of experimental manipulations in birch hummock tundra. As expected, birch apical stem growth was more strongly enhanced by the substantial increases in nutrient supply than by our changes in any of the other ecological factors. The factorial additions revealed that P availability was at least as important as that of N, and our low N additions demonstrated that growth was unresponsive to moderate increases in soil nitrogen alone. Experimental warming increased apical stem growth 2.5-fold-considerably more than in past studies-probably due to the relatively strong effect of our greenhouses on soil temperature. Together, these results have important implications for our understanding of the biogeochemical functioning of mesic tundra ecosystems as well as predicting their vegetation responses to climate change. OI Zamin, Tara/0000-0002-0991-6651 SN 1748-9326 PD JUL-SEP PY 2012 VL 7 IS 3 AR 034027 DI 10.1088/1748-9326/7/3/034027 UT WOS:000309555300028 ER PT J AU Gough, L Moore, JC Shaver, GR Simpson, RT Johnson, DR AF Gough, Laura Moore, John C. Shaver, Gauis R. Simpson, Rodney T. Johnson, David R. TI Above- and belowground responses of arctic tundra ecosystems to altered soil nutrients and mammalian herbivory SO ECOLOGY AB Theory and observation indicate that changes in the rate of primary production can alter the balance between the bottom-up influences of plants and resources and the top-down regulation of herbivores and predators on ecosystem structure and function. The Exploitation Ecosystem Hypothesis (EEH) posited that as aboveground net primary productivity (ANPP) increases, the additional biomass should support higher trophic levels. We developed an extension of EEH to include the impacts of increases in ANPP on belowground consumers in a similar manner as aboveground, but indirectly through changes in the allocation of photosynthate to roots. We tested our predictions for plants aboveground and for phytophagous nematodes and their predators belowground in two common arctic tundra plant communities subjected to 11 years of increased soil nutrient availability and/or exclusion of mammalian herbivores. The less productive dry heath (DH) community met the predictions of EEH aboveground, with the greatest ANPP and plant biomass in the fertilized plots protected from herbivory. A palatable grass increased in fertilized plots while dwarf evergreen shrubs and lichens declined. Belowground, phytophagous nematodes also responded as predicted, achieving greater biomass in the higher ANPP plots, whereas predator biomass tended to be lower in those same plots (although not significantly). In the higher productivity moist acidic tussock (MAT) community, aboveground responses were quite different. Herbivores stimulated ANPP and biomass in both ambient and enriched soil nutrient plots; maximum ANPP occurred in fertilized plots exposed to herbivory. Fertilized plots became dominated by dwarf birch (a deciduous shrub) and cloudberry (a perennial forb); under ambient conditions these two species coexist with sedges, evergreen dwarf shrubs, and Sphagnum mosses. Phytophagous nematodes did not respond significantly to changes in ANPP, although predator biomass was greatest in control plots. The contrasting results of these two arctic tundra plant communities suggest that the predictions of EEH may hold for very low ANPP communities, but that other factors, including competition and shifts in vegetation composition toward less palatable species, may confound predicted responses to changes in productivity in higher ANPP communities such as the MAT studied here. RI Moore, John/E-9802-2011 SN 0012-9658 EI 1939-9170 PD JUL PY 2012 VL 93 IS 7 BP 1683 EP 1694 DI 10.1890/11-1631.1 UT WOS:000306829300019 PM 22919914 ER PT J AU Hassan, AA Sandanger, TM Brustad, M AF Hassan, Ammar Ali Sandanger, Torkjel M. Brustad, Magritt TI Selected Vitamins and Essential Elements in Meat from Semi-Domesticated Reindeer (Rangifer tarandus tarandus L.) in Mid- and Northern Norway: Geographical Variations and Effect of Animal Population Density SO NUTRIENTS AB Meat samples (n = 100) were collected from semi-domesticated reindeer originating from 10 grazing districts in Norway. We aimed at studying concentrations, correlations, geographical variations and the effect of animal population density on vitamins A, B3, B7, B12 and E, and calcium, iron, zinc, selenium, chromium and cobalt. Mean concentrations of vitamins A, B3, B7; B12 and E were <5 mu g, 6.6 mg, <0.5 mu g, 4.7 mu g and 0.5 mg/100 g wet weight, respectively. Concentrations of calcium, iron, zinc, selenium, chromium and cobalt were 4.7 mg, 2.8 mg, 6.4 mg, 19.4 mu g, 1.7 mu g and 0.5 mu g/100 g wet weight, respectively. Vitamin E and selenium were the nutrients that exhibited the largest geographical variations (p < 0.05), although no geographical gradient was observed for any of the studied nutrients. Age had a significant effect on zinc and selenium concentrations. Iron was significantly positive correlated with calcium (r = 0.3416, p < 0.01) and vitamin B12 with zinc (r = 0.35, p < 0.05). Reindeer from districts with low animal population density had significantly higher selenium concentration than those from districts with medium and high population densities (p < 0.01). Reindeer meat contained higher vitamin B12, iron, zinc and selenium concentrations when compared to Norwegian beef, lamb, mutton, pork and chicken meat. SN 2072-6643 PD JUL PY 2012 VL 4 IS 7 BP 724 EP 739 DI 10.3390/nu4070724 UT WOS:000306799800011 PM 22852060 ER PT J AU Pape, R Loffler, J AF Pape, Roland Loeffler, Joerg TI Climate Change, Land Use Conflicts, Predation and Ecological Degradation as Challenges for Reindeer Husbandry in Northern Europe: What do We Really Know After Half a Century of Research? SO AMBIO AB Reindeer grazing has been entitled as ecological keystone in arctic-alpine landscapes. In addition, reindeer husbandry is tightly connected to the identity of the indigenous Sami people in northern Europe. Nowadays, reindeer husbandry is challenged in several ways, of which pasture degradation, climate change, conflicting land uses and predation are the most important. Research on reindeer-related topics has been conducted for more than half a century and this review illuminates whether or not research is capable to match these challenges. Despite its high quality, traditional reindeer-related research is functionally isolated within the various disciplines. The meshwork of ecology, socio-economy, culture and politics, however, in which reindeer husbandry is embedded by various interactions, will remain unclear and difficult to manage, if actors and relationships are kept separate. We propose some targets for new integrative research approaches that incorporate traditional knowledge and focus on the entire human-ecological system 'reindeer husbandry' to develop solutions for its challenges. SN 0044-7447 EI 1654-7209 PD JUL PY 2012 VL 41 IS 5 BP 421 EP 434 DI 10.1007/s13280-012-0257-6 UT WOS:000306121200001 PM 22451266 ER PT J AU Ims, RA Henden, JA AF Ims, Rolf A. Henden, John-Andre TI Collapse of an arctic bird community resulting from ungulate-induced loss of erect shrubs SO BIOLOGICAL CONSERVATION AB Rapid, but contrasting, changes in the extent of erect thicket-forming shrubs is presently seen in the Arctic, either resulting from a warmer climate (increasing extent) or intensified herbivory (decreasing extent). We investigated the impact of loss of willow shrubs on a bird community in arctic riparian sediment plains in northern Norway subject to varying intensities of reindeer browsing. In riparian habitats where willow thickets had been lost, bird species richness was more than halved compared to habitats where some patches of thickets were still present. As could be expected species previously suggested to use erect woody vegetation as nesting places and/or foraging habitats were most consistently impacted. However, even some open ground habitat specialists appeared to be negatively impacted, possibly due to loss of spatial spill-over effects of insects from willow thickets. To preserve low-arctic avian biodiversity in a warming climate, management should strive to identify levels of ungulate browsing that strike the balance between shrub-encroached and shrub-denuded arctic tundra. (c) 2012 Elsevier Ltd. All rights reserved. OI Henden, John-Andre/0000-0002-8825-1167 SN 0006-3207 PD MAY PY 2012 VL 149 IS 1 BP 2 EP 5 DI 10.1016/j.biocon.2012.02.008 UT WOS:000305723400001 ER PT J AU Colman, JE Tsegaye, D Pedersen, C Eidesen, R Arntsen, H Holand, O Mann, A Reimers, E Moe, SR AF Colman, Jonathan E. Tsegaye, Diress Pedersen, Christian Eidesen, Ruben Arntsen, Herbjorg Holand, Oystein Mann, Alex Reimers, Eigil Moe, Stein R. TI Behavioral Interference Between Sympatric Reindeer and Domesticated Sheep in Norway SO RANGELAND ECOLOGY & MANAGEMENT AB Interspecific interaction among sympatric ungulates is important in management and conservation. We investigated behavioral interference between sympatric wild or semidomestic reindeer (Rangifer tarandus tarandus) and sheep (Ovis aries) in two field studies and one enclosure experiment. For free-ranging wild and semidomestic reindeer, interference between the two species increased with decreasing distances, occurring only at less than 200 m and 30 m, for wild and semidomestic reindeer, respectively, and neither species consistently dominated the other. In a controlled, duplicated experiment we tested interference and confrontations at the feeding patch level among semidomestic reindeer and sheep within 40 x 50 m enclosures. When new reindeer or sheep were introduced into enclosures already occupied by reindeer, new reindeer resulted in significantly more interference and confrontations among individuals compared to new sheep; i.e., intraspecific interference was more prevalent than interspecific interference at equal. densities. For all study areas, confrontations decreased with time after "first encounter," indicating cohabituation. A sympatric use of pastures was not visually disruptive for recorded grazing behavior for either species. RI Moe, Stein R./G-1507-2011 OI Moe, Stein R./0000-0003-1005-3192 SN 1550-7424 PD MAY PY 2012 VL 65 IS 3 BP 299 EP 308 DI 10.2111/REM-D-11-00094.1 UT WOS:000305203900011 ER PT J AU Hassan, AA Brustad, M Sandanger, TM AF Hassan, Ammar Ali Brustad, Magritt Sandanger, Torkjel M. TI Concentrations and Geographical Variations of Selected Toxic Elements in Meat from Semi-Domesticated Reindeer (Rangifer tarandus tarandus L.) in Mid- and Northern Norway: Evaluation of Risk Assessment SO INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH CT 8th International Symposium on Recent Advances in Environmental Health Research CY SEP 18-21, 2011 CL Jackson, MS SP Jackson State Univ (JSU), Natl Inst Hlth, RCMI-Ctr Environm Hlth, U S Dept Educ, Title III Grad Educ Program, U S Environm Protect Agcy, JSU Off Acad Affairs, JSU Off Res & Fed Relat AB Meat samples (n = 100) from semi-domesticated reindeer (Rangifer tarandus tarandus L.) were randomly collected from 10 grazing districts distributed over four Norwegian counties in 2008 and 2009. The main aim was to study concentrations and geographical variations in selected toxic elements; cadmium (Cd), lead (Pb), arsenic (As), copper (Cu), nickel (Ni) and vanadium (V) in order to assess the risk associated with reindeer meat consumption. Sample solutions were analysed using an inductively coupled plasma high resolution mass spectrometer (ICP-HRMS), whereas analysis of variance (ANOVA) was used for statistical analyses. Geographical variations in element concentrations were revealed, with As and Cd demonstrating the largest geographical differences. No clear geographical gradient was observed except for the east-west downward gradient for As. The As concentrations were highest in the vicinity of the Russian border, and only Cd was shown to increase with age (p < 0.05). Sex had no significant effect on the concentration of the studied elements. The concentrations of all the studied elements in reindeer meat were generally low and considerably below the maximum levels (ML) available for toxic elements set by the European Commission (EC). Thus, reindeer meat is not likely to be a significant contributor to the human body burden of toxic elements. SN 1660-4601 PD MAY PY 2012 VL 9 IS 5 BP 1699 EP 1714 DI 10.3390/ijerph9051699 UT WOS:000304543200013 PM 22754467 ER PT J AU Helle, T Hallikainen, V Sarkela, M Haapalehto, M Niva, A Puoskari, J AF Helle, Timo Hallikainen, Ville Sarkela, Matti Haapalehto, Marko Niva, Aarno Puoskari, Jouni TI Effects of a holiday resort on the distribution of semi-domesticated reindeer SO ANNALES ZOOLOGICI FENNICI AB We studied the impacts of a large skiing and hiking resort on the distribution of semi-domesticated reindeer in Saariselka, eastern Finnish Lapland, in 1986 and 2000. The effect of intensity of outdoor activities on reindeer density in terms of pellet-group density was dependent variably on habitat, the year of inventory and season. Despite the overall doubling of visitor numbers between the inventory years, pellet-group density in winter increased in the study area by 20%. The sex ratio of reindeer in summer 1986 was male-biased up to a distance of 8-12 km, indicating that females with calves avoided the vicinity of the resort, but in 2000 the bias existed only at a distance of 0-4 km. However, pellet-group density in summer at the distance of 0-4 km was 53% and 28% lower than that at 4-8 km and 8-12 km, respectively. In winter, a similar pattern was observed in lichen-rich coniferous habitats. Cladonia stellaris, which has low tolerance to heavy grazing, reached its maximum abundance at the distance of 0-4 km. Observations on the increased tolerance of reindeer were very probably associated with improved channeling of tourists into fewer and better marked hiking and skiing routes, changes in the reindeer herd-management and frequent contacts with humans, but the adverse effects of outdoor activities could not be avoided. RI Hallikainen, Ville/E-8766-2013 OI Hallikainen, Ville/0000-0001-5384-8265 SN 0003-455X EI 1797-2450 PD APR 20 PY 2012 VL 49 IS 1-2 BP 23 EP 35 DI 10.5735/086.049.0103 UT WOS:000303355600003 ER PT J AU Okayasu, T Okuro, T Jamsran, U Takeuchi, K AF Okayasu, T. Okuro, T. Jamsran, U. Takeuchi, K. TI Inherent density-dependency of wet-season range even at the extreme of nonequilibrium environments SO JOURNAL OF ARID ENVIRONMENTS AB There has been considerable recent progress in integrating equilibrium and nonequilibrium rangeland ecologies on the basis of landscape heterogeneity. This follows from the argument that small key resource areas provide spatial buffer effects that sustain animal populations and are prone to animal-vegetation density-dependency, whereas wet-season ranges are density-independent. Although dryland spatial heterogeneity generally occurs through a combination of heterogeneous precipitation and landscape heterogeneity, the former is rarely considered in the development of such theories. Here, we used a published multi-agent model to examine how both types of heterogeneity interact. We found that a certain level of density-dependency occurred in wet-season range, even under extreme nonequilibrium conditions. During a drought, most of the key resources and part of the wet-season range that was not subject to drought simultaneously exhibited density-dependency, reflecting the impact of rainfall heterogeneity. With decreased key resource area, the density-dependency of the wet-season range after livestock population recovery-a factor included in current theory-decreased dramatically, whereas that during drought-a factor neglected in current theory-did not decrease markedly. Therefore, our results extend current theory by suggesting that the contradiction stemmed from neglecting the spatial buffer effect of heterogeneous precipitation, which is responsible for density-dependency of wet-season ranges during drought. (C) 2011 Elsevier Ltd. All rights reserved. SN 0140-1963 PD MAR PY 2012 VL 78 BP 144 EP 153 DI 10.1016/j.jaridenv.2011.11.015 UT WOS:000300074000016 ER PT J AU Strand, GH Aune-Lundberg, L AF Strand, Geir-Harald Aune-Lundberg, Linda TI Small-area estimation of land cover statistics by post-stratification of a national area frame survey SO APPLIED GEOGRAPHY AB The objective of this paper is to examine a method for estimation of land cover statistics for local environments from available area frame surveys of larger, surrounding areas. The method is a simple version of the small-area estimation methodology. The starting point is a national area frame survey of land cover. This survey is post-stratified using a coarse land cover map based on topographic maps and segmentation of satellite images. The approach is to describe the land cover composition of each stratum and subsequently use the results to calculate land cover statistics for a smaller area where the relative distribution of the strata is known. The method was applied to a mountain environment in Gausdal in Eastern Norway and the result was compared to reference data from a complete in situ land cover map of the study area. The overall correlation (Pearson's rho) between the observed and the estimated land cover figures was r = 0.95. The method does not produce a map of the target area and the estimation error was large for a few of the land cover classes. The overall conclusion is, however, that the method is applicable when the objective is to produce land cover statistics and the interest is the general composition of land cover classes not the precise estimate of each class. The method will be applied in outfield pasture management in Norway, where it offers a cost-efficient way to screen the management units and identify local areas with a land cover composition suitable for grazing. The limited resources available for in situ land cover mapping can then be allocated efficiently to in-depth studies of the areas with the highest grazing potential. It is also expected that the method can be used to compile land cover statistics for other purposes as well, provided that the motivation is to describe the overall land cover composition and not to provide exact estimates for the individual land cover classes. (C) 2011 Elsevier Ltd. All rights reserved. OI Strand, Geir-Harald/0000-0002-7516-0282; Aune-Lundberg, Linda/0000-0003-2039-7386 SN 0143-6228 EI 1873-7730 PD MAR PY 2012 VL 32 IS 2 BP 546 EP 555 DI 10.1016/j.apgeog.2011.06.006 UT WOS:000298362400032 ER PT J AU Kivinen, S Berg, A Moen, J Ostlund, L Olofsson, J AF Kivinen, Sonja Berg, Anna Moen, Jon Ostlund, Lars Olofsson, Johan TI Forest Fragmentation and Landscape Transformation in a Reindeer Husbandry Area in Sweden SO ENVIRONMENTAL MANAGEMENT AB Reindeer husbandry and forestry are two main land users in boreal forests in northern Sweden. Modern forestry has numerous negative effects on the ground-growing and arboreal lichens that are crucial winter resources for reindeer husbandry. Using digitized historical maps, we examined changes in the forest landscape structure during the past 100 years, and estimated corresponding changes in suitability of forest landscape mosaics for the reindeer winter grazing. Cover of old coniferous forests, a key habitat type of reindeer herding system, showed a strong decrease during the study period, whereas clear-cutting and young forests increased rapidly in the latter half of the 20th century. The dominance of young forests and fragmentation of old-growth forests (decreased patch sizes and increased isolation) reflect decreased amount of arboreal lichens as well as a lowered ability of the landscape to sustain long-term persistence of lichens. The results further showed that variation in ground lichen cover among sites was mainly related to soil moisture conditions, recent disturbances, such as soil scarification and prescribed burning, and possibly also to forest history. In general, the results suggest that the composition and configuration of the forest landscape mosaic has become less suitable for sustainable reindeer husbandry. OI Ostlund, Lars/0000-0002-7902-3672 SN 0364-152X PD FEB PY 2012 VL 49 IS 2 BP 295 EP 304 DI 10.1007/s00267-011-9788-z UT WOS:000301300200002 PM 22102063 ER PT J AU Tommervik, H Bjerke, JW Gaare, E Johansen, B Thannheiser, D AF Tommervik, Hans Bjerke, Jarle W. Gaare, Eldar Johansen, Bernt Thannheiser, Dietbert TI Rapid recovery of recently overexploited winter grazing pastures for reindeer in northern Norway SO FUNGAL ECOLOGY CT Scientific Sessions on Fungi and Global Change/IMC9 Conference CY AUG, 2010 CL Edinburgh, SCOTLAND AB During the last 25 yr, Sami reindeer husbandry in parts of Finnmarksvidda in the Norwegian Arctic has been in a critical state because of overexploitation of lichen-dominated tundra, which serves as winter forage. To better understand the ecosystem's capabilities for recovery we investigated vegetation cover changes over a 7-yr period, starting in 1998, at 52 sites dispersed over a large area at Finnmarksvidda. Two types of plots were established: one fenced from reindeer grazing and trampling and one open for reindeer. The investigations in 2005 showed that lichen cover had had a significant and rapid increase (up to 8.6-fold per year). The cover of vascular plants, mainly dwarf shrubs, also increased significantly, while barren areas and the cover of litter decreased significantly during the period. Mean relative growth rate of lichen biomass was 0.083 +/- 0.011 per year in open plots, which is considered very rapid recovery compared to previous studies. Lichen recovery was significantly faster on leeward ridges than on exposed ridges, and fencing alone did not have any significant effects on lichen recovery, but in interaction with time, fencing contributed to increasing recovery rates. The lichen heath recovery was reciprocally correlated with reindeer density. In addition, lichen recovery was probably facilitated by recent climate changes, viz, shallower snow depths which made leeward tundra and forest floor vegetation accessible for reindeer, and increased summer precipitation rates which improved growth rates. The results from this study show that in a very short time there was a transition from an overexploited depauperate vegetation and barren ground state to a flourishing lichen-dominated vegetation state, suggesting that the injuries were repairable. The vegetation transitions which have taken place in the study area are considered to be reversible with fewer persistent effects. (C) 2011 Elsevier Ltd and The British Mycological Society. All rights reserved. OI Bjerke, Jarle/0000-0003-2721-1492 SN 1754-5048 PD FEB PY 2012 VL 5 IS 1 BP 3 EP 15 DI 10.1016/j.funeco.2011.08.002 UT WOS:000299915700002 ER PT J AU Cahoon, SMP Sullivan, PF Post, E Welker, JM AF Cahoon, Sean M. P. Sullivan, Patrick F. Post, Eric Welker, Jeffrey M. TI Large herbivores limit CO2 uptake and suppress carbon cycle responses to warming in West Greenland SO GLOBAL CHANGE BIOLOGY AB Changes in the terrestrial carbon cycle may ameliorate or exacerbate future climatic warming. Research on this topic has focused almost exclusively on abiotic drivers, whereas biotic factors, including trophic interactions, have received comparatively little attention. We quantified the singular and interactive effects of herbivore exclusion and simulated warming on ecosystem CO2 exchange over two consecutive growing seasons in West Greenland. Exclusion of caribou and muskoxen over the past 8 years has led to dramatic increases in shrub cover, leaf area, ecosystem photosynthesis, and a nearly threefold increase in net C uptake. These responses were accentuated by warming, but only in the absence of herbivores. Carbon cycle responses to herbivore exclusion alone and combined with warming were driven by changes in gross ecosystem photosynthesis, as limited differences in ecosystem respiration were observed. Our results show that large herbivores can be of critical importance as mediators of arctic ecosystem responses to climate change. RI Welker, Jeffrey/C-9493-2013 SN 1354-1013 PD FEB PY 2012 VL 18 IS 2 BP 469 EP 479 DI 10.1111/j.1365-2486.2011.02528.x UT WOS:000299042500007 ER PT S AU Kryazhimskiy, FV Maklakov, KV Morozova, LM Ektova, SN AF Kryazhimskiy, F. V. Maklakov, K. V. Morozova, L. M. Ektova, S. N. BE Yang, Z Chen, B TI Simulation Modelling of the System "Vegetation Cover - Domestic Reindeer" in the Yamal Peninsula: Could Global Warming Help to Save the Traditional Way of Land Use? SO 18TH BIENNIAL ISEM CONFERENCE ON ECOLOGICAL MODELLING FOR GLOBAL CHANGE AND COUPLED HUMAN AND NATURAL SYSTEM SE Procedia Environmental Sciences CT 18th Biennial ISEM Conference on Ecological Modelling for Global Change and Coupled Human and Natural Systems CY SEP 20-23, 2011 CL Beijing Normal Univ, Beijing, PEOPLES R CHINA SP Int Soc Ecol Modelling HO Beijing Normal Univ AB Terrestrial ecosystems of the Yamal Peninsula were subjected to the impact of domestic reindeer for several decades: the reindeer husbandry was extensively developed in the traditional nomadic way during the past century and especially recently. The ecosystem dynamics was analyzed by means of computer simulations. It was shown that nomadic reindeer husbandry is the primary cause of the observed degradation of vegetative and lichens cover. Dramatic changes in both productivity and standing crop characteristics indicate the impossibility of keeping on this way of land use under the present industrial and climatic situation in the region. Warming must be fantastically rapid for improving the present situation; global warming seems to be not a sufficient factor for restoration of forage resources in Yamal. The general question we tried to answer was: if global warming (the signs of which seems to be detected since the end of 1950s) may serve as a favoring factor of indigenous manner of land use or not? In the model we supposed that production (per year) of vegetation (lichens mainly) would exponentially increase with the growth of mean ambient temperature. Several model experiments were carried on in the attempt to determine what rate of such changes would be sufficient for keeping the number of reindeer at the modern level (ca. 350000 individuals) without degradation of vegetation. The model experiments showed that these changes have to be much faster that one can reasonably imagine. Therefore, in spite of wide-spread cliche, traditional nomadic reindeer husbandry is not an example of human and vegetation coexistence in harmony at all. Even more, the existent exponential growth of domestic reindeer herds seems to be more dangerous for the natural complexes in the region, than, say, the development of oil and gas industry. The present situation requires significant corrections in ethno-cultural and economical policy in the region, and global worming would not improve the alarming situation. (C) 2011 Published by Elsevier B. V. Selection and/or peer-review under responsibility of School of Environment, Beijing Normal University. SN 1878-0296 PY 2012 VL 13 BP 598 EP 605 DI 10.1016/j.proenv.2012.01.051 UT WOS:000312386000051 ER PT J AU Ehrich, D Henden, JA Ims, RA Doronina, LO Killengren, ST Lecomte, N Pokrovsky, IG Skogstad, G Sokolov, AA Sokolov, VA Yoccoz, NG AF Ehrich, Dorothee Henden, John-Andre Ims, Rolf Anker Doronina, Lilyia O. Killengren, Siw Turid Lecomte, Nicolas Pokrovsky, Ivan G. Skogstad, Gunnhild Sokolov, Alexander A. Sokolov, Vasily A. Yoccoz, Nigel Gilles TI The importance of willow thickets for ptarmigan and hares in shrub tundra: the more the better? SO OECOLOGIA AB In patchy habitats, the relationship between animal abundance and cover of a preferred habitat may change with the availability of that habitat, resulting in a functional response in habitat use. Here, we investigate the relationship of two specialized herbivores, willow ptarmigan (Lagopus lagopus) and mountain hare (Lepus timidus), to willows (Salix spp.) in three regions of the shrub tundra zone-northern Norway, northern European Russia and western Siberia. Shrub tundra is a naturally patchy habitat where willow thickets represent a major structural element and are important for herbivores both as food and shelter. Habitat use was quantified using feces counts in a hierarchical spatial design and related to several measures of willow thicket configuration. We document a functional response in the use of willow thickets by ptarmigan, but not by hares. For hares, whose range extends into forested regions, occurrence increased overall with willow cover. The occurrence of willow ptarmigan showed a strong positive relationship to willow cover and a negative relationship to thicket fragmentation in the region with lowest willow cover at landscape scale, where willow growth may be limited by reindeer browsing. In regions with higher cover, in contrast, such relationships were not observed. Differences in predator communities among the regions may contribute to the observed pattern, enhancing the need for cover where willow thickets are scarce. Such region-specific relationships reflecting regional characteristics of the ecosystem highlight the importance of large-scale investigations to understand the relationships of habitat availability and use, which is a critical issue considering that habitat availability changes quickly with climate change and human impact. RI Pokrovsky, Ivan/B-5144-2010; Ehrich, Dorothee/F-6492-2015; Sokolov, Vasiliy/B-3657-2013; Sokolov, Aleksandr/P-3421-2017; Yoccoz, Nigel/C-8561-2014 OI Pokrovsky, Ivan/0000-0002-6533-674X; Ehrich, Dorothee/0000-0002-3028-9488; Sokolov, Vasiliy/0000-0002-0115-3151; Sokolov, Aleksandr/0000-0002-1521-3856; Yoccoz, Nigel/0000-0003-2192-1039; Henden, John-Andre/0000-0002-8825-1167 SN 0029-8549 PD JAN PY 2012 VL 168 IS 1 BP 141 EP 151 DI 10.1007/s00442-011-2059-0 UT WOS:000299058100014 PM 21833646 ER PT J AU Rai, H Upreti, DK Gupta, RK AF Rai, Himanshu Upreti, D. K. Gupta, Rajan K. TI Diversity and distribution of terricolous lichens as indicator of habitat heterogeneity and grazing induced trampling in a temperate-alpine shrub and meadow SO BIODIVERSITY AND CONSERVATION AB Lichens are among the most sensitive biomonitors of ecosystem health and human induced disturbances. Terricolous lichens of Chopta-Tungnath (Garhwal, western Himalaya, India) were analysed for their ability to indicate habitat variability and disturbances induced by livestock grazing. Terricolous lichens were sampled from 12 sites, distributed across the three macrohabitats between 2,700 and 4,001 m, using 50 x 10 cm narrow frequency grids having five 10 x 10 cm sampling units. The terricolous lichen community of the area constituted, 20 species belonging to 10 genera, five families and four growth forms. Altitude and relative humidity were the major habitat factors found influencing the terricolous lichen community of the landscape. Fruticose and compound soil lichen growth forms were found indicative of habitat disturbance largely caused by grazing induced trampling. Terricolous lichen diversity of the area was delimited by grazing pressure at mid-altitudes (3,000-3,400 m) and by decreasing soil cover at higher altitudes (> 3,400 m). OI Rai, Dr. Himanshu/0000-0001-8070-0602 SN 0960-3115 EI 1572-9710 PD JAN PY 2012 VL 21 IS 1 BP 97 EP 113 DI 10.1007/s10531-011-0168-z UT WOS:000298190000007 ER PT J AU Horstkotte, T Moen, J Lamas, T Helle, T AF Horstkotte, Tim Moen, Jon Lamas, Tomas Helle, Timo TI The Legacy of Logging-Estimating Arboreal Lichen Occurrence in a Boreal Multiple-Use Landscape on a Two Century Scale SO PLOS ONE AB In northern Sweden, the availability of arboreal lichens (Bryoria fuscescens, Alectoria sarmentosa) as winter grazing resources is an important element in reindeer husbandry. With the industrialization of forestry, forests rich in arboreal lichens have diminished considerably. Here, we analyze how forestry has impacted lichen availability from the 1920's to the present day and model its future development assuming different forest management scenarios. We recorded the current occurrence of B. fuscescens in 144 sampling plots, stratified by forest age class and dominant tree species in a 26,600 ha boreal forest landscape that is used for both reindeer herding and forestry. Lichen abundance was visually estimated in four classes: none, sparse, moderate and abundant. A binary logistic model using forest age as the independent variable was developed to predict the probability of lichens being present. Using this model, we found that lichens were present in stands that are at least 63 years old. Because of the relative paucity of stands rich in arboreal lichens, it was not possible to reliably determine how age affects the variation in abundance of older forest stands. The historical development of forests where arboreal lichens could potentially occur was studied using historic forestry records dating back 80 years. Between 1926 and the present day, forestry has reduced the cover of forests older than 60 years from 84% to 34%. The likely future spatial coverage of these stands over the next 120 years was estimated for two different management scenarios and an unmanaged reference scenario, using the Heureka strategic planning program. Under both the "business as usual'' scenario and that involving more intensive forestry, continued decreases in lichen availability are projected. Our results emphasize the importance of alternative forestry practices, such as prolonged rotation periods, to increase the availability of arboreal lichens as a grazing resource for reindeer. SN 1932-6203 PD DEC 16 PY 2011 VL 6 IS 12 AR e28779 DI 10.1371/journal.pone.0028779 UT WOS:000298664400018 PM 22194912 ER PT J AU Kazmin, VD Abaturov, BD AF Kazmin, V. D. Abaturov, B. D. TI Quantitative characteristics of nutrition in free-ranging reindeer (Rangifer tarandus) and musk oxen (Ovibos moschatus) on Wrangel Island SO BIOLOGY BULLETIN AB In 2004 to 2006, studies on free-ranging reindeer and musk oxen on Wrangel island were performed to estimate the nutrient value, daily intake, and digestibility of forage in different seasons of the year. Forage digestibility was determined from the ratio between the contents of indigestible components (lignin) in forage and animal feces. Daily forage intake was calculated from data on daily feces excretion and forage digestibility. The amount of feces and parameters of life activity of individual animals were estimated by following their 24-hour tracks. The results show that the daily intake of forage (dry weight) in musk oxen amounts to 7.8 kg in the summer period and decreases to 6.1 kg in the snow period (March-April). Grazing reindeer in the snow period consume 3.9 kg of forage per day. Forage digestibility in reindeer reaches 56% in March to April and decreases to 52% in June. In musk oxen, forage digestibility in different seasons (March, June, September) varies within a similar range (53-57%). Nutrition parameters (diet composition, forage intake rate and digestibility) of reindeer and musk oxen on grazing grounds of Wrangel Island are similar. Metabolizable energy consumption in both animals during the winter period is at the maintenance level (917-930 kJ/kg0.75 body weight). In the summer period, this parameter in musk oxen increases to 1163 kJ/kg0.75 body weight to meet the energy demand of the animals. SN 1062-3590 PD DEC PY 2011 VL 38 IS 9 BP 935 EP 941 DI 10.1134/S1062359011090056 UT WOS:000298193600009 ER PT J AU Kolas, A AF Kolas, Ashild TI Reclaiming the Forest: Ewenki Reindeer Herding as Exception SO HUMAN ORGANIZATION AB The Ewenki of Aoluguya, Inner Mongolia, used to be hunters and keep reindeer as pack animals. In 2003, they were relocated as "ecological migrants," their guns were confiscated, and hunting was banned. Reindeer herding in state-owned forests is the only remnant of their transhumant lifestyle, which is now based mainly on the production of reindeer horn for use in Chinese medicine. A government-run enterprise is in charge of cutting and marketing the reindeer horn. China's nationwide policy of de-collectivizing farming and herding was never fully implemented in Aoluguya, with implications for the herders' rights to grazing land and even the ownership of the reindeer. Based on a study of land management policies, governance, and herding practices, this paper argues that Ewenki reindeer herders find themselves in a liminal space, or zone of anomie, where they are constantly treated as exceptional. They are no longer a "hunting tribe," nor are they regarded as true pastoralists (Chinese: shoulie buluo; mumin), while government departments variously deal with the reindeer as domestic and wild animals. Despite the challenges, the reindeer herders are finding ways to manage by negotiating their own exceptions, sometimes enabling them to turn the discourse of exceptionality to their own advantage. RI Kolas, Ashild/H-6833-2016 OI Kolas, Ashild/0000-0002-1114-1701 SN 0018-7259 PD WIN PY 2011 VL 70 IS 4 BP 397 EP 404 DI 10.17730/humo.70.4.f20r707219213865 UT WOS:000297862500007 ER PT J AU Finstad, GL Kielland, K AF Finstad, Gregory L. Kielland, Knut TI Landscape Variation in the Diet and Productivity of Reindeer in Alaska Based on Stable Isotope Analyses SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Productivity of a managed grazing system is dependent upon both the grazing strategy of ungulates and decisions made by humans. Herds of domestic reindeer (Rangifer tarandus tarandus) graze on discrete ranges of the Seward Peninsula, Alaska with variable production rates. We show that the N-15 natural abundance of reindeer forages vary significantly and the delta N-15 value of collagen deposited in antler bone from spring until ossification was significantly correlated with the delta N-15 signature of the diet. Calf weight in June was related to isotopic signatures in antler and soft tissue of adult females, and was inversely correlated with the absolute differential between summer and winter serum delta N-15 values. This observation suggests that female reindeer with smaller calves had catabolized more body protein during winter than females in adjacent herds. Moreover, in herds with smaller calves, female reindeer consumed proportionately more shrubs in early spring resulting in a strong relationship between delta N-15 signatures of antler collagen deposited in May and calf weight. These data suggest female reindeer catabolizing relatively more body protein during winter may attempt to compensate by increasing consumption of high-protein catkins and leaf buds of shrubs during May. Herders with relatively smaller calves in their herds may be able to improve protein balance of reproductive females and thus increase calf productivity by increasing access to shrub habitats during spring. SN 1523-0430 EI 1938-4246 PD NOV PY 2011 VL 43 IS 4 BP 543 EP 554 DI 10.1657/1938-4246-43.4.543 UT WOS:000298722400005 ER PT J AU Yu, Q Epstein, HE Walker, DA Frost, GV Forbes, BC AF Yu, Q. Epstein, H. E. Walker, D. A. Frost, G. V. Forbes, B. C. TI Modeling dynamics of tundra plant communities on the Yamal Peninsula, Russia, in response to climate change and grazing pressure SO ENVIRONMENTAL RESEARCH LETTERS AB Understanding the responses of the arctic tundra biome to a changing climate requires knowledge of the complex interactions among the climate, soils and biological system. This study investigates the individual and interaction effects of climate change and reindeer grazing across a variety of climate zones and soil texture types on tundra vegetation community dynamics using an arctic vegetation model that incorporates the reindeer diet, where grazing is a function of both foliar nitrogen concentration and reindeer forage preference. We found that grazing is important, in addition to the latitudinal climate gradient, in controlling tundra plant community composition, explaining about 13% of the total variance in model simulations for all arctic tundra subzones. The decrease in biomass of lichen, deciduous shrub and graminoid plant functional types caused by grazing is potentially dampened by climate warming. Moss biomass had a nonlinear response to increased grazing intensity, and such responses were stronger when warming was present. Our results suggest that evergreen shrubs may benefit from increased grazing intensity due to their low palatability, yet a growth rate sensitivity analysis suggests that changes in nutrient uptake rates may result in different shrub responses to grazing pressure. Heavy grazing caused plant communities to shift from shrub tundra toward moss, graminoid-dominated tundra in subzones C and D when evergreen shrub growth rates were decreased in the model. The response of moss, lichen and forbs to warming varied across the different subzones. Initial vegetation responses to climate change during transient warming are different from the long term equilibrium responses due to shifts in the controlling mechanisms (nutrient limitation versus competition) within tundra plant communities. RI Forbes, Bruce/L-4431-2013 OI Forbes, Bruce/0000-0002-4593-5083; Frost, Gerald/0000-0002-5134-0334 SN 1748-9326 PD OCT-DEC PY 2011 VL 6 IS 4 AR 045505 DI 10.1088/1748-9326/6/4/045505 UT WOS:000298674700061 ER PT J AU Klein, DR Shulski, M AF Klein, David R. Shulski, Martha TI The Role of Lichens, Reindeer, and Climate in Ecosystem Change on a Bering Sea Island SO ARCTIC AB Archived reports. from an international controversy in the early 1890s over management of the harvest of fur seals, Callorhinus ursinus, on the Pribilof Islands in the southeastern Bering Sea provided an unanticipated record of observations on the growth of lichens in association with the prevailing climatic conditions. The abundance of lichens observed in plant communities on the Pribilof Islands prompted the introduction of reindeer, Rangifer tarandus, in 1911. Grazing pressure by the introduced reindeer brought changes to lichen presence in the plant communities of St. Paul Island of the Pribilof's: lichens were depleted, and vascular plants expanded to replace the depleted lichens in a climate that became markedly warmer and drier in comparison to that of the late 19th century. These changes are described primarily through the use of historical documentation. Dominance of lichens in the plant communities on the Pribilof Islands at the time of their discovery and settlement appears to have been a relict of their development in the cooler and moister climate that characterized the southern Bering Sea in the mid-Holocene. SN 0004-0843 EI 1923-1245 PD SEP PY 2011 VL 64 IS 3 BP 353 EP 361 UT WOS:000294887000007 ER PT J AU Wehn, S Pedersen, B Hanssen, SK AF Wehn, Solvi Pedersen, Bard Hanssen, Susanne Kristin TI A comparison of influences of cattle, goat, sheep and reindeer on vegetation changes in mountain cultural landscapes in Norway SO LANDSCAPE AND URBAN PLANNING AB Earlier land use in European mountains included grazing by different kinds of livestock, while today it may be more homogenous, and the grazing may have either been intensified or been abandoned. Different domestic animal species graze in different areas of the landscape. Therefore, grazing stocks composed of different species have an unequal effect on the landscape. This study compares the influence of four domestic animal species (cattle, sheep, goats, reindeer) on landscape dynamics in Jotunheimen, a Norwegian mountain range. Interviews and maps showing grazing land of domestic animals were performed to collect information about land use in the summer farm surroundings. Grazing pressure maps (prior to 1960 and 1960-2002) using the land use information obtained, and vegetation maps (from the 1960s and 2002) using aerial photographs, were digitized. Vegetation was spatially linked with grazing pressure using GIS and multiple multinomial and linear regressions were used to investigate each species' effect on vegetation type change and displacement of the forest line, respectively. The results show that cattle grazing influenced transitions from grasslands, cattle together with goats affected transitions from heaths, and cattle, goats, and reindeer influenced displacement of the birch forest line. High grazing pressure from these three domestic animals suppressed forest and scrub establishment in open habitats. Only goats, however, caused transitions from scrub and birch forest to open vegetation types. (C) 2011 Elsevier B.V. All rights reserved. SN 0169-2046 PD SEP PY 2011 VL 102 IS 3 BP 177 EP 187 DI 10.1016/j.landurbplan.2011.04.003 UT WOS:000293422200004 ER PT J AU Olofsson, A Danell, O Forslund, P Ahman, B AF Olofsson, Anna Danell, Oje Forslund, Par Ahman, Birgitta TI Monitoring changes in lichen resources for range management purposes in reindeer husbandry SO ECOLOGICAL INDICATORS AB Mat-forming lichens are important as food source for reindeer during the winter, and thus a vital resource to manage in reindeer husbandry. In this paper we suggest a method for monitoring of changes in lichen height with the purpose to early detect changes in lichen abundance in reindeer grazing areas. The method is intended for measuring geographically uniform lichen areas, evenly used for reindeer grazing. We analysed spatial variations in lichen height at the meter and 100 m scales, and calculated sample size requirements, and estimated effects of forest density and age, lichen moisture and lichen density on lichen height, and assessed the correspondence between lichen height and biomass. The variation in lichen height differed considerably between sites and, hence, the required sample size to detect a 5 mm change in lichen height with a power of 0.95 ranged from 200 to 2000, depending on the standard deviation of measured heights. Based on the autocorrelation in lichen height found between adjacent measurement points, a minimum distance of 4 m between measurement points is also recommended. Lichen height was significantly affected by lichen moisture, and the results suggest that this effect of moisture might vary with lichen density. Lichen height varied spatially within the study sites, and the spatial variations were partly caused by forest age and density. Thus, gradual changes in the forest characteristics are likely to alter the spatial variation in lichen height and it is therefore important to regularly re-evaluate the locations of measurement points within the monitored area. This study provides suggestions for a variable that could be used as an indicator of changes in the lichen resource, and aspects that should be considered when designing a monitoring program. The accuracy of detecting changes depends on the monitoring efforts, i.e. the number and distribution of measurement points and how often an area is monitored. In conclusion, our results indicate that measurements of lichen height have considerable potential for monitoring of changes in lichen resources within reindeer husbandry. (C) 2010 Elsevier Ltd. All rights reserved. SN 1470-160X PD SEP PY 2011 VL 11 IS 5 BP 1149 EP 1159 DI 10.1016/j.ecolind.2010.12.015 UT WOS:000291409700016 ER PT J AU Anttila, A Leppanen, AP Rissanen, K Ylipieti, J AF Anttila, Annukka Leppanen, Ari-Pekka Rissanen, Kristiina Ylipieti, Jarkko TI Concentrations of Cs-137 in summer pasture plants that reindeer feed on in the reindeer management area of Finland SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY AB Samples of summer pasture plants that reindeer feed on were collected in order to study Cs-137 concentrations in different plant species and in species nested in certain site types, and to study the regional distribution of Cs-137 in the Finnish reindeer management area. Plant species were categorized by the site types of mineral soil forest (xeric heath forest and mesic heath forest) and peatland. A third category called 'other plant species' included plants with various site types, poorly determined species and species with poor statistics. The Cs-137 concentrations in different site types differed significantly. The mean Cs-137 concentrations of the whole reindeer management area in the xeric heath forest plant species was 44 +/- 27 Bq/kg dw, in the mesic heath forest plant species 75 +/- 59 Bq/kg dw and in the peatland plant species 219 +/- 150 Bq/kg dw. The peatland species uptake Cs-137 more efficiently than plant species of mineral soil forests. A particularly efficient collector of Cs-137 was Trichophorum sp. It is suggested that Trichophorum sp. could be used as an indicator species for reindeer summer fodder plants. The highest concentrations of Cs-137 were found in Southern Lapland and the lowest in Northern Lapland. Today, the concentrations of Cs-137 in summer pasture plants that reindeer feed on in Finland are at such a level that there is no need to avoid any plant species. In the case of future nuclear fallout, reindeer grazing in peatlands would increase concentrations of Cs-137 in reindeer meat. (C) 2011 Elsevier Ltd. All rights reserved. SN 0265-931X PD JUL PY 2011 VL 102 IS 7 BP 659 EP 666 DI 10.1016/j.jenvrad.2011.03.009 UT WOS:000291912400002 PM 21514704 ER PT J AU Riseth, JA Tommervik, H Helander-Renvall, E Labba, N Johansson, C Malnes, E Bjerke, JW Jonsson, C Pohjola, V Sarri, LE Schanche, A Callaghan, TV AF Riseth, Jan Age Tommervik, Hans Helander-Renvall, Elina Labba, Niklas Johansson, Cecilia Malnes, Eirik Bjerke, Jarle W. Jonsson, Christer Pohjola, Veijo Sarri, Lars-Erik Schanche, Audhild Callaghan, Terry V. TI Sami traditional ecological knowledge as a guide to science: snow, ice and reindeer pasture facing climate change SO POLAR RECORD AB Scientific studies of challenges of climate change could be improved by including other sources of knowledge, such as traditional ecological knowledge (TEK), in this case relating to the Sami. This study focuses on local variations in snow and ice conditions, effects of the first durable snow, and long term changes in snow and ice conditions as pre-requisites for understanding potential future changes. Firstly, we characterised snow types and profiles based on Sami categories and measured their density and hardness. Regression analysis showed that density can explain much of the variation in hardness, while snow depth was not significantly correlated with hardness. Secondly, we found that whether it is dry/cold or warm/wet around the fall of the first durable snow is, according to Sami reindeer herders, crucial information for forecasting winter grazing conditions, but this has had limited focus within science. Thirdly, elderly herders' observations of changes in snow and ice conditions by 'reading nature' can aid reinterpretation of meteorological data by introducing researchers to alternative perspectives. In conclusion we found remarkable agreement between scientific measurements and Sami terminology. We also learnt that TEK/science cooperation has much potential for climate change studies, though time and resources are needed to bridge the gap between knowledge systems. In particular, TEK attention to shifts in nature can be a useful guide for science. RI Helander-Renvall, Elina/L-4448-2013; Callaghan, Terens/N-7640-2014 OI Riseth, Jan Age/0000-0002-4607-5927; Bjerke, Jarle/0000-0003-2721-1492 SN 0032-2474 EI 1475-3057 PD JUL PY 2011 VL 47 IS 242 BP 202 EP 217 DI 10.1017/S0032247410000434 UT WOS:000292194200002 ER PT J AU Hummel, J Findeisen, E Sudekum, KH Ruf, I Kaiser, TM Bucher, M Clauss, M Codron, D AF Hummel, Juergen Findeisen, Eva Suedekum, Karl-Heinz Ruf, Irina Kaiser, Thomas M. Bucher, Martin Clauss, Marcus Codron, Daryl TI Another one bites the dust: faecal silica levels in large herbivores correlate with high-crowned teeth SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES AB The circumstances of the evolution of hypsodonty (high-crowned teeth) are a bone of contention. Hypsodonty is usually linked to diet abrasiveness, either from siliceous phytoliths (monocotyledons) or from grit (dusty environments). However, any empirical quantitative approach testing the relation of ingested silica and hypsodonty is lacking. In this study, faecal silica content was quantified as acid detergent insoluble ash and used as proxy for silica ingested by large African herbivores of different digestive types, feeding strategies and hypsodonty levels. Separate sample sets were used for the dry (n = 15 species) and wet (n = 13 species) season. Average faecal silica contents were 17-46 g kg(-1) dry matter (DM) for browsing and 52-163 g kg(-1) DM for grazing herbivores. No difference was detected between the wet (97.5 +/- 14.4 g kg(-1) DM) and dry season (93.5 +/- 13.7 g kg(-1) DM) faecal silica. In a phylogenetically controlled analysis, a strong positive correlation (dry season r = 0.80, p < 0.0005; wet season r = 0.74, p < 0.005) was found between hypsodonty index and faecal silica levels. While surprisingly our results do not indicate major seasonal changes in silica ingested, the correlation of faecal silica and hypsodonty supports a scenario of a dominant role of abrasive silica in the evolution of high-crowned teeth. RI Self, Casey/B-6871-2011; Clauss, Marcus/A-4710-2008; Codron, Daryl/B-8867-2008 OI Clauss, Marcus/0000-0003-3841-6207; Codron, Daryl/0000-0001-5223-9513; Kaiser, Thomas/0000-0002-8154-1751 SN 0962-8452 EI 1471-2954 PD JUN 7 PY 2011 VL 278 IS 1712 BP 1742 EP 1747 DI 10.1098/rspb.2010.1939 UT WOS:000289719900019 PM 21068036 ER PT J AU Mustajoki, J Saarikoski, H Marttunen, M Ahtikoski, A Hallikainen, V Helle, T Hypponen, M Jokinen, M Naskali, A Tuulentie, S Varmola, M Vatanen, E Ylisirnio, AL AF Mustajoki, Jyri Saarikoski, Heli Marttunen, Mika Ahtikoski, Anssi Hallikainen, Ville Helle, Timo Hypponen, Mikko Jokinen, Mikko Naskali, Arto Tuulentie, Seija Varmola, Martti Vatanen, Eero Ylisirnio, Anna-Liisa TI Use of decision analysis interviews to support the sustainable use of the forests in Finnish Upper Lapland SO JOURNAL OF ENVIRONMENTAL MANAGEMENT AB Controversy between alternative uses of forests in Finnish Upper Lapland has been going on for decades, and in recent years it has been escalated to a serious conflict. The core of the conflict is the adverse impacts of forestry on old forests which are important grazing areas for reindeer and which are regarded as intact nature and wilderness areas. This paper describes the experiences of applying multi-criteria decision analysis interview approach on this conflict. The approach provides tools for structuring the problem and preferences of the stakeholders as well as for analyzing the effects of different alternatives in a common framework. We focus on the practical experiences gained from the application of this approach in this context. Multi-criteria decision analysis was found to be a useful approach to evaluate the economic, ecological and cultural aspects of this intense conflict. The obtained experiences also support the view that the approach works best when tightly integrated into the planning process. (C) 2011 Elsevier Ltd. All rights reserved. RI Hallikainen, Ville/E-8766-2013; Ylisirnio, Anna-Liisa/L-4444-2013; Tuulentie, Seija/H-8901-2018 OI Hallikainen, Ville/0000-0001-5384-8265; Mustajoki, Jyri/0000-0003-3520-9173 SN 0301-4797 EI 1095-8630 PD JUN PY 2011 VL 92 IS 6 BP 1550 EP 1563 DI 10.1016/j.jenvman.2011.01.007 UT WOS:000289137000014 PM 21288630 ER PT J AU Berg, A Gunnarsson, B Ostlund, L AF Berg, Anna Gunnarsson, Bjorn Ostlund, Lars TI 'At this point, the lichens in the trees are their only means of survival': A History of Tree Cutting for Winter Reindeer Fodder by Sami People in Northern Sweden SO ENVIRONMENT AND HISTORY AB The importance of land use history and its impact on ecological systems has recently been recognised, primarily because most 'natural areas' have been found to have experienced greater human interference than previously assumed. The extent of forest exploitation in pre-industrial times, especially by native people, has been consistently underestimated. In northern Sweden all the reindeer are herded by the native Sami people. During the winter, reindeer usually feed on ground lichens, which they dig for under the snow. Traditionally, trees with arboreal lichens were cut to provide supplementary food when adverse snow conditions prevented grazing. The stumps from such cuttings are commonly known as lichen-stumps' and they can be found in the few remaining unmanaged forest areas. In this study we examine the history, ecology and extent of this specific aspect of forest use by using an integrated approach involving both historical records and field studies. We found that the cutting of trees for lichens was a widespread practice during harsh winters, that significant numbers of trees were cut and that it ceased at the end of the nineteenth century, coinciding with large-scale changes in the land use of northern Scandinavia. OI Ostlund, Lars/0000-0002-7902-3672 SN 0967-3407 PD MAY PY 2011 VL 17 IS 2 BP 265 EP 289 DI 10.3197/096734011X12997574043044 UT WOS:000296215600004 ER PT J AU Persson, BRR Holm, E AF Persson, Bertil R. R. Holm, Elis TI Polonium-210 and lead-210 in the terrestrial environment: a historical review SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY CT International Topical Conference on Po and Radioactive Pb Isotopes CY OCT 26-28, 2009 CL Seville, SPAIN AB The radionuclides Po-210 and Pb-210 widely present in the terrestrial environment are the final long-lived radionuclides in the decay of U-238 in the earth's crust. Their presence in the atmosphere is due to the decay of Rn-222 diffusing from the ground. The range of activity concentrations in ground level air for Po-210 is 0.03-0.3 Bq m(-3) and for Pb-210 0.2-1.5 Bq m(-3). In drinking water from private wells the activity concentration of Po-210 is in the order of 7-48 mBq l(-1) and for Pb-210 around 11-40 mBq l(-1). From water works, however, the activity concentration for both Po-210 and Pb-210 is only in the order of 3 mBq l(-1). Mosses, lichens and peat have a high efficiency in capturing Po-210 and Pb-210 from atmospheric fallout and exhibit an inventory of both Po-210 and Pb-210 in the order of 0.5-5 kBq m(-2) in mosses and in lichens around 0.6 kBq m(-2). The activity concentrations in lichens lies around 250 Bq kg(-1), dry mass. Reindeer and caribou graze lichen which results in an activity concentration of Po-210 and Pb-210 of about 1-15 Bq kg(-1) in meat from these animals. The food chain lichen-reindeer or caribou, and Man constitutes a unique model for studying the uptake and retention of Po-210 and Pb-210 in humans. The effective annual dose due to Po-210 and Pb-210 in people with high consumption of reindeer/caribou meat is estimated to be around 260 and 132 mu Sv a(-1) respectively. In soils, Po-210 is adsorbed to clay and organic colloids and the activity concentration varies with soil type and also correlates with the amount of atmospheric precipitation. The average activity concentration levels of Po-210 in various soils are in the range of 20-240 Bq kg(-1). Plants become contaminated with radioactive nuclides both by absorption from the soil (supported Po) and by deposition of radioactive fallout on the plants directly (unsupported Po). In fresh leafy plants the level of Po-210 is particularly high as the result of the direct deposition of Rn-222 daughters from atmospheric deposition. Tobacco is a terrestrial product with high activity concentrations of Po-210 and Pb-210. The overall average activity concentration of Po-210 is 13 +/- 2 Bq kg(-1). It is rather constant over time and by geographical origin. The average median daily dietary intakes of Po-210 and Pb-210 for the adult world population was estimated to 160 mBq day(-1) and 110 mBq day(-1), corresponding to annual effective doses of 70 mu Sv a(-1) and 28 mu Sv a(-1), respectively. The dietary intakes of Po-210 and Pb-210 from vegetarian food was estimated to only 70 mBq day(-1) and 40 mBq day(-1) corresponding to annual effective doses of 30.6 mu Sv a(-1) and 10 mu Sv a(-1), respectively. Since the activity concentration of Po-210 and Pb-210 in seafood is significantly higher than in vegetarian food the effective dose to populations consuming a lot of seafood might be 5-15 fold higher. (C) 2011 Elsevier Ltd. All rights reserved. OI Persson, Bertil/0000-0002-5502-5972 SN 0265-931X EI 1879-1700 PD MAY PY 2011 VL 102 IS 5 SI SI BP 420 EP 429 DI 10.1016/j.jenvrad.2011.01.005 UT WOS:000291287100003 PM 21377252 ER PT J AU Van Bogaert, R Haneca, K Hoogesteger, J Jonasson, C De Dapper, M Callaghan, TV AF Van Bogaert, Rik Haneca, Kristof Hoogesteger, Jan Jonasson, Christer De Dapper, Morgan Callaghan, Terry V. TI A century of tree line changes in sub-Arctic Sweden shows local and regional variability and only a minor influence of 20th century climate warming SO JOURNAL OF BIOGEOGRAPHY AB Aim Models project that climate warming will cause the tree line to move to higher elevations in alpine areas and more northerly latitudes in Arctic environments. We aimed to document changes or stability of the tree line in a sub-Arctic model area at different temporal and spatial scales, and particularly to clarify the ambiguity that currently exists about tree line dynamics and their causes. Location The study was conducted in the Tornetrask area in northern Sweden where climate warmed by 2.5 degrees C between 1913 and 2006. Mountain birch (Betula pubescens ssp. czerepanovii) sets the alpine tree line. Methods We used repeat photography, dendrochronological analysis, field observations along elevational transects and historical documents to study tree line dynamics. Results Since 1912, only four out of eight tree line sites had advanced: on average the tree line had shifted 24 m upslope (+0.2 m year-1 assuming linear shifts). Maximum tree line advance was +145 m (+1.5 m year-1 in elevation and +2.7 m year-1 in actual distance), whereas maximum retreat was 120 m downslope. Counter-intuitively, tree line advance was most pronounced during the cooler late 1960s and 1970s. Tree establishment and tree line advance were significantly correlated with periods of low reindeer (Rangifer tarandus) population numbers. A decreased anthropozoogenic impact since the early 20th century was found to be the main factor shaping the current tree line ecotone and its dynamics. In addition, episodic disturbances by moth outbreaks and geomorphological processes resulted in descent and long-term stability of the tree line position, respectively. Main conclusions In contrast to what is generally stated in the literature, this study shows that in a period of climate warming, disturbance may not only determine when tree line advance will occur but if tree line advance will occur at all. In the case of non-climatic climax tree lines, such as those in our study area, both climate-driven model projections of future tree line positions and the use of the tree line position for bioclimatic monitoring should be used with caution. RI Callaghan, Terens/N-7640-2014 OI Haneca, Kristof/0000-0002-7719-8305 SN 0305-0270 EI 1365-2699 PD MAY PY 2011 VL 38 IS 5 BP 907 EP 921 DI 10.1111/j.1365-2699.2010.02453.x UT WOS:000289630200009 ER PT J AU Roden, C Stevens, JMG Vervaecke, H Van Elsacker, L AF Roden, Catherine Stevens, Jeroen M. G. Vervaecke, Hilde Van Elsacker, Linda TI Reproductive effort of bison bulls (Bison bison) in semi-natural conditions SO JOURNAL OF ETHOLOGY AB Reproductive effort (RE) is defined as the investment in any current reproductive act. In male ungulates, variation in RE can be explained by differences in age, dominance, phase in the breeding season and number of oestrus females simultaneously present. We investigated the relation between these factors and RE in American bison males in semi-natural conditions. We looked for differences between males in RE, measured by tending behaviour, and maintenance activities (feeding/resting) during the rut. We found no effect of age on RE. During early rut there was no difference in RE between males of different rank. Dominant males had a higher RE during peak rut, and in late rut both the first and second ranking males showed more RE than lower ranking bulls. For all males, there was a clear increase in RE towards peak rut and when more females were attractive. Maintenance behaviours decreased when more females were synchronously in oestrus. The most dominant bulls spent less time grazing than lower ranking males, and all males decreased feeding during peak rut. Resting decreased with age. We conclude that dominance, phase of rut and the number of females synchronously in oestrus are the factors that best explain variation in RE. SN 0289-0771 PD MAY PY 2011 VL 29 IS 2 BP 285 EP 291 DI 10.1007/s10164-010-0256-7 UT WOS:000289564800012 ER PT J AU Henden, JA Ims, RA Yoccoz, NG Sorensen, R Killengreen, ST AF Henden, John-Andre Ims, Rolf Anker Yoccoz, Nigel Gilles Sorensen, Raymond Killengreen, Siw Turid TI Population dynamics of tundra voles in relation to configuration of willow thickets in southern arctic tundra SO POLAR BIOLOGY AB The areal extent and configuration of thickets of willow shrubs are currently changing in the Arctic both as an effect of global warming and changed browsing pressure of reindeer. These changes have been predicted to impact the distribution and abundance of wildlife species relying on willow thickets as habitat. We assessed the relation between variables quantifying willow thicket configuration and population dynamics of tundra voles (Microtus oeconomus) in three riparian regions in Finnmark, northern Norway, which were subject to intense browsing by semi-domesticated reindeer. The tundra vole, which exhibits 5-year population cycles in Finnmark, is the dominant small rodent species in riparian landscape elements in southern arctic tundra. In the course of a 4-year trapping study, tundra vole populations went through the cyclic phases of increase, peak and crash, however, with distinct differences between the three regions in the population dynamics. Within regions, the occupancy pattern during the increase phase was positively related to willow thicket configuration (in particular edge density and willow height) only in the region attaining the highest abundance and occupancy. However, local abundance was not clearly related to habitat features within any regions. The lack of consistency in the response of tundra vole populations to willow thicket configuration, as well as the positive relation between the degree of thicket shredding and tundra vole habitat occupancy in one of the regions, indicates that tundra voles will not be much affected by climate or browsing induced changes in the shrubbiness of the tundra in the future. RI Killengreen, Siw/G-9205-2016; Yoccoz, Nigel/C-8561-2014 OI Yoccoz, Nigel/0000-0003-2192-1039; Henden, John-Andre/0000-0002-8825-1167 SN 0722-4060 PD APR PY 2011 VL 34 IS 4 BP 533 EP 540 DI 10.1007/s00300-010-0908-7 UT WOS:000288454400006 ER PT J AU Kumpula, J Stark, S Holand, O AF Kumpula, Jouko Stark, Sari Holand, Oystein TI Seasonal grazing effects by semi-domesticated reindeer on subarctic mountain birch forests SO POLAR BIOLOGY AB In northern Fennoscandia, the spatial and temporal grazing practices of semi-domesticated reindeer (Rangifer tarandus tarandus) vary, which implies different grazing effects dependent on natural conditions as well as management regime (i.e., timing and intensity of grazing). We compared density and biomass of main plant groups in semi-dry mountain birch forests exposed to either long-term summer or winter grazing in three reindeer herding districts in the northernmost Finland. Percent plant cover, height, and biomass of reindeer lichens (Cladonia spp.) and dwarf shrubs (Vaccinium uliginosum, Calluna vulgaris, and Betula nana) were lower on summer ranges compared with winter ranges. The biomass of other dwarf shrubs (Vaccinium myrtillus and V. vitis-idaea), and graminoids and herbs, and the % cover of non-vegetated bare soil and litter were, however, higher on summer ranges than on winter ranges. Young mountain birch shoots (Betula pubescens ssp. czerepanovii) were less frequent on summer ranges than on winter ranges. The total leaf biomass under the browsing height of reindeer (<1.5 m) was also lower on summer ranges compared with winter ranges. Especially in drier and nutrient poor mountain birch forests, intensive summer grazing reduces the quantity of lichens and total plant biomass which affects the ecological state and productivity of these forests and also reduces especially their winter grazing value for reindeer. Therefore, in addition to regulating the maximum sustained numbers of reindeer, pasture rotation systems that effectively protect dry and nutrient poor vegetation from summer grazing and trampling should be encouraged. RI Stark, Sari/L-4440-2013 SN 0722-4060 PD MAR PY 2011 VL 34 IS 3 BP 441 EP 453 DI 10.1007/s00300-010-0899-4 UT WOS:000288349800013 ER PT J AU Aune, S Hofgaard, A Soderstrom, L AF Aune, Sigrun Hofgaard, Annika Soderstrom, Lars TI Contrasting climate- and land-use-driven tree encroachment patterns of subarctic tundra in northern Norway and the Kola Peninsula SO CANADIAN JOURNAL OF FOREST RESEARCH AB High-latitude regions are experiencing substantial climate change, and the forest-tundra transition is assumed to sensitively track these changes through advancing treeline and increased tundra encroachment. However, herbivores may influence these responses. The present study addresses, through analyses of age structures, growth characteristics, and climate correspondence, how mountain birch (Betula pubescens Ehrh. ssp. czerepanovii (Orlova) Hamet-Ahti) treelines and sapling cohorts beyond the treeline have responded to the last decade's warming in six North European subarctic areas with different climate and grazing characters. The results show different response patterns among areas representing advancing, stationary, and possibly retreating treelines. Recruitment was abundant over the last decades in all areas except one, with predominantly arctic conditions, where both tree and sapling cohorts were old. Areas with high annual precipitation show advancing birch populations characterized by young individuals and partly overlapping tree and sapling age distributions. Areas in reindeer herding districts show stationary or retreating birch populations characterized by nonoverlapping age distributions and low sapling survival. Recruitment patterns beyond the treeline generally corresponded with non-growing-season climate variables, mainly precipitation, indicating the importance of a protecting snow cover. The results highlight the important interplay between abiotic and biotic control over tundra encroachment and treeline dynamics and the importance of multisite studies when addressing responses to warming. RI Soderstrom, Lars/A-1196-2013 OI Soderstrom, Lars/0000-0002-9315-4978; Aune, Sigrun/0000-0002-8389-1624 SN 0045-5067 EI 1208-6037 PD MAR PY 2011 VL 41 IS 3 BP 437 EP 449 DI 10.1139/X10-086 UT WOS:000288032300002 ER PT J AU Collins, WB Dale, BW Adams, LG Mcelwain, DE Joly, K AF Collins, William B. Dale, Bruce W. Adams, Layne G. Mcelwain, Darien E. Joly, Kyle TI Fire, Grazing History, Lichen Abundance, and Winter Distribution of Caribou in Alaska's Taiga SO JOURNAL OF WILDLIFE MANAGEMENT AB In the early 1990s the Nelchina Caribou (Rangifer tarandus) Herd (NCH) began a dramatic shift to its current winter range, migrating at least an additional 100 km beyond its historic range. We evaluated the impacts of fire and grazing history on lichen abundance and subsequent use and distribution by the NCH. Historic (prior to 1990) and current (2002) winter ranges of the NCH had similar vascular vegetation, lichen cover (P = 0.491), and fire histories (P = 0.535), but the former range had significantly less forage lichen biomass as a result of grazing by caribou. Biomass of forage lichens was twice as great overall (P = 0.031) and 4 times greater in caribou selected sites on the current range than in the historic range, greatly increasing availability to caribou. Caribou on the current range selected for stands with >20% lichen cover (P < 0.001), greater than 1,250 kg/ha (P < 0.001) forage lichen biomass and stands older than 80 yr postfire (P < 0.001). After fires, forage lichen cover and biomass seldom recovered sufficiently to attract caribou grazing until after >= 60 yr, and, as a group, primary forage lichen species did not reach maximum abundance until 180 yr postfire. Recovery following overgrazing can occur much more quickly because lichen cover, albeit mostly fragments, and organic substrates remain present. Our results provide benchmarks for wildlife managers assessing condition of caribou winter range and predicting effects of fires on lichen abundance and caribou distribution. Of our measurements of cover and biomass by species, densities and heights of trees, elevation, slope and aspect, only percentage cover by Cladonia amaurocraea, Cladina rangiferina, Flavocetraria cuculata, and lowbush cranberry (Vaccinium vitis-idaea) were necessary for predicting caribou use of winter range. (C) 2011 The Wildlife Society SN 0022-541X PD FEB PY 2011 VL 75 IS 2 BP 369 EP 377 DI 10.1002/jwmg.39 UT WOS:000289670800014 ER PT J AU Gomez-Guzman, JM Lopez-Gutierrez, JM Holm, E Pinto-Gomez, AR AF Gomez-Guzman, J. M. Lopez-Gutierrez, J. M. Holm, E. Pinto-Gomez, A. R. TI Level and origin of I-129 and Cs-137 in lichen samples (Cladonia alpestris) in central Sweden SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY AB Lichen is a symbiosis between algae and fungi. They have for decades been used as bioindicators for atmospheric deposition of heavy metals, organic compounds and radioactive elements. Especially the species Cladonia alpestris and Cladonia rangiferina are important for the food chain lichen-reindeer-man. The concentration of I-129 was determined in lichen samples (Cladonia alpestris) contaminated by fallout from atmospheric nuclear tests explosions and the Chernobyl accident. The samples were collected at Lake Rogen District (62.3 degrees N, 12.4 degrees E) in central Sweden in the periods 1961-1975 and 1987-1998, and analysed with accelerator mass spectrometry (AMS) at CNA (Seville) to study its distribution in different layers. Data on the Cs-137 activity measured previously were also included in this study. The I-129 concentration ranged from (0.95 +/- 0.13) x 10(8) at g(-1) in 1961 in the uppermost layer to (14.2 +/- 0.5) x 10(8) at g(-1) in 1987 in deepest layer. The I-129/Cs-137 atom ratio ranged between 0.12 and 0.27 for lichen samples collected in the period 1961-1975, indicating weapons tests fallout. For lichen samples collected between 1987 and 1998 the behaviour of Cs-137 concentrations reflected Chernobyl fallout. The concentrations of the two radionuclides followed each other quite well in the profile, reflecting the same origin for both. From the point of view of the spatial distribution in the lichen, it appears that I-129 was predominantly accumulated in the lowest layer, the opposite to Cs-137 for which the highest amounts were detected systematically in the topmost layer of lichen. This vertical distribution is important for radioecology because lichen is the initial link in the food chain lichen-reindeer-man, and reindeer only graze the upper parts of lichen carpets. (C) 2010 Elsevier Ltd. All rights reserved. RI Lopez-Gutierrez, Jose Maria/G-4389-2015 OI Lopez-Gutierrez, Jose Maria/0000-0001-8672-8075; Gomez Guzman, Jose Manuel/0000-0002-9055-2268 SN 0265-931X PD FEB PY 2011 VL 102 IS 2 BP 200 EP 205 DI 10.1016/j.jenvrad.2010.11.014 UT WOS:000287339100016 PM 21177003 ER PT J AU Henden, JA Ims, RA Yoccoz, NG Killengreen, ST AF Henden, John-Andre Ims, Rolf Anker Yoccoz, Nigel Gilles Killengreen, Siw Turid TI Declining willow ptarmigan populations: The role of habitat structure and community dynamics SO BASIC AND APPLIED ECOLOGY AB The recent range contractions and population declines of many grouse species worldwide have been attributed to loss and fragmentation of their habitats, although the empirical evidence for the actual drivers is often weak. In case of the willow ptarmigan Lagopus lagopus in Fennoscandia, ungulate overbrowsing of willows has been hypothesized to exert such negative habitat-related impacts. Moreover, a steep population decline of willow ptarmigan in southern Fennoscandia has recently been attributed to community interactions linking the fate of the willow ptarmigan to a change in keystone tundra rodent populations. Community and habitat factors may also interact in their impact on willow ptarmigan abundance. Here we assess whether willow thicket structural characteristics sensitive to ungulate browsing impacted willow ptarmigan habitat occupancy and whether such impacts depended on small rodent population dynamics. We employed an extensive survey approach spatially encompassing three riparian tundra regions and covering the phases of increase, peak and crash of the small rodent cycle. Willow ptarmigan habitat occupancy increased with the areal extent of willow thickets, whereas it decreased with increasing degree of thicket fragmentation (i.e. habitat shredding). Both of these effects were consistent with ungulate over-browsing impacting willow ptarmigan abundance negatively. Over the 4-year study period, willow ptarmigan habitat occupancy declined steeply independently of spatial variation in willow thicket areal extent and fragmentation. Moreover, the expected increase in ptarmigan populations during the increase/peak phase of the rodent cycle was not observed. Thus although our study provides support for the hypothesis that intense ungulate browsing negatively impacts willow ptarmigan, our study also suggests that causes of the current steep decline of ptarmigan populations in northern Fennoscandia should be sought in factors other than habitat fragmentation and changed rodent population dynamics. RI Yoccoz, Nigel/C-8561-2014; Killengreen, Siw/G-9205-2016 OI Yoccoz, Nigel/0000-0003-2192-1039; Henden, John-Andre/0000-0002-8825-1167 SN 1439-1791 EI 1618-0089 PY 2011 VL 12 IS 5 BP 413 EP 422 DI 10.1016/j.baae.2011.05.006 UT WOS:000294742400004 ER PT J AU Ossbo, A Lantto, P AF Ossbo, Asa Lantto, Patrik TI COLONIAL TUTELAGE AND INDUSTRIAL COLONIALISM Reindeer husbandry and early 20th-century hydroelectric development in Sweden SO SCANDINAVIAN JOURNAL OF HISTORY AB The incentives for large-scale hydropower development in Sweden are usually explained in terms of the early 20th-century belief in progress and the need for energy to fuel industrialization and modernization. For reindeer husbandry, the consequences and cumulative effects of this large-scale landscape conversion, and the societal changes it entailed are still largely a story to be told as impacts and effects constantly evolve in the socio-ecological system of the reindeer grazing lands. The present article(1) investigates hydropower development in the northern parts of Sweden, and how the reindeer husbandry of the indigenous Sami people was involved, through a case study of three hydropower projects in the early 20th century. An additional perspective is illuminated: how early hydroelectric development in the reindeer grazing areas was made possible through an immersed colonialism. SN 0346-8755 EI 1502-7716 PY 2011 VL 36 IS 3 BP 324 EP 348 DI 10.1080/03468755.2011.580077 UT WOS:000294119300004 ER PT J AU Svoboda, NJ Belant, JL Beyer, DE Duquette, JF Stricker, HK Albright, CA AF Svoboda, Nathan J. Belant, Jerrold L. Beyer, Dean E. Duquette, Jared F. Stricker, Heather K. Albright, Craig A. TI American black bear predation of an adult white-tailed deer SO URSUS AB American black bears (Ursus americanus) are opportunistic omnivores and can be proficient predators of neonate ungulates, but predation of adult ungulates is rare. In November 2009 we investigated a probable black bear predation of a radiocollared, adult (7.5 years old) female white-tailed deer (Odocoileus virginianus) in a densely vegetated, lowland conifer forest in the Upper Peninsula of Michigan, USA. The deer carcass was 80% buried with puncture wounds and lacerations on the back and hindquarters. The hide was everted, the intestines and stomach partially eaten, the mammary glands were punctured, and the skeleton remained articulated. All woody vegetation <5.0 cm diameter within 5 m of the carcass was trampled and contained bear and deer hair. We found no evidence of other carnivores. Based on the condition of the carcass, physical evidence at the site, and the similarity of this predation to reported black bear predations, we suggest this deer was attacked and killed by a black bear. SN 1537-6176 PY 2011 VL 22 IS 1 BP 91 EP 94 DI 10.2192/URSUS-D-10-00024.1 UT WOS:000290372000009 ER PT J AU Swain, DL Friend, MA Bishop-Hurley, GJ Handcock, RN Wark, T AF Swain, D. L. Friend, M. A. Bishop-Hurley, G. J. Handcock, R. N. Wark, T. TI Tracking livestock using global positioning systems - are we still lost? SO ANIMAL PRODUCTION SCIENCE AB Since the late 1980s, satellite-based global positioning systems (GPS) have provided unique and novel data that have been used to track animal movement. Tracking animals with GPS can provide useful information, but the cost of the technology often limits experimental replication. Limitations on the number of devices available to monitor the behaviour of animals, in combination with technical constraints, can weaken the statistical power of experiments and create significant experimental design challenges. The present paper provides a review and synthesis of using GPS for livestock-based studies and suggests some future research directions. Wildlife ecologists working in extensive landscapes have pioneered the use of GPS-based devices for tracking animals. Wildlife researchers have focussed efforts on quantifying and addressing issues associated with technology limitations, including spatial accuracy, rate of data collection, battery life and environmental factors causing loss of data. It is therefore not surprising that there has been a significant number of methodological papers published in the literature that have considered technical developments of GPS-based animal tracking. Livestock scientists have used GPS data to inform them about behavioural differences in free-grazing experiments. With a shift in focus from the environment to the animal comes the challenge of ensuring independence of the experimental unit. Social facilitation challenges independence of the individual in a group. The use of spatial modelling methods to process GPS data provides an opportunity to determine the degree of independence of data collected from an individual animal within behavioural-based studies. By using location and movement information derived from GPS data, researchers have been able to determine the environmental impact of grazing animals as well as assessing animal responses to management activities or environmental perturbations. Combining satellite-derived remote-sensing data with GPS-derived landscape preference indices provides a further opportunity to identify landscape avoidance and selection behaviours. As spatial livestock monitoring tools become more widely used, there will be a greater need to ensure the data and associated processing methods are able to answer a broader range of questions. Experimental design and analytical techniques need to be given more attention if GPS technology is to provide answers to questions associated with free-grazing animals. RI Handcock, Rebecca/B-5378-2011; Friend, Michael/P-1454-2018; Bishop-Hurley, Gregory/G-6914-2013; Wark, Tim/C-9920-2009; CSIRO, SAF/H-3134-2013 OI Handcock, Rebecca/0000-0001-5903-6620; Friend, Michael/0000-0001-7750-0570; Bishop-Hurley, Gregory/0000-0002-7671-8292; SN 1836-5787 PY 2011 VL 51 IS 3 BP 167 EP 175 DI 10.1071/AN10255 UT WOS:000288014900001 ER PT J AU Roturier, S Sunden, M Bergsten, U AF Roturier, Samuel Sunden, Maria Bergsten, Urban TI Re-establishment rate of reindeer lichen species following conventional disc trenching and HuMinMix soil preparation in Pinus-lichen clear-cut stands: a survey study in northern Sweden SO SCANDINAVIAN JOURNAL OF FOREST RESEARCH AB The re-establishment rates of reindeer lichen following conventional soil preparation by disc trenching and gentle soil preparation using HuMinMix apparatus were calculated from data acquired in surveys of 17 Pinus-lichen clear-cut stands in northern Sweden conducted 1-15 years after the treatments. The maximum lichen cover and biomass recorded in areas scarified by disc trenching were 29% and 24% of the lichen cover and biomass measured in adjacent intact lichen mats in the surveyed stands after 15 years. By contrast, 9 years after scarification, the corresponding percentages measured in areas disturbed by the HuMinMix treatment were 91% and 100%, respectively. According to calculated linear regressions, the reindeer lichen cover could be completely re-established just one decade after HuMinMix treatment. Ground lichen diversity in the scarified areas was also inventoried. The significant increase in lichen diversity for HuMinMix, especially of early-successional species, could explain the more rapid re-establishment of late-successional lichens (e.g. Cladonia stellaris spp.), compared with disc trenching. Thus, the study demonstrates that both the degree of initial disturbance and the re-establishment rate of reindeer lichen must be considered when estimating the effects of scarification on lichen loss for reindeer grazing over time. SN 0282-7581 EI 1651-1891 PY 2011 VL 26 IS 2 BP 90 EP 98 AR PII 929352970 DI 10.1080/02827581.2010.528019 UT WOS:000287490100003 ER PT J AU Gilichinsky, M Sandstrom, P Reese, H Kivinen, S Moen, J Nilsson, M AF Gilichinsky, Michael Sandstrom, Per Reese, Heather Kivinen, Sonja Moen, Jon Nilsson, Mats TI Mapping ground lichens using forest inventory and optical satellite data SO INTERNATIONAL JOURNAL OF REMOTE SENSING AB Lichen is a major forage resource for reindeer and may constitute up to 80% of a reindeer's winter diet. The reindeer grazing area in Sweden covers almost half of the country, with reindeer using mountainous areas in the summer and forested areas in the winter. Knowledge about the spatial distribution of ground lichens is important for both practical and decision-making purposes. Since the early 1980s, remote sensing research of lichen cover in northern environments has focused on reindeer grazing issues. The objective of this study was to use lichen information collected in the Swedish National Forest Inventory (NFI) as training data to classify optical satellite images into ground lichen cover classes. The study site was located within the reindeer husbandry area in northern Sweden and consisted of the common area between two contiguous Satellite Pour l'Observation de la Terre (SPOT)-5 scenes and one Landsat-7 Enhanced Thematic Mapper Plus (ETM+) scene. Three classification methods were tested: Mahalanobis distance, maximum likelihood and spectral mixture analysis. Post-classification calibration was applied using a membership probability threshold in order to match the NFI-measured proportions of lichen coverage classes. The classification results were assessed using an independently collected field dataset (229 validation areas). The results demonstrated high classification accuracy of SPOT imagery for the classification of lichen-abundant and lichen-poor areas when using the Mahalanobis distance classifier (overall accuracy 84.3%, kappa = 0.68). The highest classification accuracy for Landsat was achieved using a maximum likelihood classification (overall accuracy 76.8%, kappa = 0.53). These results provided an initial indication of the utility of NFI data as training data in the process of mapping lichen classes over large areas. RI Reese, Heather/B-5719-2008 OI Reese, Heather/0000-0003-2128-7787 SN 0143-1161 PY 2011 VL 32 IS 2 BP 455 EP 472 AR PII 933108855 DI 10.1080/01431160903474962 UT WOS:000287026900009 ER PT J AU Ravolainen, VT Brathen, KA Ims, RA Yoccoz, NG Henden, JA Killengreen, ST AF Ravolainen, Virve Tuulia Brathen, Kari Anne Ims, Rolf Anker Yoccoz, Nigel Gilles Henden, John-Andre Killengreen, Siw T. TI Rapid, landscape scale responses in riparian tundra vegetation to exclusion of small and large mammalian herbivores SO BASIC AND APPLIED ECOLOGY AB Productive tundra plant communities composed of a variety of fast growing herbaceous and woody plants are likely to attract mammalian herbivores. Such vegetation is likely to respond to different-sized herbivores more rapidly than currently acknowledged from the tundra. Accentuated by currently changing populations of arctic mammals there is a need to understand impacts of different-sized herbivores on the dynamics of productive tundra plant communities. Here we assess the differential effects of ungulate (reindeer) and small rodent herbivores (voles and lemmings) on high productive tundra vegetation. A spatially extensive exclosure experiment was run for three years on river sediment plains along two river catchments in low-arctic Norway. The river catchments were similar in species pools but differed in species abundance composition of both plants and vertebrate herbivores. Biomass of forbs, deciduous shrubs and silica-poor grasses increased by 40-50% in response to release from herbivory, whereas biomass of silica-rich grasses decreased by 50-75%. Hence both additive and compensatory effects of small rodents and reindeer exclusion caused these significant changes in abundance composition of the plant communities. Changes were also rapid, evident after only one growing season, and are among the fastest and strongest ever documented in Arctic vegetation. The rate of changes indicates a tight link between the dynamics of productive tundra vegetation and both small and large herbivores. Responses were however not spatially consistent, being highly different between the catchments. We conclude that despite similar species pools, variation in plant species abundance and herbivore species dynamics give different prerequisites for change. RI Killengreen, Siw/G-9205-2016; Yoccoz, Nigel/C-8561-2014 OI Yoccoz, Nigel/0000-0003-2192-1039; Brathen, Kari Anne/0000-0003-0942-1074; Henden, John-Andre/0000-0002-8825-1167 SN 1439-1791 PY 2011 VL 12 IS 8 BP 643 EP 653 DI 10.1016/j.baae.2011.09.009 UT WOS:000299187500001 ER PT J AU Stark, S Mannisto, MK Smolander, A AF Stark, Sari Mannisto, Minna K. Smolander, Aino TI Multiple effects of reindeer grazing on the soil processes in nutrient-poor northern boreal forests SO SOIL BIOLOGY & BIOCHEMISTRY AB Reindeer grazing has a great influence on the ground vegetation of nutrient-poor northern boreal forests dominated by Cladonia lichens in Fennoscandia. Grazing may influence the soil processes in these systems either by influencing the quality of plant litter, or by indirect effects through the soil micro-climate. In order to investigate the mechanisms underlying the effects of reindeer on boreal forest soils, we analyzed litter decomposition, soil and microbial C and N. microbial community composition, and soil organic matter quality in three forest sites with old reindeer exclosures adjacent to grazed areas. There was no effect of grazing on soil C/N ratio, inorganic N concentrations, microbial biomass C. microbial community structure analyzed by phospholipid fatty acid (PLFA) analysis, and organic matter quality analyzed by sequential fractionation, in the soil organic layer. However, microbial N was enhanced by grazing at some of the sampling dates and was negatively correlated with soil moisture, which indicates that increased microbial N could be a stress response to drought. The effect of grazing on litter decomposition varied among the decomposition stages: during the first 1.5 months, the litter C loss was significantly higher in the grazed than the ungrazed areas, but the difference rapidly levelled out and, after one year, the accumulated litter C loss was higher in the ungrazed than the grazed areas. Litter N loss was, however, higher in the grazed areas. Our study demonstrates that herbivores may influence soil processes through several mechanisms at the same time, and to a varying extent in the different stages of decomposition. (C) 2010 Elsevier Ltd. All rights reserved. RI Stark, Sari/L-4440-2013 SN 0038-0717 PD DEC PY 2010 VL 42 IS 12 BP 2068 EP 2077 DI 10.1016/j.soilbio.2010.08.001 UT WOS:000284294600005 ER PT J AU Torp, M Witzell, J Baxter, R Olofsson, J AF Torp, Mikaela Witzell, Johanna Baxter, Robert Olofsson, Johan TI The Effect of Snow on Plant Chemistry and Invertebrate Herbivory: Experimental Manipulations Along a Natural Snow Gradient SO ECOSYSTEMS AB Changing snow conditions have strong effects on northern ecosystems, but these effects are rarely incorporated into ecosystem models and our perception of how the ecosystems will respond to a warmer climate. We investigated the relationships between snow cover, plant phenology, level of invertebrate herbivory and leaf chemical traits in Betula nana in four different habitats located along a natural snow cover gradient. To separate the effect of snow per se from other differences, we manipulated the snow cover with snow fences in three habitats. The experimentally prolonged snow cover delayed plant phenology, but not as much as expected based on the pattern along the natural gradient. The positive effect of the snow treatment on plant nitrogen concentration was also weaker than expected, because plant nitrogen concentration closely followed plant phenology. The level of herbivory by leaf-chewing invertebrates increased in response to an increased snow cover, at least at the end of the growing season. The concentration of phenolic substances varied among habitats, treatments and sampling occasions, indicating that B. nana shrubs were able to retain a mosaic of secondary chemical quality despite altered snow conditions. This study shows that the effect of the snow cover period on leaf nitrogen concentration and level of herbivory can be predicted based on differences between habitats, whereas the effect of a changed plant phenology on plant nitrogen concentration is better explained by temporal trends within habitats. These results have important implications for how northern ecosystems should respond to future climate changes. RI Baxter, Robert/C-7688-2012 OI Baxter, Robert/0000-0002-7504-6797; Witzell, Johanna/0000-0003-1741-443X SN 1432-9840 PD AUG PY 2010 VL 13 IS 5 BP 741 EP 751 DI 10.1007/s10021-010-9351-4 UT WOS:000280260100009 ER PT J AU Sanchez-Prieto, CB Carranza, J Perez-Gonzalez, J Alarcos, S Mateos, C AF Sanchez-Prieto, Cristina B. Carranza, Juan Perez-Gonzalez, Javier Alarcos, Susana Mateos, Concha TI Effects of small barriers on habitat use by red deer: Implications for conservation practices SO JOURNAL FOR NATURE CONSERVATION AB Artificial barriers such as wire fences constitute a common conservation management practice to protect vegetation from the browsing impact of large herbivores. A part from protecting the fenced area, these barriers may affect the use of adjacent areas by animals. For example, they may interrupt major movement routes. We studied the effect of fences on an area used by red deer in Donana National Park (Andalucia, southwest Spain). We used an observational approach to study the effect of existing permanent barriers, and an experimental approach to investigate the effect of new barriers placed between the main areas through which animals moved from resting to for aging sites. Our study was carried out during the mating season, so we could also observe the effects on the distribution of females among harems. We found that "shadow areas'', where projection lines of the movement from resting to foraging areas were interrupted by the barrier, were used less by deer. In agreement with this result, grasses in shadow areas tended to belonger than in other areas, indicating unequaluse of resources depending on the placement of barriers. Also, permanent barriers appeared to have negative, long-term effects on the maintenance of meadows as denoted by a higher proportion of rushes in meadows within shadow areas. Experimental barriers supported the cause-effect relationship by decreasing the number of deer using the experimental shadow areas. Our results demonstrated unexpected ecological effects of small barriers on the landscape, mediated by modification of the spatial behaviour of red deer. (C) 2009 Elsevier GmbH. All rights reserved. RI Carranza, Juan/E-4472-2010 OI Carranza, Juan/0000-0002-0368-7173; Perez-Gonzalez, Javier/0000-0003-0624-835X SN 1617-1381 EI 1618-1093 PD AUG PY 2010 VL 18 IS 3 BP 196 EP 201 DI 10.1016/j.jnc.2009.09.002 UT WOS:000278650600006 ER PT J AU Singh, NJ Grachev, IA Bekenov, AB Milner-Gulland, EJ AF Singh, N. J. Grachev, I. A. Bekenov, A. B. Milner-Gulland, E. J. TI Saiga antelope calving site selection is increasingly driven by human disturbance SO BIOLOGICAL CONSERVATION AB Many terrestrial mammalian species aggregate to give birth. Such aggregations are likely to be a response to changing resource and water availability, for predator swamping and avoidance of disturbance. The critically endangered saiga antelope (Saiga tatarica) is one such species. We analysed spatio-temporal locations of saiga calving aggregations in Kazakhstan over the last four decades obtained from aerial and ground surveys, to identify the factors determining the selection of calving sites within the species' range as well as any changes in these locations over time. Generalized mixed models were employed in a use - availability framework to assess the factors distinguishing calving from random sites and predict suitable areas for calving. Saigas selected sites, with lower than average productivity and low year to year variability in productivity, at an intermediate distance from water sources, and away from human settlements. A significant change in calving locations was observed during the last decade, with calving areas occurring further north and further away from settlements than previously. The results demonstrate that the choice of calving areas is largely driven by environmental factors. However, disturbance also has a significant impact on calving site selection and in recent decades, its influence overrides that of environmental factors. This increase in the influence of disturbance coincides with a precipitous decline in saiga numbers due to poaching, as well as substantial reductions in the intensity of land use for livestock grazing following the breakup of the Soviet Union. Predictive models based on such studies can improve species conservation by guiding the stratification of sampling for effective monitoring and deployment of rangers to protect the females at this critical time. (C) 2010 Elsevier Ltd. All rights reserved. RI Singh, Navinder/E-3914-2010 OI Milner-Gulland, E.J./0000-0003-0324-2710 SN 0006-3207 EI 1873-2917 PD JUL PY 2010 VL 143 IS 7 BP 1770 EP 1779 DI 10.1016/j.biocon.2010.04.026 UT WOS:000279413800021 ER PT J AU Gustine, DD Barboza, PS Lawler, JP AF Gustine, David D. Barboza, Perry S. Lawler, James P. TI Dynamics of Body Protein and the Implications for Reproduction in Captive Muskoxen (Ovibos moschatus) during Winter SO PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY AB Muskoxen are considered to be obligate capital breeders because they rely exclusively on endogenous stores to reproduce. We studied 14 captive female muskoxen (not pregnant, n = 9; pregnant, n = 5) in February-June 2007 to assess changes in body composition and isotopic correlates of protein status (proportions of amino acid [p-AN] and urea N [p-UN] derived from body N). We measured body mass, body composition, and N metabolites in blood and urine between midgestation in February and early lactation (postcalving). All muskoxen lost body mass (-6% to -12%) and fat (-22% to -24%) over the winter, and pregnant muskoxen lost body protein (-6%) in late gestation. Nonpregnant animals maintained stores of body protein (+6%) in late winter. Losses of body protein in pregnant muskoxen (255 +/- 71.5 mg protein kg(-0.75) d(-1)) were similar to the amount of protein deposited in reproductive tissues (319 +/- 33.4). Plasma urea concentration increased (27-59 mg dL(-1)) with p-UN (0.13-0.33), which indicated oxidation of amino N during late winter. High estimates of p-AN (0.72 +/- 0.07) indicated that amino N from body protein was reutilized in late winter. Muskoxen conserve the capital of body protein stores for reproductive investment while using income of dietary protein for maintenance functions. We conclude that variation in protein supplies from body stores and the diet explain a large part of the variation in productivity of Arctic ungulates. SN 1522-2152 PD JUL-AUG PY 2010 VL 83 IS 4 BP 687 EP 697 DI 10.1086/652729 UT WOS:000278785100012 PM 20497043 ER PT J AU Kivinen, S Moen, J Berg, A Eriksson, A AF Kivinen, Sonja Moen, Jon Berg, Anna Eriksson, Asa TI Effects of Modern Forest Management on Winter Grazing Resources for Reindeer in Sweden SO AMBIO AB Boreal forests in Sweden are exploited in a number of ways, including forestry and reindeer husbandry. In the winter, reindeer feed mainly on lichens, and lichen-rich forests are a key resource in the herding system. Commercial forestry has mainly negative effects on reindeer husbandry, and conflicts between these two industries have escalated over the last century. This article reviews the effects of modern forest management practices on the winter resources available for reindeer husbandry. Forestry affects reindeer husbandry at both the stand level and the landscape level and over various time scales. Clear-cutting, site preparation, fertilization, short rotation times, and forest fragmentation have largely resulted in a reduced amount of ground growing and arboreal lichens and restricted access to resource. This article also discusses alternative forestry practices and approaches that could reduce the impacts of forestry on reindeer husbandry, both in the short and long term. SN 0044-7447 PD JUN PY 2010 VL 39 IS 4 BP 269 EP 278 DI 10.1007/s13280-010-0044-1 UT WOS:000281755800001 PM 20799676 ER PT J AU Kaeuffer, R Bonenfant, C Chapuis, JL Devillard, S AF Kaeuffer, Renaud Bonenfant, Christophe Chapuis, Jean-Louis Devillard, Sebastien TI Dynamics of an introduced population of mouflon Ovis aries on the sub-Antarctic archipelago of Kerguelen SO ECOGRAPHY AB A commonly reported pattern in large herbivores is their propensity to irrupt and crash when colonizing new areas. However, the relative role of density-dependence, climate, and cohort effects on demographic rates in accounting for the irruptive dynamics of large herbivores remains unclear. Using a 37-yr time series of abundance in a mouflon Ovis aries population located on Haute Island, a sub-Antarctic island of Kerguelen, 1) we investigated if irruptive dynamics occurred and 2) we quantified the relative effects of density and climate on mouflon population dynamics. Being released in a new environment, we expected mouflon to show rapid growth and marked over-compensation. In support of this prediction, we found a two-phase dynamics, the first phase being characterised by an irruptive pattern best described by the theta-Caughley model. Parameter estimates were r(m)=0.29 +/- 0.005(maximum growth rate), K=473 +/- 45 (carrying capacity) and S=2903 +/- 396 (surplus) mouflon. With a theta=3.18 +/- 0.69 our model also supported the hypothesis that density dependence is strongest at high density in large herbivores. The second phase was characterised by an unstable dynamics where growth rate was negatively affected by population abundance and winter precipitation. Climate, however, did not trigger population crashes and our model suggested that lagged density-dependence and over-grazing were the probable causes of mouflon irruptive dynamics. We compare our results with those of Soay sheep and discuss the possibility of a reversible alteration of the island carrying capacity after the initial over-grazing period. OI Bonenfant, Christophe/0000-0002-9924-419X SN 0906-7590 PD JUN PY 2010 VL 33 IS 3 BP 435 EP 442 DI 10.1111/j.1600-0587.2009.05604.x UT WOS:000280457500002 ER PT J AU Hackmann, TJ Spain, JN AF Hackmann, T. J. Spain, J. N. TI Invited review: Ruminant ecology and evolution: Perspectives useful to ruminant livestock research and production SO JOURNAL OF DAIRY SCIENCE AB The article reviews ruminant ecology and evolution and shows insights they offer into livestock research. The first ruminants evolved about 50 million years ago and were small (<5 kg) forest-dwelling omnivores. Today there are almost 200 living ruminant species in 6 families. Wild ruminants number about 75 million, range from about 2 to more than 800 kg, and generally prefer at least some browse in their diets. Nine species have been domesticated within the last 10,000 yr. Their combined population currently numbers 3.6 billion. In contrast to wild ruminants, domestic species naturally prefer at least some grass in their diets, are of large body weight (BW; roughly from 35 to 800 kg), and, excepting reindeer, belong to one family (Bovidae). Wild ruminants thus have a comparatively rich ecological diversity and long evolutionary history. Studying them gives a broad perspective that can augment and challenge the status quo of ruminant research and production. Allometric equations, often used in ecology, relate BW to physiological measurements from several species (typically both wild and domestic). They are chiefly used to predict or explain values of physiological parameters from BW alone. Results of one such equation suggest that artificial selection has increased peak milk energy yield by 250% over its natural level. Voluntary feed intake is proportional to BW0.9 across wild and domestic ruminant species. This proportionality suggests that physical and metabolic factors regulate intake simultaneously, not mutually exclusively as often presumed. Studying the omasum in wild species suggests it functions primarily in particle separation and retention and only secondarily in absorption and other roles. Studies on the African Serengeti show that multiple species, when grazed together, feed such that they use grasslands more completely. They support the use of mixed-species grazing systems in production agriculture. When under metabolic stress, wild species will not rebreed, but rather will extend lactation (to nourish their current offspring). This bolsters the suggestion that lactation length be extended in dairy operations. Cooperation between animal scientists and ecologists could generate more valuable insight. SN 0022-0302 EI 1525-3198 PD APR PY 2010 VL 93 IS 4 BP 1320 EP 1334 DI 10.3168/jds.2009-2071 UT WOS:000275867200002 PM 20338409 ER PT J AU Gonzalez, VT Brathen, KA Ravolainen, VT Iversen, M Hagen, SB AF Gonzalez, Victoria T. Brathen, Kari Anne Ravolainen, Virve T. Iversen, Marianne Hagen, Snorre B. TI Large-scale grazing history effects on Arctic-alpine germinable seed banks SO PLANT ECOLOGY AB Grazing constitutes a selective pressure on vegetation recruitment through modification of the seed banks. Here we address changes in seed bank density and its life history trait composition in century-old pastures, where contrasting reindeer densities have developed during the last decades. We cover the actual scales used by these wide-roaming herbivores by sampling 70 productive tundra habitats over 7,421 km(2) in the reindeer summer pastures of Northern Norway. Results showed that the seed bank density was significantly lowered where reindeer densities had increased in recent decades, whereas the century-long history of grazing probably explains the main seed bank traits typical of grazing tolerant plants. The dominant trait characteristics were small seeds (< 0.5 mg), seeds lacking dispersal mechanism and individuals with a graminoid growth form. Finally, differences between regions introduced trait variation independent of grazing history, reinforcing the importance of using scales covering several contexts when designing ecological studies. RI Hagen, Snorre/O-5220-2015 OI Hagen, Snorre/0000-0001-8289-7752; Brathen, Kari Anne/0000-0003-0942-1074 SN 1385-0237 PD APR PY 2010 VL 207 IS 2 BP 321 EP 331 DI 10.1007/s11258-009-9676-2 UT WOS:000275123700012 ER PT J AU Nybakken, L Helmersen, AM Gauslaa, Y Selas, V AF Nybakken, Line Helmersen, Anne-Marit Gauslaa, Yngvar Selas, Vidar TI Lichen Compounds Restrain Lichen Feeding by Bank Voles (Myodes glareolus) SO JOURNAL OF CHEMICAL ECOLOGY AB Some lichen compounds are known to deter feeding by invertebrate herbivores. We attempted to quantify the deterring efficiency of lichen compounds against a generalist vertebrate, the bank vole (Myodes glareolus). In two separate experiments, caged bank voles had the choice to feed on lichens with natural or reduced concentrations of secondary compounds. We rinsed air-dry intact lichens in 100% acetone to remove extracellular compounds non-destructively. In the first experiment, pairs of control and rinsed lichen thalli were hydrated and offered to the bank voles. Because the lichens desiccated fast, we ran a second experiment with pairs of ground control and compound-deficient thalli, each mixed with water to porridge. Eight and six lichen species were tested in the first and second experiment, respectively. In the first, bank voles preferred compound-deficient thalli of Cladonia stellaris and Lobaria pulmonaria, but did not discriminate between the other thallus pairs. This was likely a result of deterring levels of usnic and stictic acid in the control thalli. When lichens were served as porridge, significant preference was found for acetone-rinsed pieces of Cladonia arbuscula, C. rangiferina, Platismatia glauca, and Evernia prunastri. The increased preference was caused mainly by lower consumption of control thalli. Grinding and mixing of thallus structures prevented bank voles from selecting thallus parts with lower concentration of secondary compounds and/or strengthened their deterring capacity. We conclude that some lichen secondary compounds deter feeding by bank voles. RI Gauslaa, Yngvar/K-9006-2012 SN 0098-0331 PD MAR PY 2010 VL 36 IS 3 BP 298 EP 304 DI 10.1007/s10886-010-9761-y UT WOS:000275539800006 PM 20186468 ER PT J AU Lechner, I Barboza, P Collins, W Fritz, J Gunther, D Hattendorf, B Hummel, J Sudekum, KH Clauss, M AF Lechner, Isabel Barboza, Perry Collins, William Fritz, Julia Guenther, Detlef Hattendorf, Bodo Hummel, Juergen Suedekum, Karl-Heinz Clauss, Marcus TI Differential passage of fluids and different-sized particles in fistulated oxen (Bos primigenius f. taurus), muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces): Rumen particle size discrimination is independent from contents stratification SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY AB Ruminant species differ in the degree that their rumen contents are stratified but are similar insofar that only very fine particles are passed from the forestomach to the lower digestive tract. We investigated the passage kinetics of fluid and particle markers (2, 10 and 20 mm) in fistulated cattle (Bos primigenius E taurus), muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces) on different diets. The distribution of dry matter in the rumen and the viscosity of rumen fluids suggested that the rumen contents were more stratified in muskoxen than moose. Correspondingly, as in previous studies, the species differed in the ratio of mean retention times of small particles to fluids in the reticulorumen, which was highest in cattle (2.03) and muskoxen (1.97-1.98), intermediate in reindeer (1.70) and lowest in moose (0.98-1.29). However, the ratio of large to small particle retention did not differ between the species, indicating similarity in the efficiency of the particle sorting mechanism. Passage kinetics of the two largest particle classes did not differ, indicating that particle retention is not a continuous function of particle size but rather threshold-dependent. Overall, the results suggest that fluid flow through the forestomach differs between ruminant species. A lower relative fluid passage, such as in moose, might limit species to a browse-based dietary niche, whereas a higher relative fluid passage broadens the dietary niche options and facilitates the inclusion of, or specialization on, grass. The function of fluid flow in the ruminant forestomach should be further investigated. (C) 2009 Elsevier Inc. All rights reserved. RI Clauss, Marcus/A-4710-2008 OI Clauss, Marcus/0000-0003-3841-6207; Lechner, Isabel/0000-0001-5155-9734 SN 1095-6433 EI 1531-4332 PD FEB PY 2010 VL 155 IS 2 BP 211 EP 222 DI 10.1016/j.cbpa.2009.10.040 UT WOS:000273926200012 PM 19896552 ER PT J AU Rivals, F Mihlbachler, MC Solounias, N Mol, D Semprebon, GM de Vos, J Kalthoff, DC AF Rivals, Florent Mihlbachler, Matthew C. Solounias, Nikos Mol, Dick Semprebon, Gina M. de Vos, John Kalthoff, Daniela C. TI Palaeoecology of the Mammoth Steppe fauna from the late Pleistocene of the North Sea and Alaska: Separating species preferences from geographic influence in paleoecological dental wear analysis SO PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY AB The paleodietary ecology of Late Pleistocene ungulate faunas of the Mammoth Steppe ecosystem was investigated at Fairbanks (Alaska) and Brown Bank (North Sea) through dental mesowear and microwear analysis. The purpose of the study is to address questions concerning the paleoecology of the Mammoth Steppe, an ecosystem that has no extant analog. Dental wear patterns indicate that the niche partitioning at Brown Bank (BB) region was consistent with ecosystem dynamics found in diverse ungulate faunas in recent time. In contrast, despite the lower numbers of extinct taxa, the Fairbanks (FB) fauna is ecologically bizarre. In general, the microwear of this fauna includes excessive numbers of very (narrow) fine scratches that are atypical for extant mixed feeders and grazers. Moreover, the mesowear signal suggests unusual paleodiets (niche dynamics), where low-crowned mixed-feeding cervids, Rangifer and Cervus, adopted diets that are similar to Equus in terms of mesowear (abrasion) and much more abrasive than the diets of either Bison or Ovis. We suggest that the anomalies may relate to unique, possibly disharmonious, ecosystem dynamics during the Pleistocene-Holocene transition. In addition to these findings, it was discovered (found) that dental wear patterns, particularly microwear variables such as scratch frequency and scratch width are strongly affected by geographic region, irrespective of species-specific dietary preferences. (C) 2009 Elsevier B.V. All rights reserved. RI Rivals, Florent/B-7962-2014 OI Rivals, Florent/0000-0001-8074-9254 SN 0031-0182 EI 1872-616X PD FEB 1 PY 2010 VL 286 IS 1-2 BP 42 EP 54 DI 10.1016/j.palaeo.2009.12.002 UT WOS:000274970400004 ER PT J AU Olofsson, J Moen, J Ostlund, L AF Olofsson, Johan Moen, Jon Ostlund, Lars TI Effects of reindeer on boreal forest floor vegetation: Does grazing cause vegetation state transitions? SO BASIC AND APPLIED ECOLOGY AB Intensive reindeer grazing has been hypothesized to drive vegetation shifts in the arctic tundra from a low-productive lichen dominated state to a more productive moss dominated state Although the more productive state can potentially host more herbivores, it may still be less suitable as winter grazing grounds for reindeer, if lichens, the most preferred winter forage, are less abundant Therefore, such a shift towards mosses may have severe consequences for reindeer husbandry if ground-growing lichens have difficulties to recover We tested if reindeer cause this type of vegetation state shifts in boreal forest floor vegetation, by comparing plant species composition and major soil processes inside and outside of more than 40-year-old exclosures Lichen biomass was more than twice as high inside exclosures than in grazed controls and almost 5 times higher than in heavily grazed patches Contrary to our predictions, net N mineralization and plant production were higher in the exclosures than in the grazed controls The lack of response of phytometer plants in a common garden bioassay indicated that changed soil moisture may drive effects of reindeer on plant productivity in these dry Pine forest ecosystems OI Ostlund, Lars/0000-0002-7902-3672 SN 1439-1791 PY 2010 VL 11 IS 6 BP 550 EP 557 DI 10.1016/j.baae.2010.03.004 UT WOS:000283977200009 ER PT S AU Gilichinsky, M Sandstrom, P Reese, H Kivinen, S Moen, J Nilson, M AF Gilichinsky, Michael Sandstrom, Per Reese, Heather Kivinen, Sonja Moen, Jon Nilson, Mats BE Peled, A TI APPLICATION OF NATIONAL FOREST INVENTORY FOR REMOTE SENSING CLASSIFICATION OF GROUND LICHEN IN NOTHERN SWEDEN SO CORE SPATIAL DATABASES - UPDATING, MAINTENANCE AND SERVICES - FROM THEORY TO PRACTICE SE International Archives of the Photogrammetry Remote Sensing and Spatial Information Sciences CT Conference on Core Spatial Databases - Updating, Maintenance and Services - from Theory to Practice CY MAR 15-17, 2010 CL Haifa, ISRAEL AB Lichen is a major forage resource for reindeer and may constitute up to 80% of a reindeer's winter diet. The reindeer grazing area in Sweden covers almost half of the country, with reindeer using mountainous areas in the summer and forested areas in the winter. Knowledge about the spatial distribution of ground lichens is important for both practical and sustainable decision-making purposes. Since the early 1980s, remote sensing research of lichen cover in northern environments has focused on reindeer grazing issues. The objective of the present study was to use lichen information from the Swedish Forest Inventory (NFI) for classification of satellite data into ground lichen classes. The classification procedure was focused on using of NFI plots as training sets for supervised classification of the ground lichen cover in purpose to classify areas with different lichen coverage. The present research has shown the advantage of use forest inventory plot data by assessment of three methods: mahalanobis distance (MD) classification, maximum likelihood (ML) classification and spectral mixture analysis (SMA). The results of this study demonstrate high classification accuracy of SPOT imagery in distinction between lichen-abundant and lichen-poor areas by mahalanobis distance classifier (overall accuracy 84.3%, kappa=0.68). The highest classification accuracy for Landsat scene was achieved by maximum likelihood classification (overall accuracy 76.8%, kappa=0.53). The continuation research on more detailed fragmentation of lichen cover into fractions is proposed. SN 2194-9034 PY 2010 VL 38-4-8 IS 2W BP 146 EP 152 UT WOS:000341929500026 ER PT J AU Joly, K Chapin, FS Klein, DR AF Joly, Kyle Chapin, F. Stuart, III Klein, David R. TI Winter habitat selection by caribou in relation to lichen abundance, wildfires, grazing, and landscape characteristics in northwest Alaska SO ECOSCIENCE AB Lichens are an important winter forage for large, migratory herds of caribou (Rangifer tarandus granti) that can influence population dynamics through effects on body condition and in turn calf recruitment and survival. We investigated the vegetative and physiographic characteristics of winter range of the Western Arctic Herd in northwest Alaska, one of the largest caribou herds in North America. We made 3 broad comparisons: habitats used by caribou versus random locations, burned versus unburned habitats, and habitats within the current winter range versus those in the historic winter range and potential winter ranges. We found that lichen abundance was more than 3 times greater at locations used by caribou than found at random. The current winter range does not appear to be overgrazed as a whole, but continued high grazing pressure and consequences of climate change on plant community structure might degrade its condition. Within the current winter range, lichen abundance was more than 4 times greater at unburned locations than at recently (< 58 y) burned locations. Other than lichen abundance, there were few vegetative differences between burned (mean = 37 +/- 1.7 y) and unburned locations. The historic winter range has low lichen abundance, likely due to sustained grazing pressure exerted by the herd, which suggests that range deterioration can lead to range shifts. Recovery of this range may be slowed by continued grazing and trampling during migration of caribou to and from their current winter range, as well as by high wildfire frequency and other consequences of climate change. The area identified as potential winter range is unlikely to be utilized regularly by large numbers of caribou primarily due to low lichen abundance associated with extensive deciduous stands, large areas of riparian habitat, high moose (Alces alces) densities, and greater prevalence of wildfire. Our results suggest that lichens are important in the overwintering ecology of caribou that face the energetic costs of predator avoidance and migration. SN 1195-6860 PY 2010 VL 17 IS 3 BP 321 EP 333 DI 10.2980/17-3-3337 UT WOS:000282827800009 ER PT J AU Ravolainen, VT Yoccoz, NG Brathen, KA Ims, RA Iversen, M Gonzalez, VT AF Ravolainen, V. T. Yoccoz, N. G. Brathen, K. A. Ims, R. A. Iversen, M. Gonzalez, V. T. TI Additive Partitioning of Diversity Reveals No Scale-dependent Impacts of Large Ungulates on the Structure of Tundra Plant Communities SO ECOSYSTEMS AB Large herbivores can change ecosystem functioning by impacting plant diversity. However, although such impacts are expected to be scale-dependent in ecosystems with wide-roaming ungulates, scaling issues rarely enter empirical assessments. We here test the hypothesis that the impact of increased reindeer abundance on plant diversity in alpine tundra is scale-dependent. Based on potentially high productivity of the focal habitat units and hence the possibility of positive grazer impacts on plant diversity we predicted higher alpha and beta diversity at the habitat scale where reindeer densities are high. We also explored whether there were differences in diversity patterns at larger scales, including the scale of reindeer management districts. We estimated grazing disturbance as high versus low reindeer density in selected districts (a total extent of 7421 km(2)) of Northern Norway where reindeer-induced vegetation shifts are debated. We focus on dominance patterns because they can quantify the vegetation state and thus performed additive partitioning of Simpson diversity on multiple scales assessing also species' contributions to diversity. Contrary to our predictions, we found only weak scale-dependent effects of reindeer grazing on plant diversity. Under high reindeer densities there was evidence for a landscape-scale homogenization of the vegetation, but the predicted alpha and beta diversity increases at the habitat scale were not found. Consistently through all scales considered, four shrub species contributed the most to plant diversity. These results contradict the idea that reindeer at high stocking densities induce shifts in plant species dominance in productive habitats. We conclude that context-dependencies such as spatial scales of management units and habitat types need to be explicitly considered in evaluations of the impacts of large ungulates on plant diversity. RI Yoccoz, Nigel/C-8561-2014 OI Yoccoz, Nigel/0000-0003-2192-1039; Brathen, Kari Anne/0000-0003-0942-1074 SN 1432-9840 PD JAN PY 2010 VL 13 IS 1 BP 157 EP 170 DI 10.1007/s10021-009-9308-7 UT WOS:000275172700012 ER PT J AU Drucker, DG Hobson, KA Ouellet, JP Courtois, R AF Drucker, Dorothee G. Hobson, Keith A. Ouellet, Jean-Pierre Courtois, Rehaume TI Influence of forage preferences and habitat use on 13C and 15N abundance in wild caribou (Rangifer tarandus caribou) and moose (Alces alces) from Canada SO ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES AB Stable isotope composition (13C and 15N) of moose (Alces alces) and caribou (Rangifer tarandus) hair from the boreal forest of Jacques-Cartier Park and Cote-Nord (Quebec) and arctic tundra of Queen Maud Gulf and Southampton Island (Nunavut) was investigated as an indicator of dietary preferences and habitat use. Values of 13Chair and 15Nhair in moose were consistently lower compared to those of caribou. This is consistent with the depletion in 13C and 15N in the plants preferred by moose, essentially browse (shrub and tree leaves), compared to caribou forage, which included significant amounts of graminoids, lichen and fungi. The 13Chair values of caribou differed between closed boreal forest and open-tundra ecosystems. This pattern followed that expected from the canopy effect observed in plant communities. Variation in 15Nhair values of caribou was probably linked to the effect of different climatic conditions on plant communities. This study underlines the potential of isotopic analysis for studies on diet and habitat selection within a pure C3 plant environment. RI Drucker, Dorothee/E-8900-2011 OI Drucker, Dorothee/0000-0003-0854-4371 SN 1025-6016 EI 1477-2639 PY 2010 VL 46 IS 1 BP 107 EP 121 AR PII 919851107 DI 10.1080/10256010903388410 UT WOS:000275532900009 PM 20229388 ER PT J AU Matthews, A AF Matthews, Alison TI Changes in fine-scale movement and foraging patterns of common wombats along a snow-depth gradient SO WILDLIFE RESEARCH AB Context. Feeding strategies of large herbivores in snow-covered environments can be influenced by snow depth and snow quality. Common wombats, Vombatus ursinus, are large marsupial herbivores that occur in subalpine areas of Australia where they must dig through the snow to reach low vegetation. Deeper snow at higher elevations is considered to limit foraging and constrain their range, although there have been no quantitative studies investigating the influence of snow on their foraging behaviour. Aims. The present study examined how snow influenced the foraging behaviour of common wombats along a snow-depth gradient. Methods. During the 2008 winter season, snow tracks of 17 wombats were located within the subalpine zone, in a study area ranging from 1520 to 1850 masl, and followed to record attributes of the snow cover and environment in relation to wombat activity. Key results. Wombats selected sites to feed where the snow was shallower, and deeper snow at feeding sites caused changes in foraging behaviour. Foraging occurred along fairly direct routes between burrows; however, as snow depth increased, wombats deviated more from their path to seek out suitable foraging sites. Most foraging occurred in shallow snow in open areas or where the snow had melted around the bases of trees, shrubs or boulders. About half (52%) of the feeding sites necessitated the wombats digging through the snow to reach low vegetation, predominantly the grasses of Poa spp. Digging craters for feeding occurred in snow depths up to 100 cm, although depths less than 35 cm were preferred. Some shrub species, such as dusty daisy bush, Olearia phlogopappa, that protruded from the snow, were also eaten where the snow was deeper. Dietary analysis confirmed that monocots made up the majority of the diet (93.3%), although some individuals consumed up to 26% dicots. Conclusions. The present study demonstrated that wombats can adjust to a snow-covered environment by altering both their foraging patterns and diet as snow depth increases. However, they will be limited where snow depths are consistently greater than 100 cm. Implications. Under future climate-change scenarios of declining snow cover, wombats may be able to forage and inhabit higher altitudes than where they currently occur, and this has implications for the grazing-sensitive alpine ecosystem. Predicting shifts in the range of other herbivores to higher altitudes will require knowledge of their species-specific foraging thresholds in snow, such as presented in this study. OI Matthews, Alison/0000-0001-9099-9572 SN 1035-3712 PY 2010 VL 37 IS 3 BP 175 EP 182 DI 10.1071/WR09121 UT WOS:000279163600001 ER PT J AU Sundset, MA Edwards, JE Cheng, YF Senosiain, RS Fraile, MN Northwood, KS Praesteng, KE Glad, T Mathiesen, SD Wright, ADG AF Sundset, Monica A. Edwards, Joan E. Cheng, Yan Fen Senosiain, Roberto S. Fraile, Maria N. Northwood, Korinne S. Praesteng, Kirsti E. Glad, Trine Mathiesen, Svein D. Wright, Andre-Denis G. TI Rumen microbial diversity in Svalbard reindeer, with particular emphasis on methanogenic archaea SO FEMS MICROBIOLOGY ECOLOGY AB Ruminal methanogens, bacteria and ciliate protozoa of Svalbard reindeer grazing natural pastures in October (late fall) and April (late winter) were investigated using molecular-based approaches. The appetite of the Svalbard reindeer peaks in August (summer) and is at its lowest in March (winter). Microbial numbers, quantified by real-time PCR, did not change significantly between October and April, when food intakes are at similar levels, although the numbers of methanogens tended to be higher in October (P = 0.074), and ciliate numbers tended to be higher in April (P = 0.055). Similarly, no change was detected in the bacterial and protozoal population composition by rRNA gene-based denaturing gradient gel electrophoresis analysis. Dominant methanogens were identified using a 16S rRNA gene library (97 clones) prepared from pooled PCR products from reindeer on October pasture (n = 5). Eleven of the 22 distinct operational taxonomic units (OTUs) generated exhibited a high degree of sequence similarity to methanogens affiliated with Methanobacteriales (eight OTUs), Methanomicrobiales (one OTU) and Methanosarcinales (two OTUs). The remaining 11 OTUs (53% of the clones) were associated with a cluster of uncultivated ruminal archaea. This study has provided important insights into the rumen microbiome of a high-arctic herbivorous animal living under harsh nutritional conditions, and evidence suggesting that host type affects the population size of ruminal methanogens. RI Napal Fraile, Maria/A-7985-2013 OI Napal Fraile, Maria/0000-0002-1058-9395 SN 0168-6496 EI 1574-6941 PD DEC PY 2009 VL 70 IS 3 BP 553 EP 562 DI 10.1111/j.1574-6941.2009.00750.x UT WOS:000272348800020 PM 19702875 ER PT J AU Colman, JE Mysterud, A Jorgensen, NH Moe, SR AF Colman, J. E. Mysterud, A. Jorgensen, N. H. Moe, S. R. TI Active land use improves reindeer pastures: evidence from a patch choice experiment SO JOURNAL OF ZOOLOGY AB The industrialization of agriculture in western societies has often led to either intensified use or abandonment of farmland and open pastures, but experimental evidence on how the dynamics of farmed ecosystems affect space use by large herbivores is limited. We experimentally manipulated farmland patches with cutting and (early summer) low- and high-intensity domestic sheep Ovis aries grazing according to traditional use in north Norway. After treatments, grazing reindeer Rangifer tarandus were exposed to the pastures the subsequent fall (2 months after treatments) and spring (11 months after treatments) as they typically do on their migratory route between summer and winter ranges. The experiment was conducted over 2 subsequent years. We predicted that sheep grazing on farmland during early summer may affect the critical fall and spring range conditions for reindeer either through negative (delayed competition) or positive (grazing facilitation) interactions. We found that the most marked effect of land use on the grazing pattern of reindeer was between no use (the control treatment) and all the other management options involving active land use. The grazing reindeer avoided the pastures no longer in use likely due to senescent plant material. There was a tendency that the lower intensity sheep grazing patches attracted more reindeer than the highest intensity use. These results highlight not only the general principle that large-scale agricultural changes may affect large herbivores in natural ecosystems, but they also increase our understanding of grazing facilitation as a mechanism in large herbivore assemblages. RI Moe, Stein R./G-1507-2011 OI Moe, Stein R./0000-0003-1005-3192 SN 0952-8369 EI 1469-7998 PD DEC PY 2009 VL 279 IS 4 BP 358 EP 363 DI 10.1111/j.1469-7998.2009.00626.x UT WOS:000272172300006 ER PT J AU Joly, K Jandt, RR Klein, DR AF Joly, Kyle Jandt, Randi R. Klein, David R. TI Decrease of lichens in Arctic ecosystems: the role of wildfire, caribou, reindeer, competition and climate in north-western Alaska SO POLAR RESEARCH AB We review and present a synthesis of the existing research dealing with changing Arctic tundra ecosystems, in relation to caribou and reindeer winter ranges. Whereas pan-Arctic studies have documented the effects on tundra vegetation from simulated climate change, we draw upon recent long-term regional studies in Alaska that have documented the actual, on-the-ground effects. Our review reveals signs of marked change in Arctic tundra ecosystems. Factors known to be affecting these changes include wildfire, disturbance by caribou and reindeer, differential growth responses of vascular plants and lichens, and associated competition under climate warming scenarios. These factors are interrelated, and, we posit, unidirectional: that is, they are all implicated in the significant reduction of terricolous lichen ground cover and biomass during recent decades. Lichens constitute the primary winter forage for large, migratory caribou and reindeer herds, which in turn are a critical subsistence resource for rural residents in Alaska. Thus, declines in these lichens are a major concern for rural people who harvest caribou and reindeer for subsistence, as well as for sport hunters, reindeer herders, wildlife enthusiasts and land managers. We believe a more widely distributed and better integrated research programme is warranted to quantify the magnitude and extent of the decline in lichen communities across the Arctic. RI Jandt, Randi/E-9018-2013 OI Jandt, Randi/0000-0001-8471-792X SN 0800-0395 EI 1751-8369 PD DEC PY 2009 VL 28 IS 3 BP 433 EP 442 DI 10.1111/j.1751-8369.2009.00113.x UT WOS:000272163900012 ER PT J AU Pajunen, AM AF Pajunen, Anu Marjukka TI Environmental and Biotic Determinants of Growth and Height of Arctic Willow Shrubs along a Latitudinal Gradient SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Ecological factors determining the growth of arctic shrubs remain poorly understood, thereby obscuring the current predictions about climate change effects. I conducted a study on the Yamal Peninsula, West Siberia, to find out which factors determine the growth and height of upright willows (Sali.-V glauca and S. lanata). I sampled willow thickets at different slope positions at 13 sites along a 300-km-long north-south transect. The measurements included the height of willow shrubs and the length and diameter of shoots. The length and diameter of willow shoots increased southwards and with increasing distance from the sea. At the top of the slope and in areas with shallow thaw, the height and growth of willow were low compared to other slope positions and to areas with deep thaw. An increasing level of reindeer (Rangifer tarandus) grazing intensity was associated with decreased height and growth of willow and also associated with reduced foraging activity of willow grouse (Lagopus lagopus). The results show that even though increasing summer warmth is likely to enhance willow growth, there are other factors such as distance from the sea that also affect the growth and height of willow. The results suggest that reindeer grazing may locally counteract the effects of climate change. SN 1523-0430 PD NOV PY 2009 VL 41 IS 4 BP 478 EP 485 DI 10.1657/1938-4246-41.4.478 UT WOS:000272503400009 ER PT J AU Olofsson, J Oksanen, L Callaghan, T Hulme, PE Oksanen, T Suominen, O AF Olofsson, Johan Oksanen, Lauri Callaghan, Terry Hulme, Philip E. Oksanen, Tarja Suominen, Otso TI Herbivores inhibit climate-driven shrub expansion on the tundra SO GLOBAL CHANGE BIOLOGY AB Recent Pan-Arctic shrub expansion has been interpreted as a response to a warmer climate. However, herbivores can also influence the abundance of shrubs in arctic ecosystems. We addressed these alternative explanations by following the changes in plant community composition during the last 10 years in permanent plots inside and outside exclosures with different mesh sizes that exclude either only reindeer or all mammalian herbivores including voles and lemmings. The exclosures were replicated at three forest and tundra sites at four different locations along a climatic gradient ( oceanic to continental) in northern Fennoscandia. Since the last 10 years have been exceptionally warm, we could study how warming has influenced the vegetation in different grazing treatments. Our results show that the abundance of the dominant shrub, Betula nana, has increased during the last decade, but that the increase was more pronounced when herbivores were excluded. Reindeer have the largest effect on shrubs in tundra, while voles and lemmings have a larger effect in the forest. The positive relationship between annual mean temperature and shrub growth in the absence of herbivores and the lack of relationships in grazed controls is another indication that shrub abundance is controlled by an interaction between herbivores and climate. In addition to their effects on taller shrubs (>0.3 m), reindeer reduced the abundance of lichens, whereas microtine rodents reduced the abundance of dwarf shrubs (<0.3 m) and mosses. In contrast to short-term responses, competitive interactions between dwarf shrubs and lichens were evident in the long term. These results show that herbivores have to be considered in order to understand how a changing climate will influence tundra ecosystems. RI Hulme, Philip/F-7454-2011; Callaghan, Terens/N-7640-2014 OI Hulme, Philip/0000-0001-5712-0474; SN 1354-1013 PD NOV PY 2009 VL 15 IS 11 BP 2681 EP 2693 DI 10.1111/j.1365-2486.2009.01935.x UT WOS:000270662000010 ER PT J AU Roturier, S Roue, M AF Roturier, Samuel Roue, Marie TI Of forest, snow and lichen: Sami reindeer herders' knowledge of winter pastures in northern Sweden SO FOREST ECOLOGY AND MANAGEMENT AB Over the last few decades, the use of forests both by Sami reindeer herders and for commercial forestry has been a source of increasing conflict in northern Sweden. Forestry disturbs forest ecosystems and thus damages reindeer pastures, especially those rich in ground lichen, for which reindeer forage during the wintertime by digging through the snow. Despite increased communication between the two groups, the Sami still feel that their interests are not adequately considered by the commercial forestry sector. This paper presents the results of an interdisciplinary study that comprised semi-directed interviews and participant observations. The objective was to understand the Sami reindeer herders' extensive ecological knowledge of winter forest pastures, and the characteristics they observe when managing this resource. The study also analysed specific terminology used by the Sami herders, to describe, analyse and communicate these properties. These terms, as well as Sami herder knowledge in general, emphasize the importance of snow cover for reindeer grazing in forest pastures, as well as the effects of forest structure and ground vegetation on variations in snow cover during the winter. Whereas the Western use of the word 'pasture' is often associated with a specific plant community, the Sami herders' understanding of the word also includes the effect of snow on grazing and for this they use a culturally specific word in their language guohtun. This term conveys the additional notion of whether it is possible for reindeer to access the pasture under the snow. Sami herder knowledge and know-how allow them to use the mosaic of forest ecosystems to accommodate variability in snow cover during the wintertime, using different forest areas in response to different grazing conditions. Finally, the authors argue that, in order to promote the balanced, multiple use of boreal forest ecosystems, it is necessary to acknowledge and understand Sami reindeer herders knowledge and thus to fully integrate their needs and aspirations. (C) 2009 Elsevier B.V. All rights reserved. SN 0378-1127 PD OCT 10 PY 2009 VL 258 IS 9 BP 1960 EP 1967 DI 10.1016/j.foreco.2009.07.045 UT WOS:000271093200018 ER PT J AU Walker, DA Leibman, MO Epstein, HE Forbes, BC Bhatt, US Raynolds, MK Comiso, JC Gubarkov, AA Khomutov, AV Jia, GJ Kaarlejarvi, E Kaplan, JO Kumpula, T Kuss, P Matyshak, G Moskalenko, NG Orekhov, P Romanovsky, VE Ukraientseva, NG Yu, Q AF Walker, D. A. Leibman, M. O. Epstein, H. E. Forbes, B. C. Bhatt, U. S. Raynolds, M. K. Comiso, J. C. Gubarkov, A. A. Khomutov, A. V. Jia, G. J. Kaarlejarvi, E. Kaplan, J. O. Kumpula, T. Kuss, P. Matyshak, G. Moskalenko, N. G. Orekhov, P. Romanovsky, V. E. Ukraientseva, N. G. Yu, Q. TI Spatial and temporal patterns of greenness on the Yamal Peninsula, Russia: interactions of ecological and social factors affecting the Arctic normalized difference vegetation index SO ENVIRONMENTAL RESEARCH LETTERS AB The causes of a greening trend detected in the Arctic using the normalized difference vegetation index (NDVI) are still poorly understood. Changes in NDVI are a result of multiple ecological and social factors that affect tundra net primary productivity. Here we use a 25 year time series of AVHRR-derived NDVI data (AVHRR: advanced very high resolution radiometer), climate analysis, a global geographic information database and ground-based studies to examine the spatial and temporal patterns of vegetation greenness on the Yamal Peninsula, Russia. We assess the effects of climate change, gas-field development, reindeer grazing and permafrost degradation. In contrast to the case for Arctic North America, there has not been a significant trend in summer temperature or NDVI, and much of the pattern of NDVI in this region is due to disturbances. There has been a 37% change in early-summer coastal sea-ice concentration, a 4% increase in summer land temperatures and a 7% change in the average time-integrated NDVI over the length of the satellite observations. Gas-field infrastructure is not currently extensive enough to affect regional NDVI patterns. The effect of reindeer is difficult to quantitatively assess because of the lack of control areas where reindeer are excluded. Many of the greenest landscapes on the Yamal are associated with landslides and drainage networks that have resulted from ongoing rapid permafrost degradation. A warming climate and enhanced winter snow are likely to exacerbate positive feedbacks between climate and permafrost thawing. We present a diagram that summarizes the social and ecological factors that influence Arctic NDVI. The NDVI should be viewed as a powerful monitoring tool that integrates the cumulative effect of a multitude of factors affecting Arctic land-cover change. RI Kaplan, Jed/P-1796-2015; Forbes, Bruce/L-4431-2013; Khomutov, Artem/M-6490-2017; Bhatt, Uma/D-3674-2009; Yu, Qin/D-6362-2011 OI Kaplan, Jed/0000-0001-9919-7613; Forbes, Bruce/0000-0002-4593-5083; Bhatt, Uma/0000-0003-1056-3686; Jia, Gensuo/0000-0001-5950-9555; Orekhov, Pavel/0000-0002-3154-5295 SN 1748-9326 PD OCT-DEC PY 2009 VL 4 IS 4 AR 045004 DI 10.1088/1748-9326/4/4/045004 UT WOS:000272900500021 ER PT J AU Yu, Q Epstein, H Walker, D AF Yu, Qin Epstein, Howard Walker, Donald TI Simulating the effects of soil organic nitrogen and grazing on arctic tundra vegetation dynamics on the Yamal Peninsula, Russia SO ENVIRONMENTAL RESEARCH LETTERS AB Sustainability of tundra vegetation under changing climate on the Yamal Peninsula, northwestern Siberia, home to the world's largest area of reindeer husbandry, is of crucial importance to the local native community. An integrated investigation is needed for better understanding of the effects of soils, climate change and grazing on tundra vegetation in the Yamal region. In this study we applied a nutrient-based plant community model-ArcVeg-to evaluate how two factors (soil organic nitrogen (SON) levels and grazing) interact to affect tundra responses to climate warming across a latitudinal climatic gradient on the Yamal Peninsula. Model simulations were driven by field-collected soil data and expected grazing patterns along the Yamal Arctic Transect (YAT), within bioclimate subzones C (high arctic), D (northern low arctic) and E (southern low arctic). Plant biomass and NPP (net primary productivity) were significantly increased with warmer bioclimate subzones, greater soil nutrient levels and temporal climate warming, while they declined with higher grazing frequency. Temporal climate warming of 2 degrees C caused an increase of 665 g m(-2) in total biomass at the high SON site in subzone E, but only 298 g m (2) at the low SON site. When grazing frequency was also increased, total biomass increased by only 369 g m(-2) at the high SON site in contrast to 184 g m(-2) at the low SON site in subzone E. Our results suggest that high SON can support greater plant biomass and plant responses to climate warming, while low SON and grazing may limit plant response to climate change. In addition to the first order factors (SON, bioclimate subzones, grazing and temporal climate warming), interactions among these significantly affect plant biomass and productivity in the arctic tundra and should not be ignored in regional scale studies. RI Yu, Qin/D-6362-2011 SN 1748-9326 PD OCT-DEC PY 2009 VL 4 IS 4 AR 045027 DI 10.1088/1748-9326/4/4/045027 UT WOS:000272900500044 ER PT J AU Moen, J Boogerd, C Skarin, A AF Moen, Jon Boogerd, Coen Skarin, Anna TI Variations in mountain vegetation use by reindeer (Rangifer tarandus) affects dry heath but not grass heath SO JOURNAL OF VEGETATION SCIENCE AB Question: Are differences in landscape use of semi-domesticated reindeer reflected in the vegetation of summer grazing grounds? Location: Alpine heaths, central east Sweden. Methods: Dry heath and grass heath vegetation plots with inferred grazing intensities (high, intermediate and low) were selected a priori from an interpolated pellet count map compiled in 2002. In each plot, faecal pellets were counted, environmental variables measured and vegetation sampled by listing presence and absence. Species composition was compared with a detrended correspondence analysis, and a canonical correspondence analysis was used to infer relations between species composition and environmental variables. Plots were also clustered to provide groupings for an indicator species analysis. Results: Significant differences in faecal pellet count were present between the highest and lowest grazing intensities for both vegetation types, showing that the pattern in the interpolated pellet maps was robust. Differences in species composition between grazing intensities were found for the dry heath only. Here, there was an apparent grazing gradient, with lichens and mosses in the low-use plots and grasses and herbs in the high-use plots. No such gradient was found for the grass heath. Conclusions: Within the dry heath vegetation type, grazing levels had a subtle effect on the vegetation, while no effects were seen in the grass heath, probably as a result of the dominance of more grazing-tolerant graminoids. Even in the dry heath, species richness did not differ between grazing levels, but the relative abundances of species differed. SN 1100-9233 PD OCT PY 2009 VL 20 IS 5 BP 805 EP 813 DI 10.1111/j.1654-1103.2009.01074.x UT WOS:000270031300003 ER PT J AU Lokken, JA Finstad, GL Dunlap, KL Duffy, LK AF Lokken, James A. Finstad, Gregory L. Dunlap, Kriya L. Duffy, Lawrence K. TI Mercury in lichens and reindeer hair from Alaska: 2005-2007 pilot survey SO POLAR RECORD AB Reindeer and caribou are terrestrial herbivores, that feed on lichens and are used for commercial and subsistence food products. Caribou are a key component of the arctic food web and the bioaccumulation of toxic contaminants, such as mercury (Hg), needs to be monitored to establish a baseline as the arctic environment is impacted by both climate change and future industrial development. A changing climate in Alaska is influencing plant species composition, fire regime, melting and flooding events, and thus, impacting Hg bioavailability in the food chain. Industrial development in Asia is also projected to increase the atmospheric global pool of Hg from increased coal combustion. Reindeer, a domesticated representative of caribou, can be used as a terrestrial biomonitor for metal exposure. In this study total mercury concentrations were measured in lichens and in hair of grazing reindeer on defined, regarding Hg deposition. ranges across Alaska to establish a baseline for future hypothesis development and testing The Hg mean level for Seward Peninsula lichens on the Davis Range was 37.4 ng g(-1), on the Gray Range 47.1 ng g(-1), on the Kakaruk Range 42.2 ng g(-1), and 41.7 ng g(-1) on the Noyakuk Range. Lichen Hg levels on St. Lawrence Island was 46.6 ng g(-1). Methyl mercury levels in lichens were found to be below detection levels. Reindeer grazing on these ranges had mean Hg hair levels of 14.6 ng g(-1) (Davis herd), 83.4 ng g(-1) (Gray herd), and 40.3 ng g(-1) (Noyakuk herd). Two reindeer on St. Lawrence Island had an average of Hg of 43.0 ng g(-1). Sample sizes ranged from n = 2 to n = 11. Hg mean levels in lichen on Seward Peninsula were higher than Hg means of two ranges in northern Mongolia. The Hg levels observed in this study indicate that Hg levels in Alaska are low at this time and pose no risk to the health of reindeer or human subsistence harvesters. A significant relationship between Hg in lichens on the ranges and the Hg in reindeer on those ranges has not been established. There are insufficient data on Hg levels in many areas of the north and more information is needed on location specific and time trends in Hg concentrations. Lichens and reindeer hair provide a good, non-invasive method of monitoring metal exposure changes in Alaskan ecosystems. SN 0032-2474 PD OCT PY 2009 VL 45 IS 235 BP 368 EP 374 DI 10.1017/S0032247409008353 UT WOS:000270208700007 ER PT J AU Lechner, I Barboza, P Collins, W Gunther, D Hattendorf, B Hummel, J Clauss, M AF Lechner, Isabel Barboza, Perry Collins, William Guenther, Detlef Hattendorf, Bodo Hummel, Juergen Clauss, Marcus TI No 'bypass' in adult ruminants: Passage of fluid ingested vs. fluid inserted into the rumen in fistulated muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces) SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY AB In young ruminants, the reticular groove ensures that ingested milk is channelled past the forestormach to avoid mal fermentation. It has been speculated that some adult wild ruminants, in particular browsing species, maintain a functional oesophageal (reticular) groove, that soluble nutrients can thus bypass the rumen, and that thus the energetic gain from the diet can be increased. We inserted a fluid marker (Co-EDTA) via cannula into the rumen and simultaneously fed a diet that contained a second fluid marker (Sm-EDTA), and analysed the faecal marker excretion patterns, in muskoxen (Ovibos moschatus, n = 4 in two experiments each), reindeer (Rangifer tarandus, n = 4 in a total of six experiments) and moose (Alces alces, n = 1 in one experiment). In no case was the orally fed marker excreted distinctively earlier than the marker inserted into the rumen, which indicates that substantial bypass did not occur in these animals. However, differences between the three species in the excretion of the two markers from the rumen are consistent with hypothetical differences in the stratification of rumen contents. We suggest that effects previously ascribed to a "rumen bypass" in wild ruminants most likely reflect differences in the passage from the rumen. (C) 2009 Elsevier B.V. All rights reserved. RI Clauss, Marcus/A-4710-2008 OI Clauss, Marcus/0000-0003-3841-6207; Lechner, Isabel/0000-0001-5155-9734 SN 1095-6433 EI 1531-4332 PD SEP PY 2009 VL 154 IS 1 BP 151 EP 156 DI 10.1016/j.cbpa.2009.05.122 UT WOS:000268625600019 PM 19497382 ER PT J AU Olofsson, J AF Olofsson, Johan TI Effects of Simulated Reindeer Grazing, Trampling, and Waste Products on Nitrogen Mineralization and Primary Production SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB An experiment was conducted in arctic tundra to evaluate the role of reindeer grazing, trampling, and feces and urine deposition in nutrient turnover and primary production. Grazing was simulated by mowing. trampling by the impact of a wooden pole, and waste product deposition by the application of fertilizer. In the first year, aboveground primary production increased with simulated grazing in the fertilized plots and decreased with simulated grazing in the unfertilized plots; this indicates a higher regrowth capacity at higher nutrient levels. However, nitrogen mineralization and primary production were mainly determined by the input or removal of nutrients and, therefore, decreased in plots that were grazed but not fertilized and increased in plots that were fertilized but not grazed. Simulated trampling decreased the depth of the moss layer and increased soil temperatures, but the higher temperatures increased N mineralization only in unmowed plots, and the increased nitrogen availability was not translated into increased primary production. Since aboveground and belowground net primary production in plots with simulated grazing was the same as in plots without simulated animal activity, this study indicates that an entire trophic level can be supported with no apparent effect on primary production. SN 1523-0430 PD AUG PY 2009 VL 41 IS 3 BP 330 EP 338 DI 10.1657/1938-4246-41.3.330 UT WOS:000269019100006 ER PT J AU Sorensen, LI Mikola, J Kytoviita, MM Olofsson, J AF Sorensen, Louise Ilum Mikola, Juha Kytoviita, Minna-Maarit Olofsson, Johan TI Trampling and Spatial Heterogeneity Explain Decomposer Abundances in a Sub-Arctic Grassland Subjected to Simulated Reindeer Grazing SO ECOSYSTEMS AB Mammal grazing is composed of three mechanisms-removal of foliar tissue (defoliation), return of nutrients via dung and urine (fertilization), and trampling. To evaluate the relative role of these mechanisms in the effect of reindeer grazing on soil biota in northern grasslands, we subjected experimental plots in a sub-arctic alpine meadow to defoliation, fertilization (using NPK-solution), simulated trampling, and their factorial combinations once a year from 2002 to 2004 and measured the response of plants and decomposers (including microbes, nematodes, collembolans, and enchytraeids) in 2004. Trampling affected both plant and decomposer communities: the coverage of the moss Pleurozium schreberi and the sedge Carex vaginata, as well as the abundance of collembolans and enchytraeids were reduced in trampled plots. Trampling and fertilization also interacted significantly, with fertilization increasing the abundance of bacteria and bacterial-feeding and omnivorous nematodes in trampled plots only, and trampling decreasing fungal biomass in non-fertilized plots only. Defoliation had no overall effects on plants or decomposers. Nematode genera were not affected by the experimental treatments, but nematode and plant communities were significantly associated, and all decomposer biota, except collembolans, were strongly affected by the spatial heterogeneity of the study site. Our results indicate that trampling may have larger and defoliation and fertilization smaller roles than anticipated in explaining reindeer grazing effects in sub-arctic grasslands. However, even the effects of trampling seem to be outweighed by the spatial heterogeneity of decomposer abundances. This suggests that in sub-arctic grasslands spatial variation in abiotic factors can be a more important factor than grazing in controlling soil biota abundances. RI Mikola, Juha/A-1630-2015 OI Mikola, Juha/0000-0002-4336-2648; Kytoviita, Minna-Maarit/0000-0002-8928-6951 SN 1432-9840 EI 1435-0629 PD AUG PY 2009 VL 12 IS 5 BP 830 EP 842 DI 10.1007/s10021-009-9260-6 UT WOS:000268492000010 ER PT J AU Masse, A Cote, SD AF Masse, Ariane Cote, Steeve D. TI HABITAT SELECTION OF A LARGE HERBIVORE AT HIGH DENSITY AND WITHOUT PREDATION: TRADE-OFF BETWEEN FORAGE AND COVER? SO JOURNAL OF MAMMALOGY AB Although herbivores are generally known to trade off forage in open habitat patches and cover in forested habitat patches, it remains unclear if high population density and low predation risk can modulate the trade-off between forage and cover. We studied a population of white-tailed deer (Odocoileus virginianus) that was at high density and on a large island free of predators to assess the influence of forage and cover on habitat selection under harsh environmental conditions. We fitted 19 female white-tailed deer with global positioning system collars and delineated summer home ranges and core areas. We sampled vegetation in the core areas and in the rest of the home ranges to determine abundance of forage and forest cover within habitat patches, and assessed habitat selection between open and forested habitat patches. At a coarse scale, white-tailed deer preferred open habitat patches over forested ones, suggesting that they adopted a foraging strategy favoring energy intake. At a fine scale, habitat selection was influenced positively by the percentage of ground cover of forbs and deciduous shrubs, but negatively by conifer density. The biomass of preferred plant species, lateral cover, fir regeneration, and distance to the nearest open-forest edge were not strong predictors of habitat selection by deer. We conclude that fine-scale habitat selection by white-tailed deer at high population density and in the absence of predation is mainly determined by forage abundance. These patterns of habitat selection demonstrate that herbivores can adjust their behavior to other limiting factors when predation risk is relaxed. SN 0022-2372 PD AUG PY 2009 VL 90 IS 4 BP 961 EP 970 DI 10.1644/08-MAMM-A-148.1 UT WOS:000269391700020 ER PT J AU Clauss, M Hofmann, RR Fickel, J Streich, WJ Hummel, J AF Clauss, Marcus Hofmann, Reinhold R. Fickel, Joerns Streich, W. Juergen Hummel, Juergen TI The Intraruminal Papillation Gradient in Wild Ruminants of Different Feeding Types: Implications for Rumen Physiology SO JOURNAL OF MORPHOLOGY AB Browsing and grazing ruminants are thought to differ in the degree their rumen contents are stratified-which may be due to different characteristics of their respective forages, to particular adaptations of the animals, or both. However, this stratification is difficult to measure in live animals. The papillation of the rumen has been suggested as an anatomical proxy for stratification-with even papillation indicating homogenous contents, and uneven papillation (with few and small dorsal and ventral papillae, and prominent papillae in the atrium ruminis) stratified contents. Using the surface enlargement factor (SEF, indicating how basal mucosa surface is increased by papillae) of over 55 ruminant species, we demonstrate that differences between the SEFdorsal or SEFventral and the SEFatrium are significantly related to the percentage of grass in the natural diet. The more a species is adapted to grass, the more distinct this difference, with extreme grazers having unpapillated dorsal and ventral mucosa. The relative SEFdorsal as anatomical proxy for stratification, and the difference in particle and fluid retention in the rumen as physiological proxy for stratification, are highly correlated in species (n = 9) for which both kind of data are available. The results support the concept that the stratification of rumen contents varies among ruminants, with more homogenous contents in the more browsing and more stratified contents in the more grazing species. J. Morphol. 270:929-942, 2009. (C) 2009 Wiley-Liss, Inc. RI Clauss, Marcus/A-4710-2008 OI Clauss, Marcus/0000-0003-3841-6207 SN 0362-2525 EI 1097-4687 PD AUG PY 2009 VL 270 IS 8 BP 929 EP 942 DI 10.1002/jmor.10729 UT WOS:000268286800003 PM 19247992 ER PT J AU Kazmin, VD Abaturov, BD AF Kazmin, V. D. Abaturov, B. D. TI MECHANICAL PROPERTIES OF THE SNOW COVER AND AVAILABILITY OF FORAGE FOR REINDEER (RANGIFER TARANDUS) AND MUSK OXEN (OVIBOS MOSCHATUS) ON PASTURES OF WRANGEL ISLAND SO ZOOLOGICHESKY ZHURNAL AB The depth of the snow cover, snow density and hardness, as well as the influence of these parameters on the availability of forage for reindeer and musk ox in the territory of Wrangel Island were assessed. The snow hardness of snow was measured by a penetrometer late in winter (April-May). In 2007, 148 measurements were made on 35 plots; in 2008, 28 ones on 9 plots. At the present time, due to warming of the climate and frequent winter thaws, the snow cover is well stratified. The snow layers clearly differ in hardness, which varies from 5 up to 374 kg/cm(2). The hard layers and elevated snow depth prevent the animals against getting the food from under snow. The threshold level of the snow hardness limiting the availability of forage for reindeer is 189 kg/cm(2), for musk ox - 96 kg/cm(2). The threshold levels of snow thickness for a reindeer and musk ox are 30 and 23 cm, respectively. Almost over the whole territory of Wrangel Island, the snow hardness and depth exceed or equal the threshold levels. Therefore, getting the food for reindeers and musk oxen becomes impossible or demands high expenditure of energy. The consequences described are reflected in the reindeer population, which has been reduced from 8-10 thousand to 450-500 individuals. The number of musk oxen is not great, therefore, these animals find suitable areas for grazing, and their population is stable. SN 0044-5134 PD AUG PY 2009 VL 88 IS 8 BP 990 EP 1000 UT WOS:000270504800010 ER PT J AU Miller, FL Barry, SJ AF Miller, Frank L. Barry, Samuel J. TI Long-Term Control of Peary Caribou Numbers by Unpredictable, Exceptionally Severe Snow or Ice Conditions in a Non-equilibrium Grazing System SO ARCTIC AB The number of Peary caribou (Rang fer tarandus pearyi) on the Queen Elizabeth Islands, Canadian High Arctic, is at an all-time known low. Yet some populations are still hunted, and there is no adequate monitoring program in place to determine the consequences. We evaluate information from the Peary caribou population on the south-central Queen Elizabeth Islands as a standard for an accurate and realistic assessment of what controls Peary caribou population dynamics. Between 1973 and 1997, major population crashes related to severe winter or spring weather are known to have occurred on the south-central Queen Elizabeth Islands in four caribou-years (i.e., 1 July-30 June). Population losses were 67% in 1973-74, 33% in 1994-95, 78% in 1995-96, and 83% in 1996-97. There is no evidence for direct density-dependent responses during either the favorable weather years of population growth or during any one of the years with a disastrous die-off. It appears that Peary caribou on the Queen Elizabeth Islands are living in a non-equilibrium grazing system driven mainly by abiotic factors (emergent properties), particularly by exceptionally unfavorable snow or ice conditions. Changing levels of predation by the High Arctic gray wolf (Canis lupus arctos) compound the uncertainty. In this High Arctic ecosystem, non-equilibrium-governed population dynamics plus wolf predation represents an appropriate conceptual model for Peary caribou populations on the Canadian High Arctic islands. The application of our findings to decision making, together with an adequate monitoring program by the responsible agencies, would promote the biological management and ecological conservation of Peary caribou on the Queen Elizabeth Islands. SN 0004-0843 EI 1923-1245 PD JUN PY 2009 VL 62 IS 2 BP 175 EP 189 UT WOS:000267132200005 ER PT J AU Kaasalainen, U Jokela, J Fewer, DP Sivonen, K Rikkinen, J AF Kaasalainen, Ulla Jokela, Jouni Fewer, David P. Sivonen, Kaarina Rikkinen, Jouko TI Microcystin Production in the Tripartite Cyanolichen Peltigera leucophlebia SO MOLECULAR PLANT-MICROBE INTERACTIONS AB We show that the cyanobacterial symbionts of a tripartite cyanolichen can produce hepatotoxic microcystins in situ. Microcystins were detected with high-performance liquid chromatography mass spectrometry both from cephalodia of the tripartite cyanolichen Peltigera leucophlebia and from a symbiotic Nostoc strain isolated from the same lichen specimen. Genetic identities of symbiotic Nostoc strains were studied by amplifying and sequencing the 16S rRNA gene. Also, the presence of the microcystin synthetase gene mcyE was confirmed by sequencing. Three highly toxic microcystins were detected from the lichen specimen. Several different Nostoc 16S rRNA haplotypes were present in the lichen sample but only one was found in the toxin-producing cultures. In culture, the toxin-producing Nostoc strain produced a total of 19 different microcystin variants. In phylogenetic analysis, this cyanobacterium and related strains from the lichen thallus grouped together with a previously known microcystin-producing Nostoc strain and other strains previously isolated from the symbiotic thalloid bryophyte Blasia pusilla. Our finding is the first direct evidence of in situ production of microcystins in lichens or plant-cyanobacterial symbioses. Microcystins may explain why cyanolichens and symbiotic bryophytes are not among the preferred food sources of most animal grazers. RI Fewer, David/A-8704-2008 OI Fewer, David/0000-0003-3978-4845; Rikkinen, Jouko/0000-0002-4615-6639; Sivonen, Kaarina/0000-0002-2904-0458; Jokela, Jouni/0000-0001-5096-3575; Kaasalainen, Ulla/0000-0001-9899-4768 SN 0894-0282 EI 1943-7706 PD JUN PY 2009 VL 22 IS 6 BP 695 EP 702 DI 10.1094/MPMI-22-6-0695 UT WOS:000266213700008 PM 19445594 ER PT J AU Hansen, BB Herfindal, I Aanes, R Saether, BE Henriksen, S AF Hansen, Brage Bremset Herfindal, Ivar Aanes, Ronny Saether, Bernt-Erik Henriksen, Snorre TI Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore SO OIKOS AB How herbivore behaviour is influenced by changes in resource levels is central for understanding trophic interactions. We examined whether foraging tradeoffs change with food levels by comparing habitat selection and space use within and between two neighbouring, predator-free Svalbard reindeer populations. The populations faced different food levels due to contrasting grazing history. Summer resource selection in radiocollared females was assessed by a multi-dimensional niche approach based on habitat variables obtained from a satellite image (e.g. the normalised difference vegetation index, NDVI) and a digital terrain model. The population at the overgrazed Broggerhalvoya faced overall lower plant cover, biomass and primary productivity (i.e. lower NDVI) than the population at Sarsoyra. At Broggerhalvoya, most reindeer selected for productive habitat when choosing home range and patches within the home range. In contrast, habitat selection at Sarsoyra was more affected by abiotic conditions such as moisture, which may influence plant quality. Here, reindeer used patches with even less biomass than the average reindeer at the poorer Broggerhalvoya. Such a difference in habitat preference with different habitat availability (a functional response in habitat selection) probably reflected increased selection for high-quality forage at the expense of high forage quantity at Sarsoyra. Accordingly, a negative relationship between habitat productivity and home range size was only present across individuals within Broggerhalvoya, where forage quantity was the important foraging niche component. Individuals having poor (and large) home ranges apparently could not compensate for this by higher patch selectivity compared to individuals with richer home ranges. The results indicate changes in foraging tradeoffs at contrasting resource levels and that strong interactions occur between habitat selection, space use and the foraging niche structure in the absence of predation. RI Hansen, Brage/B-9942-2008; Herfindal, Ivar/A-4609-2015 OI Hansen, Brage/0000-0001-8763-4361; Herfindal, Ivar/0000-0002-5860-9252 SN 0030-1299 PD JUN PY 2009 VL 118 IS 6 BP 859 EP 872 DI 10.1111/j.1600-0706.2009.17098.x UT WOS:000266429600008 ER PT J AU Couturier, S Cote, SD Huot, J Otto, RD AF Couturier, Serge Cote, Steeve D. Huot, Jean Otto, Robert D. TI Body-condition dynamics in a northern ungulate gaining fat in winter SO CANADIAN JOURNAL OF ZOOLOGY AB Individual condition generally depends on density and is partly determined by habitat quality and climate. We studied long-term trends in the condition and productivity of female caribou (Rangifer tarandus (L., 1758)) in two large migratory herds in the Quebec-Labrador peninsula (Canada), the George and the Feuilles herds. Females from the George herd were in better summer condition than those from the more abundant Feuilles herd in 2001-2002, while it was the opposite in 1988 when the Feuilles herd was less abundant than the George herd. Summer nutrition followed the same pattern between herds through time. Spring body condition of females in the George herd declined from 1976 to the mid-1980s during early population growth. Fall condition, however, did not change from 1983 to 2002 when caribou numbers first peaked and later declined. Pregnancy rates were inversely related to herd size in both herds. Vegetation quality (NDVI) in June was significantly related to body proteins in the fall. Albeit unusual for a northern ungulate, body fat increased from fall to spring in the George herd. We conclude that a relatively small and highly grazed summer range, as well as density-dependent effects, affected summer nutrition and the need to continue lipogenesis during winter. SN 0008-4301 EI 1480-3283 PD MAY PY 2009 VL 87 IS 5 BP 367 EP 378 DI 10.1139/Z09-020 UT WOS:000266441700001 ER PT J AU Mcart, SH Spalinger, DE Collins, WB Schoen, ER Stevenson, T Bucho, M AF McArt, Scott H. Spalinger, Donald E. Collins, William B. Schoen, Erik R. Stevenson, Timothy Bucho, Michele TI Summer dietary nitrogen availability as a potential bottom-up constraint on moose in south-central Alaska SO ECOLOGY AB Recent studies suggest that the growth and fecundity of northern ungulates may be coupled to their summer nutrition. Here, we compare summer dietary nitrogen availability of the five major browse plants (comprising similar to 79% of the diet) of moose (Alces alces) in Denali National Park and Nelchina Basin, Alaska, USA. In recent years the productivity of Denali moose has been significantly higher than that of Nelchina moose, prompting this comparison. We examined the phenological progression of leaf nitrogen concentration, tannin-protein precipitation capacity, and digestible protein over three summers in both regions. We then modeled the potential nutritional consequences for a cow moose consuming representative diets on each range, predicting both net protein intake (NPI) and lean body mass accumulation each year. We found that leaf nitrogen and digestible protein decreased, while tannin-protein precipitation capacity increased throughout the summer for all forages. There was 23% more digestible protein in Denali leaves than Nelchina leaves on average, and this difference was significant in all three years. Tannins accounted for a large (mean = 46%) reduction in protein availability, suggesting a key role of these secondary compounds in the nitrogen balance of moose in these regions. Finally, our NPI model predicted that Denali cows were in positive protein balance 17 days longer than Nelchina cows and accumulated 18 kg more lean body mass over the summer, on average. We conclude that summer dietary nitrogen availability may act as a nutritional constraint on moose and suggest that more emphasis be placed on elucidating its role in population dynamics and conservation of northern ungulates. RI Schoen, Erik/H-3829-2013 OI Schoen, Erik/0000-0001-8301-6419 SN 0012-9658 EI 1939-9170 PD MAY PY 2009 VL 90 IS 5 BP 1400 EP 1411 DI 10.1890/08-1435.1 UT WOS:000265816200016 PM 19537559 ER PT J AU De Roos, AM Galic, N Heesterbeek, H AF De Roos, Andre M. Galic, Nika Heesterbeek, Hans TI How resource competition shapes individual life history for nonplastic growth: ungulates in seasonal food environments SO ECOLOGY AB We analyze an age-, size- and sex-structured model to investigate how the interplay between individual-level energy budget dynamics and the feedback of population grazing on resources shapes the individual life history and the dynamics of ungulate populations, living in a predator-free, seasonal resource environment. We formulate a dynamic energy budget model for individual energetics, which accounts for energy requirements for maintenance and growth, and possibly pregnancy and lactation. Growth in structural mass is assumed prescribed. Dynamics of energy reserves are the resultant of energy acquisition through grazing and suckling of milk and the aforementioned energy-consuming processes. The dynamic energy budget model is used as the core for an individual-based population model, which captures general features of ungulate life history and population dynamics, although it is parameterized for a particular system. Model predictions reveal a characteristic dynamic pattern, in which years with low death tolls (<10% of the population dying) alternate with a single year of high death toll ( up to 40% of the population dies). In these "collapse'' years almost all individuals younger than 2 years die, creating holes in the population age distribution. The die-off of these age classes is shown to be caused by the energy requirements for growth that these individuals face. Individuals between 1 and 2 years of age are more at risk than foals, because they are burdened with the legacy of a poor body condition developed throughout their first winter. The characteristic dynamic pattern is more pronounced at high levels of resource productivity. In contrast, neither a period of snow cover, during which all foraging stops, nor a dependence of fecundity on female body condition change dynamics significantly. RI De Roos, Andre/A-1590-2008 OI De Roos, Andre/0000-0002-6944-2048; Galic, Nika/0000-0002-4344-3464 SN 0012-9658 EI 1939-9170 PD APR PY 2009 VL 90 IS 4 BP 945 EP 960 DI 10.1890/07-1153.1 UT WOS:000264753400013 PM 19449690 ER PT J AU Klein, DR Shulski, M AF Klein, David R. Shulski, Martha TI Lichen Recovery Following Heavy Grazing by Reindeer Delayed by Climate Warming SO AMBIO AB Introduced reindeer, Rangifer tarandus, overexploited lichen-rich plant communities on St. Matthew Island in the Bering Sea. A die-off of the reindeer followed, exacerbated by extreme weather in 1964, resulting in extirpation of the reindeer. A similar pattern of removal of lichens as major components of plant communities has occurred following introductions of reindeer to other islands at high latitudes. By 1985, two decades following die-off of the reindeer, total lichen biomass was only 6% of that in similar plant communities on adjacent Hall Island, not reached by the reindeer. By 2005, 41 y after the reindeer die-off, lichen regrowth on St. Matthew was only 12% of lichen biomass in the Hall Island communities. A warmer, drier climate and decreased fog in recent decades contributed to deterioration of conditions favoring lichen growth on St. Matthew Island. SN 0044-7447 EI 1654-7209 PD FEB PY 2009 VL 38 IS 1 BP 11 EP 16 DI 10.1579/0044-7447-38.1.11 UT WOS:000263083500003 PM 19260341 ER PT J AU Kullman, L AF Kullman, Leif TI High Species Turnover and Decreasing Plant Species Richness on Mountain Summits in Sweden: Reindeer Grazing Overrides Climate Change? Comment SO ARCTIC ANTARCTIC AND ALPINE RESEARCH SN 1523-0430 PD FEB PY 2009 VL 41 IS 1 BP 151 EP 151 DI 10.1657/1938-4246(2008-1)[COMMENT]2.0.CO;2 UT WOS:000263313000016 ER PT J AU Moen, J Lagerstrom, A AF Moen, Jon Lagerstroem, Anna TI High Species Turnover and Decreasing Plant Species Richness on Mountain Summits in Sweden: Reindeer Grazing Overrides Climate Change? Reply SO ARCTIC ANTARCTIC AND ALPINE RESEARCH SN 1523-0430 PD FEB PY 2009 VL 41 IS 1 BP 152 EP 152 DI 10.1657/1938-4246(2008-1)[REPLY]2.0.CO;2 UT WOS:000263313000017 ER PT J AU Sundset, M Edwards, J Cheng, Y Senosiain, R Fraile, M Northwood, K Praesteng, KE Glad, T Mathiesen, S Wright, AD AF Sundset, Monica A. Edwards, Joan E. Cheng, Yan Fen Senosiain, Roberto S. Fraile, Maria N. Northwood, Korinne S. Praesteng, Kirsti E. Glad, Trine Mathiesen, Svein D. Wright, Andre-Denis G. TI Molecular Diversity of the Rumen Microbiome of Norwegian Reindeer on Natural Summer Pasture SO MICROBIAL ECOLOGY AB The molecular diversity of the rumen microbiome was investigated in five semi-domesticated adult female Norwegian reindeer (Rangifer tarandus tarandus) grazing on natural summer pastures on the coast of northern Norway (71.00A degrees N, 25.30A degrees E). Mean population densities (numbers per gram wet weight) of methanogenic archaea, rumen bacteria and ciliate protozoa, estimated using quantitative real-time polymerase chain reaction (PCR), were 3.17 x 10(9), 5.17 x 10(11) and 4.02 x 10(7), respectively. Molecular diversity of rumen methanogens was revealed using a 16S rRNA gene library (54 clones) constructed using pooled PCR products from the whole rumen contents of the five individual reindeer. Based upon a similarity criterion of < 97%, a total of 19 distinct operational taxonomic units (OTUs) were identified, nine of which are potential new species. The 16S rRNA sequences generated from the reindeer rumen exhibited a high degree of sequence similarity to methanogens affiliated with the families Methanobacteriaceae (14 OTUs) and Methanosarcinaceae (one OTU). Four of the OTUs detected belonged to a group of uncultivated archaea previously found in domestic ruminants and thought to be dominant in the rumen together with Methanobrevibacter spp. Denaturing gradient gel electrophoresis profiling of the rumen bacterial 16S rRNA gene and the protozoal 18S rRNA gene indicated a high degree of animal variation, although some bands were common to all individuals. Automated ribosomal intergenic spacer analysis (ARISA) profiling of the ruminal Neocallimastigales population indicated that the reindeer are likely to contain more than one type of anaerobic fungus. The ARISA profile from one animal was distinct from the other four. This is the first molecular investigation of the ruminal methanogenic archaea in reindeer, revealing higher numbers than expected based on methane emission data available. Also, many of the reindeer archaeal 16S rRNA gene sequences were similar to those reported in domesticated ruminants in Australia, Canada, China, New Zealand and Venezuela, supporting previous findings that there seems to be no host type or geographical effect on the methanogenic archaea community structure in ruminants. RI Napal Fraile, Maria/A-7985-2013 OI Napal Fraile, Maria/0000-0002-1058-9395 SN 0095-3628 PD FEB PY 2009 VL 57 IS 2 BP 335 EP 348 DI 10.1007/s00248-008-9414-7 UT WOS:000262829500012 PM 18604648 ER PT J AU Kitti, H Forbes, BC Oksanen, J AF Kitti, Heidi Forbes, Bruce C. Oksanen, Jari TI Long- and short-term effects of reindeer grazing on tundra wetland vegetation SO POLAR BIOLOGY AB We studied long-term (50 years) and short-term (4 years) effects of summer grazing of reindeer on subarctic tundra wetland vegetation. The long-term effects of summer grazing were studied by comparing vegetation on Finnish and Norwegian sides of the fence line separating reindeer grazing regimes. The Finnish side was intensively grazed and trampled throughout the year, whereas the Norwegian side was grazed in winter. Experimental fences were erected to examine short-term effects of grazing exclusion. Both in the long- and short-term, summer grazing decreased the height of Salix lapponum whereas the short-term effects on willow cover were less clear than the long-term effects. In contrast, Carex spp. benefited from grazing. Long-term grazing had little effect on total bryophyte cover. Grazing had negligible effects on the nutrient content of leaves of S. lapponum and Eriophorum angustifolium. We conclude that tundra wetlands can withstand moderately high grazing pressure sustained over several decades. RI Oksanen, Jari/A-5236-2013; Forbes, Bruce/L-4431-2013 OI Forbes, Bruce/0000-0002-4593-5083; Oksanen, Jari/0000-0001-7102-9626 SN 0722-4060 PD FEB PY 2009 VL 32 IS 2 BP 253 EP 261 DI 10.1007/s00300-008-0526-9 UT WOS:000262439300013 ER PT J AU Tommervik, H Johansen, B Riseth, JA Karlsen, SR Solberg, B Hogda, KA AF Tommervik, H. Johansen, B. Riseth, J. A. Karlsen, S. R. Solberg, B. Hogda, K. A. TI Above ground biomass changes in the mountain birch forests and mountain heaths of Finnmarksvidda, northern Norway, in the period 1957-2006 SO FOREST ECOLOGY AND MANAGEMENT AB Birch forests cover large areas of the northern Fennoscandia and the mountain birch (Betula pubescens ssp. czerepanovii) often forming the altitudinal and Arctic forest and tree lines. Interpreting the factors leading to landscape changes in mountain birch forest involves disturbance from anthropogenic use and climate as important factors. Using vegetation maps based on aerial photographs and satellite images from 7 years in combination with statistical data and ground estimation data of biomass in the period 1957-2006, we were able to assess the transitions among mountain heaths and different types of forest, the displacement of the altitudinal forest line and hence the change in biomass. The tree biomass as well as the growing stock for birch in Finnmarksvidda doubled in the period 1957-2006. Only lichen biomass has been significantly reduced in the period 1957 to 2000, with a subsequent slight increase of lichen biomass in the period 2000 to 2006. The results presented in this paper show significant and positive relationships between measured tree biomass and the increase in reindeer population in the period 1957-2006 in the study area. The hypothesis concerning the removal of the "lichen barrier effect" by heavy reindeer grazing which leads to increased success for birch seeds to germinate and sprout is therefore considered to be valid. However, also, climate change effects like increased precipitation, moth attacks, freezing and thawing events during winter and long-transported air pollution (e.g. nitrogen) may also have reinforced the changes in biomass. Climatic variables from regional weather stations for the period 1955-2006 did not, however, reveal any consistent change except for that the increased snow depth had a negative impact on the reindeer population while increase in snow depth hindering the reindeer in grazing seemed to have a positive impact on the lichen biomass. The ongoing development of increased forest cover and hence elevated forest line will lead to reduction of open habitats, and hence decreased grazing accessibility for the reindeer. The effects on forestry and carbon sequestration are also discussed, and here one of the suggestions is to let the northern birch forests act as carbon sinks contributing to the reduction of total net emission Of CO2 in the Nordic countries. Land use like reindeer husbandry has shown to strongly affect relationships between ecological processes like tree-growth and climate. Moreover, reindeer husbandry is such a widespread human activity in the arctic and boreal region that it might affect the global carbon budget (C) 2008 Elsevier B.V. All rights reserved. OI Riseth, Jan Age/0000-0002-4607-5927 SN 0378-1127 EI 1872-7042 PD JAN 20 PY 2009 VL 257 IS 1 BP 244 EP 257 DI 10.1016/j.foreco.2008.08.038 UT WOS:000261856000027 ER PT J AU Massey, FP Massey, K Ennos, AR Hartley, SE AF Massey, Fergus P. Massey, Kate Ennos, A. Roland Hartley, Sue E. TI Impacts of silica-based defences in grasses on the feeding preferences of sheep SO BASIC AND APPLIED ECOLOGY AB Grasses, which dominate many terrestrial ecosystems, sustain high densities of grazing mammals, so are of great economic and ecological importance. Traditionally, grasses are thought to be adapted to tolerate grazing rather than defend against it; however, silica deposited in the leaves of grasses has recently been shown to act as a feeding deterrent to invertebrate herbivores and small mammals. This study assesses whether silica is effective as a feeding deterrent to larger mammalian herbivores. We assess the impact of manipulated silica levels in five grass species on the feeding preferences of sheep both within and between grass species. Sheep feeding behaviour was driven by between-species differences in palatability. Hence, within a single species silica addition did not cause significant changes in feeding preference. However, there were significant differences in both the feeding preferences and bite rates between grass species, and these differences were much more marked when the grasses had been exposed to high levels of silica. The impacts that silica had on preference were least pronounced in palatable species (e.g. Poa annua) compared with less-palatable species (e.g. Brachypodium pinnatum and Festuca ovina). Sheep fed for longer, took more bites and had a higher bite rate on the grass species with the lowest leaf silica concentrations, namely P. annua. Sheep were less affected by silica defences than smaller, non-ruminant herbivores, but the changes in species preference rankings caused by silica suggest it may lead to changes in sward composition. Further, in species that are already relatively low in palatability, silica-induced reductions in bite rate could potentially reduce forage intake rates, with consequences for sheep performance. (c) 2009 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved. SN 1439-1791 EI 1618-0089 PY 2009 VL 10 IS 7 BP 622 EP 630 DI 10.1016/j.baae.2009.04.004 UT WOS:000270567600005 ER PT J AU Caballero, R Gil, A AF Caballero, Rafael Gil, Angel TI Binding Constraints in Castile-La Mancha, Spain's Cereal-Sheep System SO JOURNAL OF SUSTAINABLE AGRICULTURE AB Low-input and large scale grazing systems (LSGS) in Europe are at a crossroads and are facing two contrasting threats: intensification and abandonment (the most extreme form of extensification). Paradoxically, these LSGS constitute large tracts of European rural land in the less favored areas (LFA), which harbor a great part of high nature value (HNV) farmland. Natural and cultural values depend on continuity of the traditional farming practices and this on the social and economic sustainability of the respective farming systems. In this report, we argue that understanding the social dynamic and main binding constraints of particular LSGS is a precedent to institutional reforms and devising sensible schemes of policy support. A community-based research approach with stakeholders' participation was devised within the EU-funded LACOPE research project and applied to five European LSGS. A more structured approach with three phases of the diagnostic methodology and corresponding data is presented for the cereal-sheep farming system of Castile-La Mancha (South-Central Spain). Comparative data are presented for other four European LSGS: the reindeer herding in northernmost Fennoscandia (Northern Sapmi); sheep grazing in the Carpathian (Tatra) mountains of Poland; and heifers' rearing on the Alps in the UNESCO Biosphere Reserve Entlebuch (Switzerland) and Upper Bavaria (Germany). Results in the cereal-sheep systems showed congenial views (social consensus) on the main constraints between the two principal stakeholders, but uncooperative attitudes and lack for social cohesion. Comparative results indicated a common ground of abandonment of the less-favored and far-reaching grazing areas with causes related to inter-Scandinavian border barriers (Northern Sapmi), intensification of more-favored lowland farms (Entlebuch and Upper Bavaria) and lack of social cohesion and structural constraints (Tatra and Castile-La Mancha). A social sustainability tier should be included into the Rural Development guidelines of the EU for actions in HNV farmland, but regional strategy plans should be adapted to particular social dynamic of European LSGS. RI Roman, Urszula/G-2225-2011 SN 1044-0046 PY 2009 VL 33 IS 1 BP 3 EP 27 AR PII 907457250 DI 10.1080/10440040802394976 UT WOS:000264834400002 ER PT J AU van der Wal, R Hessen, DO AF van der Wal, Rene Hessen, Dag O. TI Analogous aquatic and terrestrial food webs in the high Arctic: The structuring force of a harsh climate SO PERSPECTIVES IN PLANT ECOLOGY EVOLUTION AND SYSTEMATICS AB Understanding food web structure and dynamics remains a central theme in ecology. Whilst differences between aquatic and terrestrial food webs have been the focus of several studies, we aim to reveal similarities where abiotic conditions are particularly extreme such as in the high Arctic. We propose that here, the combination of a short growing season, low temperature and low light, leads to the absence of predator control and the development of typically two-trophic, grazer-dominated food webs with high plant quality in terms of elemental ratios. Moreover, we advocate that this mechanism is evident in both aquatic and terrestrial high-Arctic environments, allowing the build-up of herbivore densities that consume a large fraction of plant primary production and tightly recycle nutrients. Thus, the particular abiotic conditions that characterise the high Arctic give rise to a unique environment that allows biotic factors to orchestrate food web structure and influence ecosystem function. Specially, the short growing season, low temperatures and low light levels collectively constrain the accumulation of structural autotroph tissue that, in temperate regions, effectively keeps herbivores at bay. While fundamental differences between terrestrial and aquatic ecosystems have been frequently advocated, we show here that harsh live-constraining conditions in the high Arctic have led to analogous, grazer-dominated, food web dynamics in both terrestrial and freshwater ecosystems. (C) 2009 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved. RI Hessen, Dag/F-4039-2011; van der Wal, Rene/F-3177-2010 SN 1433-8319 PY 2009 VL 11 IS 3 BP 231 EP 240 DI 10.1016/j.ppees.2009.03.003 UT WOS:000269186200005 ER PT J AU Fauria, MM Helle, T Niva, A Posio, H Timonen, M AF Fauria, Marc Macias Helle, Timo Niva, Aarno Posio, Heikki Timonen, Mauri TI Removal of the lichen mat by reindeer enhances tree growth in a northern Scots pine forest SO CANADIAN JOURNAL OF FOREST RESEARCH AB Reindeer (Rangifer tarandus L.) lichen grazing enhanced Scots pine (Pinus sylvestris L.) growth in a northeastern Fennoscandian forest. Lichen mat removal by grazing in a previously ungrazed area increased soil versus air temperature coupling. This caused faster soil spring warming and higher soil temperatures during late spring and summer, which are related to an earlier start of and better growth conditions during the trees' growing season. Tree growth was related to spring and summer climate during the study period, 1896-2001. Snowmelt date, and ultimately soil warming and start of the growing season, may have caused the relationships between tree growth and spring climate. A drop in July temperature and an increase in the spring signals were found and attributed to the "divergence problem,'' a widespread weakening in the relationships between tree growth and summer temperature in northern latitudes observed in the late 20th century. Differences in the relationships between tree growth and climate were found between trees growing in grazed and ungrazed parts of the stand. Tree growth differences were detected similar to 10 years after the removal of the lichen mat. The fertilizing effect of reindeers on tree growth was considered minimal in this study, but its influence cannot be completely ruled out. Grazing intensity may thus be an important component of boreal forest carbon uptake. RI Macias-Fauria, Marc/A-4591-2009 OI Macias-Fauria, Marc/0000-0002-8438-2223 SN 0045-5067 EI 1208-6037 PD DEC PY 2008 VL 38 IS 12 BP 2981 EP 2993 DI 10.1139/X08-135 UT WOS:000261909300007 ER PT J AU Rivals, F Schulz, E Kaiser, TM AF Rivals, Florent Schulz, Ellen Kaiser, Thomas M. TI Climate-related dietary diversity of the ungulate faunas from the middle Pleistocene succession (OIS 14-12) at the Caune de l'Arago (France) SO PALEOBIOLOGY AB The Caune de l'Arago Cave (southern France) has yielded one of the best preserved and best documented sedimentary successions of the European Middle Pleistocene (Oxygen Isotopic Stages 14 to 12). Herbivorous ungulates (horse, reindeer, red deer, fallow deer, bison, musk ox, argali, and tahr) are well represented in the three major stratigraphic units CM1, CM2, and CM3. CMl and CM3 correspond to cold and dry climate and CM2 represents temperate and humid environmental conditions. Dental microwear and mesowear analyses were performed for the ungulates from CM1-3 to test whether these methods of dental wear evaluation were suitable for detecting climate-driven changes in the dietary resources of the Arago ungulate community. We found that both dental mesowear and microwear indicate dietary traits and their relationship to climatic conditions as reflected by vegetation cover and community structure. In all units, even if some species seem to share habitats or resources, it appears that the overlap in their feeding ecology is very low. The CM1 and CM3 units, where pollen analysis indicates that the climate was cold and dry, show the lowest diversity in dietary traits. The CM2, where climate is known to be more temperate and humid, the spectrum of dietary traits is large-grazers, browsers, and mixed feeders are present. RI Rivals, Florent/B-7962-2014 OI Rivals, Florent/0000-0001-8074-9254; Kaiser, Thomas/0000-0002-8154-1751; Schulz-Kornas, Ellen/0000-0003-1657-8256 SN 0094-8373 EI 1938-5331 PD WIN PY 2008 VL 34 IS 1 BP 117 EP 127 DI 10.1666/07023.1 UT WOS:000253188600008 ER PT J AU Stark, S Kytoviita, MM Mannisto, MK Neumann, AB AF Stark, S. Kytoviita, M. -M. Mannisto, M. K. Neumann, A. B. TI Soil microbial and microfaunal communities and organic matter quality in reindeer winter and summer ranges in Finnish subarctic mountain birch forests SO APPLIED SOIL ECOLOGY AB Reindeer husbandry has significant influences on the aboveground plant communities and the structure of the mountain birch forests in the Fennoscandian subarctic. We investigated how the reindeer-mediated aboveground changes affect soil microbial and microfaunal communities and enzymatic activities. We hypothesized that in areas with intensive summer browsing by reindeer, the carbon flow to belowground is reduced, but the carbon substances are more readily degradable. This is likely to influence both the abundance and the trophic structure of microbial and microfaunal communities. However, despite large differences in the vegetation, the reindeer ranges did not differ in the amount of microbial biomass or the abundance of nematodes. Furthermore, there was no difference in the microbial phospholipid fatty acid composition or in the trophic groups of soil nematodes. There were few effects on the organic fractions (non-polar extractives, water-soluble extractives, acid-soluble fraction, and acid-insoluble residue) of the soil organic matter. We suggest that the high stocks of organic matter in subarctic systems weaken the direct link between the aboveground and the belowground environments. Because soil carbon has a long turnover time in these systems, it takes at least several decades until the aboveground changes caused by large herbivores will influence the trophic structure in soils. (C) 2008 Elsevier B.V. All rights reserved. RI Stark, Sari/L-4440-2013 OI Kytoviita, Minna-Maarit/0000-0002-8928-6951 SN 0929-1393 PD NOV PY 2008 VL 40 IS 3 BP 456 EP 464 DI 10.1016/j.apsoil.2008.06.009 UT WOS:000260319400006 ER PT J AU Anschlag, K Broll, G Holtmeier, FK AF Anschlag, Kerstin Broll, Gabriele Holtmeier, Friedrich-Karl TI Mountain Birch Seedlings in the Treeline Ecotone, Subarctic Finland: Variation in Above- and Below-Ground Growth Depending on Microtopography SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB The treeline ecotone in northern Finnish Lapland is characterized by a mosaic of sites with highly varying environmental conditions. Density, age structure, growth, and root systems of mountain birch seedlings (Betula pubescens ssp. czerepanovii [Orlova] Hamet-Ahti) were Studied in different microsite classes (deflation, lichen heath, dwarf shrub heath, hummock, willow shrub, sedge mire). On wind-exposed convex topography characterized by shortage of Moisture and nutrients, seedling establishment is impeded, as is indicated by low seedling densities and lack of very Voting seedlings as well as by high rooting depths and root/shoot ratios of the few individuals. It, sedge mires, birch seedlings occasionally Occur in great numbers but die off at an early stage. Extremely shallow root systems point to anoxia as the main reason. Severe shoot damage is common to almost all saplings. This is likely due to grazing by reindeer (Rangifer t. tarandus). As a result, height growth is suppressed even on sites with otherwise relatively suitable conditions (e.g. willow shrub sites). Future effects of climate change Which Could locally improve conditions for germination and establishment of birch young growth might be overridden by the effects of high reindeer density. SN 1523-0430 EI 1938-4246 PD NOV PY 2008 VL 40 IS 4 BP 609 EP 616 DI 10.1657/1523-0430(07-087)[ANSCHLAG]2.0.CO;2 UT WOS:000261441100001 ER PT J AU Sorensen, LI Mikola, J Kytoviita, MM AF Sorensen, Louise I. Mikola, Juha Kytoviita, Minna-Maarit TI Defoliation effects on plant and soil properties in an experimental low arctic grassland community - the role of plant community structure SO SOIL BIOLOGY & BIOCHEMISTRY AB In Northern Fennoscandia, sub-arctic and arctic grasslands are commonly grazed by the semi-domesticated reindeer. Reindeer grazing is known to affect plant production and belowground processes, such as nutrient mineralization in these grasslands, but little is known of the role of plant Community Structure in the response of plant and soil properties to the defoliation of plants. Using soil and seeds from a low arctic meadow, we established a 23-week greenhouse experiment to test whether communities of different plant species richness (one, two or four species) and composition (three different replicated compositions within each richness level) respond to defoliation in a different way. We defoliated plants twice to 2 cm above the soil surface in half of the replicates of each community and analyzed the response of different communities in terms of changes in plant mass accumulation and the abundance of soil organisms (microbes, protozoa and nematodes). We predicted that these parameters and their resistance to defoliation will: (1) differ among plant species compositions; and (2) increase with increasing plant species richness. We found that plant species composition affected shoot mass accumulation (comprising both defoliated and harvested shoot mass), harvested root mass (in nondefoliated systems) and the abundance of decomposer fungi in the soil. Defoliation increased the numbers of fungal-feeding and predatory nematodes regardless of plant community structure, while the effects on roots and decomposer fungi varied across plant species compositions. Of the measured variables, only the abundance of omnivorous Aporcelaimellus spp. nematodes responded to plant species richness and no evidence was found that the effects of defoliation on any variable were modified by species richness. Soil bacteria, arbuscular mycorrhizal fungi, protozoa and bacterial- and root-feeding nematodes did not respond to any treatment. Our results suggest that defoliation effects may to some extent differ between different plant species compositions in the low arctic grasslands grazed by the reindeer. However, it appears that they may not depend on plant species richness. (C) 2008 Elsevier Ltd. All rights reserved. RI Mikola, Juha/A-1630-2015 OI Mikola, Juha/0000-0002-4336-2648; Kytoviita, Minna-Maarit/0000-0002-8928-6951 SN 0038-0717 PD OCT PY 2008 VL 40 IS 10 BP 2596 EP 2604 DI 10.1016/j.soilbio.2008.06.021 UT WOS:000260444000015 ER PT J AU Laurian, C Dussault, C Ouellet, JP Courtois, R Poulin, M Breton, L AF Laurian, Catherine Dussault, Christian Ouellet, Jean-Pierre Courtois, Rehaume Poulin, Marius Breton, Laurier TI Behavior of moose relative to a road network SO JOURNAL OF WILDLIFE MANAGEMENT AB Roads often negatively affect terrestrial wildlife, via habitat loss or fragmentation, noise, and direct mortality. We studied moose (Alces alces) behavior relative to a road network, in an area with a history of moose-vehicle accidents, to determine when moose were crossing roadways or using areas near roads and to investigate if environmental factors were involved in this behavior. We tracked 47 adult moose with Global Positioning System collars in a study area crossed by highways and forest roads. We hypothesized that moose would avoid crossing roads but would make occasional visits to roadsides to feed on sodium-rich vegetation and avoid biting insects. Further, we expected moose avoidance to be greater for highways than forest roads. We recorded 196,710 movement segments but only observed 328 highway and 1,172 forest-road crossings (16 and 10 times lower than expected by chance). Moose usually avoided road proximity up to >= 500 in on each side but 20% of collared moose made visits to areas within 50 in of highways, which might have resulted from moose searching for sodium in vegetation and roadside salt pools. In fact, vegetation along highways had higher sodium concentrations and was browsed in similar proportions to vegetation in adjacent forest, despite moose avoidance of these zones. Moose, however, did not use areas near roads more during periods of biting insect abundance. Our results supported the hypothesis of scale-dependent selection by moose; avoidance of highways at a coarse scale may confer long-term benefits, whereas selection of highway corridors at finer scales may be part of a strategy to overcome short-term limiting factors such as sodium deficiency. We found a positive relationship between home-range size and the proportion of road axes they contained, Suggesting that moose either compensated for habitat loss or made specific movements along highways to gather sodium. The presence of sodium along highways likely increases moose-vehicle accident risks. Removal of salt pools or use of a de-icing salt other than sodium chloride should render highway surroundings less attractive to moose. SN 0022-541X PD SEP PY 2008 VL 72 IS 7 BP 1550 EP 1557 DI 10.2193/2008-063 UT WOS:000258930800014 ER PT J AU Pajunen, A Virtanen, R Roininen, H AF Pajunen, Anu Virtanen, Risto Roininen, Heikki TI The effects of reindeer grazing on the composition and species richness of vegetation in forest-tundra ecotone SO POLAR BIOLOGY AB We conducted an 8-year exclosure experiment (1999-2006) in a forest-tundra ecotonal area in northwestern Finnish Lapland to study the effects of reindeer grazing on vegetation in habitats of variable productivity and microhabitat structure. The experimental sites included tundra heath, frost heath and riparian habitats, and the two latter habitats were characterized by hummock-hollow ground forms. The total cover of vegetation, cover of willow (Salix spp.), dwarf birch (Betula nana), dwarf shrubs, forbs and grasses (Poaceae spp.) increased in exclosures in all habitats. The increase in the total cover of vegetation and in the covers of willow and dwarf birch tended to be greatest in the least productive tundra heath. Opposing to the increase in the dominant vascular plant groups, the cover and species number of bryophytes decreased in exclosures. We conclude that the effects of reindeer grazing on vegetation composition depend on environmental heterogeneity and the responses vary among plant groups. RI Virtanen, Risto/G-1810-2010 OI Virtanen, Risto/0000-0002-8295-8217 SN 0722-4060 PD SEP PY 2008 VL 31 IS 10 BP 1233 EP 1244 DI 10.1007/s00300-008-0462-8 UT WOS:000258635600009 ER PT J AU Post, E Pedersen, C AF Post, Eric Pedersen, Christian TI Opposing plant community responses to warming with and without herbivores SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB If controls over primary productivity and plant community composition are mainly environmental, as opposed to biological, then global change may result in large-scale alterations in ecosystem structure and function. This view appears to be favored among investigations of plant biomass and community responses to experimental and observed warming. in far northern and arctic ecosystems, such studies predict increasing dominance of woody shrubs with future warming and emphasize the carbon (C)-sequestration potential and consequent atmospheric feedback potential of such responses. In contrast to previous studies, we incorporated natural herbivory by muskoxen and caribou into a 5-year experimental investigation of arctic plant community response to warming. In accordance with other studies, warming increased total community biomass by promoting growth of deciduous shrubs (dwarf birch and gray willow). However, muskoxen and caribou reduced total community biomass response, and responses of birch and willow, to warming by 19%, 46%, and 11 %, respectively. Furthermore, under warming alone, the plant community shifted after 5 years away from graminoid-dominated toward dwarf birch-dominated. In contrast, where herbivores grazed, plant community composition on warmed plots did not differ from that on ambient plots after 5 years. These results highlight the potentially important and overlooked influences of vertebrate herbivores on plant community response to warming and emphasize that conservation and management of large herbivores may be an important component of mitigating ecosystem response to climate change. SN 0027-8424 PD AUG 26 PY 2008 VL 105 IS 34 BP 12353 EP 12358 DI 10.1073/pnas.0802421105 UT WOS:000258905700047 PM 18719116 ER PT J AU Berg, A Ostlund, L Moen, J Olofsson, J AF Berg, Anna Ostlund, Lars Moen, Jon Olofsson, Johan TI A century of logging and forestry in a reindeer herding area in northern Sweden SO FOREST ECOLOGY AND MANAGEMENT AB Boreal forest ecosystems are generally highly sensitive to logging and other forestry activities. Thus, commercial forestry has had major effects on the forests and landscape structure in northern Sweden since the middle of the 19th Century, when it rapidly extended across the region. Lichens (which constitute up to 80% of reindeer forage in winter and early spring) have often been amongst the most severely affected ecosystem components. The overall aim of the present study was to analyze how forestry has influenced the potential supply of ground-growing lichens as winter forage for the reindeer in this region over the past ca. 100 years. For this purpose, we analysed changes in forest and stand structure in Scots pine-dominated (Pinus sylvestris L) reindeer wintering areas in the southern part of the county Norrbotten (covering ca. 58,000 ha) using detailed historical forest inventories and management plans. We found that the amount of the forest types considered potentially good pasture (mainly middle-aged and old pine forests) decreased during the first part of the 20th Century. However, the quality of grazing grounds was improved by forestry during this time mainly because selective logging made the forests more open which benefits lichen growth. During the last part of the 20th century forestry impaired the quality of grazing grounds in several ways, e.g. by clear-cutting and intensified use of various silvicultural measures. We conclude that ca. 30-50% of the winter grazing grounds have been lost in the study area because of intensive forest management during the last century. The spatially precise historical information about the affects of forestry on lichen pasture provided in this study can be used to direct forest management which will facilitate and promote reindeer herding in the future. (c) 2008 Elsevier B.V. All rights reserved. RI Olofsson, Johan/A-9362-2009 OI Ostlund, Lars/0000-0002-7902-3672 SN 0378-1127 PD AUG 20 PY 2008 VL 256 IS 5 BP 1009 EP 1020 DI 10.1016/j.foreco.2008.06.003 UT WOS:000259388400018 ER PT J AU Mysterud, A Austrheim, G AF Mysterud, Atle Austrheim, Gunnar TI The effect of domestic sheep on forage plants of wild reindeer; a landscape scale experiment SO EUROPEAN JOURNAL OF WILDLIFE RESEARCH AB Domestic herbivores often compete with wildlife for limited resources, and on longer time-scales, grazing may also increase or decrease coverage of important food plants to wildlife affecting the threshold density for when competition can be expected. In Norway, there are growing concerns about the effect of releasing 2.1 million domestic sheep (Ovis aries) for summer grazing into areas hosting wild populations of alpine reindeer (Rangifer tarandus). We quantified the effect of sheep grazing (0, 25 and 80 sheep/km(2)) on the development in coverage and abundance of plants known to be important in the diet of reindeer during summer (vascular plants) and winter (lichens) within a fully replicated, landscape scale (2.7 km(2)) experiment. From 2001 to 2005, the sedge, Carex bigelowii, increased while the herb Solidago virgaurea decreased in frequency at high density of sheep relative to controls (both marginally non-significant). There was no marked development in Deschampsia flexuosa, Salix herbacea or Hierarcium alpinum that could be related to sheep grazing intensity. Lichen coverage and height both decreased at high density of sheep from 2002 to 2005. Effects of low grazing intensity were closer to controls than to high grazing intensity. Our study highlights that high sheep grazing intensity induce changes to the plant community that, at the same time, can improve the summer habitat and detriment the winter habitat to reindeer. Many wild reindeer populations are fragmented and may thus be limited by either summer or winter range. The effect of sheep grazing is predicted to vary accordingly. However, currently, we have limited ability to quantify how much this explicitly means in terms of increased or reduced carrying capacity for reindeer. SN 1612-4642 PD AUG PY 2008 VL 54 IS 3 BP 461 EP 468 DI 10.1007/s10344-008-0171-1 UT WOS:000258109900009 ER PT J AU Simard, MA Cote, SD Weladji, RB Huot, J AF Simard, M. Anouk Cote, Steeve D. Weladji, Robert B. Huot, Jean TI Feedback effects of chronic browsing on life-history traits of a large herbivore SO JOURNAL OF ANIMAL ECOLOGY AB 1. Increasing ungulate populations are affecting vegetation negatively in many areas, but few studies have assessed the long-term effects of overbrowsing on individual life-history traits of ungulates. 2. Using an insular population of white-tailed deer (Odocoileus virginianus Zimmermann; Anticosti, Quebec, Canada) introduced in 1896, and whose density has remained high since the first evidence of severe browsing in the 1930s, we investigated potential feedbacks of long-term and heavy browsing on deer life-history traits. 3. We assessed whether chronic browsing contributed to a decline of the quality of deer diet in early autumn during the last 25 years, and evaluated the impacts of reduced diet quality on deer body condition and reproduction. 4. Rumen nitrogen content declined 22% between two time periods, 1977-79 and 2002-04, indicating a reduction in diet quality. 5. After accounting for the effects of year within the time period, age and date of harvest in autumn, peak body mass of both sexes declined between the two time periods. At the end of November, males were on average 12% heavier and adult does 6% heavier in 1977-79 than in 2002-04. Hind foot length did not vary between time periods. 6. The probability of conception increased 15% between the two time periods, but litter size at ovulation declined 7%, resulting in a similar total number of ovulations in 2002-04 and in 1977-79. 7. Our results suggest that following a decline in diet quality, white-tailed deer females modified their life-history strategies to maintain reproduction at the expense of growth. 8. Deer appear to tolerate drastic reductions in diet quality by modifying their life history traits, such as body mass and reproduction, before a reduction in density is observed. Such modifications may contribute to maintain high population density of large herbivores following population irruption. SN 0021-8790 EI 1365-2656 PD JUL PY 2008 VL 77 IS 4 BP 678 EP 686 DI 10.1111/j.1365-2656.2008.01374.x UT WOS:000256539800007 PM 18312337 ER PT J AU Moen, J AF Moen, Jon TI Climate change: Effects on the ecological basis for reindeer husbandry in Sweden SO AMBIO AB This paper examines potential effects of predicted climate changes on the forage conditions during both summer and winter for semidomesticated reindeer in Sweden. Positive effects in summer ranges include higher plant productivity and a longer growing season, while negative effects include increased insect harassment. Forage quality may change in both positive and negative ways. An increase in shrubs and trees in alpine heaths is also likely. A warmer climate means shorter winters, which will have positive effects for the survival of reindeer. However, warmer and wetter weather may also result in increased probabilities of ice-crust formations, which strongly decrease forage availability. A warmer climate with higher forest productivity will also likely reduce lichen availability through competitive interactions. Adaptations to these changes will include maintaining a choice of grazing sites in both summer and winter. However, this capacity may already be severely limited because of other forms of land use. SN 0044-7447 EI 1654-7209 PD JUN PY 2008 VL 37 IS 4 BP 304 EP 311 DI 10.1579/0044-7447(2008)37[304:CCEOTE]2.0.CO;2 UT WOS:000257637400011 PM 18686511 ER PT J AU Austrheim, G Mysterud, A Pedersen, B Halvorsen, R Hassel, K Evju, M AF Austrheim, Gunnar Mysterud, Atle Pedersen, Bard Halvorsen, Rune Hassel, Kristian Evju, Marianne TI Large scale experimental effects of three levels of sheep densities on an alpine ecosystem SO OIKOS AB Plant herbivore dynamics is a major topic in ecological research, but empirical knowledge on the ecological effects of different densities of large grazers from fully replicated experiments is rare. Previous studies have focused on grazing vs no grazing, and our understanding of the extent to which different levels of grazing alter vegetation composition, and how quickly such effects can be measured, is therefore limited. We performed a fully replicated, short-term (four-year) experiment using large enclosures (each similar to 0.3 km(2)) with three different sheep densities (no grazing, low grazing and high grazing, respectively) in an alpine environment with summer grazing in southern Norway to address these issues. Sheep grazing mainly affected plant species at high densities of sheep as compared to no sheep after a four-year treatment; few effects of low sheep densities were detectable. Highly selected herbs, herbs suggested vulnerable to trampling, and woody species decreased, while most graminoids, one ruderal, one prostrate species and two bryophyte taxa increased at high sheep densities. We found contrasting responses within main functional groups highlighting that fine details of plant life histories need to be known for responses to grazing to be successfully predicted. Vascular plant cover and bare soil responded to sheep density after two years of treatment, but only for one of the species was frequency change observed at this stage. Overall, plants in low grazing plots were found to be almost unaffected. Changes in abundance were mainly found at the no grazing and high grazing treatments. Plant species that decreased at high grazing generally increased at no grazing and vice versa, suggesting a response to both cessation of grazing and enhanced grazing respectively. Our study demonstrates, beyond a simple comparison of heavily grazed and non-grazed sites, that herbivore effects on plants are typically non-linearly related to herbivore density, and that the speed of plant responses will depend both on the plant property examined and the grazing pressure. OI Hassel, Kristian/0000-0002-1906-8166 SN 0030-1299 PD JUN PY 2008 VL 117 IS 6 BP 837 EP 846 DI 10.1111/j.2008.0030-1299.16543.x UT WOS:000256839300004 ER PT J AU Loffler, J Pape, R AF Loeffler, Joerg Pape, Roland TI Diversity patterns in relation to the environment in alpine tundra ecosystems of northern Norway SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB We analyzed diversity patterns of alpine tundra ecosystems along environmental gradients. We hypothesized that alpine diversity is affected by climate at local and regional scales, nutrient availability, soil moisture, and disturbance related to herbivory. In all, 232 samples in 11 study areas in Troms and Finnmark counties were analyzed with regard to alpha- and beta-diversity of vascular plants and lichens. Relationships between a-diversity and environmental variables were analyzed by regression trees. beta-diversity defined as species turnover was investigated using indirect ordination methods. Sites with non-acidic soil parent material showed highest species densities. Lowest species numbers were typical for extreme topographic positions. Heavily grazed samples showed less species numbers and coverage percentage of vegetation. The number of graminoid species was found to be highest in areas of high grazing pressure. We concluded that alpha-diversity was controlled by growing season, snow cover, pH, soil moisture, disturbance, temperature, and precipitation, stressing the importance of multi-factorial approaches in diversity studies. Determinants of P-diversity were predominantly local environmental conditions, whereas regional conditions were less important. SN 1523-0430 EI 1938-4246 PD MAY PY 2008 VL 40 IS 2 BP 373 EP 381 DI 10.1657/1523-0430(06-097)[LOEFFLER]2.0.CO;2 UT WOS:000257268100011 ER PT J AU Moen, J Lagerstrom, A AF Moen, Jon Lagerstroem, Anna TI High species turnover and decreasing plant species richness on mountain summits in Sweden: Reindeer grazing overrides climate change? SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB We investigated changes in vascular plant species richness in nine summit floras in the central part of the Fennoscandian mountain range compared to historical data from 1950. We revisited the summits (defined as the top 50 altitudinal meters of each mountain) in 2002, and recorded all species. The changes in species richness were tested against both species and mountain characteristics. Species richness had declined on eight of the nine summits. Five of the species were new since the 1950s, while 17 species were lost from the summits. However, species turnover was even higher: 57 of our recorded species occurrences had established on at least one mountain since the 1950s, while we could not find 132 of the recorded occurrences in 1950 on one or more mountains. Temperature had increased since 1950 by about 1 degrees C and precipitation by 12%. The reindeer population has more than doubled. No correlations between plant responses, plant characteristics, and mountain characteristics were found, suggesting individualistic and mountain-specific responses. We conclude that climate changes may be responsible for an increased establishment and reindeer trampling for increased mortality of established individuals. However, the net result is a decline in species richness. SN 1523-0430 PD MAY PY 2008 VL 40 IS 2 BP 382 EP 395 DI 10.1657/1523-0430(07-031)[MOEN]2.0.CO;2 UT WOS:000257268100012 ER PT J AU Susiluoto, S Rasilo, T Pumpanen, J Berninger, F AF Susiluoto, Sanna Rasilo, Terhi Pumpanen, Jukka Berninger, Frank TI Effects of grazing on the vegetation structure and carbon dioxide exchange of a fennoscandian fell ecosystem SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB We used the chamber method to measure growing season ecosystem carbon exchange and ecosystem respiration in Finnish 2 alpine tundra. The average ecosystem respiration in the sites was 0.8-0.9 mu mol m(-2) s(-1) and the daytime net ecosystem exchange (NEE) was around -0.4 to -0.5 mu mol m(-2) s(-1). There were no detectable differences in cuvette-based net ecosystem exchange or ecosystem respiration between grazed fell areas and long term reindeer exclosure. Further analysis showed that net carbon exchange as well as ecosystem respiration were significantly correlated with the dwarf shrub cover, while the proportion of lichen cover (Cladina sp.) was not correlated with ecosystem carbon exchange. Clipping experiments showed that about half of the measured ecosystem respiration was heterotrophic. Plots that had been protected from reindeer grazing had almost two times higher above-ground plant biomass than grazed plots. The reason for this was 86% lower lichen biomass on the grazed side of the fell, while the biomass of Ericaceous dwarf shrubs did not differ even though there were changes in species composition. Surprisingly, the proportion of bare ground did not differ due to grazing pressure, but the reduction in biomass lead to a less stratified vegetation cover. RI Berninger, Frank/A-8891-2010; Rasilo, Terhi/Q-8248-2016; Pumpanen, Jukka/B-1254-2012 OI Berninger, Frank/0000-0001-7718-1661; Pumpanen, Jukka/0000-0003-4879-3663; Rasilo, Terhi/0000-0002-3502-4040 SN 1523-0430 PD MAY PY 2008 VL 40 IS 2 BP 422 EP 431 DI 10.1657/1523-0430(07-035)[SUSILUOTO]2.0.CO;2 UT WOS:000257268100015 ER PT J AU Helle, T Kojola, I AF Helle, Timo Kojola, Ilpo TI Demographics in an alpine reindeer herd: effects of density and winter weather SO ECOGRAPHY AB We examined how population density, winter weather, snow conditions, and 2 large-scale climatic indices (North Atlantic Oscillation, NAO, and Arctic Oscillation, AO) influenced demography (reproduction and mortality) in an alpine herd of semi-domesticated reindeer Rangifer tarandus between 1959 and 2000 in Finnish Lapland. The herd lived on heavily grazed lichen pastures, with winter densities between 0.8 and 3.9 individuals km(-2). Icing conditions occurred every 7th yr, on an average, and decreased reproductive rate (calves/females) by 49%. In general linear models icing remarkably increased the fit of snow models to reproductive rate. Incorporation of an interaction term between icing and the snow depth index provided better fit than a model without interaction. Delayed snowmelt decreased reproductive rate. For the day of snowmelt, however, the model without interaction was better than the interaction model. These 3 models provided the best fit to the data and accounted for 51-54% of the variation in reproductive rate. Winter mortality was related to density and large-scale climatic indices, but not to local winter weather except a slight increase in mortality during an icing winter. The best model for winter mortality, including reindeer density and NAO, accounted for 26% of variation in mortality. Three factors may be involved explaining weak density dependence or the lack of such dependence; climate change scenarios that predict higher winter temperature, more frequent thawing-freezing periods, and deeper snow would be expected to decrease reproductive rate and increase winter mortality of reindeer and thus to reduce profitability of reindeer husbandry. In contrast, early springs would be advantageous for reindeer in the short term. SN 0906-7590 PD APR PY 2008 VL 31 IS 2 BP 221 EP 230 DI 10.1111/j.0906-7590.2008.4912.x UT WOS:000254499200007 ER PT J AU Haskell, SP Ballard, WB Butler, DA Wallace, MC Stephenson, TR Alcumbrac, OJ Humphrey, MH AF Haskell, Shawn P. Ballard, Warren B. Butler, David A. Wallace, Mark C. Stephenson, Thomas R. Alcumbrac, Ole J. Humphrey, Mary H. TI Factors affecting birth dates of sympatric deer in west-central Texas SO JOURNAL OF MAMMALOGY AB During a study of fawn mortality, we investigated proximate factors affecting birth dates of sympatric desert mule deer (Odocoileus hemionus eremicus) and white-tailed deer (O. virginianus texanus) in west-central Texas from 2004 to 2006. We treated this aspect of the study as time-to-event survival (i.e., pregnancy to birth) and modeled the process with accelerated failure-time regression. Our best model included effects from 3 hierarchal levels: within-year variation among individuals within species, because older and heavier females gave birth earlier; among-year variation at the population level, because greater rain during the previous prerut and rut periods resulted in earlier birth dates; and a chronic-cohort effect also at the population level, because even after previous effects were accounted for in regression models, deer gave birth later on more intensely grazed ranches. After accounting for mass, age of females as a significant predictor may have indicated a behavioral phenomenon associated with social dominance. We did not find meaningful relationships between birth dates and either offspring sex or rain during gestation. Overall, Kaplan-Meier product-limit estimates indicated that birthing by white-tailed deer peaked on 20 June (90% range = 31 days) and birthing by mule deer peaked on 21 July (90% range = 45 days). We suggest that the 1-month separation between peak birth dates and breeding periods of these sympatric species of deer was partly due to phylogenetic constraint from parent populations and not localized adaptation with selection against hybridization. Prevention of genetic introgression may be a result by coincidence. RI Wallace, Mark/A-1263-2010 SN 0022-2372 EI 1545-1542 PD APR PY 2008 VL 89 IS 2 BP 448 EP 458 DI 10.1644/07-MAMM-A-127R.1 UT WOS:000255306200019 ER PT J AU Grenfell, TC Putkonen, J AF Grenfell, T. C. Putkonen, J. TI A method for the detection of the severe rain-on-snow event on Banks Island, October 2003, using passive microwave remote sensing SO WATER RESOURCES RESEARCH AB Severe wintertime rain- on- snow ( ROS) events create a strong ice layer ( or layers) in the snow on arctic tundra that act as a barrier to ungulate grazing. They are linked with large- scale ungulate ( reindeer, caribou, elk, and musk- ox) herd declines via starvation and reduced calf production rate when the animals are unable to penetrate the resulting subsnowpack ice layer. ROS events also produce considerable perturbation in the mean wintertime soil temperature under the snowpack. ROS is a sporadic but well- known and significant phenomenon that is currently very poorly documented. Characterization of the distribution and occurrence of severe ROS events is based only on anecdotal evidence, indirect observations of carcasses found adjacent to iced snowpacks, and irregular detection by a sparse observational weather network. We have analyzed in detail a particular ROS event that took place on Banks Island in early October 2003 that resulted in the death of 20,000 musk oxen. We make use of multifrequency passive microwave imagery from the Special Sensor Microwave Imager satellite sensor suite in conjunction with a strong- fluctuation- theory ( SFT) emissivity model. We show that a combination of time series analysis and cluster analysis based on microwave spectral gradients and polarization ratios provides a means to detect the stages of the ROS event resulting from the modification of the vertical structure of the snowpack, specifically wetting the snow, the accumulation of liquid water at the base of the snow during the rain event, and the subsequent modification of the snowpack after refreezing. SFT model analysis provides quantitative confirmation of our interpretation of the evolution of the microwave properties of the snowpack as a result of the ROS event. In addition to the grain coarsening owing to destructive metamorphism, we detect the presence of the internal water and ice layers, directly identifying the physical properties producing the hazardous conditions. This analysis offers the potential to characterize both the frequency and global distribution of ROS using multifrequency satellite passive microwave imagery. SN 0043-1397 PD MAR 25 PY 2008 VL 44 IS 3 AR W03425 DI 10.1029/2007WR005929 UT WOS:000254535200001 ER PT J AU Virtanen, R Salminen, J Strommer, R AF Virtanen, Risto Salminen, Janne Strommer, Rauni TI Soil and decomposer responses to grazing exclusion are weak in mountain snow-beds SO ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY AB Most of the empirical evidence available from different types of ecosystems have shown that aboveground plant-based and belowground decomposer systems are interconnected, and change in one leads to a response in the other. We analyzed responses of the soil decomposer system and soil decomposition processes to grazing exclusion and associated vegetation changes in a mountain snowbed. These habitats are of low productivity supporting bryophyte and graminoid-rich vegetation which is grazed by the Norwegian lemming and reindeer. We measured bacteria, enchytraeids, fungi, nematodes, microbial respiration, soil nitrogen (ammonium and nitrate), and soil water content from exclosure treatment plots of 5 and 15 years, where the exclusion of grazers had led to considerable vegetation changes. Soil decomposer variables showed only weak responses to the exclosure treatments or changes in aboveground vegetation (biomass and dead organic matter). Only nematodes responded positively to the short-term grazing exclusion. This suggests that above- and belowground processes are not necessarily closely interconnected in snowbed habitats and that the decomposition of plant material is directly controlled by grazer activity. (c) 2008 Elsevier Masson SAS. All rights reserved. RI Virtanen, Risto/G-1810-2010 OI Virtanen, Risto/0000-0002-8295-8217 SN 1146-609X PD MAR-APR PY 2008 VL 33 IS 2 BP 207 EP 212 DI 10.1016/j.actao.2007.10.009 UT WOS:000254794700009 ER PT J AU Holt, EA Mccune, B Neitlich, P AF Holt, Emily A. Mccune, Bruce Neitlich, Peter TI Grazing and fire impacts on macrolichen communities of the Seward Peninsula, Alaska, USA SO BRYOLOGIST AB We sought to assess impacts of fire and grazing by reindeer and caribou on lichen communities in northwestern Alaska. Macrolichen abundance was estimated from 45, 0.38-ha plots. Eighteen of those plots, scattered throughout the southern Seward Peninsula, represented two levels of grazing, heavy and light. We found lightly grazed areas had taller lichens and greater total lichen cover than heavily grazed sites. Minor yet statistically significant changes in community structure were also observed between heavily and lightly grazed sites. However, lichen species richness did not differ by grazing status. Overall, average lichen height appears to be the best indication of grazing intensity on the Seward Peninsula. Apart from the 18 grazing plots, 8 additional plots were established in previously burned sites to represent reference conditions with a known time since disturbance date. These plots provided a framework of vegetation recovery from severe, recent disturbance towards pre-disturbance conditions. Patterns in lichen, bryophyte and vascular plant characteristics from these fire plots in combination with our findings from the grazing plots were then used to interpret the disturbance history of new plots. These new plots comprise the remaining 19 plots (of the total 45) that were sampled within the Bering Land Bridge National Preserve (BELA). We believe the location of BELA, regardless of disturbance history, is more favorable to vascular plants and Sphagnum, and lichens grow taller in response, compared to areas on the Seward Peninsula further south. In addition, lower cover in the Preserve may be attributed to site or climatic differences rather than grazing. SN 0007-2745 PD SPR PY 2008 VL 111 IS 1 BP 68 EP 83 DI 10.1639/0007-2745(2008)111[68:GAFIOM]2.0.CO;2 UT WOS:000253903400004 ER PT J AU Zockler, C Miles, L Fish, L Wolf, A Rees, G Danks, F AF Zockler, Christoph Miles, Lera Fish, Lucy Wolf, Annett Rees, Gareth Danks, Fiona TI Potential impact of climate change and reindeer density on tundra indicator species in the Barents Sea region SO CLIMATIC CHANGE AB Climate change is expected to alter the distribution of habitats and thus the distribution of species connected with these habitats in the terrestrial Barents Sea region. It was hypothesised that wild species connected with the tundra and open-land biome may be particularly at risk as forest area expands. Fourteen species of birds were identified as useful indicators for the biodiversity dependent upon this biome. By bringing together species distribution information with the LPJ-GUESS vegetation model, and with estimates of future wild and domestic reindeer density, potential impacts on these species between the present time and 2080 were assessed. Over this period there was a net loss of open land within the current breeding range of most bird species. Grazing reindeer were modelled as increasing the amount of open land retained for nine of the tundra bird species. RI Wolf, Annett/A-1207-2012; Miles, Lera/C-7334-2009 OI Miles, Lera/0000-0003-0377-5904 SN 0165-0009 EI 1573-1480 PD MAR PY 2008 VL 87 IS 1-2 BP 119 EP 130 DI 10.1007/s10584-007-9344-2 UT WOS:000253347000008 ER PT J AU Jurado, OM Clauss, M Streich, WH Hatt, JM AF Jurado, Olga Martin Clauss, Marcus Streich, W. Juergen Hatt, Jean-Michel TI Irregular tooth wear and longevity in captive wild ruminants: A pilot survey of necropsy reports SO JOURNAL OF ZOO AND WILDLIFE MEDICINE AB Tooth wear is often suggested as an important factor limiting the life span of free-ranging wildlife. Given the frequent occurrence of poor dental health in captive animals reported in the literature, one would expect tooth health to be a limiting factor in captivity as well. Additionally, it could be assumed that brachydont (browsing) animals are more susceptible to dental health problems than are hypsodont (grazing) animals, given current indications for systematic increased tooth wear in some browsing species. A pilot survey of necropsy reports of adult captive wild ruminants (n = 294, 12 species) in one facility was performed in order to test these hypotheses and to calculate the incidence of irregular tooth wear. The overall incidence of irregular tooth wear was 20%, with a very high proportion of reports that did not mention the teeth at all. In contrast to this study's hypotheses, animals with irregular tooth wear were older than animals that died from other causes, indicating that reaching above-average age was a prerequisite for the development of reported abnormalities in this data set. A grazing species (blackbuck, Antilope cervicapra) was most affected, whereas two browsing species were not affected. Affected species had been regularly fed on sandy soil, whereas browsers had received feeds from racks, indicating that husbandry practices are most important for dental health. There was a high proportion of reported serous fat atrophy in animals with irregular tooth wear, indicating the clinical relevance of the problem. On average, adult individuals of the species investigated reached 41 % of the maximum reported life span. Although this number appears low, the lack of comparative data from other facilities does not allow for conclusions on the adequacy of the husbandry practices used. RI Hatt, Jean-Michel/C-3850-2015; Clauss, Marcus/A-4710-2008 OI Clauss, Marcus/0000-0003-3841-6207 SN 1042-7260 PD MAR PY 2008 VL 39 IS 1 BP 69 EP 75 DI 10.1638/06-064.1 UT WOS:000254006600009 PM 18432098 ER PT J AU Skarin, A Danell, O Bergstrom, R Moen, J AF Skarin, Anna Danell, Oje Bergstrom, Roger Moen, Jon TI Summer habitat preferences of GPS-collared reindeer Rangifer tarandus tarandus SO WILDLIFE BIOLOGY AB Reindeer Rangifer tarandus tarandus husbandry In Sweden commonly uses the Scandinavian mountain chain as grazing area during the snow-free season and the coniferous forests in the east during winter. Current knowledge of habitat use by reindeer is primarily based on traditional or local knowledge, or on investigations carried out on wild reindeer and caribou in other parts of the world. We identified spatial and temporal habitat use of free-ranging semi-domesticated reindeer by following 48 GPS-equipped reindeer in three summer ranges in the Swedish reindeer herding area. The GPS equipment registered positions every hour or every second hour, during two snow-free seasons. The GPS-collared reindeer were randomly chosen from herds with several thousand animals. Estimated home-range utilisation distributions were used to fit resource utilisation functions (RUFs) including various topographical features, vegetation types, and the vicinity to water and hiking trails. The GPS-equipped reindeer used different parts of the range throughout the snow-free season. Preferred vegetation types were consistently meadows, grass heaths, and other heaths. Avoided vegetation types were all types of forests, sparsely vegetated areas, and bare rocks. The reindeer were seemingly indifferent to hiking trails within their home ranges, which, however, usually coincided with preferred vegetation types, but they avoided areas with houses and holiday huts during early summer. Later in the season, the reindeer preferred higher elevated areas where human constructions were sparse. The home ranges of the GPS-equipped reindeer overlapped considerably during early parts of the season, indicating a dense use of the range by the entire herds. Crowding within the herds appeared to make individual reindeer select non-optimal habitats. However, in our study, we found a nonsignificant tendency of less predictable individual home ranges when there were large range overlaps. Vegetation types, direction of slopes, time within the season and the possibilities of avoiding insect harassment appear to be key factors for predicting valuable reindeer habitats in novel areas in a land management context. SN 0909-6396 PD MAR PY 2008 VL 14 IS 1 BP 1 EP 15 DI 10.2981/0909-6396(2008)14[1:SHPOGR]2.0.CO;2 UT WOS:000255921800001 ER PT J AU Querrec, L Filion, L AF Querrec, Lydia Filion, Louise TI White-tailed deer activity reconstructed from tree-rings in eastern boreal Canada SO FOREST ECOLOGY AND MANAGEMENT AB We evaluated the potential of tree-ring techniques for the reconstruction of recent and past seasonal activity of introduced white-tailed deer in a boreal environment of eastern Canada. Hoof scrape scars on balsam fir stems and trampling scars on roots were used to reconstruct deer activity during the winter and snow-free seasons, respectively. Tree damage showed that there was continuous deer activity in the north-central part of Anticosti Island since the mid-1960s. High scrape scars along tree stems (3-3.5 in from the ground) indicate that 1975, 1976, 1981, 1983 and 1985 were years of intensive food search by deer on high balsam fir foliage. The annual number of hoof scrape scars was low between 1982 and 1985, when severe defoliation by the spruce budworm, combined with deer browsing, led to high fir sapling mortality, food depletion, degradation of the winter shelter forests and a decrease in deer activity. The lowest scrape scars 50 cm above ground correspond to the mean height of the residual snowpack in the shelter forest at springtime, when deer start searching for food in nearby open sites and use logging roads, where dead and bonsai-like fir predominate due to overbrowsing. The trampling scar age frequency distribution from two sites indicated that deer activity during the snow-free season started synchronously in the late 1960s. In response to degradation of winter shelter forests, deer may have moved from the southern part to the north-central part of the island and other sectors to survive. Deer-induced tree damage and tree-ring techniques can thus be used to reconstruct past seasonal activity of white-tailed deer. (c) 2007 Elsevier B.V. All rights reserved. SN 0378-1127 PD FEB 20 PY 2008 VL 255 IS 1 BP 234 EP 244 DI 10.1016/j.foreco.2007.09.034 UT WOS:000253618400026 ER PT J AU Gough, L Shrestha, K Johnson, DR Moon, B AF Gough, Laura Shrestha, Kanchan Johnson, David R. Moon, Brian TI Long-term mammalian herbivory and nutrient addition alter lichen community structure in Alaskan dry heath tundra SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Mammalian herbivores in arctic tundra often alter plant species composition and lichen abundance, with effects dependent on grazing season and herbivore preference. We investigated how long-term mammal exclosures designed to exclude large mammals (caribou) alone, large and medium-sized mammals (e.g., ground squirrels), or all mammals (including voles and lemmings) affected lichen abundance and species composition as well as the vascular plant community. The exclosures were partly established in combination with long-term soil nutrient additions to investigate the interaction between mammal activity and nutrient availability. Our study was conducted in dry heath tundra in northern Alaska, dominated by dwarf evergreen shrubs and lichens. Excluding mammals for 17 years allowed the lichen community to increase in biomass, particularly within the genus Cladonia, which also had more intrageneric diversity in the exclosures; after 10 years, results were subtler. Fertilization, however, almost eliminated the lichens, regardless of herbivore treatment. This coincided with a dramatic shift in vascular vegetation toward a more palatable grass-dominated community, similar to studies of other arctic heaths. Our results suggest that with greater soil nutrient availability that occurs with climate warming, lichens will decrease in abundance, and this effect may be exacerbated by increased mammalian herbivory. SN 1523-0430 PD FEB PY 2008 VL 40 IS 1 BP 65 EP 73 DI 10.1657/1523-0430(06-087)[GOUGH]2.0.CO;2 UT WOS:000252869000007 ER PT J AU Vistnes, II Nellemann, C AF Vistnes, Ingunn Ims Nellemann, Christian TI Reindeer winter grazing in alpine tundra: Impacts on ridge community composition in Norway SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB We analyzed lichen species composition and biomass in 815 plots on 163 sites across wild reindeer regions in Norway, ranging from ranges with a long history of very low grazing pressure to heavily grazed sites. Reindeer density (1974-2000) and lichen biomass were well correlated for sites with comparable snow cover, altitude and terrain (R-2 = 0.81, P = 0.006, n = 12). Absence of grazing for potentially several centuries has virtually resulted in a monoculture consisting of Cladina stellaris, Flavocetraria nivalis, and Alectoria ochroleuca (Syn. Bryocaulon ochroleuca). Light grazing in terms of 20 to 30% removal of initial lichen cover easily eroded Cladina stellaris from exposed ridges by cratering and trampling by reindeer through the snow, while Flavocetraria nivalis persisted longer. This decline in lichen cover observed along a historic grazing gradient further resulted in increasing cover of bare ground, but less than expected from lichen removal due to gradual colonization of other species, such as mosses (incl. Polytrichum piliferum), crustose and fruticose lichens, dwarf shrubs (Arctostaphylos spp., Empetrum nigrum, Loiseleuria procumbens), and graminoids, particularly rushes (Juncus trifidus). Moderate grazing may thus increase plant diversity on ridges compared to ungrazed lands, and hence strongly influence gradients in biomass, composition and abundance of ridge communities across the landscape. SN 1523-0430 PD FEB PY 2008 VL 40 IS 1 BP 215 EP 224 DI 10.1657/1523-0430(07-001)[VISTNES]2.0.CO;2 UT WOS:000252869000023 ER PT J AU Dahle, B Reimers, E Colman, JE AF Dahle, Bjorn Reimers, Eigil Colman, Jonathan E. TI Reindeer (Rangifer tarandus) avoidance of a highway as revealed by lichen measurements SO EUROPEAN JOURNAL OF WILDLIFE RESEARCH AB Reindeer and caribou Rangifer tarandus are reported to avoid human infrastructure such as roads, high-voltage power lines, pipelines, and tourist resorts. Lichens are important forage for reindeer during winter, and their relatively slow growth rates make them vulnerable to overgrazing. Height and volume of lichens are often used as an indicator of grazing pressure by reindeer and, thus, as an indirect measure of Rangifer avoidance of human infrastructure. We sampled lichen height in Cetraria nivalis-dominated communities along 4 and 3 parallel transects located on two parallel mountain ridges in Hardangervidda, south central Norway. The lichen measurements were analyzed in relation to altitude and the distance from four tourist cabins in the area and a highway (Rv7) running perpendicular to the 7 transects. The mountain ridge with 4 transects is part of a much used migratory corridor for wild reindeer R. tarandus tarandus. Along the nonmigratory ridge, lichen height decreased 35% over an 8-km distance from Rv7 and a tourist cabin, indicating reindeer aversion toward Rv7 and/or a tourist cabin. No similar relationship was found for the migration ridge in relation to distance from Rv7 or the tourist cabins. Our results suggest that avoidance of human infrastructure by wild reindeer might be limited where reindeer use of winter pastures is influenced by herd traditions and/or motivation to follow established migration corridors. This has important implications for addressing the use of similar pasture measurements when testing for Rangifer aversion toward human disturbances. SN 1612-4642 EI 1439-0574 PD FEB PY 2008 VL 54 IS 1 BP 27 EP 35 DI 10.1007/s10344-007-0103-5 UT WOS:000252191600005 ER PT J AU Daerga, L Edin-Lijegren, A Sjolander, P AF Daerga, Laila Edin-Lijegren, Anette Sjolander, Per TI Quality of life in relation to physical, psychosocial and socioeconomic conditions among reindeer-herding Sami SO INTERNATIONAL JOURNAL OF CIRCUMPOLAR HEALTH AB Objectives. To analyse different aspects of health-related quality of life factors among members of reindeer-herding families. Study design. Cross-sectional study based on data from a comprehensive survey. Methods. The health-related quality of life (SF-36) factors were analysed on 99 (56 men, 43 women) adult members of reindeer-herding families. Comparisons were made between the reindeer-herding family members and a Swedish reference population. Associations between mental and physical component summary measures and a number of sociodemographic, biomedical, physical, psychosocial and socio-economic variables were analysed with multivariate regression statistics. Results. Men scored higher than women on physical and social function and vitality. The average scores on the subscales for the reindeer-herdin family members were similar to those of the Swedish reference population, except for reindeer-herding men who scored higher on physical function and lower on bodily pain. For women, the quality of life was related to age, sense of coherence, lifestyle and behavioural variables, as well as to issues such as diseases among close relatives, social networks and the economy of their business. For men, it was mainly related to musculoskeletal pain conditions, age, sense of coherence and physical and psychosocial working conditions. Conclusions. Men and women of the reindeer-herding families need partly different conditions to enjoy a high quality of life. From the results, it might be predicted that poor somatic and psychosocial health, increased intrusion from exploiters on the grazing land and declining profit in reindeer husbandry constitute important threats to a good quality of life among members of reindeer-herding families. SN 1239-9736 EI 2242-3982 PD FEB PY 2008 VL 67 IS 1 BP 8 EP 26 UT WOS:000254724500004 PM 18468256 ER PT J AU Brooks, C Bonyongo, C Harris, S AF Brooks, C. Bonyongo, C. Harris, S. TI Effects of global positioning system collar weight on zebra behavior and location error SO JOURNAL OF WILDLIFE MANAGEMENT AB Global Positioning System (GPS) collars are increasingly being used to study fine-scale patterns of animal behavior. Previous studies on GPS collars have tried to determine the causes of location error without attempting to investigate whether the accuracy of fixes provides a correspondingly accurate measure of the animal's natural behavior. When comparing 2 types of GPS collar, we found a significant effect of collar weight and fit on the rate of travel of plains zebra (Equus burchelli antiquorum) females in the Makgadikgadi, Botswana. Although both types of collar were well within accepted norms of collar weight, the slightly heavier collars (0.6% of total body mass [TBM]) reduced rate of travel by >50% when foraging compared with the collar that was 0.4% of TBM. Collar effect was activity specific, particularly interfering with grazing behavior; the effect was less noticeable when zebras crossed larger interpatch distances. We highlight that small differences in collar weight or fit can affect specific behaviors, limiting the extrapolation of fine-scaled GPS data. This has important implications for wildlife biologists, who hitherto have assumed that collars within accepted weight Emits have little or no effect on animal movement parameters. SN 0022-541X EI 1937-2817 PD FEB PY 2008 VL 72 IS 2 BP 527 EP 534 DI 10.2193/2007-061 UT WOS:000253210200026 ER PT J AU Asplund, J Gauslaa, Y AF Asplund, Johan Gauslaa, Yngvar TI Mollusc grazing limits growth and early development of the old forest lichen Lobaria pulmonaria in broadleaved deciduous forests SO OECOLOGIA AB This study aims: (1) to quantify mollusc grazing on juvenile and mature thalli of the foliose epiphytic lichen Lobaria pulmonaria, and (2) to test the hypothesis inferring a herbivore defensive role of lichen depsidones in forests with indigenous populations of lichen-feeding molluscs. Lichens were transplanted in shaded and less shaded positions in each of two calcareous broadleaved deciduous forests, one poor in lichens, one with a rich Lobarion community. Preventing the access of molluscs significantly reduced the loss of juvenile L. pulmonaria, particularly in the naturally lichen-poor forest. Molluscs also severely grazed mature thalli in the lichen-poor forest, especially thalli placed under the more shading canopies. Furthermore, reducing the natural concentration of depsidones by pre-rinsing with acetone increased subsequent grazing significantly, showing that lichen depsidones function as herbivore defence in natural habitats. Our results suggest that mollusc grazing may play important roles in shaping the epiphytic vegetation in calcareous deciduous forests, and that recently established juvenile L. pulmonaria thalli seem to be particularly vulnerable. RI Gauslaa, Yngvar/K-9006-2012 OI Asplund, Johan/0000-0001-5610-4480 SN 0029-8549 PD FEB PY 2008 VL 155 IS 1 BP 93 EP 99 DI 10.1007/s00442-007-0891-z UT WOS:000252640000010 PM 17985157 ER PT J AU den Herder, M Virtanen, R Roininen, H AF den Herder, Michael Virtanen, Risto Roininen, Heikki TI Reindeer herbivory reduces willow growth and grouse forage in a forest-tundra ecotone SO BASIC AND APPLIED ECOLOGY AB Browsing mammals strongly modify the structure of vegetation of forest-tundra ecotones. We investigated the impact of reindeer browsing on growth and morphology of an arctic willow, Salix glauca, by studying plants inside and outside fenced areas in a tundra habitat at the tree line. We also studied if reindeer feeding has an effect on the forage availability for willow grouse, a herbivore sharing the same food plant. Analyses of 6-year data show that reindeer strongly reduces the growth of tundra willow and changes plant morphology to a stunted growth form. Intense reindeer browsing on willow limited the forage availability for willow grouse and grouse fed less on reindeer-browsed willow than willows protected from reindeer browsing. The results of this study imply that herbivores can counteract the increase of shrubs in forest-tundra ecotones, as has been predicted in some studies discussing the effects of climatic warming on vegetation. Furthermore, trophic interactions should be incorporated in modelling vegetation changes as a response to increased temperatures. (C) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved. RI Virtanen, Risto/G-1810-2010 OI Virtanen, Risto/0000-0002-8295-8217 SN 1439-1791 PY 2008 VL 9 IS 3 BP 324 EP 331 DI 10.1016/j.baae.2007.03.005 UT WOS:000256734600014 ER PT J AU Eskelinen, A AF Eskelinen, Anu TI Herbivore and neighbour effects on tundra plants depend on species identity, nutrient availability and local environmental conditions SO JOURNAL OF ECOLOGY AB 1. I performed a factorial transplant experiment to test the roles of plant-plant interactions, herbivory by mammal grazers and resource availability for plant performance in two contrasting habitat types in a mountain tundra environment. 2. Three perennial dicot herbs, Solidago virgaurea, Erigeron uniflorus and Saussurea alpina, were used as target plants to study the effects of neighbour removal and grazer exclusion, and nutrient enrichment and liming on plant growth, survival and reproductive success. These treatments were replicated in two contrasting habitat types, infertile acidic and fertile non-acidic tundra heaths. 3. The effects of plant-plant interactions on Saussurea varied from facilitation in infertile acidic habitats to competition in fertile non-acidic habitats and in nutrient-enriched conditions, while the overall performance of Saussurea was strongly negatively influenced by the presence of grazers, the effects being greater when plants were fertilized and in fertile non-acidic heaths. Erigeron performed better under nutrient-enriched conditions than in unfertilized plots, when neighbours had been removed. Solidago was negatively affected by grazing and this impact was greater in nutrient-enriched plots and in non-acidic heaths than in acidic heaths and for unfertilized controls. There were no interactions between neighbour removal and herbivory in any of the three species, indicating that these processes operated independently. 4. Grazer-preferred tall plants are strongly limited by consumption by mammal herbivores in nutrient-enriched conditions and in inherently fertile habitats. By contrast, arctic-alpine specialists and species of low stature experience increased competition with neighbouring vegetation in fertile habitats and in enriched nutrient conditions. 5. Synthesis. Overall, the results suggest that the strength and directions of plant-plant and plant-herbivore interactions depend on plant species identity and are modified by soil edaphic factors to govern vegetation processes in tundra plant communities. These findings have important implications for understanding the forces structuring vegetation in barren tundra ecosystems under a changing environment. SN 0022-0477 PD JAN PY 2008 VL 96 IS 1 BP 155 EP 165 DI 10.1111/j.1365-2745.2007.01322.x UT WOS:000252846500017 ER PT J AU Jakubas, D Zmudczynska, K Wojczulanis-Jakubas, K Stempniewicz, L AF Jakubas, Dariusz Zmudczynska, Katarzyna Wojczulanis-Jakubas, Katarzyna Stempniewicz, Lech TI Faeces deposition and numbers of vertebrate herbivores in the vicinity of planktivorous and piscivorous seabird colonies in Hornsund, Spitsbergen SO POLISH POLAR RESEARCH AB Ornithogenic tundra developing near large seabird colonies with its dense vegetation creates sites for foraging, hiding and breeding of herbivores. Grazing, trampling and faeces deposition are considered as the most important ways that vertebrate herbivores influence the plants. Excrement deposition level informs us on the intensity of grazing i.e. foraging ground attractiveness. We have compared vertebrate herbivores' faeces deposition (biomass) in the vicinity of big colonies of piscivorous (kittiwake Rissa tridactyla and Brunnich's guillemot Uria lomvia) and planktivorous (little aukAlle alle) seabirds and the control area was in Hornsund, SW Spitsbergen. Much higher level of faeces deposition was recorded nearby seabird colonies as compared to the control area. These finding points out that vertebrate herbivores concentrate and feed more intensively on rich ornithogenic pastures. Number of herbivores and their faeces deposition level recorded nearby planktivorous seabird colony were greater as compared to those found nearby the colony of piscivores. The highest number of geese (Branta bemicla and Anser brachyrhynchus) and of their faeces biomass were found near the colony of planktivorous little auk, where distinct gradient in faeces deposition level along the colony-seashore axis was recorded. Reindeers Rangifer tarandus were observed in considerable numbers near the little auk colony, and were not recorded at all near cliff-nesting sites of kittiwakes and guillemots. Total deposition of excrements produced by geese was generally higher if compared to reindeers. RI Wojczulanis-Jakubas, Katarzyna/L-9785-2015; Jakubas, Dariusz/L-9660-2015 OI Wojczulanis-Jakubas, Katarzyna/0000-0001-6230-0509; Jakubas, Dariusz/0000-0002-1879-4342; Zmudczynska-Skarbek, Katarzyna/0000-0003-2276-4565; Stempniewicz, Lech/0000-0001-9405-7320 SN 0138-0338 EI 2081-8262 PY 2008 VL 29 IS 1 BP 45 EP 58 UT WOS:000256666300005 ER PT J AU Munn, AJ Barboza, PS AF Munn, Adam J. Barboza, Perry S. TI Could a big gut be too costly for muskoxen (Ovibos moschatus) in their first winter? SO ZOOLOGY AB Young mammalian herbivores are more vulnerable to harsh winter conditions than adults, especially among large circumpolar species like the muskox (Ovibos moschatus). We compared feeding responses of muskox calves (body mass 95 kg) with those of mature, non-reproductive females (body mass 227 kg) in mid-winter when air temperatures fell to -40 degrees C. Food intakes (1.8-2.2 kg digestible dry matter (DM) d(-1)), digesta fill (27-32 kg wet mass) and digestibility of hay (52-58% of DM; 49-55% of gross energy) were similar between age groups even though calves were much smaller than adults. Calves fed more frequently (12 vs. 8 feeding bouts per day) and thus spent more time feeding each day than adults (387 vs. 343 min per day). High mass-specific food intakes of calves indicate higher requirements for maintenance of body tissue than adults, which could be related to a larger intestinal tract in young muskoxen. Notably, cows and calves maintained a constant body mass throughout, indicating that they were feeding at maintenance levels and that the relatively higher intakes of calves were not related to growth. Together, these data suggest that limited food availability due to snow cover or high animal density may reduce the survival of muskoxen in their first winter. (C) 2008 Elsevier GmbH. All rights reserved. OI Barboza, Perry/0000-0002-1489-6448 SN 0944-2006 PY 2008 VL 111 IS 5 BP 350 EP 362 DI 10.1016/j.zool.2007.10.004 UT WOS:000258751800002 PM 18550348 ER PT J AU Potthoff, K AF Potthoff, Kerstin TI Persistence of alpine grass-dominated vegetation on abandoned mountain summer farms in Western Norway SO NORSK GEOGRAFISK TIDSSKRIFT-NORWEGIAN JOURNAL OF GEOGRAPHY AB Centuries of seasonal farming in the Norwegian mountains led to a decrease in forested areas, a lowering of the alpine tree- and. forest lines, and an increase in grassland coverage in the subalpine zone. Since the mid-19th century seasonal farming has declined significantly. In the sub-alpine belt, this has resulted in woodland succession on former hay meadows and open grasslands and heathlands. In contrast, vegetation changes caused by seasonal farming and its decline in alpine environments may be comparatively subtle because of unsuitable conditions for tree growth. The study examines vegetation changes in a former mountain summer farming area in the alpine zone of Western Norway using data on present and previous vegetation and old photographs. On curtilages high levels of defoliation, trampling and nutrient accumulation resulted in grass- and herb-dominated vegetation that differs significantly from that of surrounding areas. This curtilage-specific vegetation is persistent and occurs even at locations that have been grazed with only low intensity for several decades. Local concentrations of nutrients are probably a key factor that maintains the grass-dominated vegetation and strongly delays or even prevents regrowth of shrub heath. SN 0029-1951 PD DEC PY 2007 VL 61 IS 4 BP 192 EP 206 DI 10.1080/00291950701709283 UT WOS:000253854300004 ER PT J AU Newbury, TE Simon, NPP Chubbs, TE AF Newbury, Tony E. Simon, Neal P. P. Chubbs, Tony E. TI Moose, Alces alces, Winter Browse Use in Central Labrador SO CANADIAN FIELD-NATURALIST AB To determine the effect of forestry practices oil the availability of winter Moose forage, we recorded Moose browse along four 250 in transecte, in each of five forest regeneration ages. Browse use was greater oil 20- and 30-year-old regenerating stands as compared with recently clearcut stands (5 and 10 years old) or mature forest (> 150 years old). Willow (Salix sp.) followed by White Birch (Betula papyrifera) had the highest proportion of: browsing by Moose. SN 0008-3550 PD OCT-DEC PY 2007 VL 121 IS 4 BP 359 EP 363 DI 10.22621/cfn.v121i4.505 UT WOS:000206554200001 ER PT J AU Rees, WG Danks, FS AF Rees, W. G. Danks, F. S. TI Derivation and assessment of vegetation maps for reindeer pasture analysis in Arctic European Russia SO POLAR RECORD CT 9th Circumpolar Remote Sensing Symposium CY MAY 15-19, 2006 CL Seward, AK AB Throughout northern Eurasia, the presence of reindeer is a complicating factor in the consideration of interactions between vegetation and climate. The ability to interpret future changes in these interactions will depend on access to maps of sufficient detail to represent aspects of vegetation distribution relevant to reindeer grazing, amongst which we particularly identify lichens and shrubs. Such maps, if they are to have circumpolar coverage, can only feasibly be produced on a routine basis using satellite imagery having wide swaths but comparatively coarse resolution. This paper presents qualitative and quantitative comparisons between three such maps, and two more detailed vegetation maps compiled from fieldwork and from recent field-trained satellite image analysis, all for a study area in the Nenets Autonomous Okrug, Russia. It is shown that, despite its high degree of generalisation, the Circumpolar Arctic Vegetation Map provides the best representation of the vegetation in the study area amongst the three circumpolar land-cover maps that were examined, but that none of the three is entirely satisfactory. While the adequate representation of shrubs and lichens currently continues to depend on the analysis of field data or high-resolution satellite imagery which is unsuitable for circumpolar mapping, it is suggested that the prospects for satellite-based circumpolar vegetation mapping capable of including these components is promising. SN 0032-2474 EI 1475-3057 PD OCT PY 2007 VL 43 IS 227 BP 290 EP 304 DI 10.1017/S0032247407006420 UT WOS:000250601400002 ER PT J AU Brathen, KA Ims, RA Yoccoz, NG Fauchald, P Tveraa, T Hausner, VH AF Brathen, Kari Anne Ims, Rolf A. Yoccoz, Nigel G. Fauchald, Per Tveraa, Torkild Hausner, Vera H. TI Induced shift in ecosystem productivity ? Extensive scale effects of abundant large herbivores SO ECOSYSTEMS AB Abundant large herbivores can strongly alter vegetation composition, shifting the ecosystem into a lasting state of changed productivity. Previous studies of the effects of abundant reindeer on alpine and arctic vegetation have yielded equivocal results, probably due to differing environmental contexts. To overcome context dependency we devised a large-scale survey in the region of Finnmark, northern Norway, possessing some of the most densely stocked reindeer herds in the world. The effects of reindeer abundance on summer pasture vegetation were assessed by employing a quasi-experimental design, including site fertility as a potential modifier of the reindeer-vegetation interaction. The study design comprised ten pairs of neighboring management districts (encompassing 18,003 km(2)), where over the two last decades a high-density district on average had reindeer densities more than twice as high and calf weights consistently lower than the low-density district. The abundance of different plant functional groups, ranging from those having facilitating to retarding effects on ecosystem productivity, were quantified by the point intercept method on plots selected according to a hierarchical, stratified random sampling design. Species with strong retarding effects on ecosystem productivity (for example, ericoids) were by far the most abundant. However, we found no consistent effects of reindeer density on their abundance. The most consistent differences between high- and low-density districts were found in plant functional groups with facilitating to neutral effects on ecosystem productivity. In particular, the abundance of N-facilitators, large dicotyledons and grasses were substantially reduced in the high-density districts. However, this reduction was restricted to fertile sites. Thus, reindeer when present at high densities have homogenized the biomass of palatable plants across environmental productivity gradients according to predictions from exploitation ecosystem models. Such reduction of plants with facilitating to neutral effects on ecosystem productivity indicates a reduced state of ecosystem productivity in high-density districts. RI Yoccoz, Nigel/A-1493-2008; Yoccoz, Nigel/C-8561-2014 OI Yoccoz, Nigel/0000-0003-2192-1039; Brathen, Kari Anne/0000-0003-0942-1074 SN 1432-9840 PD AUG PY 2007 VL 10 IS 5 BP 773 EP 789 DI 10.1007/s10021-007-9058-3 UT WOS:000249969200008 ER PT J AU Kumpula, J Colpaert, A Anttonen, M AF Kumpula, Jouko Colpaert, Alfred Anttonen, Marja TI Does forest harvesting and linear infrastructure change the usability value of pastureland for semi-domesticated reindeer (Rangifer tarandus tarandus)? SO ANNALES ZOOLOGICI FENNICI AB During the harshest winter, preference of forest habitat by reindeer should be dependent on the availability of energy-rich lichens, while in summer and easy snow conditions on the availability of protein-richer food. Reindeer should also avoid linear infrastructure (roads, power lines) if it causes disturbance and energy loss. We tested seasonal home range and habitat selection by semi-domesticated reindeer (Rangifer tarandus tarandus) in a sub-arctic pine forest area, northern Finland by tracking 29 female reindeer with GPS collars from 1999-2002. As expected, reindeer preferred old-growth forest and avoided felled areas and linear infrastructure in the selection and use of their wintering areas. Old-growth forest had high preference especially in late winter. During summer and early winter, reindeer also used sapling stand areas, young cultivated forests, mires and high-elevation open land. The net energy balance hypothesis including the total energy profits and expenditures could primarily explain habitat selection by reindeer during winter in intensively grazed and logged forest areas. Maintaining a certain amount of old-growth forest and minimizing linear infrastructure in wintering areas considerably improves the suitability of these ranges for reindeer herding. SN 0003-455X PD JUN 21 PY 2007 VL 44 IS 3 BP 161 EP 178 UT WOS:000248181600001 ER PT J AU Granath, G Vicari, M Bazely, DR Ball, JP Puentes, A Rakocevic, T AF Granath, Gustaf Vicari, Mark Bazely, Dawn R. Ball, John P. Puentes, Adriana Rakocevic, Tomo TI Variation in the abundance of fungal endophytes in fescue grasses along altitudinal and grazing gradients SO ECOGRAPHY AB Epichloe festucae, a common fungal symbiont of the genus Festuca (family Poaceae), can provide its host plant with protection against herbivores. However, infection might also be associated with a cost to its host plant. We examined the distribution of Epichloe festucae infection in natural populations of three fescue grasses, Festuca rubra, F. ovina and F. vivipara, on mountains in northern Sweden to determine whether infection frequency varied with reindeer Rangifer tarandus grazing pressure and altitude. Two differently-scaled approaches were used: 1) infection frequency was measured at a local scale along ten elevational transects within a ca 400 km(2) area and 2) infection frequency was measured on a regional scale along elevational transects on 17 mountains classified as having a history of high or low reindeer grazing pressure. Mean infection frequencies in F. rubra were 10% (vegetative tillers at a local scale), and 23% (flowering culms at a regional scale), and in F. ovina they were 13% (local scale) and 15% (regional scale). Endophyte infection frequency in F. vivipara, was, on average, 12% (local scale) and 37% (regional scale). In F. rubra, infection decreased significantly with increasing altitude at both the local and regional scale, and was positively correlated with grazing pressure. In F. ovina, an opposite trend was found at the regional scale: infection frequency increased significantly with increasing altitude, while no discernible distribution pattern was observed at the local scale. No elevational trends were observed in infection of F. vivipara. These patterns in the distribution of endophyte-infected grasses in non-agricultural ecosystems may be explained by both biotic (grazing) and abiotic factors (altitude). Differences in ecology and life history of the studied grass species may also be of importance for the different results observed among species. RI Ball, John/D-2409-2011; Bazely, Dawn/H-8260-2013 OI Granath, Gustaf/0000-0002-3632-9102; Puentes, Adriana/0000-0001-9393-7449 SN 0906-7590 PD JUN PY 2007 VL 30 IS 3 BP 422 EP 430 DI 10.1111/j.2007.0906-7590.05027.x UT WOS:000247115600013 ER PT J AU Ims, RA Yoccoz, NG Brathen, KA Fauchald, P Tveraa, T Hausner, V AF Ims, Rolf A. Yoccoz, Nigel G. Brathen, Kari Anne Fauchald, Per Tveraa, Torkild Hausner, Vera TI Can reindeer overabundance cause a trophic cascade? SO ECOSYSTEMS AB The region Finnmark, in northernmost Europe, harbors dense populations of semi-domestic reindeer of which some exhibit characteristics of overabundance. Whereas overabundance is evident in terms of density-dependent reductions in reindeer body mass, population growth and abundance of forage plants, claims have been made that this reindeer overabundance also has caused a trophic cascade. These claims are based on the main premise that reindeer overgrazing negatively impacts small-sized, keystone tundra herbivores. We tested this premise by a large-scale study in which the abundance of small rodents, hares and ptarmigans was indexed across reindeer management districts with strong differences in stocking densities. We examined the scale-dependent relations between reindeer, vegetation and these small-sized herbivores by employing a spatially hierarchical sampling design within the management districts. A negative impact of reindeer on ptarmigan, probably as a result of browsing reducing tall Salix, was indicated. However, small rodents (voles and lemmings), which are usually the keystone herbivores in the plant-based tundra food web, were not negatively impacted. On the contrary, there was a strong positive relationship between small rodents and reindeer, both at the scale of landscape areas and local patches, with characteristics of snow-bed vegetation, suggesting facilitation between Norwegian lemmings and reindeer. We conclude that the recent dampening of the vole and lemming population cycle with concurrent declines of rodent predators in northernmost Europe were not caused by large herbivore overgrazing. RI Yoccoz, Nigel/C-8561-2014; Yoccoz, Nigel/A-1493-2008 OI Yoccoz, Nigel/0000-0003-2192-1039; Brathen, Kari Anne/0000-0003-0942-1074 SN 1432-9840 PD JUN PY 2007 VL 10 IS 4 BP 607 EP 622 DI 10.1007/s10021-007-9060-9 UT WOS:000249622400008 ER PT J AU Rasanen, S Froyd, C Goslar, T AF Rasanen, Satu Froyd, Cynthia Goslar, Tomasz TI The impact of tourism and reindeer herding on forest vegetation at Saariselka", Finnish Lapland: a pollen analytical study of a high-resolution peat profile SO HOLOCENE AB A high-resolution peat profile from the vicinity of Saariselka (68 degrees 25.24'N, 27 degrees 25.19'E), a large tourist centre in northern Finnish Lapland, was sampled continuously at near annual resolution to a depth of 22cm in order to interpret the changes in pollen assemblages and vegetation resulting from human interference and reindeer herding. Fifteen AMS dates were wiggle-matched with the atmospheric C-14 calibration curve. The resulting age-depth model allows the calculation of pollen accumulation rates (PAR grains/cm(2) per yr), which, in turn, enables the fine-scale human impact to be interpreted on much better grounds than would be possible with the classical pollen percentages approach. Results indicate that increasing tourist numbers since the building of the Saariselka resort in 1950 are not seen in the pollen diagrams. Only a slight, although clear, increase in the pollen taxa of disturbed sites (mainly Gramineae with some herb pollen taxa) can be detected from the PAR diagram after the 1950s, along with a decrease of Pinus pollen following the clearance of the ski slopes in the 1970s. Principal components analysis (PCA) of fossil pollen spectra and modern pollen analogues obtained from both natural and human-disturbed sites confirms that human interference that has affected the vegetation around Saariselka is not visible in the pollen record to the degree that might have been expected. This is interpreted as resulting from the considerably different nature of human impact at Saariselka, where the infrastructure is fully developed and weed species are efficiently removed. The remarkable growth of reindeer population in the area during the 1980s, however, can be observed in the peat profile through an increase in the number of coprophilous fungal spores (Podospora, Sporormiella). This increase in fungal spores occurs simultaneously with a decrease in Betula pollen, which is interpreted to be a consequence of reindeer foraging the young Betula trees and seedlings. RI Froyd, Cynthia/A-8488-2012 OI Froyd, Cynthia/0000-0001-5291-9156; Goslar, Tomasz/0000-0002-1346-3122 SN 0959-6836 EI 1477-0911 PD MAY PY 2007 VL 17 IS 4 BP 447 EP 456 DI 10.1177/0959683607077016 UT WOS:000248151200003 ER PT J AU Keren, EN Olson, BE AF Keren, Elai N. Olson, Bret E. TI Applying thermal imaging software to cattle grazing winter range SO JOURNAL OF THERMAL BIOLOGY AB 1. Metabolic demands of cattle grazing winter range may be over-predicted by models that do not account for animal behavior. Cattle may conserve energy and mitigate cold stress by short-term behavioral responses. 2. We solved the thermal balance equation for a revolving three-dimensional model using advanced thermal solution software to simulate unconstrained cattle during winter. This software, developed for inanimate objects, predicted energetic requirements within expected range of values. 3. Solar radiation and apparent surface area were instrumental in reducing energy requirements, especially on cold clear days, whereas wind velocity and ambient temperature had a lesser effect on well-insulated cows in good body condition. (c) 2007 Elsevier Ltd. All rights reserved. SN 0306-4565 PD MAY PY 2007 VL 32 IS 4 BP 204 EP 211 DI 10.1016/j.jtherbio.2006.11.004 UT WOS:000246350300004 ER PT J AU Brathen, KA Gonzalez, VT Iversen, M Killengreen, S Ravolainen, VT Ims, RA Yoccoz, NG AF Brathen, Kari Anne Gonzalez, Victoria T. Iversen, Marianne Killengreen, Siw Ravolainen, Virve T. Ims, Rolf A. Yoccoz, Nigel G. TI Endozoochory varies with ecological scale and context SO ECOGRAPHY AB Several studies on endozoochory have established large herbivores as important for seed dispersal, yet no studies have evaluated how endozoochory is dependent on ecological scale and context. Here we address effects of reindeer density on endozoochory in a hierarchical, multi-scale study, encompassing several ecological contexts. We found reindeer density effects on endozoochory to vary with spatial scale. Higher reindeer densities at the level of landscape areas, as indexed through faeces abundance, were related to both less species and lower abundance of emerging plants from faeces. In contrast, there was no effect of higher reindeer densities at the level of herding districts (i.e. large scale assemblages of landscapes). Lack of consistency between scales reflects ecological hierarchy, indicating that reindeer density effects on endozoochory best matches at the scale of landscapes. Pasture seed plant composition was only partly an important ecological factor. That is, ericoid species, the dominating plants in the pastures, were also the most abundant seed plants found to emerge from the faeces. However, most herbaceous seed plant species in the pastures were not emerging from the faeces and the few that emerged were positively related to the site fertility and altitude of the pasture. Studies addressing endozoochory of ruminants are typically concerned with seed plants, whereas in this study we also found indications of that diaspores of ferns are viable after passing the digestive tract of large herbivores. Vascular spore plants were even more abundant in the faeces than were vascular seed plants. Results from this study demonstrate that reindeer may counteract a potentially negative impact on seed limitation from their grazing by returning viable seeds in their faeces. However, in Finnmark, northern Norway, this effect is only marginal, relates only to a very few species and individuals and shows ecological scale and context dependence. RI Yoccoz, Nigel/C-8561-2014; Killengreen, Siw/G-9205-2016; Yoccoz, Nigel/A-1493-2008 OI Yoccoz, Nigel/0000-0003-2192-1039; Brathen, Kari Anne/0000-0003-0942-1074 SN 0906-7590 PD APR PY 2007 VL 30 IS 2 BP 308 EP 320 DI 10.1111/j.2007.0906-7590.04976.x UT WOS:000245604000014 ER PT J AU Hansen, BB Henriksen, S Aanes, R Saether, BE AF Hansen, Brage Bremset Henriksen, Snorre Aanes, Ronny Saether, Bernt-Erik TI Ungulate impact on vegetation in a two-level trophic system SO POLAR BIOLOGY AB A central challenge in ecology is to predict long-term consequences of high herbivore densities on their resources. Here we describe vegetation changes during 26 years following the reintroduction of a wild Svalbard reindeer (Rangifer tarandus platyrhynchus) population that was not subject to predation. The population irrupted, crashed and subsequently fluctuated around lower densities throughout the study period. The irruption generated strong trophic top-down effects on the vegetation including a decline in the cover of mosses, vascular plants and lichens. Previously dominant fruticose lichens, which are preferred forage during winter, were almost depleted and showed no response to the relief in grazing pressure. This in turn indirectly affected rates of recovery in other plant groups subsequent to the crash. Mosses recovered completely and even exceeded pre-reindeer levels 6 years after the population peak. Recovery of vascular plants was more delayed and only partial due to a long-term suppression of common species that are important as reindeer forage. Thus, a suppression of major forage species and a sustained reduction in herbivore densities suggest that overgrazing occurred during the population irruption, possibly inducing a long-term decline in reindeer carrying capacity K. This supports the "exploitation ecosystem hypothesis" predicting top-down control of vegetation by herbivores when predators are absent. RI Hansen, Brage/B-9942-2008 OI Hansen, Brage/0000-0001-8763-4361 SN 0722-4060 PD APR PY 2007 VL 30 IS 5 BP 549 EP 558 DI 10.1007/s00300-006-0212-8 UT WOS:000244753300003 ER PT J AU Stark, S Julkunen-Tiitto, R Kumpula, J AF Stark, Sari Julkunen-Tiitto, Riitta Kumpula, Jouko TI Ecological role of reindeer summer browsing in the mountain birch (Betula pubescens ssp czerepanovii) forests: effects on plant defense, litter decomposition, and soil nutrient cycling SO OECOLOGIA AB Mammalian herbivores commonly alter the concentrations of secondary compounds in plants and, by this mechanism, have indirect effects on litter decomposition and soil carbon and nutrient cycling. In northernmost Fennoscandia, the subarctic mountain birch (Betula pubescens ssp. czerepanovii) forests are important pasture for the semidomestic reindeer (Rangifer tarandus). In the summer ranges, mountain birches are intensively browsed, whereas in the winter ranges, reindeer feed on ground lichens, and the mountain birches remain intact. We analyzed the effect of summer browsing on the concentrations of secondary substances, litter decomposition, and soil nutrient pools in areas that had been separated as summer or winter ranges for at least 20 years, and we predicted that summer browsing may reduce levels of secondary compounds in the mountain birch and, by this mechanism, have an indirect effect on the decomposition of mountain birch leaf litter and soil nutrient cycling. The effect of browsing on the concentration of secondary substances in the mountain birch leaves varied between different years and management districts, but in some cases, the concentration of condensed tannins was lower in the summer than in the winter ranges. In a reciprocal litter decomposition trial, both litter origin and emplacement significantly affected the litter decomposition rate. Decomposition rates were faster for the litter originating from and placed into the summer range. Soil inorganic nitrogen (N) concentrations were higher in the summer than in the winter ranges, which indicates that reindeer summer browsing may enhance the soil nutrient cycling. There was a tight inverse relationship between soil N and foliar tannin concentrations in the winter range but not in the summer range. This suggests that in these strongly nutrient-limited ecosystems, soil N availability regulates the patterns of resource allocation to condensed tannins in the absence but not in the presence of browsing. RI Stark, Sari/L-4440-2013 SN 0029-8549 PD MAR PY 2007 VL 151 IS 3 BP 486 EP 498 DI 10.1007/s00442-006-0593-y UT WOS:000244692700011 PM 17123112 ER PT J AU Bjork, RG Molau, U AF Bjork, Robert G. Molau, Ulf TI Ecology of alpine snowbeds and the impact of global change SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB The ecosystems of alpine snowbed habitats are reviewed with emphasis on ecosystem functioning and capability to adapt to current and predicted global change. Snowbeds form in topographic depressions that accumulate large amounts of snow during the winter months, and the final snowmelt does not occur until late in the growing season. Many species preferentially grow in snowbed habitats and some of these are even restricted to these habitats. In this review we identify several ecosystem services which snowbeds provide to the alpine landscape. For instance, snowbeds provide a steady water and nutrient supply to adjacent plant communities and offer newly emerged high-quality food for herbivores late in the growing season. We also propose that alpine snowbeds are much more productive than earlier thought, especially when the very short growing season and often high grazing pressure are taken fully into account. Furthermore, we propose that bryophytes and graminoids (grasses, sedges, and rushes) probably will be most negatively impacted by global change, and the snowbed plant communities will be invaded by species from adjacent plant communities, especially by shrubs and boreal species. As snowbed plants have special growth conditions, their sensitivity and ability to respond rapidly to changes in annual snowfall patterns make snowbed communities particularly vulnerable in a warmer climate, and thereby sensitive indicators of global change. OI Bjork, Robert/0000-0001-7346-666X SN 1523-0430 EI 1938-4246 PD FEB PY 2007 VL 39 IS 1 BP 34 EP 43 DI 10.1657/1523-0430(2007)39[34:EOASAT]2.0.CO;2 UT WOS:000244658600006 ER PT J AU Reimers, E Dahle, B Eftestol, S Colman, JE Gaare, E AF Reimers, Eigil Dahle, Bjorn Eftestol, Sindre Colman, Jonathan E. Gaare, Eldar TI Effects of a power line on migration and range use of wild reindeer SO BIOLOGICAL CONSERVATION AB Linear infrastructures such as roads, pipelines and power lines can hinder Rangifer migration and reduce the total amount of area available for foraging. We studied the barrier and aversion effect of a 66 kV power line transecting the range of wild reindeer in North Ottadalen, south central Norway using aerial surveys of reindeer distribution (direct measurement of reindeer use) and lichen measurements (indirect measurement of reindeer use) at varying distances from both sides of the power line. We present a clear definition of the expected barrier and aversion effects, and present specific hypotheses and predictions based on these two terms that are often used unclearly in the literature. The aerial surveys and ground observations showed that reindeer crossed underneath and grazed under and on both sides of the power line during 14 out of the 22 years (63.6%) surveys were conducted over the last 31 years. This behaviour was confirmed by the lichen measurements, indicating a higher use of lichen pastures along ridges close to and under the power line compared to those at increasing distances and up to 3 km from both sides of the power line. This winter grazing pattern probably reflects the topographical channeling of reindeer to the ridges along an 8 km wide topographical corridor encompassing the power line and cannot be attributed to the power line itself. We found that direct measurement data (visual observations such as ours or GPS/telemetry tracking) provide less ambiguous information for testing barrier and aversion effects than indirect measurement data (pasture/ lichen measurements) that are likely influenced by numerous uncontrollable environmental variables independent of reindeer grazing. Our results contrast with recent studies indicating strong barrier and aversion effects of similar power lines for Rangifer migration and grazing behaviour in alpine terrain. (c) 2006 Elsevier Ltd. All rights reserved. SN 0006-3207 PD FEB PY 2007 VL 134 IS 4 BP 484 EP 494 DI 10.1016/j.biocon.2006.08.034 UT WOS:000244769800003 ER PT J AU Yeates, GW Hrabok, JT Oksanen, A Nieminen, M Waller, PJ AF Yeates, Gregor W. Hrabok, Jackie T. Oksanen, Antti Nieminen, Mauri Waller, Peter J. TI Soil nematode populations beneath faeces from reindeer treated with ivermectin SO ACTA AGRICULTURAE SCANDINAVICA SECTION B-SOIL AND PLANT SCIENCE AB The size and composition of the nematode assemblage in soil beneath faecal material derived from reindeer treated with ivermectin oral, or ivermectin subcutaneous formulations in early winter in northern Finland, was studied over a two-year period. This study was performed on both ungrazed and grazed areas that typify the reindeer habitat of the region and comparisons were also made with soil nematodes recovered from soils receiving untreated faecal material. Although significant differences in numbers of soil nematode fauna were observed between treatments on individual occasions, none of the differences occurred consistently with treatment, or with time. These results showed no adverse environmental impact of the faeces of reindeer given either formulation of ivermectin in early winter on soil nematode communities in subsequent years. SN 0906-4710 PY 2007 VL 57 IS 2 BP 126 EP 133 DI 10.1080/09064710600722563 UT WOS:000246619100006 ER PT J AU Austrheim, G Mysterud, A Hassel, K Evju, M Okland, RH AF Austrheim, Gunnar Mysterud, Atle Hassel, Kristian Evju, Marianne Okland, Rune H. TI Interactions between sheep, rodents, graminoids, and bryophytes in an oceanic alpine ecosystem of low productivity SO ECOSCIENCE AB Large herbivores directly affect plant communities in alpine ecosystems. In addition, they may compete with, or facilitate foraging by, small herbivores and also cause strong indirect effects on plants. We used an exclosure experiment to examine short-term (5-y) effects of cessation of sheep grazing on rodent grazing and plant communities in an oceanic alpine environment of low productivity with a long history of heavy sheep gazing. Exclusion of sheep significantly impacted plant communities. Vascular plant height increased, but Deschampsia flexuosa was the only vascular plant species that increased in sheep exclosures. Changes in the frequency of graminoids, herbs, and dwarf shrubs in exclosed plots were not related to cessation of grazing, but 6 bryophyte species significantly increased or decreased in response to exclusion of sheep. The absence of large grazers thus brought about a change in the species composition in favour of successional bryophytes and the preferred fodder plant. Neither vascular plant nor bryophyte species richness, nor the total cover of bryophytes and lichens, were affected. Cessation of sheep grazing reduced the level of rodent grazing. Rodent grazing correlated with changes in plant communities that led to reduced height and cover of vascular plants, reduced cryptogam cover, and reduced frequencies of 3 bryophyte species. A strong correlation between sheep fodder value index and rodent grazing indirectly indicated additive herbivory. In addition, some of the rodent effects were compensatory; e.g., Nardus stricta, which is not grazed by sheep, was significantly reduced by rodents. Our study points to a more central role of facilitation in structuring herbivore assemblages in the short term, with direct implications for the joint effects of large and small herbivores on the cover and frequency of graminoids and bryophytes. OI Hassel, Kristian/0000-0002-1906-8166 SN 1195-6860 PY 2007 VL 14 IS 2 BP 178 EP 187 DI 10.2980/1195-6860(2007)14[178:IBSRGA]2.0.CO;2 UT WOS:000247488100006 ER PT J AU Hrabok, JT Oksanen, A Nieminen, A Waller, PJ AF Hrabok, J. T. Oksanen, A. Nieminen, A. Waller, P. J. TI Population dynamics of nematode parasites of reindeer in the sub-arctic SO VETERINARY PARASITOLOGY AB Nematode parasite infections of semi-domestic reindeer grazing in their natural habitat in northern Finland were monitored for approximately 2 years. This was achieved by monthly faecal egg counts of male and female calves and adult females from an experimental reindeer herd, in addition to estimating the acquisition of nematode infection from pasture using tracer reindeer calves. The most abundant parasite was Ostertagia gruehneri in the worm counts of tracer animals and in faecal egg counts of adult female reindeer. Capillaria sp. eggs were detected in calves and adults, but Nematodirinae eggs were only recovered from calves. Faecal egg counts showed variations between months for each nematode species, with male and female calves shedding similar numbers of eggs. During each year, calves shed more Capillaria sp. eggs than adult female reindeer, but similar numbers of O. gruehneri eggs. Egg counts of O. gruehneri were more abundant in late summer-autumn (July-September), whereas Capillaria sp. and the Nematodirinae dominated the winter months (November-February). The seasonal trends of adult worm burdens of O. gruehneri in the tracers paralleled the egg count patterns. Capillaria sp. was not detected in tracer worm counts. Tracer worm burdens showed that the proportion of inhibited larvae of O. gruehneri and Nematodirinae steadily increased from spring to early winter, followed by a decline and a commensurate increase in the number of adult parasites in the second summer. This investigation showed that parasite transmission occurs continuously throughout the year for nematode parasites of reindeer in northern Finland. (c) 2006 Elsevier B.V. All rights reserved. SN 0304-4017 PD DEC 20 PY 2006 VL 142 IS 3-4 BP 301 EP 311 DI 10.1016/j.vetpar.2006.07.024 UT WOS:000242792400012 PM 16934935 ER PT J AU Asbakk, K Hrabok, JT Oksanen, A Nieminen, M Waller, PJ AF Asbakk, Kjetil Hrabok, Jackie T. Oksanen, Antti Nieminen, Mauri Waller, Peter J. TI Prolonged persistence of fecally excreted ivermectin from reindeer in a sub-arctic environment SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB In December 2001 and 2002, feces from reindeer calves treated with ivermectin were distributed on plots established on two types of forested reindeer pasture in northern Finland. The ungrazed plots were on an enclosure that had been fenced to prevent reindeer access for the last 6 years. The grazed plots were on an area that had been heavily stocked by reindeer during the last 5 years. After enclosures had been established, reindeer and large wildlife were prevented from entering by a fence. Topsoil samples ( feces, vegetation, and soil) were collected monthly during the summers of the following 2 years, over a period of from 25 to 95 weeks after deposition. The samples were analyzed for ivermectin using HPLC. Although ivermectin degradation rapidly took place during the first spring, considerable residual ivermectin could be measured throughout the sampling time, showing that ivermectin in feces on pasture may not be photodegraded as rapidly as previously believed. The results support the need for further environmental evaluation studies on the use of ivermectin to control reindeer parasites. SN 0021-8561 PD NOV 29 PY 2006 VL 54 IS 24 BP 9112 EP 9118 DI 10.1021/jf061633l UT WOS:000242216000018 PM 17117798 ER PT J AU Zalatan, R Gunn, A Henry, GHR AF Zalatan, R. Gunn, A. Henry, G. H. R. TI Long-term abundance patterns of barren-ground caribou using trampling scars on roots of Picea mariana in the Northwest Territories, Canada SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB The aim of this study was to reconstruct population dynamics of barren-ground caribou (Rangifer tarandus groenlandicus) herds from the frequency of trampling scars on tree roots of black spruce (Picea mariana [Mill.] BSP) in the forest-tundra of central Northwest Territories, Canada. Two groups of sites were sampled that roughly corresponded with the migration routes of the Bathurst and Beverly caribou herds. The caribou migrate annually for long distances from the forest to the open tundra in late spring, and return to the forest in the autumn. The scar frequency distribution was determined by careful crossdating and the influence of root age was assessed to account for the increasing underestimation of caribou abundance with the increasing age of the roots. The scar frequency distributions (dated from A.D. 1760 to 2000) from both groups of sites showed similar abundance patterns through time. Caribou numbers were high during the mid-1940s, and 1990s, and were very low during the 1920s, 1950s-1970s, and at the turn of the 21st century. These abundance patterns determined from scar frequencies correlate strongly with data obtained from traditional knowledge of Dogrib elders in the region and animal counts based on aerial photography. The scar frequency distribution developed in this study is the longest proxy record of caribou abundance to date. SN 1523-0430 PD NOV PY 2006 VL 38 IS 4 BP 624 EP 630 DI 10.1657/1523-0430(2006)38[624:LAPOBC]2.0.CO;2 UT WOS:000242509200015 ER PT J AU Cooper, EJ AF Cooper, Elisabeth J. TI Reindeer grazing reduces seed and propagule bank in the High Arctic SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE AB It is commonly assumed that plant establishment in the High Arctic is limited by severe abiotic conditions by a paucity of popagules and seeds. Heavy reindeer grazing may reduce plant allocation to reproduction and removes significant proportions of flowers and seeds, thus reducing contributions to seed bank. In contrast, foraging and trampling may break up existing mature plants, increasing the vegetative propagules in the soil. To determine the effect of grazing on colonization potential in the High Arctic, two studies were carried out: (i) a comparison of seed bank inside and outside three long-term reindeer (Rangifer tarandus platyrhnchus (Vrolic)) exclosures and (ii) an investigation of the germinable seed and propagule bank of two neighbouring peninsulas with contrasting reindeer grazing history in north-western Svalbard (79 degrees N, 12 degrees E). Seed banks inside reindeer exclosures germinated significantly more seedings (596 seedlings . m(-2)) than those outside (263 seedlings.m(-2)). Species composition and total plant cover was similar on both peninsulas, but forage-plant cover was lower on the heavily grazed peninsula (Broggerhalvoya) than on the adjacent lightly grazed peninsula (Sarsoyra). Broggerhalvoya had significantly lower species richness and density of seed and propagule bank (0.21 +/- 0.02 germinating species per sample, 0.15 +/- 0.02 propagule species per sample, 416 +/- 103 seedlings.m(-2), 283 +/- 78 propagules.m(-2)) than did Sarsoyra (0.44 +/- 0.40 germinating species per sample, 0.35 +/- 0.03 propagule species per sample, 1016 +/- 188 seedlings.m(-2), 782 +/- 238 propagules.m(-2)). These results imply that reindeer depleted both the seed and propagule banks, thus reducing the potential for colonization of disturbed areas. Grazing may, therefore, have a lasting impact on High Arctic communities. SN 0008-4026 PD NOV PY 2006 VL 84 IS 11 BP 1740 EP 1752 DI 10.1139/B06-127 UT WOS:000244858600012 ER PT J AU Clauss, M Hofmann, RR Hummel, J Adamczewski, J Nygren, K Pitra, C Streich, WJ Reese, S AF Clauss, M. Hofmann, R. R. Hummel, J. Adamczewski, J. Nygren, K. Pitra, C. Streich, W. J. Reese, S. TI Macroscopic anatomy of the omasum of free-ranging moose (Alces alces) and muskoxen (Ovibos moschatus) and a comparison of the omasal laminal surface area in 34 ruminant species SO JOURNAL OF ZOOLOGY AB The function of the 'third compartment' of the ruminant forestomach, the omasum, has been debated for a long time. To date, it is assumed that its major function is fluid reabsorption. In order to investigate differences in this organ between ruminant feeding types, we first compared macroscopic measurements of the omasa of free-ranging muskoxen Ovibos moschatus [n=6, mean body mass (BM) 207 kg, range 180-221], a grazer, and free-ranging moose Alces alces (n=11, mean BM 291 kg, range 144-418), a strict browser. Despite the similar BM range, omasa of muskoxen contained more ingesta, had a higher empty organ weight, had more third- and fourth-order laminae, and represented a higher proportion of the total forestomach weight. In particular, the surface area of the omasal leaves - the area available for fluid absorption - was significantly larger in muskoxen (10 933 +/- 940 cm(2)) than in moose (2228 +/- 885 cm(2)). In order to test whether the difference in available surface area is a true functional correlate of feeding type, additional data on the omasal laminar surface area were generated for 83 individuals of 19 species. These data were supplemented with data on 13 additional species from the literature. The percentage of grass (%grass) in the natural diet was used to characterize the feeding type; the phylogenetic tree used for a controlled statistical evaluation was entirely based on mitochondrial DNA information. Regardless of phylogenetic control in the statistical treatment, there was a significant positive correlation of both BM and %grass in the natural diet with omasal laminar surface area. The data suggest that certain ruminant species that ingest more grass have larger omasal leaf surface areas, possibly indicating a higher need for water reabsorption distal to the ruminoreticulum, which could be explained as a consequence of the more distinct rumen contents stratification in these species. RI Clauss, Marcus/A-4710-2008; Reese, Sven/F-1826-2016 OI Clauss, Marcus/0000-0003-3841-6207; Reese, Sven/0000-0002-4605-9791 SN 0952-8369 PD OCT PY 2006 VL 270 IS 2 BP 346 EP 358 DI 10.1111/j.1469-7998.2006.00148.x UT WOS:000240492600016 ER PT J AU Nybakken, L Julkunen-Tiitto, R AF Nybakken, Line Julkunen-Tiitto, Riitta TI UV-B induces usnic acid in reindeer lichens SO LICHENOLOGIST AB Induction of secondary compounds in three reindeer lichens (Cladonia arbuscula, C. rangiferina and G. stellaris) was studied under controlled conditions in a growth chamber. Acetone rinsed (secondary compounds removed) lichen mats were subjected to three light regimes (PAR, PAR+UV-A and PAR+LJV-A+UV-B), each combined with simulated herbivory (clipping). After 4 weeks, lichen extracts were analyzed by HPLC for any synthesized secondary compounds. UV-B induced the synthesis of usnic acid in C. arbuscula and C. stellaris and melanic pigments in C. rangiferina. Atranorin, fumarprotocetraric acid and perlatolic acid were not influenced by light quality. None of the identified compounds were significantly influenced by clipping. In conclusion, all three lichen species responded to UV-B radiation by developing cortical UV-B absorbing pigments that might function as protective screens. However, the experiment did not produce evidence for a herbivore-deterrent role of compounds studied. SN 0024-2829 PD SEP PY 2006 VL 38 BP 477 EP 485 DI 10.1017/S0024282906005883 PN 5 UT WOS:000240681200011 ER PT J AU Holt, EA McCune, B Neitlich, P AF Holt, Emily A. McCune, Bruce Neitlich, Peter TI Defining a successional metric for lichen communities in the arctic tundra SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB We provide an index of successional status for arctic macrolichen communities based on a synthesis of literature reports. We amassed research from the past 50 years that studied lichen communities following disturbance, such as fire or grazing. Species scores were derived from these reports depending on when a particular macrolichen species appeared following disturbance. Weighted averaging of these data with a community matrix can create a successional score for each sample unit of interest. These scores can be used as a surrogate for community age estimates that are otherwise difficult to obtain from tundra environments above treeline. We test this approach using an example data set of macrolichen communities collected from the Bering Land Bridge National Preserve, Alaska. We found that our successional scores represented roughly 17 and 19% of the community variation, depending on whether the community data set was binary or quantitative. Abundance data tended to yield successional scores that were slightly higher (older) than those derived from a presence-absence data set. We recommend use of our successional metric for lichen communities throughout the arctic tundra to infer successional status of an area. SN 1523-0430 EI 1938-4246 PD AUG PY 2006 VL 38 IS 3 BP 373 EP 377 DI 10.1657/1523-0430(2006)38[373:DASMFL]2.0.CO;2 UT WOS:000240449600008 ER PT J AU Lorimer, H AF Lorimer, Hayden TI Herding memories of humans and animals SO ENVIRONMENT AND PLANNING D-SOCIETY & SPACE AB The study of a herd marks the point where ethnography and ethology meet. In the midst of this shared phenomenon, versions of 'the social' hinge on relations between herders and herd. In this paper I consider how our understanding of a herd might be extended by an awareness of its diverse geographies. This is achieved by reconstructing the entwined biographies of human and animal subjects dating from the reintroduction of reindeer to Scotland in 1952. The first transportation of reindeer from Scandinavia to the Cairngorm mountains was orchestrated by Mikel Utsi, a Lappish emigre from northernmost Sweden, and Ethel John Lindgren, a social anthropologist from Cambridge, of American-Swedish descent. What began as an ecological-economic experiment would occupy the couple until their deaths: Utsi's in 1979 and Lindgren's in 1988. I draw on a 'make-do' methodology undertaken in collaboration with past herders and the scattered company of the present herd: walking a sentient topography of traditional grazing grounds; renewing encounters with charismatic animals through photographic portraits; consulting an archive of herding diaries; and mapping a hidden ecology of landscape relics. These different registers of memory are used to explore how day-to-day engagements between herders and herd were rooted in unconventional systems of ecological and cultural knowledge. By reanimating a local landscape, the resulting narrative works at an intimate scale, while simultaneously gathering momentum from transnational movements of humans, animals, and traditions. Here, salvage and exchange are possible between geography's heritage of landscape and folk study and the sculpting of contemporary research. SN 0263-7758 PD AUG PY 2006 VL 24 IS 4 BP 497 EP 518 DI 10.1068/d381t UT WOS:000241174500003 ER PT J AU Skonhoft, A AF Skonhoft, Anders TI The costs and benefits of animal predation: An analysis of Scandinavian wolf re-colonization SO ECOLOGICAL ECONOMICS AB After coming close to extinction, the grey wolf (Canis lupus) has re-colonized Scandinavia during the last two decades. The current population numbers some 100-120 individuals, and is distributed in small packs along the Swedish-Norwegian border. However, with wolf re-colonization, several conflicts have arisen. One conflict is due to wolf predation on livestock, especially sheep and reindeer. Another is predation on wild ungulates. As the wolves have shown a strong preference for moose (Alces alces) in this respect, a smaller moose population is available for game hunting. The cost of increased moose predation by wolves is examined using a two-step process. First, we analyse the costs to landowners, comprising the loss of animals potentially available for bunting less the reduction in browsing damage associated with a smaller moose population. Second, we examine the problem from a broader point of view, where costs external to landowners and local communities are included. By far the most important cost here is damage related to collisions between moose and motor vehicles. (c) 2005 Elsevier B.V. All rights reserved. SN 0921-8009 PD JUL 1 PY 2006 VL 58 IS 4 BP 830 EP 841 DI 10.1016/j.ecolecon.2005.09.020 UT WOS:000238829300011 ER PT J AU Schreve, DC AF Schreve, Danielle C. TI The taphonomy of a Middle Devensian (MIS 3) vertebrate assemblage from Lynford, Norfolk, UK, and its implications for Middle Palaeolithic subsistence strategies SO JOURNAL OF QUATERNARY SCIENCE AB The association of a rich lithic assemblage with a Middle Devensian mammalian assemblage at Lynford was initially thought indicative of a mammoth butchery locality, a rare occurrence for a European Middle Palaeolithic open site. However, taphonomic analyses suggest that the specimens have very different depositional histories and were incorporated into a palaeochannel in several stages. Most specimens are extremely fragmentary, probably the result of extensive trampling, and signs of weathering and root-damage provide further indications of exposure before burial. Carnivore damage is minimal but establishing the degree of interaction between the mammal fauna and alternative predators, such as Neanderthals, is problematic. Direct evidence of butchery is not present and the best indication of any form of mammoth exploitation lies in more circumstantial evidence such as the virtual absence of long bones from the main channel deposit and the mammoth age profiles. Instances of pathologies are also unusually common in the mammoths, implying that their greater vulnerability may have led to an accelerated demise either naturally or at the hands of a predator. The best evidence for direct faunal exploitation at the site is from green bone fractures and broken teeth that suggest marrow extraction in horse, reindeer and woolly rhinoceros. Copyright (C) 2006 John Wiley & Sons, Ltd. OI Schreve, Danielle/0000-0001-8974-5882 SN 0267-8179 EI 1099-1417 PD JUL PY 2006 VL 21 IS 5 BP 543 EP 556 DI 10.1002/jqs.1036 UT WOS:000239223700010 ER PT J AU van der Wal, R AF van der Wal, Rene TI Do herbivores cause habitat degradation or vegetation state transition? Evidence from the tundra SO OIKOS AB Range expansion and increasing densities of large herbivores are held responsible for large-scale habitat degradation in a wide range of natural and semi-natural ecosystems. Herbivore-driven ecosystem changes frequently represent predictable transitions from one vegetation state to another. Whether such predictable changes justify the value judgement 'habitat degradation' may be debatable as this strongly depends on individual perspective. To further the debate on herbivore-driven habitat degradation, I apply the concept of alternative stable states to arctic tundra as a framework to capture predictable stepwise vegetation transitions in which the productivity and hence herbivore-carrying capacity increases with grazing pressure. Specifically, evidence is provided that large parts of the tundra biome can be in either of three relatively discrete vegetation states and that changes in reindeer/ caribou density are responsible for sudden, predictable but often reversible state transitions. From this, it appears that the relatively rapidly emerging vegetation changes do not necessarily equate to habitat degradation, but in many cases reflect predictable vegetation change. Acknowledgement of the existence of predictable state transitions in tundra ecosystems may help to evaluate the observed radical vegetation changes occurring throughout the reindeer/caribou range. RI van der Wal, Rene/F-3177-2010 SN 0030-1299 EI 1600-0706 PD JUL PY 2006 VL 114 IS 1 BP 177 EP 186 DI 10.1111/j.2006.0030-1299.14264.x UT WOS:000239563300018 ER PT J AU Roturier, S Bergsten, U AF Roturier, S Bergsten, U TI Influence of soil scarification on reindeer foraging and damage to planted Pinus sylvestris seedlings SO SCANDINAVIAN JOURNAL OF FOREST RESEARCH AB The effects of soil scarification on reindeer lichen cover and re-establishment, reindeer foraging and damage possibly caused by reindeer to planted Scots pine seedlings were studied during six growing periods in a field experiment established in a reindeer lichen site that was grazed by a herd of 500-600 reindeer each winter. Seedlings ( at a density equivalent to 2000 ha(-1)) were planted in mounds with mineral soil on top, in tracks with exposed mineral soil, in tracks with mixed organic material and mineral soil and in intact lichen mat ( control) with no soil disturbance. The disturbed area varied from 0 to 28%. After six growing periods, the reindeer lichen cover and volume were 10-20% lower in the scarified plots than in the control plots. There was no clear evidence that the reindeer avoided foraging even in plots with the highest levels of soil disturbance. However, the behaviour of the reindeer during winter grazing seemed to be affected by both coverage of reindeer lichen ( positively) and the proportion of exposed mineral soil ( negatively). Damage possibly caused by reindeer trampling affected 8.2% of the living seedlings each year and approximately 50% of these seedlings were subsequently infected by fungal diseases ( compared with 20% of viable undamaged seedlings). Scarification treatments that exposed mineral soil mildly resulted in higher survival and growth rates than the other treatments, especially the control. SN 0282-7581 PD JUN PY 2006 VL 21 IS 3 BP 209 EP 220 DI 10.1080/02827580600759441 UT WOS:000238305300004 ER PT J AU Mysterud, A AF Mysterud, Atle TI The concept of overgrazing and its role in management of large herbivores SO WILDLIFE BIOLOGY AB Increasing populations of cervids in Europe and North America have made the issue of overgrazing relevant outside areas with domestic or semi-domestic herbivores. Overgrazing is defined depending on management objectives. I focus on challenges related to implementing a 'range ecologist' baseline, defining overgrazing as situations when 'forage species are not able to maintain themselves over time due to an excess of herbivory or related processes'. Herbivores may be naturally regulated at ecological carrying capacity (K) with no overgrazing, but overgrazing may occur below K. Rare, preferred plant species can decline in density due to a 'herbivore pit' created by generalist herbivores, without having much effect on K. The concept of overgrazing is almost meaningless unless the issue of spatial scale is considered, and the extent to which preferred plant species decline in coverage. Herbivore population instability increases with increased population growth rate, but overgrazing depends also on the tolerance to grazing of the forage used by a given herbivore, which is closely related to functional plant traits. Ecosystem factors such as soil quality and slope also affect the likelihood that overgrazing will occur. Currently we can only qualitatively identify some important factors to consider. A better understanding of the sequence of events happening to performance of both animals and plants over time when a herbivore population increases provides a very useful approach until tools are developed to measure overgrazing quantitatively. More detailed knowledge about grazing effects on biodiversity is necessary to implement a broader ecosystem perspective of overgrazing. SN 0909-6396 EI 1903-220X PD JUN PY 2006 VL 12 IS 2 BP 129 EP 141 DI 10.2981/0909-6396(2006)12[129:TCOOAI]2.0.CO;2 UT WOS:000238701600002 ER PT J AU Merceron, G Madelaine, S AF Merceron, Gildas Madelaine, Stephane TI Molar microwear pattern and palaeoecology of ungulates from La Berbie (Dordogne, France): environment of Neanderthals and modern human populations of the Middle/Upper Palaeolithic SO BOREAS AB This study contributes to the characterization of the environment of the Middle/Upper Palaeolithic transition in southwestern France through the reconstruction of ungulate diets. Molar microwear analysis is used to characterize the diets of herbivorous mammals from La Berbie. The data for this study were collected through examination of molar facets using white-light confocal microscopy. The results for 22 fossil specimens (representing four species) are compared with those of 59 living ruminants. Microwear variables of living specimens are used in a principal components analysis. Extinct species are then added to the analysis. Results show that Bison priscus has a microwear signature similar to that of grazers, whereas Rangifer tarandus shares characteristics with both browsers and grazers. The specimens of Equus caballus and Rupicapra rupicapra also display microwear patterns similar to those of grazers. While previous studies have shown an abundance of both C3 plants and herbaceous dicots, the present microwear analysis of fossil herbivores indicates that their last meals contained abrasive graminoids. The results suggest that during the Middle/ Upper Palaeolithic transition the habitat of Neanderthals and modern human populations in southwestern France was an open environment dominated by a rich C3-monocot herbaceous layer. RI Merceron, Gildas/C-8648-2012 OI Merceron, Gildas/0000-0001-5777-7126 SN 0300-9483 EI 1502-3885 PD MAY PY 2006 VL 35 IS 2 BP 272 EP 278 DI 10.1080/03009480600584873 UT WOS:000237859600010 ER PT J AU Crete, M Marzell, L AF Crete, Michel Marzell, Lothar TI Evolution of Quebec forests in the view of faunistic habitats: analysis of large trends over three decades SO FORESTRY CHRONICLE CT 5th North American Forest Ecology Workshop CY JUN, 2005 CL Gatineau, CANADA AB As forest management intensified between the 1970s and the 1990s, we tested the prediction that three forest attributes, likely essential for some wildlife species, became rarer during this time interval: old (> 100 years) stands, dead wood and woody species diversity. We used a network of about 7000 permanent plots, surveyed at least three times, for determining trends followed by these variables during the last three decades of the 20(th) century. We stratified our analysis according to the six vegetation domains of the southern half of Quebec where forest management occurs, i.e., from the sugar maple-bitternut to the spruce-moss domain. The proportion of old stands clearly diminished only in the western part of the sugar maple- and balsam fir-yellow birch domains. However, stands composed of old trees were already very scarce during the 1970s everywhere except in the spruce-moss domain where they could have increased in importance during the study period. Snags tended to become rarer only in the western part of sugar maple- and balsam fir-yellow birch domains whereas their abundance increased elsewhere, sometimes substantially, because of the spruce budworm epidemic that affected Quebec between 1975 and 1990. Results suggest that tree diversity was impoverished in the two southernmost forest domains; the same tendency existed also for saplings, particularly because of intense browsing by white-tailed deer. In the boreal forest, the spruce budworm epidemic favoured sapling diversity during the 1980s and 1990s. Our analysis indicates that we must: 1) quickly exclude some typical old stands from forest management in all vegetation domains; 2) determine if some woody species became rarer in forest stands of southern Quebec; 3) identify which elements of the forest fauna depend on old stands, rare tree species and senescent trees, and 4) continue to monitor the trend of dead wood present in Quebec forests. SN 0015-7546 EI 1499-9315 PD MAY-JUN PY 2006 VL 82 IS 3 BP 368 EP 382 DI 10.5558/tfc82368-3 UT WOS:000238432500031 ER PT J AU Sampels, S Wiklund, E Pickova, J AF Sampels, S. Wiklund, E. Pickova, J. TI Influence of diet on fatty acids and tocopherols in M. longissimus dorsi from reindeer SO LIPIDS AB Our aim was to compare the effects of two pelleted diets containing differing FA composition with natural lichen pasture on reindeer's meat FA composition. In addition we wanted to increase the knowledge about reindeer FA metabolism and the effect of animal sex and age on FA composition in reindeer muscle. The trial included five reindeer groups: three grazing, consisting of adult males, adult females, and calves; and two groups of calves fed conventional pellets (CPD) and pellets containing crushed linseed (LPD), respectively, for two months before slaughter. Differences between male and female animals were mainly found in the neutral lipid fraction and related to fatness. Calves differed significantly from adult males and females in FA and lipid class composition. CPD led to a higher ratio of n-6 to n-3 FA compared with grazing. The ratio n-6/n-3 in the polar lipid (PL) fraction of the animals fed LPD was slightly, but not significantly, higher than that in the grazing reindeer. LPD-fed animals had lower proportions of long-chain polyunsaturated FA (LCPUFA), namely 20:4n-6, 22:5n-3, and 22:6n-3, in the PL fraction compared with the grazing animals due to the content of these FA in the natural feed. The animals seemed unable to elongate dietary FA in significant amounts. We conclude that by adding crushed linseed to the pellets it was possible to keep the favorable FA composition of meat from grazing reindeer with regard to the n-6/n-3 ratio but not in LCPUFA. RI Sampels, Sabine/F-8479-2015 OI Sampels, Sabine/0000-0003-1695-5939; pickova, jana/0000-0002-3406-3435 SN 0024-4201 PD MAY PY 2006 VL 41 IS 5 BP 463 EP 472 DI 10.1007/s11745-006-5120-8 UT WOS:000239575600007 PM 16933791 ER PT J AU Barboza, PS Peltier, TC Forster, RJ AF Barboza, Perry S. Peltier, Tim C. Forster, Robert J. TI Ruminal fermentation and fill change with season in an arctic grazer: Responses to hyperphagia and hypophagia in muskoxen (Ovibos moschatus) SO PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY AB We studied castrated adult muskoxen fed a standard diet of grass hay and supplement throughout the year to determine seasonal changes in digesta passage, fill, and fermentation without the confounding effects of reproductive demands or changes in food quality. Although food intake increased by 74% between spring and autumn, mean retention times of fluid and particulate digesta markers were maintained between seasons in both the rumen (9-13 h) and the intestines (27-37 h). The rumen contained 84.5% of digesta and accounted for 79% of dry matter digestion in the whole digestive tract. Ruminal fluid space and whole-gut digesta fill increased by 31%-34%, while ruminal rates of in situ degradation increased by more than 100% between spring and autumn for cellulose and hemicellulose. Hyperphagia in autumn was accompanied by increased bacterial counts in ruminal fluid (30%), declines in ruminal pH, and increases in the concentration of fermentation acids (16%) when compared with spring hypophagia. Consumption of fresh hay and supplement increased the concentrations of acids most markedly during winter and spring when bacterial counts were low. Low food intakes in winter and spring may limit the microbial population, whereas hyperphagia in autumn may foster a much more active microflora that requires consistent supplies of substrate. Plasticity of fill and fermentation in muskoxen minimizes winter costs and maximizes nutrients and energy gained from coarse forages in small home ranges throughout the year. SN 1522-2152 EI 1537-5293 PD MAY-JUN PY 2006 VL 79 IS 3 BP 497 EP 513 DI 10.1086/501058 UT WOS:000237805100006 PM 16691516 ER PT J AU Eskelinen, A Oksanen, J AF Eskelinen, Anu Oksanen, Jari TI Changes in the abundance, composition and species richness of mountain vegetation in relation to summer grazing by reindeer SO JOURNAL OF VEGETATION SCIENCE AB Question: How do reduced levels of summer grazing by reindeer affect the abundance, composition and species richness of mountain plant communities? Location: Arctic-alpine mountain vegetation 700-850 m a.s.l., Saana Conservation Area, northwestern Finnish Lapland. Methods: Permanent plots were established in 1990 and resampled in 1999 or 2001. The number of reindeer had considerably declined from the 1980s to the 1990s and we followed the recovery of vegetation. The comparisons between 1990 and 1999/2001 were made at seven sites differing in their original grazing pressure. Results: At the initially heavily grazed sites, lichen abundances increased, but at the lightly grazed sites the abundances of lichens decreased. Graminoids declined at all sites, but the change seemed to be greatest at the most heavily grazed sites. Forbs increased slightly across all sites. At the species level, lichens and graminoids responded most notably to the reduction of grazing pressure. Individual species responses in shrubs were variable and among forbs, typical species of species-rich Dryas heaths increased. Total species richness increased at all sites and the change was greater at heavily grazed sites. This increase resulted mainly from increased bryophyte and lichen species richness but also from a slight increase in vascular plant species richness. Conclusions: These results suggest that lichens are the group most responsive to the reduction of heavy summer grazing by reindeer and that lichens and forbs typical in arctic-alpine Dryas heaths are favoured over graminoids under reduced grazing. Heavy grazing decreases overall species richness with the most pronounced effects on bryophyte and lichen species richness. The results support the hypothesis that heavy summer grazing may shift the composition of mountain plant communities towards that of grasslands and show how this shift may be reversed under reduced grazing. RI Oksanen, Jari/A-5236-2013 OI Oksanen, Jari/0000-0001-7102-9626 SN 1100-9233 PD APR PY 2006 VL 17 IS 2 BP 245 EP 254 DI 10.1658/1100-9233(2006)17[245:CITACA]2.0.CO;2 UT WOS:000237611900013 ER PT J AU Hrabok, JT Oksanen, A Nieminen, M Rydzik, A Uggla, A Waller, PJ AF Hrabok, JT Oksanen, A Nieminen, M Rydzik, A Uggla, A Waller, PJ TI Reindeer as hosts for nematode parasites of sheep and cattle SO VETERINARY PARASITOLOGY AB The reindeer husbandry range of Scandinavia overlaps with sheep, goat, and cattle pastures. The aim of this study was to determine whether reindeer are suitable hosts for ovine or bovine nematode parasites, and thus may spread these parasites into the reindeer husbandry regions. To render worm-free, twelve 4-month-old male reindeer calves. six lambs. and six bovine calves were given ivermectin at 200 mu g/kg body weight. Five weeks post-treatment, six reindeer calves were each artificially dosed with 10,000 third-stage larvae (L3) of gastrointestinal nematodes derived from sheep, and an additional six reindeer with L3 derived from cattle. Lambs and bovine calves received the same dose of ovine and bovine larvae as reindeer, from the same larval source, respectively. Faecal samples collected on five occasions after the larval dosing revealed that by the fourth week, all reindeer calves, lambs. and bovine calves were infected. Animals were slaughtered on days 40 (reindeer) or 47 (lambs and bovine calves) after the larval dosing, Reindeer calves were most susceptible to L3 derived from sheep. The overall mean intensity of Haemochus contortus, Trichostrongylus axei, and Teladorsagia circumcincta, did not differ between reindeer and sheep, however, early fourth-stage larvae of H. contortus were more abundant in reindeer (p = 0.002). The establishment of bovine-derived Ostertagia ostertagi was similar in reindeer (62%) and bovine calves (57%), but larval inhibition was much higher in reindeer (91% p < 0.001) than in cattle (31 %). Very poor establishment of bovine derived Cooperia oncophora was recorded in reindeer calves (2%) compared with bovine calves (59%). These results show that young reindeer are susceptible hosts to the important gastrointestinal parasites of sheep (T circumcincta, H. contonus) and cattle (O. ostertagi), as well as being a suitable host for T axei. (c) 2005 Elsevier B.V. All rights reserved. SN 0304-4017 PD MAR 31 PY 2006 VL 136 IS 3-4 BP 297 EP 306 DI 10.1016/j.vetpar.2005.11.020 UT WOS:000236342800013 PM 16386848 ER PT J AU Olofsson, J AF Olofsson, J TI Short- and long-term effects of changes in reindeer grazing pressure on tundra heath vegetation SO JOURNAL OF ECOLOGY AB Previous studies of plant-herbivore interactions have typically focused either on short-term or long-term effects. By directly comparing effects at different temporal scales, I studied whether short-term experiments provide good indications of the long-term effects of herbivory. I reciprocally transplanted turfs of tundra heath vegetation within areas covered by a long-term (40 years) reindeer manipulation experiment, in order to examine the effects of all possible permutations of light, moderate and heavy grazing pre- and post-transplantation. The effects of a short-term (three growing seasons) increase in reindeer grazing pressure gave good qualitative indications of most of the long-term effects of grazing on plant biomass, species richness, moss cover and lichen cover. In contrast, reducing grazing pressure on previously heavily grazed vegetation had no significant effects on any of these variables over the same time-scale. Although few effects on individual species were recorded from the short-term manipulations, all those that were significant were qualitatively similar to the long-term responses of the respective species to herbivory. The grass-dominated vegetation from the heavily grazed area changed little when grazing and trampling pressure were reduced for 3 years. In contrast, the dwarf shrub-dominated vegetation in the lightly grazed area changed rapidly into grasslands when the grazing pressure was enhanced. Re-establishment of dwarf shrubs appears to be both seed and microsite limited, but it appears that dwarf shrubs may be able to re-establish in previously heavily grazed vegetation in the absence of reindeer. Transitions from moss- or dwarf shrub-dominated ecosystems to grass-dominated ecosystems are currently occurring at different locations in boreal, arctic and alpine regions due to atmospheric nitrogen deposition and livestock grazing. This loss of habitat may be reversible, given a relatively long time frame. RI Olofsson, Johan/A-9362-2009 SN 0022-0477 PD MAR PY 2006 VL 94 IS 2 BP 431 EP 440 DI 10.1111/j.1365-2745.2006.01100.x UT WOS:000235332300016 ER PT J AU Olofsson, J AF Olofsson, J TI Plant diversity and resilience to reindeer grazing SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Higher plant species richness has been proposed to increase the resilience of plant communities to disturbance. The purpose of this Study was to test whether this is true for reindeer grazed arctic tundra vegetation. Plant biomass, plant community structure, and species richness were measured along four fences that separated areas grazed by reindeer from ungrazed areas in northern Norway. I found a negative relationship between plant species richness and the change in species richness and biomass Clue to grazing. These results indicate diversity did not confer greater resilience to increased reindeer grazing intensity. No support for higher grazing pressure in diverse habitats were recorded, thus, these results suggest lower resilience to grazing in species-rich arctic tundra vegetation. RI Olofsson, Johan/A-9362-2009 SN 1523-0430 PD FEB PY 2006 VL 38 IS 1 BP 131 EP 135 DI 10.1657/1523-0430(2006)038[0131:PDARTR]2.0.CO;2 UT WOS:000235385100015 ER PT J AU Gaio-Oliveira, G Moen, J Danell, O Palmqvist, K AF Gaio-Oliveira, G Moen, J Danell, O Palmqvist, K TI Effect of simulated reindeer grazing on the re-growth capacity of mat-forming lichens SO BASIC AND APPLIED ECOLOGY AB Grazing of mat-forming Cladina-lichens by reindeer (Rangifer tarandus) causes thinning and fragmentation of the carpet. Little is known about the regeneration rate of the lichen mat and how differences in quality of the remaining lichen fragments affect this process. We hypothesized that recovery rate and productivity of mat-forming lichens might be dependent on the wet active time as well as the algal (photobiont) density of the remaining lichens. This was experimentally tested for Cladina stellaris, measuring growth and microclimatic conditions during 4 months in lichen cushions with varying height, density and chlorophyll concentration. The treatments mimicked winter grazing by reindeer, resulting in a mosaic of more or less grazed and trampled patches. Absolute growth was highest (62 g m(-2)) where the photobiont-rich upper part of the Lichen thalli remained and the mat had been thinned to 75% coverage and lowest (3 g m(-2)) where only the lower parts of the thalli remained and the mat had 25% coverage. The relative growth was highest (2.2 mg g(-1) DW day(-1)) in upper thallus parts that had been thinned to 25% coverage and lowest in the control treatment and the two treatments with lower thallus parts (0.1-0.2 mg g(-1) DW day(-1)). The density or thickness of the lichen mat did not affect its wet active time, white productivity increased both with the cushions' photobiont (chlorophyll) density and the irradiance received when the lichens were wet and active. The productivity was tower in the intact cushions compared to those with lower height and density with equal amounts of chlorophyll. The regeneration capacity of mat-forming lichens wilt hence be reduced in dense mats and when reindeer grazing has preferentially removed the photobiont-rich upper half of the thallus. (c) 2005 Gesettschaft fur Okologie. Published by Elsevier GmbH. All rights reserved. RI Palmqvist, Kristin/D-5589-2016 OI Palmqvist, Kristin/0000-0002-3923-1338; Gaio-Oliveira, Gisela/0000-0002-3253-9284 SN 1439-1791 EI 1618-0089 PY 2006 VL 7 IS 2 BP 109 EP 121 DI 10.1016/j.baae.2005.05.007 UT WOS:000236099600002 ER PT J AU Eskelinen, A Virtanen, R AF Eskelinen, A Virtanen, R TI Local and regional processes in low-productive mountain plant communities: the roles of seed and microsite limitation in relation to grazing SO OIKOS AB It is becoming widely accepted that plant community structure is determined not only by local scale factors, but that regional factors may play considerable role. The research studying the associated processes in different environments with different species assemblages is still limited. We conducted a two-year seed sowing experiment to test whether a plant community in a low-productive mountain snowbed is limited by seed or microsite availability and how these variables depend on natural grazing. In a factorial design, half of the plots received a mixture of seeds of fourteen species naturally occurring at the study site and above ground biomass was removed from half of the plots. These treatments were applied to plots with long term grazer exclosures and to plots accessible to grazers. Both sowing and biomass removal increased the number of seedlings, the species richness of seedlings and total species richness. The number of seedlings was higher in open plots than in exclosures in the second year. Both seedling richness and total species richness were higher in open plots. Seedling recruitment was negatively related to the amount of above ground biomass and positively to the initial species richness. These results suggest that even fairly low-productive environments can be both seed and microsite limited and that these depend on grazing pressure. Natural grazing by mammal herbivores (e.g. lemmings and reindeer) favours species colonization and seedling emergence. Low-productive mountain snowbeds are prone to colonization from the local species pool and even high species richness may not constrain ingression of new species. RI Virtanen, Risto/G-1810-2010 OI Virtanen, Risto/0000-0002-8295-8217 SN 0030-1299 PD AUG PY 2005 VL 110 IS 2 BP 360 EP 368 DI 10.1111/j.0030-1299.2005.13579.x UT WOS:000229081300016 ER PT J AU Parker, KL Barboza, PS Stephenson, TR AF Parker, KL Barboza, PS Stephenson, TR TI Protein conservation in female caribou (Rangifer tarandus): Effects of decreasing diet quality during winter SO JOURNAL OF MAMMALOGY AB Female caribou subsist primarily on lichens and some senescent browse during winter when demands for fetal growth add to costs of thermoregulation and mobility. Lichens, although potentially high in digestible energy, contain less protein than required for maintenance by most north-temperate ungulates. To understand the adaptations of caribou to the nutritional constraints of their primary food resource, we fed captive female caribou a sequence of 3 diets designed to resemble decreasing quality of forages during early, mid-, and late winter, respectively: high energy-high protein (HIGH), medium energy-low protein (MEDIUM), and low energy-low protein (LOW). In vitro digestibility of dry matter declined from 94% (HIGH) in November, to 66% (MEDIUM) in December and January, and to 53% (LOW) from February to April. Dietary protein averaged 19.8% in November and 4.3% from December to April. We used measures of body condition, stable isotopic signatures, and concentrations of nitrogen (N) metabolites to define protein dynamics in the animals. Subcutaneous rump fat declined between October and April from 2.3 cm +/- 0.3 SE to < 0.5 cm as intake of digestible energy declined from 44.0 +/- 2.0 MJ/day to 16.3 +/- 3.2 MJ/day. In erythrocytes, increasing enrichment of carbon (C-13) throughout winter suggested that caribou reused body lipids, and increases in N-15 during January and February indicated that they also recycled amino-N. Urinary N was primarily urea with an isotopic signature that tracked dietary N-15 through late winter. Plasma urea-N declined from 44.0 +/- 2.6 mg/dl to 8.5 +/- 1.2 mg/dl as nitrogen intake declined from 91.5 +/- 5.3 g N/day to 14.1 +/- 0.9 g N/day. Examination of these data suggests that caribou catabolized dietary C and N in preference to endogenous fat reserves and body protein. Female caribou appear to tolerate low intakes of protein and energy in winter by minimizing net loss of body protein and reapportioning body reserves to support fetal growth. SN 0022-2372 PD JUN PY 2005 VL 86 IS 3 BP 610 EP 622 DI 10.1644/1545-1542(2005)86[610:PCIFCR]2.0.CO;2 UT WOS:000229720200020 ER PT J AU Ringo, E Mathiesen, SD Storeheier, PV Mayhew, TM Myklebust, R AF Ringo, E Mathiesen, SD Storeheier, PV Mayhew, TM Myklebust, R TI Effects of natural winter pasture and commercial pellet on the ultrastructure of small intestinal epithelium in reindeer SO CELL AND TISSUE RESEARCH AB Segments of small intestine (duodenum, jejunum and ileum) from slaughtered reindeer (Rangifer tarandus tarandus) grazing natural winter pastures (n=3) and reindeer fed commercially available pellets (RF-80) in winter (n=5) were collected and immediately fixed in McDowell's fixative. Transmission electron microscopy was employed to investigate the ultrastructural features of the epithelium and lamina propria along the small intestine and to relate these to the different diets. Major differences in ultrastructural features were observed between the small intestinal enterocytes of reindeer fed the two diets. Enterocytes in reindeer fed the natural diet displayed a normal appearance with a dense cytoplasm and distinct microvilli. In contrast, reindeer fed the commercial diet showed damaged enterocytes amongst the normal cells. Abnormal changes included disintegration and loss of microvilli, cytoplasmic swelling, loss of membrane integrity and increases in the width of intercellular spaces, especially in the jejunum. SN 0302-766X PD MAY PY 2005 VL 320 IS 2 BP 355 EP 359 DI 10.1007/s00441-004-1074-4 UT WOS:000228728500017 PM 15778852 ER PT J AU Gudmundsdottir, B Skirnisson, K AF Gudmundsdottir, B Skirnisson, K TI Description of a new Eimeria species and redescription of Eimeria mayeri (Protozoa : Eimeriidae) from wild reindeer Rangifer tarandus in Iceland SO JOURNAL OF PARASITOLOGY AB Altogether, 195 fecal samples of reindeer calves (Rangifer tarandus) were collected from the ground in 3 distinct areas in eastern Iceland, where geographically isolated reindeer populations graze during the summer months. The samples were examined for coccidian parasites. Two species were found, and all infections were monospecific. Eimeria mayeri was found in calves in all sampling areas, with 1-4% prevalence and 450-167,700 oocysts per gram (opg). The sporulated oocyst lacks a polar granule but has an inconspicuous micropyle, and a small Stieda body is present on sporocysts, which are ovoid but not pointed as reported in the original description. The other coccidian, found in single calves in 2 of the 3 areas (prevalence 1 and 4%, 150 and 500 opg, respectively) is described here as a new species. The oocysts are ovoid, average 34.9 x 27.6 mu m, and have 2 distinct walls. Wall thickness is similar to 1.9 mu m, and the outer wall, similar to 3/4 of total thickness, is generally smooth and appears bicolored. The outermost portion is pale red and the innermost portion yellow to pale brown. The inner wall is grey to dark brown and separated from the outer wall by a dark brown line. Oocysts contain a prominent micropyle, similar to 5 mu m, and enclose 4 spindle-shaped sporocysts, slightly pointed at the end opposite the Stieda body. Average size of sporocysts is 18.6 x 9.2 mu m. Sporocysts contain granular sporocyst residuum and usually 2, sometimes 1, large refractile bodies in each sporozoite. SN 0022-3395 EI 1937-2345 PD APR PY 2005 VL 91 IS 2 BP 353 EP 357 DI 10.1645/GE-409R UT WOS:000229494100018 PM 15986611 ER PT J AU Olofsson, J Hulme, PE Oksanen, L Suominen, O AF Olofsson, J Hulme, PE Oksanen, L Suominen, O TI Effects of mammalian herbivores on revegetation of disturbed areas in the forest-tundra ecotone in northern Fennoscandia SO LANDSCAPE ECOLOGY CT 6th World Congress of the International-Association-for-Landscape-Ecology (IALE) CY JUL 13-17, 2003 CL Darwin, AUSTRALIA SP Int Assoc Landscape Ecol AB Herbivores influence the structure of plant communities in arctic-alpine ecosystems. However, little is known of the effect of herbivores on plant colonisation following disturbance, and on its variability depending on the identity of herbivores and the characteristics of the habitats. To quantify the role of large and small vertebrate herbivores, we established exclosures of two different mesh sizes around disturbed subplots in forest and nearby tundra habitats in four contrasting locations in the forest-tundra ecotone in northernmost Sweden and Norway. The study revealed that herbivores influenced the abundance but not the species composition of regenerating vegetation. Gaps were colonised by the dominant species in the surrounding vegetation. The only exception to this expectation was Empetrum nigrum, which failed to colonise gaps even though it dominated undisturbed vegetation. Significant effects of herbivory were only detected when both small and large herbivores were excluded. Herbivores decreased the abundance of three of the most common species Vaccinium myrtillus, Vaccinium vitis idaea, and Deschampsia flexuosa. The effect of herbivory on the abundance of these three species did not differ between habitats and locations. However, the composition of the regenerating vegetation differed between habitats and locations. The disturbance treatment increased the species richness on the scale of plots, habitats, and sites. However, on the scale of whole locations, all species found in disturbed areas were also found in undisturbed areas, suggesting that the natural disturbance regime in arctic landscapes is high enough to sustain colonising species. RI Hulme, Philip/F-7454-2011; Olofsson, Johan/A-9362-2009 OI Hulme, Philip/0000-0001-5712-0474; SN 0921-2973 PD APR PY 2005 VL 20 IS 3 BP 351 EP 359 DI 10.1007/s10980-005-3166-2 UT WOS:000231824400010 ER PT J AU Bjune, AE Mangerud, J Moe, D AF Bjune, AE Mangerud, J Moe, D TI Past grazing habitats for Svalbard reindeer indicated by the pollen content of 3300-year-old faeces from Edgeoya, Svalbard SO GRANA AB Sedentary populations, like the Svalbard reindeer, tend to select the most nutritious and easily available plants during the different seasons. It has been shown that plants selected during grazing season are reflected in the pollen content of modern faeces from Svalbard reindeer. In this study the pollen and spore content of fossil reindeer faeces and peat from Raddedalen, western Edgeoya, Svalbard, are presented. The pollen content of the fossil faeces is first compared to published pollen data from modern Svalbard reindeer faeces so as to determine which season they were deposited, and second the pollen in the fossil faeces are compared to the pollen content of the peat in which they were found. The lower part of the peat section is dated to 3435+/-105 cal yr BP. The faeces are dominated by pollen from early flowering species such as Saxifraga oppositifolia-type, S. nivalis-type, Brassicaceae, and Pedicularis spp. thereby indicating that grazing and faeces deposition took place in spring and early summer. The peat and faeces have some similarities in their pollen and spore content, but different methods of deposition and concentration of pollen in faeces and peat result in different fossil assemblages. The results suggests that the climate of Raddedalen was warmer and moister than today, allowing peat to form in the past. OI Bjune, Anne Elisabeth/0000-0002-4509-0148 SN 0017-3134 PD MAR PY 2005 VL 44 IS 1 BP 45 EP 50 DI 10.1080/00173130410005564 UT WOS:000227709500004 ER PT J AU Zhou, WC Gong, PC AF Zhou, WC Gong, PC TI Multiple-use tradeoffs in Swedish mountain region forests SO FOREST POLICY AND ECONOMICS AB This paper examines the tradeoffs between different uses of forests in three communes in the mountain region in northern Sweden. The most important uses of the forests include timber production, preservation of biodiversity, reindeer grazing and recreation. Management outcomes with respect to the different uses are measured in terms of the net present value (NPV) of timber production profits, the sum of deadwood volume over time, the minimum periodic lichen production, and a minimum periodic recreation index (RI). The analysis shows that the forests can be managed to achieve dramatically different mixes of NPV. deadwood volume, and lichen production, whereas the RI varies only within a narrow range. To maximize the NPV, lichen production would reduce by 40% from its maximum level, and the volume of deadwood would be close to 0 in period 2 and thereafter. Maximization of deadwood volume would lead to the maximum lichen production, while the NPV would fall below 0. Maximization of lichen production reduces the NPV by at least 20%, and could reduce the amount of deadwood by up to 75%. When lichen production is restricted to its maximum, there is a wide range of possible choices with respect to the mix of the NPV and deadwood volume. The marginal cost of increasing the deadwood volume ranges from 1.12 to 20 SEK/m(3). The choice between lichen production and deadwood volume is most flexible when the NPV is fixed at approximately 93% of its maximum. (C) 2003 Elsevier B.V. All rights reserved. SN 1389-9341 PD JAN PY 2005 VL 7 IS 1 BP 39 EP 52 DI 10.1016/S1389-9341(03)00010-8 UT WOS:000226447300003 ER PT B AU Hopkins, A Holz, B AF Hopkins, A Holz, B BE Lillak, R Viiralt, R Linke, A Geherman, V TI Grassland for agriculture and nature conservation: production, quality and multi-functionality SO INTEGRATING EFFICIENT GRASSLAND FARMING AND BIODIVERSITY SE GRASSLAND SCIENCE IN EUROPE CT 13th International Occasional Symposium of the European-Grassland-Federation CY AUG 29-31, 2005 CL Tartu, ESTONIA SP European Grassland Federat AB European grasslands encompass a wide range of habitats that vary greatly in terms of their management, agricultural productivity, socio-economic value and nature conservation status, reflecting local differences in physical environment and economy, the effects of traditional practices and impacts of recent management. Widespread loss of biodiversity, as well as other environmental problems, have resulted from agricultural intensification or abandonment. Policies that have contributed to this have been progressively revised, initially by agri-environment schemes, and subsequently through changes in farm support payments and stricter regulatory frameworks, though many threats remain. We consider the agricultural implications of grassland biodiversity in terms of impacts on herbage production, feed intake and forage quality. Grassland biodiversity is both an externality of particular environments and farming systems and also contributes to objectives of multi-functional land-use systems. In addition to meeting species conservation and habitat protection, grassland biodiversity can contribute to enhanced value of agricultural products of regional, nutritional or gastronomic value, and to non-commodity outputs: agro-tourism, ecosystem functions linked to soil and water quality, and resilience to environmental perturbation. Needs and to conserve and improve the biodiversity potential of agricultural grasslands of typical moderate/high-input management, and for marginal, including communally managed large scale grazing systems, are considered using examples from contrasting areas of Europe. These include reindeer grazing in northern Fennoscandia, winter grazing in the Burren, Ireland, and cereal-fallow sheep grazing system of La Mancha, Spain. BN 9985-9611-3-7 PY 2005 VL 10 BP 15 EP 29 UT WOS:000235293800002 ER PT J AU Skuterud, L Gaare, E Kvam, T Hove, K Steinnes, E AF Skuterud, L Gaare, E Kvam, T Hove, K Steinnes, E TI Concentrations of Cs-137 in lynx (Lynx lynx) in relation to prey choice SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY AB Concentrations of Cs-137 were determined in 747 lynxes killed in Norway during the period 1986-2001. Highly variable Cs-137 concentrations and aggregated transfer coefficient values were observed, probably caused by variable Cs-137 concentrations in prey and the lynx's extensive home ranges and roaming distances. Adult lynxes had higher Cs-137 concentrations than sub-adults, and lynxes killed in regions with extensive reindeer grazing areas were more contaminated than others. A model with Cs-137 deposition density, the year lynxes were killed, age, and extent of reindeer grazing area accounted for 50% of the variability in observed Cs-137 concentrations. The analyses were equivocal regarding the influence of stomach content on Cs-137 concentrations in lynx muscle, i.e., on the lynx's specialization in prey species. Gender was not significant. Information on caesium retention in lynx and better estimates of deposition densities in lynxes' home ranges are important for further elucidation of factors influencing Cs-137 contamination in lynxes. (C) 2004 Elsevier Ltd. All rights reserved. OI Skuterud, Lavrans/0000-0002-1164-208X SN 0265-931X PY 2005 VL 80 IS 1 BP 125 EP 138 DI 10.1016/j.jenvard.2004.09.002 UT WOS:000227368300008 PM 15653191 ER PT J AU Morgan, ER Shaikenov, B Torgerson, PR Medley, GF Milner-Gulland, EJ AF Morgan, ER Shaikenov, B Torgerson, PR Medley, GF Milner-Gulland, EJ TI Helminths of saiga antelope in Kazakhstan: Implications for conservation and livestock production SO JOURNAL OF WILDLIFE DISEASES AB Saiga antelope (Saiga tatarica) graze extensively on livestock pasture, potentially enabling transmission of a wide range of parasitic helminths between saigas and domestic ruminants. Thirty-six of the 38 species of helminth that have been found in saigas in Kazakhstan in the past have been found also in domestic livestock. We examined 133 saigas culled for meat in autumn 1997, and found three species of cestode and 12 nematodes (nine in the abomasum), but no trematodes or lungworms. The most abundant species were Marshallagia marshalli, Marshallagia mongolica, and Nematodirus gazellae in the abomasum, Nematodirus gazellae in the small intestine, and Skrjabinema ovis in the large intestine. There was no clear relationship between intensities of abomasal nematodes and body condition. Age-intensity patterns differed between species: N. gazellae intensities were highest in saigas around 2-3 yr old, and declined in older animals, whereas the intensity of Marshallagia spp. rose asymptotically with age. Fecal egg density was directly proportional to adult worm intensity across ages for Marshallagia spp., but only in young animals for N. gazellae. There was no evidence that helminths, at the intensities observed, adversely affect saiga populations. The host range of many of the parasites found is broad, and transmission between saigas and livestock in both directions might become important to agriculture and conservation as livestock numbers recover. Simplified sampling techniques used in this study, and statistical analysis based on bootstrapping, could prove useful in other parasitologic surveys of wildlife in remote areas. RI Torgerson, Paul/A-7510-2010; Torgerson, Paul/M-4447-2013; Medley, Graham/B-7289-2008 OI Torgerson, Paul/0000-0003-4277-9983; Torgerson, Paul/0000-0003-4277-9983; Medley, Graham/0000-0002-0030-7278; Milner-Gulland, E.J./0000-0003-0324-2710 SN 0090-3558 PD JAN PY 2005 VL 41 IS 1 BP 149 EP 162 DI 10.7589/0090-3558-41.1.149 UT WOS:000228708100016 PM 15827221 ER PT J AU Taylor, WA Skinner, JD Krecek, RC AF Taylor, WA Skinner, JD Krecek, RC TI Seasonal body condition indices of.mountain reedbuck (Redunca fulvorufula) in two areas of South African Highveld: the grassland and Karoo biomes SO SOUTH AFRICAN JOURNAL OF ANIMAL SCIENCE AB Mountain reedbuck (Redunca fulvorufula) occupy marginal habitat that is rarely used by cattle. They are fecund, produce good quality meat and have the potential to be cropped commercially. Body condition indices including dressing % (DP), kidney fat indices (KFI), leg fat percentages (LFP) and leg muscle percentages (LMP) were investigated at two nature reserves in the Free State Province, South Africa, to examine seasonal and sexual differences and apply the findings to management decisions. Forty-one animals were shot at Sterkfontein Dam Nature Reserve (Sterkfontein) during eight separate operations over a two-year period. Forty-four animals were shot at Tussen die Riviere Nature Reserve (TdR) during three periods. All results reported are for adult animals. At Sterkfontein, DP was lower in spring compared to autumn, KFI were lower in spring than winter, and UP were lower in spring than winter and autumn. At TdR, KFI in males were lower in summer than winter. Seasonal patterns of body condition were mainly related to seasonal weather patterns and changes in reproductive condition. For effective harvesting, mountain reedbuck should be cropped in autumn and winter. This would give any remaining animals a better chance of surviving the spring period before the rains when grazing conditions are at their worst. SN 0375-1589 PY 2005 VL 35 IS 1 BP 19 EP 29 UT WOS:000230038600003 ER PT J AU Payette, S Boudreau, S Morneau, C Pitre, N AF Payette, S Boudreau, S Morneau, C Pitre, N TI Long-term interactions between migratory caribou, wildfires and nunavik hunters inferred from tree rings SO AMBIO AB Barren-ground caribou (Rangifer tarandus) herds in North America may reach considerable size and undertake large-scale seasonal migrations from the Arctic tundra to the boreal forest. To test the caribou decline hypothesis associated with native harvesting and fire, we have documented the long-term trends of caribou activity based on a novel approach which uses tree-ring dated trampling scars produced by caribou hooves in the extensive trails distributed over the summer and winter ranges of the Riviere-aux-Feuilles herd (RAF herd, east of Hudson Bay in northern Quebec). The age structure data of trampling scars from lichen woodlands distributed over the entire RAF range confirmed the overall trends of caribou activity from the late 1700s to present time. Over the last 200 years, the RAF herd has undergone two highs in the late 1700s and 1900s separated by a moderate activity pattern in the late 1800s. Native harvesting was possibly involved in the early 1900s decline, although at a moderate level. The reduced magnitude of caribou activity during this period has not modified the natural cycle of highs and lows, which suggests that other demographic factors were controlling the changing caribou abundance. Our data also show that only exceptionally large fires may have a minor, short-lived impact on caribou migrations but not on caribou numbers. SN 0044-7447 PD DEC PY 2004 VL 33 IS 8 BP 482 EP 486 DI 10.1639/0044-7447(2004)033[0482:LIBMCW]2.0.CO;2 UT WOS:000225801000001 PM 15666677 ER PT J AU Theau, J Duguay, CR AF Theau, J Duguay, CR TI Lichen mapping in the summer range of the George River caribou herd using Landsat TM imagery SO CANADIAN JOURNAL OF REMOTE SENSING AB The summer range of the George River caribou herd (GRCH) of northern Quebec-Labrador has been affected by various levels of grazing and trampling during the last century. A demographic explosion of (he herd during this period has caused severe local degradation of the vegetation cover and lichen mats. The slow recovery dynamics of habitats in this northern region has led to the depletion of lichen resources in critical areas for caribou nutrition. Given the very large-area (about 250 000 km(2)) covered by the GRCH, a satellite remote sensing based approach was applied to map lichen cover over the whole summer range of the herd. For this purpose, a mosaic of 13 Landsat thematic mapper (TM) imagess was radiometrically normalized and processed using spectral mixture analysis. A map showing lichen fraction for each pixel was produced and validated against field observations. The results from this method provide additional and more detailed information than those from traditional image classification methods. This new approach is relatively user independent and presents a good potential for monitoring lichen covers over large and remote areas. therefore providing a valuable tool for caribou habitat management. RI Duguay, Claude/G-5682-2011 OI Duguay, Claude/0000-0002-1044-5850; Theau, Jerome/0000-0001-5052-6308 SN 0703-8992 PD DEC PY 2004 VL 30 IS 6 BP 867 EP 881 DI 10.5589/m04-047 UT WOS:000226575700002 ER PT J AU Gordon, IJ Hester, AJ Festa-Bianchet, M AF Gordon, IJ Hester, AJ Festa-Bianchet, M TI The management of wild large herbivores to meet economic, conservation and environmental objectives SO JOURNAL OF APPLIED ECOLOGY AB 1. Wild large herbivores provide goods and income to rural communities, have major impacts on land use and habitats of conservation importance and, in some cases, face local or global extinction. As a result, substantial effort is applied to their management across the globe. To be effective, however, management has to be science-based. We reviewed recent fundamental and applied studies of large herbivores with particular emphasis on the relationship between the spatial and temporal scales of ecosystem response, management decision and implementation. 2. Long-term population dynamics research has revealed fundamental differences in how sex/age classes are affected by changes in density and weather. Consequently, management must be tailored to the age and sex structure of the population, rather than to simple population counts. 3. Herbivory by large ungulates shapes the structure, diversity and functioning of most terrestrial ecosystems. Recent research has shown that fundamental herbivore/vegetation interactions driving landscape change are localized, often at scales of a few metres. For example, sheep and deer will selectively browse heather Calluna vulgaris at the edge of preferred grass patches in heather moorland. As heather is vulnerable to heavy defoliation, in the long term this can lead to loss of heather cover despite the average utilization rate of heather in a management area being low. Therefore, while herbivore population management requires a large-scale approach, management of herbivore impacts on vegetation may require a much more flexible and site-specific approach. 4. Localized impacts on vegetation have cascading effects on biodiversity, because changes in vegetation structure and composition, induced by large herbivores affect habitat suitability for many other species. As such, grazing should be considered as a tool for broader biodiversity management requiring a more sophisticated approach than just, for example, eliminating grazing from conservation areas through the use of exclosures. 5. Synthesis and applications. The management of wild large herbivores must consider different spatial scales, from small patches of vegetation to boundaries of an animal population. It also requires long-term planning based on a deep understanding of how population processes, such a birth rate, death rate and age structure, are affected by changes in land use and climate and how these affect localized herbivore impacts. Because wild herbivores do not observe administrative or political boundaries, adjusting their management to socio-political realities can present a challenge. Many developing countries have established co-operative management groups that allow all interested parties to be involved in the development of management plans; developed countries have a lot to learn from the developing world's example. RI Gordon, Iain/K-8636-2012 OI Gordon, Iain/0000-0001-9704-0946; Festa-Bianchet, Marco/0000-0002-2352-3379 SN 0021-8901 PD DEC PY 2004 VL 41 IS 6 BP 1021 EP 1031 DI 10.1111/j.0021-8901.2004.00985.x UT WOS:000225632800001 ER PT J AU Cairns, DM Moen, J AF Cairns, DM Moen, J TI Herbivory influences tree lines SO JOURNAL OF ECOLOGY AB 1. Transitions between major vegetation types, such as the tree line, are useful systems for monitoring the response of vegetation to climate change. Tree lines have, however, shown equivocal responses to such change. 2. Tree lines are considered to be primarily thermally controlled, although recent work has highlighted the importance of biotic factors. Dispersal limitation and the invasibility of the tundra matrix have been implicated and here we propose herbivory as an additional control at some tree lines. 3. We propose a conceptual model in which differing relative impacts of foliage consumption, availability of establishment sites, trampling, dispersal and seed predation can lead to very different tree-line responses. 4. The presence of large numbers of small trees above the current tree line at a site in northern Sweden that experiences limited reindeer (Rangifer tarandus) herbivory suggests range expansion. Other locations in the same region with higher reindeer populations have considerably fewer small trees, suggesting that range expansion is occurring much more slowly, if at all. 5. The use of tree lines as indicators of climate change is confounded by the activity of herbivores, which may either strengthen or nullify the impacts of a changed climate. Similar arguments are likely to be applicable to other ecotones. RI Cairns, David/F-3395-2014 OI Cairns, David/0000-0003-4110-196X SN 0022-0477 PD DEC PY 2004 VL 92 IS 6 BP 1019 EP 1024 DI 10.1111/j.1365-2745.2004.00945.x UT WOS:000225631400010 ER PT J AU Den Herder, M Virtanen, R Roininen, H AF Den Herder, M Virtanen, R Roininen, H TI Effects of reindeer browsing on tundra willow and its associated insect herbivores SO JOURNAL OF APPLIED ECOLOGY AB 1. Browsing by large mammals may strongly constrain the growth and reproduction of woody plants, and may alter the food quality and resource availability for herbivorous insects. The response of the plants may vary between different growth stages, and the preference of herbivores may be related to plant age. Understanding the effects of reindeer Rangifer tarandus browsing on the growth of woody forage plants is important in formulating guidelines for reindeer grazing management, especially in low productivity subarctic environments. 2. We studied the effects of summer browsing by reindeer on the growth and reproduction of willow Salix phylicifolia and on the abundance of its insect herbivores, by studying plants inside and outside exclosures over a period of 6 years. 3. The experiment was run in northern Finland and included 80 willow genets in an area near the timberline formed by mountain birch Betula pubescens. At the beginning of the experiment, half of the willows were cut at ground level to rejuvenate ramets. 4. Reindeer feeding was more intense on rejuvenated willow compared with old willow, and the effects of browsing were more pronounced on rejuvenated plants. 5. Reindeer browsing reduced the height of willow by c. 50%, shoot length by c. 30% and accelerated dieback of the shoots by c. 50%. Browsed willow produced fewer shoots, with fewer buds and floral catkins, than unbrowsed willow. Browsing also reduced the densities of the most common insect herbivores: leaf beetles of the genus Gonioctena (Coleoptera: Chrysomelidae) and gall-inducing sawflies (Hymenoptera: Tenthredinidae) belonging to the genera Phyllocolpa, Eupontania and Euura. 6. Synthesis and applications. We show that reindeer browsing in summer reduces biomass and diminishes reproductive success of willow; it also lowers the numbers of its associated insect herbivores. Our results suggest that this effect will be most evident in low-productivity tundra heaths where alternative forage plants, such as relatively palatable and productive graminoids, are scarce. We advise that reindeer should be maintained below the present levels of 2-3 reindeer km(-2) to sustain the long-term persistence of important forage plants such as willow in these low productivity habitats. RI Virtanen, Risto/G-1810-2010 OI Virtanen, Risto/0000-0002-8295-8217 SN 0021-8901 PD OCT PY 2004 VL 41 IS 5 BP 870 EP 879 DI 10.1111/j.0021-8901.2004.00952.x UT WOS:000224167700008 ER PT J AU Brathen, KA Hagberg, O AF Brathen, KA Hagberg, O TI More efficient estimation of plant biomass SO JOURNAL OF VEGETATION SCIENCE AB Question: The optimal use of the point intercept method (PIM) for efficient estimation of plant biomass has not been addressed although PIM is a commonly used method in vegetation analysis. In this study we compare results achieved using PIM at a range of efforts, we assess a method for calculating these results that are new with PIM and we provide a formula for planning the optimal use of PIM. Location: Northern Norway. Methods: We collected intercept data at a range of efforts, i.e. from one to 100 pins per 0.25 m(2) plots, on three plant growth forms in a mountain meadow. After collection of intercept data we clipped and weighed the plant biomass. The relationship between intercept frequency and weighed biomass (b) was estimated using both a weighted linear regression model (WLR) and an ordinary linear regression model (OLR). The accuracy of the estimate of biomass achieved by PIM at different efforts was assessed by running computer simulations at different pin densities. Results: The relationship between intercept frequency and weighed biomass (b) was far better estimated using WLR compared to the normally used OLR. Efforts above 10 pins per 0.25 m(2) lot had a negligible effect on the accuracy of the estimate of biomass achieved by PIM whereas the number of plots had a strong effect. Moreover, for a given level of accuracy, the required number of plots varied depending on plant growth form. We achieved similar results to that of the computer simulations when applying our WLR based formula. Conclusion: This study shows that PIM can be applied more efficiently than was done in previous studies for the purpose of plant biomass estimation, where several plots should be analysed but at considerably less effort per plot. Moreover, WLR rather than OLR should be applied when estimating biomass from intercept frequency. The formula we have deduced is a useful tool for planning plant biomass analysis with PIM. OI Brathen, Kari Anne/0000-0003-0942-1074 SN 1100-9233 EI 1654-1103 PD OCT PY 2004 VL 15 IS 5 BP 653 EP 660 DI 10.1111/j.1654-1103.2004.tb02307.x UT WOS:000224638600008 ER PT J AU Kumpula, J Lefrere, SC Nieminen, M AF Kumpula, J Lefrere, SC Nieminen, M TI The use of woodland lichen pasture by reindeer in winter with easy snow conditions SO ARCTIC AB Our aim was to investigate the amount of digging work (cratering) done by semi-domesticated reindeer (Rangifer t. tarandus) in woodland lichen pasture and the effect of snow and pasture conditions on the body condition of female reindeer. From 17 February until 21 April 2001, eight barren reindeer females were allowed to graze freely in a fenced area (20 ha). Measurements before the study showed the amount of lichens within the fenced area to average 632 kg DM/ha in dry pine forest. Inside the fenced area, there was 31.1 cm of relatively soft snow in February and 41.8 cm in April. Observations showed that in February the reindeer spent 39.8% of the time digging and grazing and 1.0% foraging arboreal lichens. In April, they spent 29.8% of the time digging and grazing and 5.2% foraging arboreal lichens. During cratering, reindeer foraged (dug and picked food) with a certain repeated rhythm, using both front feet equally. The size of the grazed area and the volume of snow removed from a single crater were dependent on the total foraging time per crater. The mean body mass of the reindeer was 67.1 +/- 2.67 kg in mid-February and 64.9 +/- 2.98 kg in late April. It was calculated that in February one reindeer dug and grazed 75.6 m(2) per day, and the mean change in reindeer body mass was actually +39 g per day. In April the corresponding figures for one reindeer were 60.1 m(2) and -27 g per day. In the snow and pasture conditions prevailing during this study, the reindeer were able to get enough food and thereby energy to preserve their body condition well. SN 0004-0843 PD SEP PY 2004 VL 57 IS 3 BP 273 EP 278 UT WOS:000223961400005 ER PT J AU Tommervik, H Johansen, B Tombre, I Thannheiser, D Hogda, KA Gaare, E Wielgolaski, FE AF Tommervik, H Johansen, B Tombre, I Thannheiser, D Hogda, KA Gaare, E Wielgolaski, FE TI Vegetation changes in the Nordic mountain birch forest: The influence of grazing and climate change SO ARCTIC ANTARCTIC AND ALPINE RESEARCH CT International Conference on Arctic-Alpine Ecosystems and People in a Changing Environment CY FEB 24-MAR 01, 2003 CL Tromso, NORWAY AB The study focuses on vegetation changes in the Nordic mountain birch forest in northern Norway, covering a period of more than 40 yr. The study area comprises the municipalities of Kautokeino and Karasjok on Finnmarkskvidda; it is predominantly covered by lichen and dwarf shrub vegetation. Sizes of various vegetation classes were estimated by the use of remote-sensing techniques and ground surveys. A significant change in vegetation cover during the study period was registered in the whole study area. Vegetation types dominated by bilberry (Vaccinium myrtillus), wavy hair-grass (Deschampsia fleuxuosa), the dwarf cornel (Cornus suecica), and mosses have tripled in abundance compared to 40 yr ago. In contrast, lichen-dominated heaths and woodland (forests), preferred by the reindeer stocks intensively utilizing these areas of Finnmarksvidda, have decreased by approximately 80% in abundance during the same period. Correspondingly, there has been a significant increase in the extent of birch forests especially in Kautokeino (90% increase). The reason for the steep decline in lichen-dominated areas appears to be a direct consequence of the intensive grazing by the increasing reindeer population in the period 1961-1987, but climate change (increased precipitation), caterpillar attacks, and long-transported air pollution (e.g., nitrogen) may also have accentuated the increase of forests and other vegetation types. SN 1523-0430 EI 1938-4246 PD AUG PY 2004 VL 36 IS 3 BP 323 EP 332 DI 10.1657/1523-0430(2004)036[0323:VCITNM]2.0.CO;2 UT WOS:000226706900007 ER PT J AU Epstein, HE Calef, MP Walker, MD Chapin, FS Starfield, AM AF Epstein, HE Calef, MP Walker, MD Chapin, FS Starfield, AM TI Detecting changes in arctic tundra plant communities in response to warming over decadal time scales SO GLOBAL CHANGE BIOLOGY AB Detecting the response of vegetation to climate forcing as distinct from spatial and temporal variability may be difficult, if not impossible, over the typical duration of most field studies. We analyzed the spatial and interannual variability of plant functional type biomass from field studies in low arctic tussock tundra and compared these to climate change simulations of plant community composition using a dynamic tundra vegetation model (ArcVeg). Spatial heterogeneity of peak season live aboveground biomass was estimated using field samples taken from low arctic tundra at Ivotuk, Alaska (68.5degreesN, 155.7degreesW) in 1999. Coefficients of variation for live aboveground biomass at the 1 m(2) scale ranged from 14.6% for deciduous shrubs, 18.5% for graminoids and 25.3% for mosses to over 57% for forbs and lichens. Spatial heterogeneity in the ArcVeg dynamic vegetation model was simulated to be greater than the field data, ranging from 37.1% for deciduous shrubs to 107.9% for forbs. Disturbances in the model, such as caribou grazing and freezing-thawing of soil, as well as demographic stochasticity, led to the greater variability in the simulated results. Temporal variances of aboveground live biomass over a 19-year period using data from Toolik Lake, AK fell within the range of field and simulation spatial variances. However, simulations using ArcVeg suggest that temporal variability can be substantially less than site-scale spatial variability. Field data coupled with ArcVeg simulations of climate change scenarios indicate that some changes in plant community composition may be detectable within two decades following the onset of warming, and shrubs and mosses might be the key indicators of community change. Model simulations also project increasing landscape scale spatial heterogeneity (particularly of shrubs) with increasing temperatures. OI Chapin III, F Stuart/0000-0002-2558-9910 SN 1354-1013 EI 1365-2486 PD AUG PY 2004 VL 10 IS 8 BP 1325 EP 1334 DI 10.1111/j.1365-2486.2004.00810.x UT WOS:000222869600008 ER PT J AU Olofsson, J Hulme, PE Oksanen, L Suominen, O AF Olofsson, J Hulme, PE Oksanen, L Suominen, O TI Importance of large and small mammalian herbivores for the plant community structure in the forest tundra ecotone SO OIKOS AB Both theoretical arguments and empirical evidence suggests that herbivory in general and mammalian winter herbivory in particular is important in arctic-alpine ecosystems. Although knowledge of the effect of herbivores on specific plants and communities is quite extensive, little is known about the relative impact of large and small vertebrate herbivores and how it might vary among different habitats. To address this key issue, we established exclosures with two different mesh sizes in forest and nearby tundra at three different sites in four contrasting locations in the forest-tundra ecotone in northernmost Sweden and Norway. Plant community composition was recorded annually in three permanent plots within each exclosure and an unfenced control. Local densities of vertebrate herbivores were estimated in spring and autumn from 1998 to 2002. Reindeer (Rangifer tarandus) were the most abundant large vertebrate while Norwegian lemmings (Lemmus lemmus) and grey-sided voles (Clethrionomys rufocanus) were the most common small vertebrates. The study reveals that voles and lemmings have larger effects on the vegetation than reindeer in both habitats in all four locations, even though densities of reindeer differ between locations and only two locations experienced lemming peaks during the period of the experiment. The relative abundance of five of the fifteen most common species was significantly influenced by voles and lemmings whereas only a single species was significantly influenced by reindeer. Different analyses give contrasting results on the importance of herbivory in forest versus open heathlands. A principal component analyses revealed that herbivory influenced the vegetation more in open heathlands than in forests. However, an importance index of herbivores did not differ between forest and open heathlands. Moreover, none of the plant species responded differently in the two habitats, when herbivores were removed. Our results suggest that intense and localised selective foraging by small mammals may have a more marked effect on vegetation than transient feeding by reindeer. RI Hulme, Philip/F-7454-2011; Olofsson, Johan/A-9362-2009 OI Hulme, Philip/0000-0001-5712-0474; SN 0030-1299 PD AUG PY 2004 VL 106 IS 2 BP 324 EP 334 DI 10.1111/j.0030-1299.2004.13224.x UT WOS:000222424600012 ER PT J AU Steinheim, G Weladji, RB Skogan, T Adnoy, T Skjelvag, AO Holand, O AF Steinheim, G Weladji, RB Skogan, T Adnoy, T Skjelvag, AO Holand, O TI Climatic variability and effects on ungulate body weight: the case of domestic sheep SO ANNALES ZOOLOGICI FENNICI AB Annual climatic variation is reported to affect life history traits such as body mass and reproductive parameters of several northern ungulates. Effects of spring and summer weather conditions on body weights of domestic sheep were studied, using data on 56 584 free-ranging lambs from six coastal and inland grazing areas along a 1200 km latitudinal gradient. Nineteen weather indices, most chosen from a study of relevant literature, were used in the analyses. Linear mixed models, with a variance structure designed to take within-flock and -year dependency into account, were applied. A correlation analysis indicated that the between-years lamb weight patterns of most of the areas, even ones far apart from each other, were related to each other. All weather indices had significant effects on the lamb weights in two or more areas (on average 4.6 areas). The directions of the effects (parameter estimates) were inconsistent among the areas, and possible explanations for the area-specific effects are discussed. Suggestions on future research on climate-ungulate body weight studies are given. SN 0003-455X PD JUN 22 PY 2004 VL 41 IS 3 BP 525 EP 538 UT WOS:000222687500007 ER PT J AU Olofsson, J Stark, S Oksanen, L AF Olofsson, J Stark, S Oksanen, L TI Reindeer influence on ecosystem processes in the tundra SO OIKOS AB Reindeer have been recorded to increase nutrient cycling rate and primary production in studies from fences almost 40 years old that separate areas with different grazing regimes in northern Fennoscandia. To further understand the mechanism behind the effects of herbivores on primary production, we measured the size of the major C and N pools, soil temperature, litter decomposition rate and N mineralization rate in lightly, moderately and heavily grazed areas along two of these fences. Plant N found in new biomass, indicative of plant N assimilation, was significantly higher in moderately and heavily grazed areas than in lightly grazed areas, which corresponded to a decreased amount of N in old plant parts. The amount of N found in plant litter or organic soil layer did not differ between the grazing treatments. Together with soil N concentrations and litter decomposition rates, soil temperatures were significantly higher in moderately and heavily grazed areas. We conclude that the changes in soil temperature are important for the litter decomposition rate and thus on the nutrient availability for plant uptake. However, the changes in plant community composition appear to be more important for the altered N pools and thus the enhanced primary production. The results provide some support for the keystone herbivore hypothesis, which states that intensive grazing can promote a transition from moss-rich tundra heath to productive grasslands. Grazing altered N fluxes and pools, but the total N pools were similar in all grazing treatments. Our study thus indicates that grazing can increase the primary production through enhancing the soil nutrient cycling rate, even in a long term perspective on an ecological timescale. RI Stark, Sari/L-4440-2013; Olofsson, Johan/A-9362-2009 SN 0030-1299 PD MAY PY 2004 VL 105 IS 2 BP 386 EP 396 DI 10.1111/j.0030-1299.2004.13048.x UT WOS:000220383100018 ER PT J AU Boudreau, S Payette, S AF Boudreau, S Payette, S TI Caribou-induced changes in species dominance of lichen woodlands: An analysis of plant remains SO AMERICAN JOURNAL OF BOTANY AB Plant communities in northern Quebec-Labrador, Canada have been severely grazed and trampled since the early 1980s by the increasingly large George River caribou herd (GRCH). To evaluate changes in species dominance associated with caribou disturbance, we compared past and present ground vegetation from 14 lichen woodlands. Plant remains from superficial organic horizons indicate that ground vegetation was largely dominated by lichens (especially Cladina) before the onset of caribou disturbance. In enlargments of aerial photos taken before 1975 (i.e., prior to maximum size of the GRCH), all sites were free of caribou trails and were dominated by a continuous lichen (Cladina) carpet. Principal components analysis showed that partial or complete destruction of the Cladina-dominated lichen carpet was the most striking change in ground vegetation. Severe trampling degraded superficial organic horizons, subsequently exposing mineral soil in heavily used sites. With reduced caribou activity in the 1990s, exposed ground was colonized by crustose lichens and Cladonia. Sites that faced severe grazing but light trampling were recolonized mainly by small podetia of Cladina stellaris sprouting from the lichen litter. However, patterns of post-caribou disturbance lichen succession differed from those of post-fire succession, because species from different successional stages are present at the same time in a stand and also because caribou can modify the successional trajectory at any time. SN 0002-9122 EI 1537-2197 PD MAR PY 2004 VL 91 IS 3 BP 422 EP 429 DI 10.3732/ajb.91.3.422 UT WOS:000220331800013 PM 21653398 ER PT J AU van der Wal, R Bardgett, RD Harrison, KA Stien, A AF van der Wal, R Bardgett, RD Harrison, KA Stien, A TI Vertebrate herbivores and ecosystem control: cascading effects of faeces on tundra ecosystems SO ECOGRAPHY AB We tested the hypothesis that large herbivores manipulate their own food supply by modifying soil nutrient availability. This was investigated experimentally the impact of faeces on grasses, mosses and soil biological properties in tundra ecosystems. For this, we increased the density of reindeer Rangifer tarandus platyrhynchus faeces and studied the response of a tundra system on Spitsbergen to this single faecal addition treatment for four subsequent years. From the third year onwards faecal addition had unambiguously enhanced the standing crop of grasses, as evidenced by an increase in both shoot density and mass per shoot. Although reindeer grazing across experimental plots was positively related to the abundance of grasses in anyone year, the increase in grass abundance in fouled plots failed to result in greater grazing pressure in those plots. Faecal addition enhanced soil microbial biomass C and N, particularly under wet conditions where faecal decay rates were greatest, whilst grasses appeared to benefit from faeces under dry conditions. Whilst growth of grasses and soil microbial biomass were stimulated by faecal addition, the depth of the extensive moss layer that is typical of tundra ecosystems was significantly reduced in fouled plots four years after faecal addition. The greatest reduction in moss depth occurred where fouling increased soil microbial biomass most, suggesting that enhanced decomposition of moss by a more abundant microbial community may have caused the reduced moss layer depth in fouled plots. Our field experiment demonstrates that by the production of faeces alone, vertebrate herbivores greatly impact on both above- and belowground components of tundra ecosystems and in doing so manipulate their own food supply. Our findings verify the assertion that grazing is of fundamental importance to tundra ecosystem productivity, and support the hypothesis that herbivory is instrumental in promoting grasses whilst suppressing mosses. The widely observed inverse relationship between grass and moss abundance in the field may therefore reflect the long history of plant-herbivore interactions in tundra ecosystems. RI van der Wal, Rene/F-3177-2010 OI Stien, Audun/0000-0001-8046-7337 SN 0906-7590 EI 1600-0587 PD FEB PY 2004 VL 27 IS 2 BP 242 EP 252 DI 10.1111/j.0906-7590.2004.03688.x UT WOS:000220549600012 ER PT J AU Van der Wal, R Brooker, RW AF Van der Wal, R Brooker, RW TI Mosses mediate grazer impacts on grass abundance in arctic ecosystems SO FUNCTIONAL ECOLOGY AB 1. Large herbivores have significant impacts on the structure and function of temperate and tropical ecosystems. Yet herbivore impacts on arctic systems, particularly the mechanisms by which they influence plant communities, are largely unknown. 2. High arctic vegetation, commonly overlying permafrost soils, is often moss-dominated with sparse vascular plant cover. We investigated the potential influence of large herbivores on arctic plant communities via their impact on the depth of the moss layer, leading to warmer soils and potentially benefiting vascular plants. 3. We found that grazer impacts on moss depth, and subsequently soil temperature, may influence vascular plant abundance and community composition because of the observed positive but growth-form-specific response of vascular plants to soil warming, promoting grasses in particular. 4. We propose that the positive association of grasses and large herbivores in arctic moss-dominated systems results from two simultaneously operating positive feedback loops. First, herbivore grazing and trampling reduces moss layer depth, increasing soil temperatures. Second, grasses benefit directly from grazers as a result of additional nutrients from faeces and urine. Additionally, the tolerance of grasses to grazing may enable grasses to expand despite the losses suffered from herbivory. RI van der Wal, Rene/F-3177-2010; Brooker, Rob/F-9569-2012 SN 0269-8463 EI 1365-2435 PD FEB PY 2004 VL 18 IS 1 BP 77 EP 86 DI 10.1111/j.1365-2435.2004.00820.x UT WOS:000188821200009 ER PT J AU Boudreau, S Payette, S AF Boudreau, S Payette, S TI Growth performance of Cladina stellaris following caribou disturbance in subarctic Quebec SO ECOSCIENCE AB Cladina stellaris is a dominant lichen species of old-growth lichen-spruce woodlands in subarctic Quebec, where the continuous lichen carpet persists for several decades in the absence of disturbance. The lichen carpet is, however, vulnerable to caribou (Rangifer tarandus) disturbance under dry site conditions. Through grazing and trampling, large herds of migratory caribou reduce C. stellaris abundance and modify ground vegetation composition. Here, we have evaluated the age and growth performance of C. stellaris in relation to the recent activity of the George River Caribou Herd (GRCH). We measured the age, length, and growth rate of C. stellaris podetia in and near caribou trails in 15 lichen-spruce woodlands across the summer habitat. The age of lichens, used to evaluate the initial period of lichen recruitment following the decline of the GRCH, indicated that lichen recovery began in the early 1990s in heavily disturbed sites, whereas comparisons between the age structure of border and trail lichens also suggested that the southern part of the calving ground was still heavily used in the early 1990s. Length and growth rate of C. stellaris thallus were closely associated with severity of caribou disturbance, as inferred from the residual ground cover of terrestrial lichens. Growth performance of C. stellaris during the initial stage of lichen recovery varied according to the spatial use of the summer habitat by caribou, with better performance at the edge of the summer and winter habitats and reduced performance in the extensively used calving ground. The analysis of growth performance of C. stellaris provides new insights on lichen-spruce stand recovery associated with caribou disturbance. SN 1195-6860 EI 2376-7626 PY 2004 VL 11 IS 3 BP 347 EP 355 DI 10.1080/11956860.2004.11682842 UT WOS:000224339300012 ER PT J AU Vistnes, I Nellemann, C Jordhoy, P Strand, O AF Vistnes, I Nellemann, C Jordhoy, P Strand, O TI Effects of infrastructure on migration and range use of wild reindeer SO JOURNAL OF WILDLIFE MANAGEMENT AB We studied reindeer (Rangifer tarandus tarandus) distribution in relation to possible travel barriers (roads and power lines) in south-central Norway, 1997-2000, using lichen biomass as an indicator of reindeer use. We recorded lichen cover on both sides of potential barriers within comparable habitat in 42 sites for 3 different reindeer herds. We used cover-biomass regressions to assess the relationship between lichen cover and biomass. In 2 of the regions, lichen biomass was 5.3 times and 2.8 times higher in areas isolated by 2 parallel power lines and an adjacent winter-closed road compared to biomass on the other side of the potential barrier. In a third region, lichen biomass did not vary significantly between areas on either side of a single "inter-closed road. Lichen biomass data suggested that wild reindeer used both sides of a closed road in winter, whereas 2 parallel power lines and a winter-closed road in combination reduced reindeer migration and resulted in very different grazing pressures on either side of the power lines, even 30 years after the power lines were constructed. Construction of power lines, and particularly parallel power lines, should thus be avoided in wild reindeer habitat. Fragmentation of wild reindeer ranges in Norway results in a substantial reduction in available ranges and traditional migration routes between important seasonal ranges, with a likely overall reduction in carrying capacity. SN 0022-541X EI 1937-2817 PD JAN PY 2004 VL 68 IS 1 BP 101 EP 108 DI 10.2193/0022-541X(2004)068[0101:EOIOMA]2.0.CO;2 UT WOS:000188243400010 ER PT J AU Larter, NC Nagy, JA AF Larter, NC Nagy, JA TI Seasonal changes in the composition of the diets of Peary caribou and muskoxen on Banks Island SO POLAR RESEARCH AB Caribou and muskoxen are the only ungulate species occupying Arctic tundra environments. We analysed plant fragments found in fresh (<4 hr old) samples of faecal material to determine the diets of Peary caribou (Rangifer tarandus pearyi) and muskoxen (Ovibos moschatus) on Banks Island, Canada. Willow was a major component of the diets of both animals, dominating the caribou diet during summer and representing substantial proportions of the muskoxen diet during at least seven months of the year. The diet of caribou was more diverse than that of muskoxen and was dominated by sedge, willow (Salix arctica), legume (Astragalus spp., Oxytropis spp.) and Dryas integrifolia. The diet of muskoxen was dominated by sedge and willow. There was substantial overlap (up to 70%) in the diets of these herbivores with the similarity more pronounced in areas of high muskox density (ca. 1.65 animals/km(2)). We discuss herbivore diets in relation to foraging behaviour and forage availability. SN 0800-0395 PY 2004 VL 23 IS 2 BP 131 EP 140 DI 10.1111/j.1751-8369.2004.tb00003.x UT WOS:000226052200003 ER PT J AU Knott, KK Barboza, PS Bowyer, RT Blake, JE AF Knott, KK Barboza, PS Bowyer, RT Blake, JE TI Nutritional development of feeding strategies in arctic ruminants: digestive morphometry of reindeer, Rangifer tarandus, and muskoxen, Ovibos moschatus SO ZOOLOGY AB Reindeer have been classified as intermediate feeders and muskoxen as grazers based on differences in digestive morphology and consumption of fibrous plants. We hypothesized that the digestive morphology of young (<2 months) reindeer and muskoxen anticipates transitions in diet and determines the feeding strategy of each species at adulthood. We compared structural morphology and rates of cell division in the rumen, abomasum, duodenum and liver of reindeer and muskoxen as neonates (1 day old), during the transition from milk to forage (30-60 days old) and in adults (> 7 yr). Development in utero provided the neonate with a functioning mucosa of the gastric abomasum and duodenal mucosa with high surface enlargement for digestion and absorption of concentrated milks. Transition to forage was preceded by changes in ruminal papillae structure that increased surface area and likely contributed to active fermentation by 60 days of age. The abomasum also increased in acid-secreting parietal cells during the transition to forage, which may enhance digestion of plant and microbial proteins. Rates of cell division also indicated a sustained differentiation of tissue structure during the transitional period. Young arctic ruminants expressed digestive structures that preceded full function, which indicated the ultimate feeding strategy of each species. For example, the rumen of young muskoxen had thick cornified epithelia and muscle layers that would provide ruminal mucosa with better protection from fibrous abrasion and enhance motility of bulky diets. Conversely, young reindeer had more complex papillary shapes in the rumen and more foliate villi in the duodenum, indicating a greater absorptive capacity of these structures than in muskoxen. Ontogenetic programs, therefore, play the primary role for digestive development of reindeer and muskoxen and determine the nutritional strategies of adults. (C) 2004 Elsevier GmbH. All rights reserved. OI Barboza, Perry/0000-0002-1489-6448 SN 0944-2006 PY 2004 VL 107 IS 4 BP 315 EP 333 DI 10.1016/j.zool.2004.07.005 UT WOS:000225888900004 PM 16351947 ER PT J AU Allard, A AF Allard, A TI Detection of vegetation degradation on Swedish mountainous heaths at an early stage by image interpretation SO AMBIO AB Mountainous vegetation in general, and especially in subpolar regions, is sensitive, compared to vegetation in lowland areas, as mountainous vegetation has low resilience and low productivity. Mountainous areas have been perceived as being sensitive to mechanical damage. Quick methods with a high degree of accuracy are needed for the monitoring of mountainous areas and for planning the sustainable use of resources. The aim was i) to investigate if the dry dwarf shrub heath on hummocky moraine in the southern part of the mountains with a maritime climate and in open areas used for summer grazing, is susceptible to change; and ii) to test if high-resolution IKONOS-2 satellite data can, with a high degree of accuracy, be used for detection, and for quantification and mapping of erosion patches in montane vegetation. In which case, these data can substitute color infrared aerial photos for the early detection of changes. For the detection of changes, visual interpretations on high-quality printouts of IKONOS-2 satellite images from 2000 and of color infrared aerial photographs from 1975 were carried out and the results compared. Interpretations were verified in the field. The results show that for the period 19752000, erosion was in process on and around wind heaths, indicating that the wind heath and surrounding dry dwarf shrub heath in this landscape type of hummocky moraine are sensitive to mechanical damage by trampling and grazing, and thus susceptible to change. Most of the wind heaths and changes found were small (50-1000 m(2)). The results show that it is possible to detect, with good accuracy, detailed changes in the size and distribution of erosion patches and wind heaths by visual interpretation in single images of IKONOS-2 data. This implies that for monitoring these kinds of changes, these high-resolution (4 x 4 m pixel resolution) satellite data can substitute for color infrared aerial photographs. SN 0044-7447 PD DEC PY 2003 VL 32 IS 8 BP 510 EP 519 UT WOS:000189317900004 PM 15049347 ER PT J AU Cooper, EJ Wookey, PA AF Cooper, EJ Wookey, PA TI Floral herbivory of Dryas octopetala by Svalbard reindeer (vol 35, pg 373, 2003) SO ARCTIC ANTARCTIC AND ALPINE RESEARCH RI Wookey, Philip/J-4786-2012 SN 1523-0430 PD NOV PY 2003 VL 35 IS 4 BP 539 EP 539 UT WOS:000189380400018 ER PT J AU Storeheier, PV Mathiesen, SD Sundset, MA AF Storeheier, PV Mathiesen, SD Sundset, MA TI Estimating faecal output in reindeer during winter SO LIVESTOCK PRODUCTION SCIENCE AB Faecal output (FO) was estimated indirectly in six penned male reindeer calves by use of intraruminal chromic oxide (Cr2O3) constant release capsules (CRCs) and compared with their actual FO, which was determined in a parallel study by use of total faecal collection (TFC) with faeces collecting bags. The captive animals successively ate two different diets: a diet of pelleted reindeer feed (RF-80) succeeded by a diet of mixed lichens. Using intraruminal CRCs to estimate FO resulted in 9.9 and 1.8 times overestimations of the FO of the animals on the RF-80 and the mixed lichen diet, respectively. The poor estimates of FO were probably caused by a faecal excretion rate of chromium that was lower than the capsule release rate given by the manufacturer of the capsules. Three of the reindeer calves were subsequently released into a free-ranging herd grazing at winter pasture. The FO of these calves and the FO of three free-ranging adult female reindeer was estimated by use of intraruminal CRCs. Actual FO was simultaneously measured in the calves by use of faeces collecting bags. Weight-specific estimates of FO was similar in free-ranging calves and adult females. The estimated and the actual FO were similar in the free-ranging calves, and the release rate of chromium from the CRCs was close to the release rate given by the manufacturer of the capsules in both calves and adult animals. It is concluded that the faecal excretion rate of chromium in reindeer being administered intraruminal CRCs depends upon the diet eaten by the animals. In future studies using intraruminal CRCs, the faecal excretion rate of marker should be measured under the trial conditions in a subset of animals to adjust marker estimates of faecal output. (C) 2003 Elsevier B.V. All rights reserved. SN 0301-6226 PD NOV PY 2003 VL 84 IS 1 BP 23 EP 30 DI 10.1016/S0301-6226(03)00071-X UT WOS:000186222900003 ER PT J AU Ripple, WJ Beschta, RL AF Ripple, WJ Beschta, RL TI Wolf reintroduction, predation risk, and cottonwood recovery in Yellowstone National Park SO FOREST ECOLOGY AND MANAGEMENT AB We studied young riparian cottonwoods (Populus spp.) and associated woody plants along Soda Butte Creek and the Lamar River in northeastern Yellowstone National Park (YNP) to examine the potential influence of wolf/elk interactions upon plant growth. After a period of approximately 70 years without wolves in YNP, they were reintroduced in the winter of 1995-1996. When we compared woody plant heights shown in photographs taken prior to 1998 with those shown in 2001-2002 photos, we found an increase in the height of riparian woody plants for six of the eight sites within the study area. Plants were tallest (1-4 m) at point bar, stream confluence, and island sites, while heights remained relatively low (<1 m) along straight river reaches in a wide valley setting. We measured differences in both browsing intensity and cottonwood height for sites with relatively high predation risk (low visibility and/or the presence of escape barriers) and compared them to nearby sites with relatively low predation risk (open areas). In general, the high-risk sites had lower browsing intensities (percent of stems browsed) and taller plants than low-risk sites. Although the young cottonwoods on high-risk sites were growing taller each year over the last 4 years, there was little change in the plant heights for low-risk sites. For a stand of young cottonwoods growing adjacent to a gully (potential escape barrier), we found a linear correlation (r(2) = 0.76) between cottonwood height and adjacent gully depth; as gully depth increased, the percent of stems browsed decreased and cottonwood height increased. While the release of cottonwood and willows within the study area is in a very early stage, results provide rare empirical evidence illustrating the indirect effects of a top carnivore in a terrestrial food chain and supports theories on: (1) predation risk effects and (2) trophic cascades (top-down control). Wolf reintroductions into the Yellowstone environment may thus represent a management action that was needed to help insure the restoration of riparian species and preservation of biodiversity. (C) 2003 Elsevier Science B.V. All rights reserved. SN 0378-1127 PD OCT 3 PY 2003 VL 184 IS 1-3 BP 299 EP 313 DI 10.1016/S0378-1127(03)00154-3 UT WOS:000185170600025 ER PT J AU Wiklund, E Johansson, L Malmfors, G AF Wiklund, E Johansson, L Malmfors, G TI Sensory meat quality, ultimate pH values, blood parameters and carcass characteristics in reindeer (Rangifer tarandus tarandus L.) grazed on natural pastures or fed a commercial feed mixture SO FOOD QUALITY AND PREFERENCE AB Sensory properties in meat, ultimate muscle pH values, blood metabolites and carcass characteristics from reindeer grazed on natural pasture (n = 23) or fed a commercial feed mixture (n = 17) were studied. Reindeer fed commercial feed generally had lower ultimate pH values (increased glycogen stores) in all three muscles measured (Mm. triceps brachii, longissimus and biceps femoris) compared with the animals grazing natural pasture. Raised plasma urea concentrations in all reindeer were explained by a relatively high intake of protein for both treatments. Aspartate aminotransferase (ASAT) activities in all animals were low, and did not indicate muscle degeneration due to stress. However, the measured plasma cortisol concentrations showed that all reindeer were affected by the immediate pre-slaughter handling. Sensory evaluation was performed both as a descriptive test using a selected and trained panel, and as a preference test carried out with two groups of consumers (experienced and non-experienced reindeer meat eaters). The trained panel concluded that meat from reindeer fed commercial feed scored higher for liver and sweet flavour intensities and lower for off-flavour compared with meat from reindeer grazing natural pasture. The consumer test showed no effect of consumer age, gender or residence on the preference for meat from reindeer on either feed. The importance for the reindeer industry to acknowledge and use the differences in flavour and consumer preference as a specialised marketing strategy for reindeer meat is discussed. (C) 2003 Elsevier Science Ltd. All rights reserved. SN 0950-3293 PD OCT PY 2003 VL 14 IS 7 BP 573 EP 581 DI 10.1016/S0950-3293(02)00151-9 UT WOS:000183747600004 ER PT J AU Reimers, E Eftestol, S Colman, JE AF Reimers, E Eftestol, S Colman, JE TI Behavior responses of wild reindeer to direct provocation by a snowmobile or skier SO JOURNAL OF WILDLIFE MANAGEMENT AB To better understand the effect of winter tourism and public recreation on wild mountain reindeer (Rangifer tarandus tarandus), we compared reindeer response distances after direct provocations by skiers and snowmobiles during 3 winters in Setesdal-Ryfylke, Southern Norway. Reindeer being provoked by a snow-mobile discovered the observer at longer distances than reindeer being provoked by a skier (370 [skier] vs. 534 [snowmobile] m; P = 0.002), while total flight (756 vs. 570 m; P = 0.037) and total distance moved (970 vs. 660 m; P = 0.008) by reindeer were shorter for snowmobile than skier provocation. The fright (328 [skier] vs. 328 [snowmobile] m), flight (281 vs. 264 m), and escape (543 vs. 486 m) distances due to skier or snowmobile provocation were not different (P > 0.05). For pooled data, fright distances of reindeer were affected by 2 other independent variables. Fright distance was longer when the animals were provoked from below rather than from above (P = 0.046), while their escape distances were longer when the animals were lying rather than when grazing prior to being provoked (P< 0.05). Based on maximum and minimum distance moved for all provocations pooled, daily estimated energy expenditure of reindeer increased between 31 and 590 kJ, representing 0.2 and 2.9% of their estimated total daily energy expenditure. Overall, provocations by skiers or snowmobiles revealed similar behavioral responses. An estimated maximum rate of 3 daily encounters between reindeer and skiers or snowmobiles during winter vacation and Easter would result in moderate energy costs that should be easily compensated for and thus have no demographic consequences. Increasing snowmobile use will, however, significantly expand the area where humans are in contact with reindeer during winter and spring, a period of negative energy balance for reindeer. SN 0022-541X PD OCT PY 2003 VL 67 IS 4 BP 747 EP 754 DI 10.2307/3802681 UT WOS:000186216800009 ER PT J AU Moen, J Danell, O AF Moen, J Danell, O TI Reindeer in the Swedish mountains: An assessment of grazing impacts SO AMBIO AB During the last decade, several well-publicized grazing-related incidents of vegetation degradation have helped to form an official opinion of overutilization of some mountain areas and a concern that Swedish reindeer husbandry may not be ecologically sustainable. We examine these examples in a temporal and management perspective to assess the scale of impact on summer grazing grounds in the Swedish mountains. Long-term data on population dynamics of reindeer show no trend with fluctuations around 225 000 animals for the last century. Data on grazing effects from Langfjallet (Dalarna) and Mittaklappen (Harjedalen) are discussed in detail. We compare these data to the situation in Finnmark, Norway, and in northern Finland where reindeer husbandry in recent decades does not seem to have been ecologically sustainable. We conclude that large-scale overexploitation by reindeer in the Swedish mountains is not evident. However, strong grazing and trampling effects may be found around enclosures and fences. SN 0044-7447 PD SEP PY 2003 VL 32 IS 6 BP 397 EP 402 DI 10.1639/0044-7447(2003)032[0397:RITSMA]2.0.CO;2 UT WOS:000186207900005 PM 14627368 ER PT J AU Cooper, EJ Wookey, PA AF Cooper, EJ Wookey, PA TI Floral herbivory of Dryas octopetala by Svalbard reindeer SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB In polar semidesert communities of northwest Spitsbergen the reproductive potential of keystone vascular plant species, such as Dryas octopetala, is currently being constrained by low summer temperatures, resulting in the infrequent production of viable seeds. This study tests the hypothesis that summer foraging behavior of reindeer (Rangifer tarandus platyrhynchus) may further limit successful seed production due to intense selective grazing pressure on the flowering shoots. Surveys of neighboring coastal tundra areas with contrasting reindeer population densities revealed direct evidence of strong grazing pressure on reproductive shoots of D. octopetala on the Brogger Peninsula and considerably less floral herbivory on the sparsely reindeer-populated Blomstrand island. Recruitment of Dryas on the Brogger Peninsula is therefore being hindered by intense selective grazing of flowering shoots by Svalbard reindeer. This situation is not unique to this area of Svalbard and also extends to other species of flowering plants. RI Wookey, Philip/J-4786-2012 OI Wookey, Philip/0000-0001-5957-6424 SN 1523-0430 PD AUG PY 2003 VL 35 IS 3 BP 369 EP 376 DI 10.1657/1523-0430(2003)035[0369:FHODOB]2.0.CO;2 UT WOS:000185999300011 ER PT J AU Suominen, O Niemela, J Martikainen, P Niemela, P Kojola, I AF Suominen, O Niemela, J Martikainen, P Niemela, P Kojola, I TI Impact of reindeer grazing on ground-dwelling Carabidae and Curculionidae assemblages in Lapland SO ECOGRAPHY AB Reindeer Rangifer tarandus L. grazing shapes forest vegetation, microclimate, and soil respiration in Lapland, especially due to grazing on lichens (Cladina). We studied how these changes and their magnitude affect ground-dwelling species of beetle families Carabidae (predators) and Curculionidae (herbivores), by using pitfall traps to collect invertebrates from pairs of grazed and ungrazed study plots over a wide range of site types. Changes in abundance, composition, richness and diversity of beetle assemblage were tested in relation to magnitude of the impacts on vegetation. The species compositions of Carabidae and Curculionidae differed between grazed and ungrazed plots in all sites. The relative difference between grazed and ungrazed plots in the number of individuals increased linearly with the impact of reindeer on vegetation cover. Carabid beetles, as a family, were more common in grazed plots in all sites. Curculionid beetles were more common in ungrazed plots in the birch dominated sites. This difference was mainly due to the species that feeds on deciduous leaves. In the pine dominated sites with high Cladina cover and more changes in ground vegetation, the number of curculionids feeding on conifers was higher in grazed plots. Species richness and diversity (H') of both families were higher in grazed plots. Of the total 27 species, 11 were found only in grazed plots, while not a single species was found only in ungrazed plots. The relative difference between plots in diversity and evennes (H'/H' max) had humped response to the difference in Cladina cover. The diversity values were greater in grazed plots at the intermediate levels of grazing impact, and only in sites with very low or extremely high Cladina cover difference was the diversity higher in ungrazed plots. The response of beetle diversity resembled the hypotheses suggested for the relationship between grazing and vegetation diversity: greatest positive effect at intermediate grazing intensity and negative effects at unproductive sites. SN 0906-7590 PD AUG PY 2003 VL 26 IS 4 BP 503 EP 513 DI 10.1034/j.1600-0587.2003.03445.x UT WOS:000185481900013 ER PT J AU Makipaa, R Heikkinen, J AF Makipaa, R Heikkinen, J TI Large-scale changes in abundance of terricolous bryophytes and macrolichens in Finland SO JOURNAL OF VEGETATION SCIENCE AB Major changes in forest floor vegetation were identified on the basis of three nationwide surveys conducted as part of national forest inventories in 1951-1953, 1985-1986 and 1995. These surveys provided objectively selected, statistically representative samples of all forested land in Finland. The 1951-1953 data consist of over 10000 sample plots, while the later surveys were conducted on ca. 3000 permanent plots. Changes in relative abundance of dominant species (i.e. in the proportions of species of the total cover of forest floor vegetation) were analysed across biogeographical provinces. Spatial correlation. systematic sampling, partial re-measurement and multiple testing were taken into account in assessment of the statistical significance of the observed changes. The most notable changes in forest floor vegetation were a decrease in the relative abundance of Hylocomium splendens and an increase in Dicranum polysetum. In N Finland, where forests are grazed by semi-domestic reindeer, we observed a decline in the abundance of Cladina lichens and an increase in Dicranum mosses. Peltigera aphthosa declined throughout the country. Polytrichum juniperintum, Pohlia nutans, and Brachythecium species, which occupy disturbed sites or grow on litter. increased in abundance. The relative abundance of Sphagnum species decreased, particularly in W Finland, where Pleurozium schreberi was favoured. A major decline in S. fuscum was also recorded in C and E Finland many of the changes detected in this study are apparently related to intensified forest management; but solely on the basis of this study, its effects cannot be distinguished from those of other large-scale environmental changes. RI Heikkinen, Juha/E-7863-2018 OI Heikkinen, Juha/0000-0003-3527-774X SN 1100-9233 PD AUG PY 2003 VL 14 IS 4 BP 497 EP 508 DI 10.1658/1100-9233(2003)014[0497:LCIAOT]2.0.CO;2 UT WOS:000186226400004 ER PT J AU Peltier, TC Barboza, PS Blake, JE AF Peltier, TC Barboza, PS Blake, JE TI Seasonal hyperphagia does not reduce digestive efficiency in an Arctic grazer SO PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY AB Muskoxen (Ovibos moschatus) consume fibrous plants that grow rapidly over the short Arctic summer. We studied responses of eight castrated male muskoxen to a diet of grass hay and mineral supplements during spring, autumn, and winter. Animals gained body mass in spring (239 +/- 39 kg) as body fat content increased from 26% to 38% of ingesta-free mass in winter without changes in lean mass and protein. Intakes of dry matter (DM) increased by 74% between spring and autumn as digestible energy increased from 554 to 923 kJ kg(-0.75) d(-1) during mass gain. Digestibility of cellulose (72% - 76%) was not affected by increasing food intake between spring and autumn but was reduced to 65% in winter. Digestibility of nitrogen compounds was 61%-66%, even though intake increased by 134% between spring and autumn. Excess dietary nitrogen from hay and supplements increased urea concentrations in plasma and urine. High loads of solutes such as potassium did not affect plasma or urinary osmolality but were associated with increased rates of glomerular filtration and urinary excretion. Low intakes of sodium from grasses may limit intake and digestion during summer, but high food intakes can support deposition of nitrogen, calcium, magnesium, copper, and zinc in body tissue even when dietary concentrations are low. Seasonal increases in digestive and metabolic functions allow muskoxen to rapidly accumulate energy and nutrients in body tissue during the short season of plant growth. OI Barboza, Perry/0000-0002-1489-6448 SN 1522-2152 EI 1537-5293 PD JUL-AUG PY 2003 VL 76 IS 4 BP 471 EP 483 DI 10.1086/377744 UT WOS:000185623600005 PM 13130427 ER PT J AU Rees, WG Williams, M Vitebsky, P AF Rees, WG Williams, M Vitebsky, P TI Mapping land cover change in a reindeer herding area of the Russian Arctic using Landsat TM and ETM+ imagery and indigenous knowledge SO REMOTE SENSING OF ENVIRONMENT AB Much of Russia north of the treeline is grazed by reindeer, and this grazing has materially altered the vegetation cover in many places. Monitoring vegetation change in these remote but ecologically sensitive regions is an important task for which satellite remote sensing is well suited. Further difficulties are imposed by the highly dynamic nature of arctic phenology, and by the difficulty of obtaining accurate official data on land cover in arctic Russia even where such data exist. We have approached the problem in a novel fashion by combining a conventional multispectral analysis of satellite imagery with data on current and historical land use gathered by the techniques of social anthropology, using a study site in the Nenets Autonomous Okrug (NAO). A Landsat-7 ETM+ image from the year 2000 was used to generate a current land cover classification. A Landsat-5 TM image was used to generate a land-cover classification for 1988, taking due account of phenological differences and between the two dates. A cautious comparison of these two classifications, again taking account of possible effects of phenological differences, shows that much of the study area has already undergone a notable transformation to grass-dominated tundra, almost certainly as a result of heavy grazing by reindeer. The grazing pattern is quite heterogeneous, and may have reached unsustainable levels in some areas. Finally, we suggest that this situation is unlikely to be unique to our study area and may well be widespread throughout the Eurasian tundra zone, particularly in the west. (C) 2003 Elsevier Science Inc. All rights reserved. RI Williams, Meredith/D-2903-2012 SN 0034-4257 EI 1879-0704 PD JUN 15 PY 2003 VL 85 IS 4 BP 441 EP 452 DI 10.1016/S0034-4257(03)0037-3 UT WOS:000183051600005 ER PT J AU Boudreau, S Payette, S Morneau, C Couturier, S AF Boudreau, S Payette, S Morneau, C Couturier, S TI Recent decline of the George River Caribou herd as revealed by tree-ring analysis SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Dendroecological analysis is often used in animal ecology to infer population fluctuations. In this study, we used scars produced by caribou hooves on superficial roots of conifers to evaluate the recent activity of the George River caribou herd (GRCH). In 1999 and 2000, we sampled a minimum of 300 trampling scars at each of 31 lichen woodland sites distributed over the summer habitat of the GRCH. Among the 31 selected sites, 18 had been previously sampled in 1992-1993 and showed a good agreement in trends inferred in caribou activity with the 1999-2000 data set at the same sites. We evaluated the recent activity pattern of the GRCH using mean values of pooled scar-age data from the 31 sites. We inferred two major trends from the tree-ring data: that the GRCH experienced an important increase from 1975 to the late 1980s, and that this growth was followed by a major decline that began in the early 1990s. Radio-collar data from 1991 to 1998 also support the decline as no major change was found in the geographical distribution of the GRCH during this period. SN 1523-0430 PD MAY PY 2003 VL 35 IS 2 BP 187 EP 195 DI 10.1657/1523-0430(2003)035[0187:RDOTGR]2.0.CO;2 UT WOS:000183952800007 ER PT J AU Weladji, RB Holand, O Almoy, T AF Weladji, RB Holand, O Almoy, T TI Use of climatic data to assess the effect of insect harassment on the autumn weight of reindeer (Rangifer tarandus) calves SO JOURNAL OF ZOOLOGY AB Considerable behavioural evidence supports harassment by insects as the most important causal link between warm summer temperatures and low body condition of reindeer Rangier tarandus, and that insect activity is influenced by weather condition. However, much less is known about the effect of insect harassment on individual performance, measured as reduced weight gain during summer, and the related consequences on both the reindeer pastoral economy and reindeer as a biological resource. Using climatic data, this paper develops a simple index for the analysis of insect harassment that takes into consideration weather variables known to significantly affect insect activity and/or the level of insect harassment. The insect harassment index, which is based on mid-day ambient temperature greater than or equal to 13 degreesC, wind speed < 6 m/s and cloud cover < 40%, is further used to test the hypothesis that insect harassment has a negative effect on reindeer performance during summer in three Norwegian populations. Results show that harassment by insects negatively affects the autumn weight of reindeer calves, most probably through reduced grazing time and increased energy expenditure, but also indirectly by negatively influencing milk production of the dam. Moreover, female calves were more vulnerable to insect harassment than males. Insect harassment may have consequences on future reproductive performance, calving time, calf birth weight and hence neonatal mortality. and thus affect reindeer productivity. The presented index is easy to estimate and may be used to quantify and compare harassment levels on various reindeer summer grazing areas for management purposes. Our results also suggest that the expected temperature increase in the course of global warming may increase the insect-related stress on reindeer. SN 0952-8369 PD MAY PY 2003 VL 260 BP 79 EP 85 DI 10.1017/S0952836903003510 PN 1 UT WOS:000183462900009 ER PT J AU Bostedt, G Parks, PJ Boman, M AF Bostedt, G Parks, PJ Boman, M TI Integrated natural resource management in northern Sweden: An application to forestry and reindeer husbandry SO LAND ECONOMICS AB Forests in northern Sweden are used for both timber production and reindeer grazing. Negative externalities and open access effects threaten the ability of the region to sustain economic benefits from these uses. A discrete time simulation for three municipalities in northern Sweden suggests that modifying forest harvest practices can enhance profits from reindeer production, with relatively low timber opportunity costs. Such efforts to sustain joint benefits from these boreal environments are more likely to be successful in combination with control of reindeer herd sizes. OI Bostedt, Goran/0000-0002-6540-743X SN 0023-7639 PD MAY PY 2003 VL 79 IS 2 BP 149 EP 159 DI 10.2307/3146864 UT WOS:000182568500002 ER PT J AU Aspi, J Jakalaniemi, A Tuomi, J Siikamaki, P AF Aspi, J Jakalaniemi, A Tuomi, J Siikamaki, P TI Multilevel phenotypic selection on morphological characters in a metapopulation of Silene tatarica SO EVOLUTION AB This study partitions selection in a natural metapopulation of a riparian plant species, Silene tatarica, into individual- and patch-level components by using contextual analysis, in which a patch refers to a spatially distinct stand of individual plants. We estimated selection gradients for two morphological characters (plant height and number of stems), their respective patch means, and plant density with respect to reproductive success in a two-year study. The approach was also extended to partition selection separately within habitats with varying degrees of exposure to river disturbances and herbivory. The selection differentials and gradients for plant height were positive at both individual and patch levels, with selection forces highest in the closed habitat with low exposure to disturbance. This pattern suggests that local groups with taller than average plants are more visible to pollinators than to groups that are shorter than average plants; and, within patches, individuals with short stature are visited less often than taller ones. Selection on the number of stems was in opposition at individual and patch levels. At the individual level the character was selected toward higher values, whereas selection at the patch-level favored smaller mean number of stems. The strength of the latter component was associated with the intensity of herbivory in different habitats, suggesting that the patch-level selection against a large number of stems might be due to high attractiveness of such patches to the main herbivore, reindeer. Consequently, direction and strength of selection in spatially structured populations may depend significantly on fitness effects arising at the group level. RI Aspi, Jouni/B-3087-2012 SN 0014-3820 PD MAR PY 2003 VL 57 IS 3 BP 509 EP 517 UT WOS:000182193800006 PM 12703940 ER PT J AU Gunn, A Irvine, RJ AF Gunn, A Irvine, RJ TI Subclinical parasitism and ruminant foraging strategies - a review SO WILDLIFE SOCIETY BULLETIN AB Subclinical parasitism in wild ungulates has been largely neglected, although it has both explanatory and predictive power in ruminant population dynamics. This review identifies how subclinical disease from internal parasites decreases individual reproductive success of their hosts through reductions in forage intake which reduces body condition. Accumulated evidence indicates that hosts have evolved adaptive strategies, especially in foraging behavior, to minimize their exposure to parasites: for example, reducing the risk of parasitism by avoiding areas of high fecal contamination. Experimentally, this has been tested in domestic sheep (Ovis aries), which have been shown to trade the risk of further infection against forage quality at the scale of bite size and mass. Appetite reduction, dung aversion, and parasite intensities reducing fecundity have been demonstrated experimentally in a wild ungulate, suggesting that using domestic stock as conceptual models is appropriate. We argue that it is therefore essential to include the interactions between parasites and host grazing patterns when analyzing broader spatial and temporal scales of foraging strategies. RI Irvine, Robert/G-5074-2012 OI Irvine, Robert/0000-0002-0411-6217 SN 0091-7648 PD SPR PY 2003 VL 31 IS 1 BP 117 EP 126 UT WOS:000182566900013 ER PT J AU den Herder, M Kytoviita, MM Niemela, P AF den Herder, M Kytoviita, MM Niemela, P TI Growth of reindeer lichens and effects of reindeer grazing on ground cover vegetation in a Scots pine forest and a subarctic heathland in Finnish Lapland SO ECOGRAPHY AB Reindeer lichens are an important component of northern ecosystems. The aim of this study was to measure the growth rate of terricolous lichens as it is a key parameter involved in productivity of these ecosystems and an important part of lichen tolerance to reindeer grazing. Furthermore, the natural succession and the long-term effects of reindeer grazing on lichen community characteristics in two contrasting habitats were investigated as well as the interactions between lichen cover and mosses and vascular plants. Biomass and coverage measurements were conducted in a lichen woodland and in a subarctic heath with grazed and ungrazed areas in northern Finland. Measurements spanning over 13 yr of undisturbed development show that the growth rate of Cladina stellaris can be as high as > 0.17 g g(-1) produced annually, although in average growth rates were much lower. During the succession of ground vegetation, C. stellaris, C. rangiferina, C. mitis and Cetraria nivalis increased in biomass in fenced areas and were reduced most in biomass by reindeer in unprotected areas. Reindeer grazing and trampling seem to change the vegetation towards a type that is dominated by small dwarf shrubs, bare soil and minute-cup lichens (Cladonia spp.). Removing the lichen layer by reindeer may reduce natural regeneration of pine trees as implied by increasing numbers of pine seedlings with increasing lichen cover. OI Kytoviita, Minna-Maarit/0000-0002-8928-6951 SN 0906-7590 PD FEB PY 2003 VL 26 IS 1 BP 3 EP 12 DI 10.1034/j.1600-0587.2003.03211.x UT WOS:000180797500001 ER PT J AU Stark, S Tuomi, J Strommer, R Helle, T AF Stark, S Tuomi, J Strommer, R Helle, T TI Non-parallel changes in soil microbial carbon and nitrogen dynamics due to reindeer grazing in northern boreal forests SO ECOGRAPHY AB Reindeer grazing has a considerable influence on mineralization processes in northern Fennoscandian boreal forests, but the mechanisms underlying the observed differences between grazed and ungrazed areas are not well understood. We studied the below-ground impacts of reindeer grazing by comparing the carbon and nitrogen mineralization rates inside and outside long-term fenced reindeer exclosure areas in five oligotrophic, lichen-dominated and five mesotrophic, dwarf-shrub dominated forests. The soil C mineralization rates and microbial metabolic activity (qCO(2)) were significantly lower in the grazed than the ungrazed areas in both oligotrophic and mesotrophic forests. The reductions occurred irrespective of the impact on soil moisture. We conclude that reindeer grazing causes a reduction in the supply of labile C substrates to microbes, resulting in reduced organic matter decomposition rates through changes in the activity of the microbial biomass. Simultaneously, grazing had no consistent effect on the microbial N dynamics, but the impact ranged from no change to increased or decreased in N mineralization rates at the different study sites. The impact of grazing on the N mineralization potential thus seems to be site-specific and uncoupled from the impact of grazing on soil C mineralization. Reciprocal transplant incubations showed no interactions between N mineralization rates and the reindeer-mediated impact on the soil microclimate. We suggest that plant root damage due to trampling by reindeer may be an important mechanism for the deceleration of soil C cycling. In some cases, however, the impact of grazing on the soil active N pool may be strong enough to outweigh the reduction in soil organic matter decomposition, and by these means uncouple soil N dynamics from soil C quality. RI Stark, Sari/L-4440-2013 SN 0906-7590 PD FEB PY 2003 VL 26 IS 1 BP 51 EP 59 DI 10.1034/j.1600-0587.2003.03336.x UT WOS:000180797500006 ER PT J AU Weladji, RB Steinheim, G Holand, O Moe, SR Almoy, T Adnoy, T AF Weladji, RB Steinheim, G Holand, O Moe, SR Almoy, T Adnoy, T TI Temporal patterns of juvenile body weight variability in sympatric reindeer and sheep SO ANNALES ZOOLOGICI FENNICI AB The debate over whether winter or summer grazing conditions are more important for reindeer (Rangifer tarandus) growth and reproduction is not settled. We used long-term weight data of sympatric semi-domesticated reindeer and domestic sheep (Ovis aries) in Sor-Fosen, Norway, to address indirectly the above-mentioned debate, by assessing the temporal patterns, variation and covariation of juvenile body weights. We further examined the relative importance of winter and summer weather conditions in explaining variation in reindeer autumn weights. A positive relationship between autumn body weight of reindeer and sheep was found, suggesting that a "good" summer for reindeer is also a good one for sheep. Despite the sheep being fed indoors during winter, there was no difference in intrinsic variability between yearly mean juvenile body weights of the two species. These results suggest that (i) reindeer and domestic sheep may equally benefit, or suffer, from weather-related variation in summer forage conditions, and that (ii) either reindeer calf autumn body weights are not very sensitive to environmental conditions in the previous winter (i.e. when they were in utero), or that they are able, to some extent, to compensate for winter-related stress experienced by their mother. Furthermore, (iii) winter weather conditions may influence reindeer and sheep similarly, through indirect effects on the summer forage conditions. Direct analysis revealed that summer weather index explained more of the between year variance in reindeer autumn weights than the winter weather index. Hence, our results support the view that summer, rather than winter range conditions, are more important to juvenile body growth of reindeer. RI Moe, Stein R./G-1507-2011 OI Moe, Stein R./0000-0003-1005-3192 SN 0003-455X PY 2003 VL 40 IS 1 BP 17 EP 26 UT WOS:000181965000003 ER PT J AU Colman, JE Pedersen, C Hjermann, DO Holand, O Moe, SR Reimers, E AF Colman, JE Pedersen, C Hjermann, DO Holand, O Moe, SR Reimers, E TI Do wild reindeer exhibit grazing compensation during insect harassment? SO JOURNAL OF WILDLIFE MANAGEMENT AB We studied wild reindeer (Rangifer tarandus tarandus) to determine whether a wild ungulate can sufficiently increase its grazing time to compensate for loss of ingestion and rumination caused by insect harassment. We also tested the effect that insect harassment may have on autumn carcass weights. During summer 1997 and 1998, we recorded 24-hr activity budgets and frequency of change in activity bouts for wild reindeer. Following diurnal periods' insect harassment and decreased grazing, animals did not compensate by increasing grazing time or intensity during the night when insect harassment was low. Adult females and calves weighed significantly less in autumn 1997 following a summer of diurnal insect harassment, compared to autumn 1998 following a summer of little insect harassment. This indicates that the effect of daily insect harassment on activity budgets and grazing intensity had a negative effect on the body weights of adult females and calves. For reindeer, as for most wild ungulates, reduced body weight indicates poor condition and can jeopardize survival, reproduction, and calf recruitment. RI Moe, Stein R./G-1507-2011 OI Moe, Stein R./0000-0003-1005-3192 SN 0022-541X PD JAN PY 2003 VL 67 IS 1 BP 11 EP 19 DI 10.2307/3803056 UT WOS:000181296200002 ER PT J AU Vanderpuye, AW Elvebakk, A Nilsen, L AF Vanderpuye, AW Elvebakk, A Nilsen, L TI Plant communities along environmental gradients of high-arctic mires in Sassendalen, Svalbard SO JOURNAL OF VEGETATION SCIENCE AB The wet to moist bryophyte-dominated vegetation of Sassendalen, Svalbard, was classified into seven communities. These communities were grouped into (1) Cardamino nymanii-Saxifragion foliolosae marsh; (2) Caricion stantis fen; (3) Luzulion nivalis snowbed - including manured vegetation corresponding to moss tundras. All communities have a basically arctic distribution. Marshes are developed in habitats with a water table above the bryophyte vegetation surface and fens on sites with a water table level high above the permafrost but below the bryophyte surface. Moss tundras normally have no standing water table, but in Sassendalen they have a low water table due to their development on less steep slopes than in their normal habitat near bird cliffs. CCA confirms that the standing water level is the prime differentiating factor between the alliances, while aspect favourability and permafrost depth differentiate between the fen communities and temporary desiccation is important for the Catoscopium nigritum community. Carex subspathacea is a characteristic fen species in the absence of other Carex species dominating elsewhere in the Arctic. Arctic marshes are linked to an extremely cold environment. They have a very low species diversity with a few species dominating; Arctophila fulva, Pseudocalliergon trifarium, Scorpidium scorpioides and Warnstorfia tundrae are character species. Moss tundra as defined here appears to be restricted to Svalbard and, probably, neighbouring Novaya Zemlya. This may be due to the absence of rodents and the high seabird density, which is related to the mild sea currents reaching further to the north here and which implies manuring of surrounding ecosystems. Manuring in a very cold environment produces moss carpets with a thin active layer and accumulation of thick peat layers without a standing water level. In Sassendalen the role of arctic seabirds is replaced by Svalbard reindeer which are non-migratory and are concentrated to favourable grazing areas where their manuring effect is intense. Their long-term manuring effect probably explains the occurrence of moss tundras in this weakly rolling landscape where seabird colonies are absent. SN 1100-9233 PD DEC PY 2002 VL 13 IS 6 BP 875 EP 884 DI 10.1658/1100-9233(2002)013[0875:PCAEGO]2.0.CO;2 UT WOS:000181457500014 ER PT J AU Nellemann, C Moe, SR Rutina, LP AF Nellemann, C Moe, SR Rutina, LP TI Links between terrain characteristics and forage patterns of elephants (Loxodonta africana) in northern Botswana SO JOURNAL OF TROPICAL ECOLOGY AB Spatial vegetation utilization of elephants was investigated within mixed woodland savanna along the Chobe River in northern Botswana in the dry season of 1998. Using multiple linear regression, accumulated stem breakage by elephants was predicted by a terrain index, distance to water, stand density, number of trees > 4 m tall, tree height, density of Combretum apiculatum, C. elaeagnoides, C. mossambicense and the density of other (accumulated) tree species. Within mixed woodland at 2-7 km distance from the river fine-grained terrain ruggedness was the most important factor contributing to 55% of observed differences in use by elephants, while distance to water and the density of C. apiculatum contributed an additional 20% and 4%, respectively to the multiple linear regression model. Stem breakage was, on average, almost twice as high in rugged terrain compared with flat terrain at similar distance to water within the same vegetation type. Rugged terrain had 2-3-fold higher proportion of plots with very high Combrelum shrub densities. These results suggest that the terrain index may be useful in management, predicting the areas most sensitive to vegetation change in a woodland system with increasing elephant densities. RI Moe, Stein R./G-1507-2011; Rutina, Lucas/N-1243-2013 OI Moe, Stein R./0000-0003-1005-3192 SN 0266-4674 EI 1469-7831 PD NOV PY 2002 VL 18 BP 835 EP 844 DI 10.1017/S0266467402002547 PN 6 UT WOS:000179020900003 ER PT J AU Stark, S Grellmann, D AF Stark, S Grellmann, D TI Soil microbial responses to herbivory in an arctic tundra heath at two levels of nutrient availability SO ECOLOGY AB We tested the hypothesis that herbivory accelerates nutrient cycling through nutrient-rich soils and decelerates nutrient cycling through nutrient-poor soils in a well-drained arctic tundra heath by measuring effects of herbivory on soil and plant properties in control areas and areas treated with NPK fertilizer. The impact of herbivores was studied with two types of exclosures, one excluding reindeer and the other excluding both rodents and reindeer. We predicted that herbivores would enhance soil microbial processes in the fertilized areas, but retard them in the unfertilized ones. Microbial respiration and microbial C were significantly lower in grazed areas than in herbivore exclosures in both unfertilized and fertilized treatments, indicating that herbivores limit the C available for the soil microbes. Microbial, N was significantly increased in the exclosures in the fertilized treatment, but there were no effects in the unfertilized one. This reflects both an increase in resources by fertilization and the effect of herbivores on microbial N acquisition: there was surplus N in the fertilized areas to be immobilized by microbial biomass only when access by herbivores was prevented. Thus, mammalian grazers affect the resource coupling between the plant and microbial trophic levels. Fertilization did not affect the soil inorganic, organic, or microbial N contents, or litter decomposition rates, but it significantly increased soil and microbial P. Microbial C was significantly decreased by fertilization, contradicting some earlier fertilization studies in the arctic. One reason for deceleration of soil nutrient cycling in our study area may be that herbivory by both reindeer and rodents occurs mainly outside the growing season; hence, mammalian waste products do not contribute to soil nutrient availability at the times of highest nutrient demands by plants. In addition, grazing during reindeer migrations is likely to cause net resource output from the system. RI Stark, Sari/L-4440-2013 SN 0012-9658 PD OCT PY 2002 VL 83 IS 10 BP 2736 EP 2744 DI 10.1890/0012-9658(2002)083[2736:SMRTHI]2.0.CO;2 UT WOS:000179348800008 ER PT J AU Dormann, CF Skarpe, C AF Dormann, CF Skarpe, C TI Flowering, growth and defence in the two sexes: consequences of herbivore exclusion for Salix polaris SO FUNCTIONAL ECOLOGY AB 1. For a long time, dioecious plants have been a model system for understanding the interactions between plants and herbivores. Differences in growth rate and, consequently, investment in defence between sexes may lead to skewed sex ratios due to differential herbivory. 2. In this study we evaluated the applicability of this idea to polar willow (Salix polaris ), which in the study site, Svalbard, displays a female-biased sex ratio. 3. Excluding reindeer for 3 years increased the abundance of male flowers in one of two vegetation types investigated. Growth rates differed only slightly between the sexes, with females investing more in inflorescences. 4. The concentration of chemical defence compounds (phenolics and condensed tannins) did not differ between the sexes. 5. On the basis of these findings, the idea that growth rate-dependent herbivory caused the unbalanced sex ratio in S. polaris has to be rejected. Possibly an interaction of niche differentiation between male and female willows, in combination with reindeer grazing, produced the observed female-biased sex ratio, but the mechanism remains unclear. OI Dormann, Carsten/0000-0002-9835-1794 SN 0269-8463 PD OCT PY 2002 VL 16 IS 5 BP 649 EP 656 DI 10.1046/j.1365-2435.2002.00662.x UT WOS:000178119300012 ER PT J AU Handeland, K AF Handeland, K TI Cerebrospinal nematodiasis in a moose in Norway SO JOURNAL OF WILDLIFE DISEASES AB A case of cerebrospinal nematodiasis in a young adult moose (Alces alces) from Telemark county, southeastern Norway, is described. The moose was found by bird hunters during January, displaying signs of severe posterior paresis. it was killed and submitted for autopsy. The carcass was emaciated, and there were skin excoriations and subcutaneous edema over both metacarpi. Histopathologic examination revealed traumatic malacia throughout the spinal cord and meningeal accumulations of mononuclear inflammatory cells and eosinophils in brain and spinal cord. Two adult female nematodes were found in sections, respectively, of the subarachnoid and subdural spaces of the thoracic spinal cord. The nematode cross sections were similar with those of the two neurotropic Elaphostrongylus species, E. rangiferi and E. cervi. The moose originated from an area overlapping the grazing area of a large population of wild reindeer (Rangifer tarandus tarandus) living on the mountain plateau of Hardangervidda, suggesting the moose was infected with E. rangiferi from reindeer. SN 0090-3558 PD OCT PY 2002 VL 38 IS 4 BP 817 EP 821 DI 10.7589/0090-3558-38.4.817 UT WOS:000180239500021 PM 12528451 ER PT J AU Hagemoen, RIM Reimers, E AF Hagemoen, RIM Reimers, E TI Reindeer summer activity pattern in relation to weather and insect harassment SO JOURNAL OF ANIMAL ECOLOGY AB 1. During the brief growing season in Arctic and high mountain ecosystems, undisturbed grazing is crucial in order to maximize growth and fattening. During summer 1997 we investigated the influence of weather and insect harassment on the behaviour and group dynamics of reindeer (Rangifer tarandus tarandus L.). 2. Climatic data, activity of parasitic flies, and female reindeer behaviour were recorded from two wild reindeer populations in Southern Norway. Temperature and solar irradiation were good predictors of oestrid fly activity. Throughout the warm summer, reindeer were exposed to vigorous oestrid fly harassment, which caused dramatic decrease in feeding and lying, and increase in walking, running and standing. This behavioural change may compromise the physical condition of individuals entering winter. 3. Mosquitoes had little influence on reindeer activity patterns. In the absence of oestrid flies, weather parameters had no influence on reindeer activity pattern. Even during the warmest days, no signs of heat stress were recorded. Accordingly, snow patches, marshes and windy mountaintops were used primarily to avoid oestrid fly harassment. Thus, most disruptions of feeding that are often reported on warm days are responses to oestrids, not thermal stress. SN 0021-8790 PD SEP PY 2002 VL 71 IS 5 BP 883 EP 892 DI 10.1046/j.1365-2656.2002.00654.x UT WOS:000178187900016 ER PT J AU Dormann, CF AF Dormann, CF TI Herbivore-mediated competition between defended and undefended plant species: A model to investigate consequences of climate change SO PLANT BIOLOGY AB Optimal levels of anti-herbivore defence are determined not only by grazing pressure on the target plant, but also by the efficiency of the defence and by competitive interactions with neighbours. in the high Arctic on Svalbard, grazing by reindeer is a process that can be modelled without plant-to-herbivore feedback, as reindeer population sizes are not correlated with plant growth. However, growing conditions are extreme: a short season and low temperatures inhibit optimal growth. Therefore, it is possible to model anti-herbivore defence in competition in this system, assess how its optimum depends on grazing intensity and defence efficiency, and, finally, how global climate change will effect plant-plant interactions. This model, based on a Lotka-Volterra type competition and temperature-dependent growth, indicates that competition is of considerable importance even in extreme environments. Herbivory mediates displacement of the defended plant by releasing it from competition. This process is more pronounced under high grazing pressure than under low pressure. in other words, competition potentially magnifies the effect of herbivory. Elevated temperatures and a longer growing season have no qualitative impact on these processes, as the dominant defended plant profits most. OI Dormann, Carsten/0000-0002-9835-1794 SN 1435-8603 PD SEP PY 2002 VL 4 IS 5 BP 647 EP 653 DI 10.1055/s-2002-35437 UT WOS:000179531600014 ER PT J AU Skarpe, C van der Wal, R AF Skarpe, C van der Wal, R TI Effects of simulated browsing and length of growing season on leaf characteristics and flowering in a deciduous Arctic shrub, Salix polaris SO ARCTIC ANTARCTIC AND ALPINE RESEARCH AB Plants respond to herbivory either by maximizing resource acquisition and compensatory growth or by minimizing loss of resources, e.g.. by investing in chemical or structural defence. We studied the response to simulated browsing by the deciduous dwarf shrub, Salix polaris, on high Arctic Spitsbergen. Salix polaris is browsed by Svalbard reindeer, and its response to browsing may influence subsequent utilization. We compared leaf characteristics and flowering of S. polaris from areas with relatively short, intermediate, and long growing season, and their responses 1 yr after simulated browsing in early. mid, and late summer. Leaf numbers, total and individual biomass of leaves, and the number of inflorescences were greatly reduced the year after treatment, There was no increase in phenolics but a tendency to an increase in N content in the leases of S. polaris I yr after treatment. Salix polaris showed little variation in the response to simulated browsing) with local variation in resource availability (length of growing, time of browsing. The results suggest that S. polaris responds to summer browsing the previous year by allocating resources to compensatory growth rather than to defence. For reindeer, browsing of S. polaris leads to a sizeable decrease in food quantity and, possibly, to a limited increase in food quality. RI van der Wal, Rene/F-3177-2010 SN 1523-0430 PD AUG PY 2002 VL 34 IS 3 BP 282 EP 286 DI 10.2307/1552485 UT WOS:000178100600006 ER PT J AU Grellmann, D AF Grellmann, D TI Plant responses to fertilization and exclusion of grazers on an arctic tundra heath SO OIKOS AB This study investigated the impacts of fertilization and grazing by Norwegian lemmings (Lemmus lemmus), grey-sided voles (Clethrionomys rufocanus), and reindeer (Rangifer tarandus) on a diverse tundra plant community dominated by deciduous shrubs. Four out of eight study areas, having a size of 2500 m(2) each, were fertilized with a N-P-K fertilizer and four areas served as unfertilized controls. Two types of exclosures were used within each study area, one to exclude solely reindeer, and one to exclude both rodents and reindeer.,Open, grazed plots served as controls. During 5 years following the fertilization event the changes in vegetation inside and outside the exclosures were monitored using a point frequency method. The densities of rodents on the fertilized and unfertilized areas were investigated by live trapping and by counting nests of overwintering individuals. Reindeer do not graze on the study area during the growing season but migrate through this area in autumn and spring. Fertilization increased the abundance of vascular plants while grazing by reindeer and rodents decreased the abundance of vascular plants significantly on both fertilized and unfertilized areas. Rodents preferred clearly the fertilized areas during winter, decreasing the abundance of Vaccinium myrtillus and Vaccinium vitis-idaea, while very little grazing occurred during summer. Graminoids showed the strongest positive response to fertilization and dominated the plant community on ungrazed plots, while winter grazing by both reindeer and rodents significantly decreased the abundance of graminoids. Deciduous shrubs (Betula nana, Vaccinitan myrtillus) increased slightly but significantly due to fertilization and evergreen dwarf shrubs showed no response to fertilization. However, the use of functional growth forms for predicting the responses of nutrient enrichment and grazing must be questioned, as responses to fertilization as well as preferences by herbivores were shown to be species-specific rather than uniform within functional groups based on plant growth forms. SN 0030-1299 EI 1600-0706 PD AUG PY 2002 VL 98 IS 2 BP 190 EP 204 DI 10.1034/j.1600-0706.2002.980202.x UT WOS:000177713700002 ER PT J AU Soppela, P Nieminen, M AF Soppela, P Nieminen, M TI Effect of moderate wintertime undernutrition on fatty acid composition of adipose tissues of reindeer (Rangifer tarandus tarandus L.) SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY AB We studied the effect of moderate undernutrition on the fatty acid composition of adipose tissues in reindeer calves (<1 year) between early winter and late spring. Calves studied in early winter (December) had grazed on natural pastures and were in good condition, while the calves in spring (April) had been maintained on a negative energy balance since December, had lost approximately 16% of body weight and were in a moderate undernutritional state. The fatty acid composition of total lipids in adipose tissues (perirenal-abdominal, peristemal, scapular, intralumbar, and caudal locations) had a high proportion of oleic acid (35-47%) in both seasons. The proportion of oleic acid was significantly lower (29%), and that of palmitic acid (31%) was higher in the adipose tissue of cardiac groove as compared to other locations. There were only small differences in the fatty acid composition of adipose tissues between early winter and spring. However, the proportions of the principal C18-polyunsaturated fatty acids (PUFAs), linoleic and α-linolenic acid, were significantly lower in all adipose tissues in calves in poor than in good condition. The observations suggest that linoleic and α-linolenic acids may be selectively mobilized from adipose tissues of undernourished reindeer during winter. (C) 2002 Elsevier Science Inc. All rights reserved. RI Soppela, Paivi/L-4441-2013 SN 1095-6433 PD JUN PY 2002 VL 132 IS 2 BP 403 EP 409 AR PII S1095-6433(02)00040-5 DI 10.1016/S1095-6433(02)00040-5 UT WOS:000176113300016 PM 12020656 ER PT J AU Storeheier, PV Mathiesen, SD Tyler, NJC Olsen, MA AF Storeheier, PV Mathiesen, SD Tyler, NJC Olsen, MA TI Nutritive value of terricolous lichens for reindeer in winter SO LICHENOLOGIST AB In contrast to virtually all other species of ruminants, reindeer (Rangifer tarandus) eat substantial amounts of lichens in winter. Several different species of lichens are eaten and most are highly palatable. The chemical composition and the in vitro digestibility of six species of terricolous lichens commonly eaten by reindeer were measured. Ruminal inoculum was obtained in winter from six free-ranging reindeer that had been grazing on natural pastures in northern Norway. Analysis of the plant parts recovered from their rumens confirmed that the animals had been eating a mixed diet that included both lichens and vascular plants. The chemical composition and the in vitro digestibility of the different species of lichens varied considerably between species and genera. Cetraria islandica, C. nivalis and Cladonia arbuscula were highly digestible [69-77% dry matter (DM)], Stereocaulon paschale was poorly digestible (43% DM), whereas Cladonia stellaris and C. gracilis had an intermediate digestibility (56-57% DM). Mixing Cladonia stellaris with vascular plants (50:50) had no effect on the in vitro digestibility of the combined substrates. The in vitro digestibility of Cladonia stellaris in inoculum from two captive reindeer which had had no access to lichens was very low (10% DM). This shows that the source of inoculum used for digestibility trials has a major effect on the apparent digestibility of the substrates. Evidently, the extent to which reindeer are able to utilize lichens depends on the species that are selected and on what the animals have been eating recently. (C) 2002 The British Lichen Society. Published by Elsevier Science Ltd. All rights reserved. SN 0024-2829 PD MAY PY 2002 VL 34 BP 247 EP 257 DI 10.1006/lich.2002.0394 PN 3 UT WOS:000178049400009 ER PT J AU Nordberg, ML Allard, A AF Nordberg, ML Allard, A TI A remote sensing methodology for monitoring lichen cover SO CANADIAN JOURNAL OF REMOTE SENSING AB Land degradation has been recognised in the mountainous areas of Sweden due to increased land use, particularly the intensive grazing and trampling by reindeer, which causes mechanical damage to the vegetation cover. As these areas are often inaccessible, it is valuable to be able to use satellite data to monitor vegetation changes, The Swedish Environmental Protection Agency has proposed an environmental quality objective for mountainous areas of Sweden, which emphasizes the need for monitoring. The aim of this paper is to investigate a method for such monitoring using satellite data. Of the different heath communities above the tree line, the lichen-dominated heath is among the most sensitive to mechanical damage. Hence lichen cover is used as an indicator of change because of its ecological relevance and its spectral characteristics. Landsat-5 thematic mapping (TM) data, hyperspectral imaging seamier data, and spectral characteristics of relevant mountainous plant communities and lichen species were used to study heath vegetation in the southern part of the Swedish mountain range. For comparison, colour-infrared (CIR) aerial photographs at a scale of I : 60 000 and field data were used. The changes in lichen cover have been detected by spectral changes using the normalized difference vegetation index (NDVI) differencing technique and thresholding. The results show that mountainous lichen-dominated heath, above the tree line, can be mapped with good accuracy using Landsat TM data, and this heath is proposed for change detection, as it is possible to differentiate lichen cover in the following classes: low (20-50% cover), moderate (51-80% cover), and high (>80% cover). A lichen cover <20% cannot be separated from other types of dry heath. The class boundaries have been determined using field observations and CIR aerial photographs. The method indicates that a change in lichen cover can be classified and mapped in three classes: unchanged, moderate decrease, and high decrease. The classes can be regarded as three risk-assessment classes for vegetation degradation and ensuing soil erosion. The major conclusion from this study is that a change in lichen cover, differentiated in three classes, can be used as a tool for monitoring disturbed ecosystems in the Swedish mountain range. SN 0703-8992 PD APR PY 2002 VL 28 IS 2 BP 262 EP 274 DI 10.5589/m02-026 UT WOS:000175510300018 ER PT J AU Stark, S Strommer, R Tuomi, J AF Stark, S Strommer, R Tuomi, J TI Reindeer grazing and soil microbial processes in two suboceanic and two subcontinental tundra heaths SO OIKOS AB In oceanic, nutrient-rich Fermoscandian arctic-alpine tundra heaths, grazing by reindeer has been found to increase herbs and graminoids in relation to dwarf shrubs. In continental lichen heaths in the inland with nutrient-poor conditions, however, slowly decomposable dwarf shrubs are favoured by grazing. According to a hypothesis, by favouring easily decomposing plants in nutrient-rich conditions and slowly decomposing plants in nutrient-poor conditions, herbivory enhances soil nutrient cycling in nutrient-rich and retards it in nutrient-poor areas. We tested this hypothesis by comparing the impact of reindeer grazing on soil C and N mineralization between two oceanic and two continental arctic-alpine tundra heaths. Although soil respiration and microbial metabolic activity were enhanced by grazing in the suboceanic but not in the subcontinental tundra heaths, gross N mineralization rates were higher in the grazed areas in soils from all study sites, indicating that reindeer grazing leads to increased rates of nutrient cycling in both nutrient-poor and nutrient-rich tundra heaths. Thus, in the subcontinental tundra heaths, the increase in soil N concentrations due to mammalian waste products enhances N mineralization rates, even though the organic C quality is not improved by reindeer grazing. There was some site-specific variation in the strength of the reindeer effects on various microbial processes and soil properties, which can be related to spatial variation in grazing intensity and timing, as these factors in turn affect the nutrient sink strength of the vegetation. RI Stark, Sari/L-4440-2013 SN 0030-1299 PD APR PY 2002 VL 97 IS 1 BP 69 EP 78 DI 10.1034/j.1600-0706.2002.970107.x UT WOS:000176022200007 ER PT J AU Olofsson, J Oksanen, L AF Olofsson, J Oksanen, L TI Role of litter decomposition for the increased primary production in areas heavily grazed by reindeer: a litterbag experiment SO OIKOS AB Heavy grazing and trampling by reindeer increase nutrient cycling and primary production in areas where grasslands hake replaced shrub and moss tundra. One way in which herbivores can affect nutrient cycling is through changing the litter decomposition processes. We studied the effect of herbivory on litter decomposition rate by reciprocal transplantation of litter between lightly grazed and heavily grazed areas. using the litterbag technique, We used litter from two of the most common species on the lightly grazed side, Betula nana and Empetrum nigrum, and two of the most common species on the heavily grazed side. Carex bigelowii and Deschampsia flexuosa, We found that herbivory improved litter quality by favouring species with easily decomposed litter. However. herbivore also improved litter quality by increasing the nitrogen content and lowering the C/N ratio of each species. Decomposition rates even correlated with the abundance of the plant category in question, Shrub litter decomposed faster in the lightly grazed area where shrubs were common, and graminoid litter decomposed faster in the heavily grazed area where graminoids were common. These results indicate that the decomposer micro-organisms are adapted to the most common litter types. This studs shoals that detailed information about the effect of herbivore on litter quality is important to understand differences between the short-term and long-term effects of herbivory on nutrient cycling and primary production. RI Olofsson, Johan/A-9362-2009 SN 0030-1299 PD MAR PY 2002 VL 96 IS 3 BP 507 EP 515 DI 10.1034/j.1600-0706.2002.960312.x UT WOS:000175112200012 ER PT J AU Jiang, ZW Takatsuki, S Li, JS Wang, W Ma, JZ Gao, ZX AF Jiang, ZW Takatsuki, S Li, JS Wang, W Ma, JZ Gao, ZX TI Feeding type and seasonal digestive strategy of Mongolian gazelles in China SO JOURNAL OF MAMMALOGY AB We measured seasonal variations of gut macrostructure of 36 Mongolian gazelles (Procapra gutturosa) collected in Xiqi, Inner Mongolia. Relative weight of ruminoreticular contents (9-14% of body weight) and relative length of the total intestine (15-18 times body length) were within the range of intermediate feeders. Proportional length of large intestine to total intestine (29-31%) falls within the range of browsers and suggests that distal digestion is important for small intermediate feeders. Total weight of gut with contents was 27-36% greater in winter than in spring because of the increase in contents of ruminoreticulum and large intestine, suggesting that both proximal and distal fermentation are more important in winter than in spring. RI Wang, Wei/B-5617-2019 SN 0022-2372 PD FEB PY 2002 VL 83 IS 1 BP 91 EP 98 DI 10.1644/1545-1542(2002)083<0091:FTASDS>2.0.CO;2 UT WOS:000174042000009 ER PT J AU Hyvarinen, M Walter, B Koopmann, R AF Hyvarinen, M Walter, B Koopmann, R TI Secondary metabolites in Cladina stellaris in relation to reindeer grazing and thallus nutrient content SO OIKOS AB We analysed concentrations of phenols and key macro-nutrients in a dominant mat-forming, lichen, Cladina stellaris, in dry heath Forests subjected to heavy reindeer grazing in Finnish Lapland. Lichen samples ere collected in the beginning of two growth seasons from six to eight sites with old reindeer exposures that served as control plots within sites The concentration of perlatolic acid in lichen apices (top 10 mm) was higher in grazed plots than in control ones, whereas usnic acid did not seem to respond unequivocally to grazing. Moreover. there was a strolng, negative relationship between nitrogen and phenolic content of Cladina stellari. in intact plots but this relationship was absent in grazed ones, Change, in nitrogen and phosphorus contents caused by reindeer gazing were not correlated with changes in the level of phenolics in lichen thalli. The present result demonstrated that the carbon-nutrient balance (CNB) hypothesis may well explain some of the variation in lichen phenolic content but is not sufficient for explaining changes Caused by reindeer grazing. We hypothesized that physical changes in the lichen microenvironment induced by reindeer have more profound impact on lichen phenolic content than alterations in thallus nutrient content. SN 0030-1299 PD FEB PY 2002 VL 96 IS 2 BP 273 EP 280 DI 10.1034/j.1600-0706.2002.960209.x UT WOS:000174095900009 ER PT S AU Kolesnikova, A Uzhakina, O AF Kolesnikova, A Uzhakina, O BE Soppela, P Ruth, W Ahman, B Riseth, JA TI The possibility of using soil invertebrates (Coleoptera, Carabidae, Staphylinidae) as bioindicators of the state of reindeer pastures SO REINDEER AS A KEYSTONE SPECIES IN THE NORTH - BIOLOGICAL, CULTURAL AND SOCIO-ECONOMIC ASPECTS SE UNIVERSITY OF LAPLAND, ARCTIC CENTRE REPORTS CT 1st CAES PhD Course on Reindeer as a Keystone Species in the North CY SEP 01-15, 2000 CL RUSSIA SP Circumpolar PhD Network Artic Environm Studies, NorFA, Univ Lapland, Arctic Ctr, Univ Arctic AB Reindeer grazing continues in the territory of the Malozemelskaya Tundra. Vegetation and soil have changed because of the constant use of grazing lands. In most cases, the floral composition is taken into consideration by assessing the state of the grazing lands. We have attempted to compare grazing and non-grazing plots based on the composition of beetle species. The study of soil-beetle fauna was carried out in 1998-1999 in the following regions: the Timan coast, the northern extremity of the Nenets Ridge, River Indiga basin, and the Zakhrebetny coast. As a result, areas with different degrees of reindeer grazing effects were distinguished and evidence was found of some beetles that act as indicators of the state of the reindeer pastures. SN 1235-0583 BN 951-634-838-6 PY 2002 VL 38 BP 64 EP 71 UT WOS:000181802500008 ER PT S AU Stark, S AF Stark, S BE Soppela, P Ruth, W Ahman, B Riseth, JA TI Reindeer grazing and soil carbon and nitrogen dynamics in northern boreal and oroarctic ecosystems SO REINDEER AS A KEYSTONE SPECIES IN THE NORTH - BIOLOGICAL, CULTURAL AND SOCIO-ECONOMIC ASPECTS SE UNIVERSITY OF LAPLAND, ARCTIC CENTRE REPORTS CT 1st CAES PhD Course on Reindeer as a Keystone Species in the North CY SEP 01-15, 2000 CL RUSSIA SP Circumpolar PhD Network Artic Environm Studies, NorFA, Univ Lapland, Arctic Ctr, Univ Arctic AB The mineralization of carbon and nutrients by the decomposing fungi and bacteria has an essential role in the ecosystem functioning. Strong correlations between soil fertility, plant nutrient uptake and primary productivity also make the soil processes important with respect of the land use. I have studied the effect of reindeer grazing on the soil processes in northern-boreal forests and arctic tundra heaths in several sites in northern Finland and Norway. I have compared the effect of grazing in different vegetation types and in areas of different grazing intensity. In boreal forests reindeer grazing retards carbon mineralization in both lichen- and dwarf-shrub dominated forests. In lichen-dominated forests, however, reindeer grazing enhances nitrogen mineralization, depending on soil moisture and weather conditions, as during dry summers the low soil moisture content may limit the microbial activity. Nutrient mineralization may therefore be enhanced or retarded by reindeer grazing and this may vary in different years. In arctic tundra heaths, the effect of reindeer grazing depends on the vegetation and the soil carbon storage. Reindeer grazing enhanced carbon mineralization in sub-oceanic, dwarf-shrub dominated tundra heaths, whereas it did not affect it in sub-continental, lichen dominated tundra heaths. Soil nitrogen availability was nevertheless improved by reindeer grazing in both vegetation types. In another arctic study area, however, carbon mineralization and microbial biomass was decreased by grazing. This was interpreted to depend on small carbon storage in soil. SN 1235-0583 BN 951-634-838-6 PY 2002 VL 38 BP 104 EP 112 UT WOS:000181802500015 ER PT S AU Vistnes, I Nelleman, C AF Vistnes, I Nelleman, C BE Soppela, P Ruth, W Ahman, B Riseth, JA TI Avoidance of cabins, roads and power lines by reindeer during calving SO REINDEER AS A KEYSTONE SPECIES IN THE NORTH - BIOLOGICAL, CULTURAL AND SOCIO-ECONOMIC ASPECTS SE UNIVERSITY OF LAPLAND, ARCTIC CENTRE REPORTS CT 1st CAES PhD Course on Reindeer as a Keystone Species in the North CY SEP 01-15, 2000 CL RUSSIA SP Circumpolar PhD Network Artic Environm Studies, NorFA, Univ Lapland, Arctic Ctr, Univ Arctic AB We investigated possible avoidance behavior of calving semi-domesticated reindeer (Rangifer tarandus tarandus) near recreational cabins, roads, and power transmission lines in Repparfjord Valley, Northern Norway. The distribution, sex, and general age composition of the reindeer was mapped during the 1998 and 1999 calving seasons (n = 776 and n = 678, respectively) using systematic snowmobile and ski surveys. Mean reindeer density within preferred rugged terrain was 87 % lower in the zone 0-4 km from the tourist resort compared to the zone 8-12 km from the resort (1.47 vs. 11.61 reindeer/km(2), respectively). Mean reindeer density by the power line corridor without traffic was 8 1 % lower in the zone 0-4 km from the power line compared to the zone 8-12 km from the power line. Areas 0-4 km from anthropogenic structures were avoided despite low or extremely low levels of human traffic and a high proportion of preferred habitat. Within snow-free sites available for grazing, there were no significant differences in phenological development of Eriophorum spp., in live-dead ratio of plant material, or in graminoid biomass with distance to the tourist resort. Almost 74% of all available forage was located within the avoided 0-4-km zones from the resort or the separate power line. Our results suggest that power lines, even without human traffic, may result in substantial reductions in the use of foraging areas. The combined actions of power lines and cabins may increase potential avoidance, thereby increasing the use of remaining undisturbed grazing grounds. Possible increased competition for high-quality forage may affect lactation, body condition, and, hence, reproductive success in the long term. SN 1235-0583 BN 951-634-838-6 PY 2002 VL 38 BP 113 EP 123 UT WOS:000181802500016 ER PT J AU Bostedt, G AF Bostedt, G TI Reindeer husbandry, the Swedish market for reindeer meat, and the Chernobyl effects SO AGRICULTURAL ECONOMICS AB Reindeer husbandry is a cornerstone in the culture of the Sami, northern Scandinavia's indigenous people. This paper presents a dynamic, theoretical model of the Swedish reindeer husbandry and the market for reindeer meat, as well as econometric results based on three-stage least squares regression on annual data. The most striking feature of the empirical results is a "backward-sloping" supply function, which is consistent with the theoretical model. The results also show effects of the Chernobyl accident. Prevailing winds at the time of the accident carried radioactive fallout over the grazing areas for the Swedish reindeer husbandry, causing effects on both supply and demand. (C) 2001 Elsevier Science B.V. All rights reserved. OI Bostedt, Goran/0000-0002-6540-743X SN 0169-5150 EI 1574-0862 PD DEC PY 2001 VL 26 IS 3 BP 217 EP 226 DI 10.1111/j.1574-0862.2001.tb00065.x UT WOS:000172407300003 ER PT J AU Crete, M Ouellet, JP Lesage, L AF Crete, M Ouellet, JP Lesage, L TI Comparative effects on plants of caribou/reindeer, moose and white-tailed deer herbivory SO ARCTIC AB We reviewed the literature reporting negative or positive effects on vegetation of herbivory by caribou/reindeer, moose, and white-tailed deer in light of the hypothesis of exploitation ecosystems (EEH), which predicts that most of the negative impacts will occur in areas where wolves were extirpated. We were able to list 197 plant taxa negatively affected by the three cervid species, as opposed to 24 that benefited from their herbivory. The plant taxa negatively affected by caribou/reindeer (19), moose (37), and white-tailed deer (141) comprised 5%, 9%, and 11% of vascular plants present in their respective ranges. Each cervid affected mostly species eaten during the growing season: lichens and woody species for caribou/reindeer, woody species and aquatics for moose, and herbs and woody species for white-tailed deer. White-tailed deer were the only deer reported to feed on threatened or endangered plants. Studies related to damage caused by caribou/reindeer were scarce and often concerned lichens. Most reports for moose and white-tailed deer came from areas where wolves were absent or rare. Among the three cervids, white-tailed deer might damage the most vegetation because of its smaller size and preference for herbs. SN 0004-0843 PD DEC PY 2001 VL 54 IS 4 BP 407 EP 417 UT WOS:000173097000005 ER PT J AU Austrheim, G Eriksson, O AF Austrheim, G Eriksson, O TI Plant species diversity and grazing in the Scandinavian mountains - patterns and processes at different spatial scales SO ECOGRAPHY AB There is a long tradition of grazing by semi-domestic reindeer and sheep in alpine and sub-alpine Scandinavian habitats, but present management regimes are questioned from a conservation point of view. In this review we discuss plant diversity patterns in the Scandinavian mountains in a global regional and local perspective. The main objective was to identify processes that influence diversity at different spatial scales with a particular focus on grazing. In a global perspective the species pool of the Scandinavian mountains is limited, partly reflecting the general latitudinal decline of species but also historical and ecological factors operating after the latest glaciation. At the local scale, both productivity and disturbance are primary factors structuring diversity, but abiotic factors such as soil pH, snow distribution and temperature are also important. Although evidence is scarce, grazing favours local species richness in productive habitats, whereas species richness decreases with grazing when productivity is low. Regional patterns of plant diversity is set by, 1) the species pool, 2) the heterogeneity and fragmentation of communities, and 3) local diversity of each plant community. We suggest that local shifts in community composition depend both on the local grazing frequency and the return-time of the plant community after a grazing session. In addition, an increasing number of grazing-modified local patches homogenises the vegetation and is likely to reduce the regional plant diversity. The time scale of local shifts in community composition depends on plant colonisation and persistence, From a mechanistic point of view, diversity patterns at a regional scale also depend on the regional dynamics of single species. Colonisation is usually a slow and irregular process in alpine environments, whereas the capacity for extended local persistence is generally high. Although the poor knowledge of plant regional dynamics restricts our understanding of how grazing influences plant diversity, we conclude that grazing is a key process for maintaining biodiversity in the Scandinavian mountains. SN 0906-7590 EI 1600-0587 PD DEC PY 2001 VL 24 IS 6 BP 683 EP 695 DI 10.1034/j.1600-0587.2001.240607.x UT WOS:000173491900007 ER PT J AU Cornelissen, JHC Callaghan, TV Alatalo, JM Michelsen, A Graglia, E Hartley, AE Hik, DS Hobbie, SE Press, MC Robinson, CH Henry, GHR Shaver, GR Phoenix, GK Jones, DG Jonasson, S Chapin, FS Molau, U Neill, C Lee, JA Melillo, JM Sveinbjornsson, B Aerts, R AF Cornelissen, JHC Callaghan, TV Alatalo, JM Michelsen, A Graglia, E Hartley, AE Hik, DS Hobbie, SE Press, MC Robinson, CH Henry, GHR Shaver, GR Phoenix, GK Jones, DG Jonasson, S Chapin, FS Molau, U Neill, C Lee, JA Melillo, JM Sveinbjornsson, B Aerts, R TI Global change and arctic ecosystems: is lichen decline a function of increases in vascular plant biomass? SO JOURNAL OF ECOLOGY AB 1 Macrolichens are important for the functioning and biodiversity of cold northern ecosystems and their reindeer-based cultures and economics. 2 We hypothesized that, in climatically milder parts of the Arctic, where ecosystems have relatively dense plant canopies, climate warming and/or increased nutrient availability leads to decline in macrolichen abundance as a function of increased abundance of vascular plants. In more open high-arctic or arctic-alpine plant communities such a relationship should be absent. To test this, we synthesized cross-continental arctic vegetation data from ecosystem manipulation experiments simulating mostly warming and increased nutrient availability, and compared these with similar data from natural environmental gradients. 3 Regressions between abundance or biomass of macrolichens and vascular plants were consistently negative across the subarctic and mid-arctic experimental studies. Such a pattern did not emerge in the coldest high-arctic or arctic-alpine sites. The slopes of the negative regressions increased across 10 sites as the climate became milder (as indicated by a simple climatic index) or the vegetation denser (greater site above-ground biomass). 4 Seven natural vegetation gradients in the lower-altitude sub- and mid-arctic zone confirmed the patterns seen in the experimental studies, showing consistent negative relationships between abundance of macrolichens and vascular plants. 5 We conclude that the data supported the hypothesis. Macrolichens in climatically milder arctic ecosystems may decline if and where global changes cause vascular plants to increase in abundance. 6 However, a refining of our findings is needed, for instance by integrating other abiotic and biotic effects such as reindeer grazing feedback on the balance between vascular plants and lichens. RI Michelsen, Anders/L-5279-2014; Callaghan, Terens/N-7640-2014; Alatalo, Juha/C-1269-2018; Hik, David/B-3462-2009 OI Michelsen, Anders/0000-0002-9541-8658; Alatalo, Juha/0000-0001-5084-850X; Hik, David/0000-0002-8994-9305; Phoenix, Gareth/0000-0002-0911-8107; Hobbie, Sarah/0000-0001-5159-031X; Chapin III, F Stuart/0000-0002-2558-9910 SN 0022-0477 PD DEC PY 2001 VL 89 IS 6 BP 984 EP 994 DI 10.1046/j.1365-2745.2001.00625.x UT WOS:000172926100007 ER PT J AU Moxnes, E Danell, O Gaare, E Kumpula, J AF Moxnes, E Danell, O Gaare, E Kumpula, J TI Optimal strategies for the use of reindeer rangelands SO ECOLOGICAL MODELLING AB The problem of optimal adaptation of reindeer herds to rangelands under uncertain environmental conditions and measurement errors is studied by stochastic dynamic programming (SDP) and by stochastic optimisation in policy space (SOPS). The study expands on earlier studies by including measurement error, body weights, alternatives to lichen in winter pastures, wastage of lichen by cratering reindeer, and by including both summer and winter pastures in the same model. The analysis shows that it is important to get precise estimates of lichen growth, alternatives to lichen are only important if their digestibility is above a minimum level, variable costs only matter for the optimal herd size when summer grazing is limiting, modest discounting has little effect, the policy is not sensitive to the degree of natural variation, while the value of reindeer husbandry is significantly reduced by increasing climatic variation, the policy is sensitive to measurement error, and there; is a considerable value of higher precision in measurements. (C) 2001 Elsevier Science B.V. All rights reserved. SN 0304-3800 PD NOV 15 PY 2001 VL 145 IS 2-3 BP 225 EP 241 DI 10.1016/S0304-3800(01)00393-3 UT WOS:000172668200011 ER PT J AU Reykdal, O Thorlacius, A AF Reykdal, O Thorlacius, A TI Cadmium, mercury, iron, copper, manganese and zinc in the liver and kidney of the Icelandic lamb SO FOOD ADDITIVES AND CONTAMINANTS PART A-CHEMISTRY ANALYSIS CONTROL EXPOSURE & RISK ASSESSMENT AB The purpose of this study was to evaluate the levels of cadmium, mercury, iron, copper, manganese and zinc in lamb liver and kidney from six areas in Iceland and to compare the results against aerial deposition data for the same elements obtained using moss as an indicator organism. The total number of samples was 96 for each organ. Cadmium was determined by graphite furnace atomic absorption spectrophotometry, mercury by cold-vapour atomic absorption, and iron, copper, manganese and zinc by inductively coupled plasma atomic emission spectrophotometry. Analysis of variance determined significance differences among means for areas, and Pearson's correlation coeffcients were calculated to study correlation among trace elements in liver and kidney. The mean fresh weight concentrations in lamb liver and kidney respectively were 0.045 and 0.058 mg kg(-1) for cadmium, 0.009 and 0.012 mg kg(-1) for mercury, 141 and 52.7 mg kg(-1) for iron, 28.1 and 2.89 mg kg(-1) for copper, 4.01 and 1.13 mg kg(-1) for manganese and 48.7 and 25.2 mg kg(-1) for zinc. Concentrations of cadmium, mercury and copper in the liver and kidney of the Icelandic lamb were low compared with data from other countries. Iron concentrations in the organs, however, were high. No sample exceeded 46% of the proposed maximum level for cadmium in organs for human consumption in the EC. Cadmium, mercury, iron and copper in the liver and kidney differed significantly between areas. Deposition of cadmium and copper in moss was not a useful indicator in the evaluation of the susceptibility of the Icelandic lamb to accumulation of cadmium and copper. However, iron levels in Icelandic lamb liver showed the same pattern as results for iron from the moss study. The cadmium and mercury levels of organs from lambs grazing in the vicinity of Mount Hekla a few months after its eruption did not indicate a significant contamination from volcanic activity. SN 1944-0049 EI 1944-0057 PD NOV PY 2001 VL 18 IS 11 BP 960 EP 969 DI 10.1080/02652030110053660 UT WOS:000171116500004 PM 11665737 ER PT J AU Nellemann, C Vistnes, I Jordhoy, P Strand, O AF Nellemann, C Vistnes, I Jordhoy, P Strand, O TI Winter distribution of wild reindeer in relation to power lines, roads and resorts SO BIOLOGICAL CONSERVATION AB Southern Norway holds the last remaining population of wild reindeer (Rangifer tarandus tarandus) in Europe. Roads, railroads, and power lines have fragmented the original population into 26 separate herds. The reindeer populations are regulated directly according to availability of winter forage. These winter ranges, generally at lower elevations, are however, often subjected to development. Effects of infrastructure and associated human activity on the distribution of wild reindeer during winter were investigated in the Nordfjella mountain region of western Norway. Systematic aerial surveys of the distribution of ca. 2500 reindeer were conducted during late winter 1986-1998. Areas within 2.5 km from power lines were used less than available in 6 of the 8 sampling years, and areas beyond this zone more than expected. Density of reindeer was 79% lower within 2.5 km from power lines compared with background areas, and increased with increasing distance from infrastructure for comparable habitat. Available forage in terms of lichen cover declined 15-30-fold with distance, and was lowest in the undisturbed areas with the highest density of grazing animals. Areas within 5 kni from resorts or from roads and power lines in combination were avoided in all years. Continued construction of roads, power lines and cabin resorts endanger these available winter ranges, and hence the long term survival of the population. (C) 2001 Elsevier Science Ltd. All rights reserved. SN 0006-3207 PD OCT PY 2001 VL 101 IS 3 BP 351 EP 360 DI 10.1016/S0006-3207(01)00082-9 UT WOS:000170722400008 ER PT J AU van der Wal, R Brooker, R Cooper, E Langvatn, R AF van der Wal, R Brooker, R Cooper, E Langvatn, R TI Differential effects of reindeer on high Arctic lichens SO JOURNAL OF VEGETATION SCIENCE AB We studied the effects of Svalbard reindeer on the abundance of lichens in Spitsbergen, A survey was carried out in 14 areas with contrasting reindeer densities. Separate cover estimates for crustose, fructose and foliose lichens were taken in each area, and related to the density of reindeer pellet groups, a measure of reindeer density. Dominant macrolichen families were identified in 10 areas, and a full record of macrolichen species was taken in four additional areas. Variation in reindeer density is partially due to past overhunting, and subsequent incomplete recovery, releasing some areas from reindeer grazing for 100-200 yr. The cover of fruticose lichens was negatively related to reindeer pellet group density, indicating suppression by Svalbard reindeer. This makes their impact comparable to other members of the Rangifer genus around the northern hemisphere. The generally recorded low abundance of lichens in the diet of Svalbard reindeer compared to other Rang fer species, therefore, was interpreted as the depletion of fruticose lichens in Spitsbergen, and a subsequent switch to alternative foods. Of all fruticose lichens, Stereocaulon spp. appeared least sensitive to grazing. Crustose and foliose lichen cover was independent of reindeer pellet group density. The cover of crustose lichen, was significantly related to latitude. with,greater cover in more northern areas. Foliose lichens were more abundant in places where moss cover was high. We conclude that the impact of Svalbard reindeer on lichens is dependent on growth form, with fruticose lichens suffering from grazing, whereas foliose lichens might indirectly benefit from higher densities of reindeer or, like crustose lichens, be controlled by other factors. RI van der Wal, Rene/F-3177-2010; Brooker, Rob/F-9569-2012 SN 1100-9233 PD OCT PY 2001 VL 12 IS 5 BP 705 EP 710 DI 10.2307/3236911 UT WOS:000172783900013 ER PT J AU Vistnes, I Nellemann, C AF Vistnes, I Nellemann, C TI Avoidance of cabins, roads, and power lines by reindeer during calving SO JOURNAL OF WILDLIFE MANAGEMENT AB We investigated possible avoidance behavior of calving semi-domesticated reindeer (Rangifer tarandus tarandus) near recreational cabins, roads, and power transmission lines in Repparfjord Valley, northern Norway. The distribution, sex, and general age composition of the reindeer were mapped during the 1998 and 1999 calving seasons (n=776 and n=678, respectively) using systematic snowmobile and ski surveys. Mean reindeer density within preferred habitat was 78% lower in the area <4 km from the tourist resort compared to the area >4 km from the resort (1.47 vs. 6.68 reindeer/km(2), respectively). Mean reindeer density by the power line corridor without traffic was 73% lower in the area <4 kin from the power line compared to areas >4 km from the power line for comparable habitat. Areas <4 kin from anthropogenic structures were avoided despite low levels of human traffic and a high proportion of preferred habitat. Within snow-free sites available for grazing, no significant differences occurred in phenological development of cotton-grass (Eriophorum spp.), in live:dead ratio of plant material, or in graminoid biomass with distance to the tourist resort. Almost 74% of all available forage was located within the avoided 0-4-km zones front the resort or the separate power line. Our results suggest that power lines, even without human traffic, may result in substantial reductions in the use of foraging areas. The combined actions of power lines, roads, and cabins may increase potential avoidance, thereby increasing the use of remaining undisturbed grazing grounds. Possible increased competition for high-quality forage may affect lactation, body condition, and, hence. reproductive success in the long term. SN 0022-541X PD OCT PY 2001 VL 65 IS 4 BP 915 EP 925 DI 10.2307/3803040 UT WOS:000171743200029 ER PT J AU Ruckstuhl, KE Neuhaus, P AF Ruckstuhl, KE Neuhaus, P TI Behavioral synchrony in ibex groups: Effects of age, sex and habitat SO BEHAVIOUR AB Synchrony of activities is usually high in foraging groups, possibly to maintain group cohesion. Individuals with different levels of activity budgets, however, may have a hard time synchronizing their behavior to each other without incurring a cost. We predicted that the age and sex structure of a group would affect synchronization levels within a group because of differing individual activity budgets. Individuals in same-sex-age groups were hypothesized to show higher levels of activity synchrony than individuals in mixed sex-age groups. We investigated activity synchrony in adult mate, adult female, subadult, and mixed sex-age groups of Alpine ibex - one of the most sexually dimorphic ruminant species. Activity budgets and movement rates were measured to calculate synchrony of activities between group members in June and July 1999. Adult males were more synchronized with group peers than either females or subadults of both sexes. However, while adult males were synchronized in 81 % when in bachelor (adult mate) groups, they were only synchronized in 65% of the time when in mixed sex-age groups. Adult females were synchronized 61% of their time when in mixed sex-age groups and 69% when in female groups. Individual subadult males displayed higher synchrony when in bachelor or female groups than when in mixed sex-age or subadult mixed-sex groups. Subadult groups and mixed sex-age groups showed the lowest degree of synchrony of all group types. In general, animals in groups of same body-sized individuals were more synchronized with their group members than animals in mixed body-size groups. Two and three year-old males did not adjust their time spent lying to the group but their time spent walking, They also tended to change their time spent grazing and standing according to group type. Among subadults, females spent more time foraging than males but less time lying and standing. There was no difference in time spent walking. Bachelor and subadult groups had the greatest movement rates while female groups were relatively sedentary within escape terrain. Individuals in escape terrain did only marginally synchronize their behavior to each other likely because groups did not move much and synchrony was presumably less important. We conclude that habitat type, group movement rates, and a group's sex-age composition may affect the extent to which an individual will synchronize its activities to the other group members. RI Ruckstuhl, Kathreen/B-4469-2013 OI Ruckstuhl, Kathreen/0000-0002-2949-242X SN 0005-7959 PD AUG PY 2001 VL 138 BP 1033 EP 1046 DI 10.1163/156853901753286551 PN 8 UT WOS:000172475400008 ER PT J AU Brathen, KA Oksanen, J AF Brathen, KA Oksanen, J TI Reindeer reduce biomass of preferred plant species SO JOURNAL OF VEGETATION SCIENCE AB Reduced weights in reindeer that graze in pastures with high reindeer densities have raised the question if coastal summer pastures are modified by grazing. To evaluate this, the impact of reindeer grazing on standing crop was measured by the plant intercept method inside and outside grazing exclosures in the understorey of a coastal mountain birch forest in northern Norway. The understories of coastal birch forests are dominated by vascular plants and are important summer pastures to reindeer. Based on the literature. we made a priori categorization of the vascular plant species into functional groups of preferred forage, less preferred forage and forage of unknown value to reindeer. Intercept frequency was measured within the same plots on three occasions in the summer of 1996. At the end of the grazing season. total standing crop was 33% lower in open plots compared to plots protected by exclosures, However, the reduction varied between the functional groups, with only preferred forage plants being significantly reduced in standing crop (by 49%). Results suggest that reindeer have a strong annual impact on most of the preferred forage species. However, some of the preferred graminoids are tolerant of grazing and dominate the understorey despite decades of high grazing pressure. We suggest that current grazing pressure is favouring the establishment of a few grazing tolerant graminoids. and that this reduces the forage plant variability. The results are discussed in relation to the grazing optimization hypothesis and the potential importance of plant variability for pasture quality. RI Oksanen, Jari/A-5236-2013 OI Brathen, Kari Anne/0000-0003-0942-1074; Oksanen, Jari/0000-0001-7102-9626 SN 1100-9233 PD AUG PY 2001 VL 12 IS 4 BP 473 EP 480 DI 10.2307/3236999 UT WOS:000171984200004 ER PT J AU Wiklund, E Pickova, J Sampels, S Lundstrom, K AF Wiklund, E Pickova, J Sampels, S Lundstrom, K TI Fatty acid composition of M-longissimus lumborum, ultimate muscle pH values and carcass parameters in reindeer (Rangifer tarandus tarandus L) grazed on natural pasture or fed a commercial feed mixture SO MEAT SCIENCE AB The effects of feeding regimen on the fatty acid composition of M. longissimus, ultimate pH values in three muscles (Mm. longissimus, triceps brachii and biceps femoris) and carcass quality were studied in15 reindeer bulls. Nine animals came from natural pasture and six had been fed a pelleted commercial feed mixture for two months prior to slaughter. The pellet fed reindeer had significantly better carcass grading scores (EUROP conformation), higher trim fat content, more intramuscular fat and lower ultimate pH values in all three muscles than the group from pasture. The polar and neutral lipid fatty acid composition of the meat was analysed separately. Meat from pasture fed reindeer showed a high content of the fatty acid 18:3 n-3 in the polar lipid fraction. In the same lipid fraction, the Fatty acid 18:2 n-6 was dominant in meat from the pellet fed animals. Similar differences in the neutral lipid fraction were found when comparing fatty acid composition between treatment groups, however the abundance of these fatty acids was much less. The present results confirm previous findings that reindeer fed typical pelleted commercial feed mixtures generally have an improved nutritional status. (C) 2001 Elsevier Science Ltd. All rights reserved. RI Sampels, Sabine/F-8479-2015 OI Sampels, Sabine/0000-0003-1695-5939; pickova, jana/0000-0002-3406-3435 SN 0309-1740 PD JUL PY 2001 VL 58 IS 3 BP 293 EP 298 DI 10.1016/S0309-1740(01)00030-4 UT WOS:000168918300011 PM 22062259 ER PT J AU Ferguson, MAD Gauthier, L Messier, F AF Ferguson, MAD Gauthier, L Messier, F TI Range shift and winter foraging ecology of a population of Arctic tundra caribou SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB Some researchers have suggested that over periods of several decades, Arctic tundra caribou (Rangifer tarandus) may be regulated by density-dependent forage depletion. Winter range shifts could potentially delay such regulation when a population is at or near long-term maximum abundance. In the 1980s, Inuit correctly predicted the mass emigration of caribou from a traditional winter range on Foxe Peninsula (FP) on southern Baffin Island, Nunavut, Canada. Most FP caribou subsequently emigrated to a new winter range on Meta Incognita Peninsula (MIP). To determine if MIP provided emigrating caribou with better foraging habitats, we compared winter forage resources and snow cover at caribou foraging sites, and food selection by caribou on FP and MIP in April 1992. Caribou that remained on FP dug feeding craters in shallower, softer snow than those on MIP did. Biomass of most fruticose lichens was greater within foraging sites on MIP than on FP. Biomass of shrubs, other than Cassiope tetragona and Dryas integrifolia, was also greater on MIP than on FP. Dryas integrifolia was the only plant class that had higher biomass on FP than on MIP. Cladina spp. / Cladonia spp., Sphaerophorus fragilis, and Cetraria nivalis occurred less frequently in the rumens of FP caribou. Proportions of fruticose lichens in rumens of caribou on both peninsulas were similar to those on other overgrazed and High Arctic tundra winter ranges. Caribou on FP showed a higher preference for the shrub C. tetragona. Biomasses of plants sensitive to long-term feeding or trampling by caribou (i.e., the five most common fruticose lichens, other shrubs, and plant debris) were consistently lower on FP, which is congruous with Inuit reports that long-term cumulative overgrazing had reduced the supply of important forage plants on FP sites that were accessible to caribou in winter. FP caribou that emigrated to MIP gained access to more abundant, higher quality forage resources than those that remained on FP. Because most FP caribou had emigrated, this South Baffin subpopulation escaped, at least temporarily, the regulating effects of historical cumulative overgrazing. SN 0008-4301 PD MAY PY 2001 VL 79 IS 5 BP 746 EP 758 DI 10.1139/cjz-79-5-746 UT WOS:000168588100002 ER PT J AU Olofsson, J Kitti, H Rautiainen, P Stark, S Oksanen, L AF Olofsson, J Kitti, H Rautiainen, P Stark, S Oksanen, L TI Effects of summer grazing by reindeer on composition of vegetation, productivity and nitrogen cycling SO ECOGRAPHY AB In this study, we investigated the effect of reindeer grazing on tundra heath vegetation in northern Norway. Fences. erected 30 yr ago, allowed us to compare winter grazed, lightly summer grazed and heavily summer grazed vegetation at four different sites. At two sites, graminoids dominated the heavily grazed zone completely, while ericoid dwarf shrubs had almost disappeared. In the other two areas, the increase of graminoids was almost significant. At one of the sites where graminoids dominated the heavily grazed area. we also measured plant biomass, primary production and nitrogen cycling. In this site: heavy grazing increased primary production and rate of nitrogen cycling, while moderate grazing decreased primary production. These results were inconsistent with the view that the highest productivity is found at intermediate grazing pressure. These results rather support the hypothesis that intensive grazing can promote a transition of moss-rich heath tundra into productive, graminoid-dominated steppe-like tundra vegetation. More over the results suggests that intermittent intensive reindeer grazing can enhance productivity of summer ranges. RI Stark, Sari/L-4440-2013; Olofsson, Johan/A-9362-2009 SN 0906-7590 PD FEB PY 2001 VL 24 IS 1 BP 13 EP 24 DI 10.1034/j.1600-0587.2001.240103.x UT WOS:000167992100002 ER PT J AU Kumpula, J AF Kumpula, J TI Winter grazing of reindeer in woodland lichen pasture Effect of lichen availability on the condition of reindeer SO SMALL RUMINANT RESEARCH AB Winter grazing of semi-domesticated reindeer (Rangifer t. tarandus) was investigated at the woodland lichen pasture (lichen approximately 550 kg DM ha(-1)) in Kaamanen, northern Finland during the winter 1996-1997. Nine female reindeer mainly due their food in the snow for 122 days (3 Decembrr-1 April) in a fenced area of 36.3 ha. Over half of the fenced area was lichen dominated dry pine forest. The amount of lichens in lichen forest inside the fence was estimated before and after grazing. Area of grazed and condition of reindeer as well as snow conditions were monitored. Reindeer grazed over the whole area of lichen forest in early winter but from mid-winter they tended to graze on the areas with the greatest lichen abundancy. The amount of lichens measured decreased in the latter areas by 40% and in the other part of the lichen pasture by 17%, respectively. In both of these areas the residual amounts of lichens left after grazing were similar. Of the dominant lichens, the amount of C. stellaris decreased the must and the amount of Cl. uncialis the least. During the study, the estimated average daily area grazed varied from 4 to 87 m(2) per reindeer. It was calculated that individual reindeer obtained 2.6 kg of lichen DM per day during the most intensive digging period when the body condition score and weight of reindeer increased. Otherwise, the body condition score and weight decreased. Reindeer finished foraging for ground lichens and started to search for arboreal lichens in mid-March when the snow layer was 70-80 om thick and contained some hard snow layers which lifted reindeer. Both the amount of lichens in the pasture and the snow conditions essentially affect the nutritional status of reindeer in the woodland region during winter. Assuming that a reindeer is able to graze around 30 m(2) per day in the snow during mid and late winter, there should be, on the basis of energy demand and grazing behaviour of reindeer as well as the nutritive value of lichen, an estimated 1000 kg lichen DM ha(-1) available in a good condition woodland lichen pasture. (C),: 2001 Elsevier Science B.V. All rights reserved. SN 0921-4488 PD FEB PY 2001 VL 39 IS 2 BP 121 EP 130 DI 10.1016/S0921-4488(00)00179-6 UT WOS:000167196500004 ER PT J AU van der Wal, R van Lieshout, SMJ Loonen, MJJE AF van der Wal, R van Lieshout, SMJ Loonen, MJJE TI Herbivore impact on moss depth, soil temperature and arctic plant growth SO POLAR BIOLOGY AB We provide evidence for a mechanism by which herbivores may influence plant abundance in arctic ecosystems, These systems are commonly dominated by mosses, the thickness of which influences the amount of heat reaching the soil surface. Herbivores can reduce the thickness of the moss layer by means of trampling and consumption. Exclusion of grazing by barnacle geese and reindeer over a period of 7 years at Ny-Alesund, Spitsbergen, caused an increase in the thickness of the moss layer, and a reduction in soil temperature of 0.9 degreesC. Soil temperature was negatively correlated with moss-layer thickness across sites, with highest soil temperatures where moss layers were shallow. We found that moss growth did not respond to experimental manipulation of soil temperature, but the grass Poa arctica (arctic meadow-grass) and the dicot Cardamine nymanii (polar cress) suffered a 50% reduction in biomass when growing in chilled soils. RI van der Wal, Rene/F-3177-2010 SN 0722-4060 PD JAN PY 2001 VL 24 IS 1 BP 29 EP 32 DI 10.1007/s003000000170 UT WOS:000166077500005 ER PT J AU Cooper, EJ Smith, FM Wookey, PA AF Cooper, EJ Smith, FM Wookey, PA TI Increased rainfall ameliorates the negative effect of trampling on the growth of High Arctic forage lichens SO SYMBIOSIS CT 4th International-Association-of-Lichenology Symposium CY SEP 03-08, 2000 CL BARCELONA, SPAIN SP Int Assoc Lichenol AB Recolonisation of trampled lichen pastures in the High Arctic is dependent on the regrowth from small fragments of lichen thalli. Intact lichens have been shown to grow most rapidly during periods of sustained moisture caused by rainfall or cloudy days. Climate change models for Arctic areas predict wetter summers, milder winters and greater stochastic variability. Therefore we hypothesised that the growth of both damaged and intact Svalbard reindeer forage lichens would be increased under the future climatic scenarios. The effects of rainfall frequency, increased precipitation, and simulated cloud cover on relative growth rate (RGR) of Cetraria delisei, C. islandica and C, nivalis, from NW Svalbard were examined under controlled conditions. Low light did not depress RGR, suggesting that shading provided by increased cloud cover would not affect the lichen growth. The ability to gain mass and the RGR was lower in cut thalli than intact thalli under most watering regimes. Frequency of watering was the most important factor influencing growth, but this also interacted synergistically with quantity. Damaged thalli watered frequently grew significantly more than intact thalli watered less frequently. These results suggest that an increase in summer precipitation as predicted by climate modelling would increase the growth rate of fragmented thalli and may help to ameliorate the damage done to the Lichen thalli by reindeer trampling and grazing. OI Wookey, Philip/0000-0001-5957-6424 SN 0334-5114 EI 1878-7665 PY 2001 VL 31 IS 1-3 BP 153 EP 171 UT WOS:000169857900012 ER PT J AU Cooper, EJ Wookey, PA AF Cooper, EJ Wookey, PA TI Field measurements of the growth rates of forage lichens, and the implications of grazing by Svalbard Reindeer SO SYMBIOSIS CT 4th International-Association-of-Lichenology Symposium CY SEP 03-08, 2000 CL BARCELONA, SPAIN SP Int Assoc Lichenol AB Mean relative growth rates of lichens on Broggerhalvoya, Svalbard, (78 degrees 60 ' N, 12 degrees0 ' E, Norwegian High Arctic) ranged from 2.4 (Alectoria nigricans) to 10.6 (Cladonia rangiferina) mg.g(-1) per week. This related, to a seasonal increase of between 2.5% and 11.2% of original dry mass. The number of species and percentage cover of lichens were greater inside than outside three long-term reindeer exclosures, suggesting that through their indiscriminate trampling and selective grazing Svalbard reindeer have the ability to completely alter lichen community structure, in both the short and long term. The lichen communities are only likely to be able to reestablish if there is a significant reduction in the reindeer population for at least 20 years, such as could occur by a complete emigration of deer from the area. Reduced lichen forage availability has potentially serious implications for the reindeer population. OI Wookey, Philip/0000-0001-5957-6424 SN 0334-5114 PY 2001 VL 31 IS 1-3 BP 173 EP 186 UT WOS:000169857900013 ER PT J AU Mehli, H Skuterud, L Mosdol, A Tonnessen, A AF Mehli, H Skuterud, L Mosdol, A Tonnessen, A TI The impact of Chernobyl fallout on the Southern Saami reindeer herders of Norway in 1996 SO HEALTH PHYSICS AB The reindeer-herding Southern Saamis, from Central Norway. were the population group exposed to the highest levels of radioactivity in Norway, following the Chernobyl accident. Radiocesium whole-body contents and dietary habits have been investigated regularly in this population group since 1987, Meat of semi-domesticated reindeer is important in their diet, and earlier studies have shown that contaminated reindeer meat contributes about 90% to the total intake of radiocesium. A major part of the group also consumes mild food products like game, freshwater fish, mushrooms, and berries. The application of countermeasures has been a common practice for the reindeer herders since the Chernobyl accident, According to the interviews in 1996, the three most commonly used and socially accepted countermeasures were (1) selection of reindeer for consumption after live monitoring of radiocesium concentrations; (2) selection of reindeer for consumption from less contaminated grazing areas; and (3) clean feeding of animals before slaughtering. Despite these countermeasures about one third of the population still have reduced reindeer meat intake because of the Chernobyl fallout, In 1996. the average whole body concentration of Cs-137 for this population was found to be 88+/-7 By kg(-1) for women and 164+/-11 Bq kg(-1) for men (arithmetic mean +/- standard error), This is approximately half of the whole-body concentration of Cs-137 measured in the same population in 1990-1991. OI Skuterud, Lavrans/0000-0002-1164-208X SN 0017-9078 EI 1538-5159 PD DEC PY 2000 VL 79 IS 6 BP 682 EP 690 DI 10.1097/00004032-200012000-00014 UT WOS:000165391700011 PM 11089805 ER PT J AU Olofsson, J Strengbom, J AF Olofsson, J Strengbom, J TI Response of galling invertebrates on Salix lanata to reindeer herbivory SO OIKOS AB Browsing and defoliation often increase the densities of insect herbivores on woody plants. Densities of herbivorous invertebrates were estimated in a long-term grazing manipulation experiment. More then 30-yr-old fences allow us to compare densities of invertebrate herbivores on Salix lanata in areas heavily grazed and areas lightly grazed by reindeer. The number of gall-forming insects (Pontania glabrifons) and gall-forming mitts were higher on the heavily grazed shrubs than on lightly grazed shrubs. In contrast to most short-term studies, the heavily grazed S. lanata had shorter current annual shoots. No difference in leaf size, leaf nitrogen content, or C:N ratio between grazing intensities were detected. However, the enhanced natural delta (15)N value indicates that heavily grazed shrubs get a higher proportion of their N directly from reindeer faeces. Lear weight per unit area and relative fluctuating asymmetry of leaf shape increased in heavily grazed S. lanata. Enhanced relative fluctuating asymmetry might indicate higher susceptibility to herbivores. Long-term grazing seems to increase the density of invertebrate herbivory in the same way as short-term grazing, even if the plant responses differ substantially. RI Olofsson, Johan/A-9362-2009 SN 0030-1299 PD DEC PY 2000 VL 91 IS 3 BP 493 EP 498 DI 10.1034/j.1600-0706.2000.910310.x UT WOS:000166777500010 ER PT J AU Loffler, J AF Loffler, J TI High mountain ecosystems and landscape degradation in northern Norway SO MOUNTAIN RESEARCH AND DEVELOPMENT CT Workshop of the German-Study-Group on High Mountain Ecology CY 1999 CL BERN, SWITZERLAND SP Univ Berne, Inst Geog AB The influence of reindeer pasturing on high mountain ecosystems in northern Norway was investigated using a landscape-ecological analysis. The most visible impacts of overgrazing are On the vegetation. In addition, soils and humus have been changed due to morphodynamic processes induced to a large extent by reindeer pasturing. Degradation of the high mountain landscapes within the last 30 years is described on 3 spatial levels: large-scale effects at specific localities, linear effects along reindeer fences, and small-scale effects on the altitudinal zonation of entire mountain systems. The structure of the ecosystem ha changed completely due to reindeer pasturing, which has resulted in landscape degradation under great pasturing pressure. The processes that influence the ecosystem as a function of different pasture intensities are described and show a complex correlation and interaction between the ecofactors. These include destruction of vegetation cover, reduction of roof density, erosion of humus and mineral soil horizons, reduction of soil moisture and soil stability, and changes in plant species composition. On the whole, degradation leads to a depression of the altitudinal belts, indicated by the new organization of the ecosystems. It can be concluded that reindeer herding at current levels is a destructive form of land use in the northern Norwegian high mountains and hence is not sustainable. The author believes that destruction of the natural environment could be reversed, although this is not to be expected. SN 0276-4741 PD NOV PY 2000 VL 20 IS 4 BP 356 EP 363 DI 10.1659/0276-4741(2000)020[0356:HMEALD]2.0.CO;2 UT WOS:000166166900012 ER PT J AU Morneau, C Payette, S AF Morneau, C Payette, S TI Long-term fluctuations of a caribou population revealed by tree-ring data SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB We used a dendroecological approach that involved examination of debarking lesions (trampling scars) produced by caribou (Rangifer tarandus) hooves on surficial roots and low branches of conifers to assess caribou activity in the summer range of the Riviere George caribou herd in northeastern Quebec-Labrador over the last 100 years. We deduced changes in caribou activity from the age-frequency distributions of trampling scars in three widely spaced (> 100 km) old-growth conifer stands in the Riviere George area. We used the fluctuating patterns in age distributions, described by residuals of the log-linear regression, as an index of the number of trampling scars with time. This index indicated that caribou activity at the three sites followed a general decreasing trend from the turn of the last century to around 1950. There were two stages of rapid decline, around 1905-1915 and 1940, separated by a minor increase in the 1920-1930s. A sustained increase occurred from the 1950s to the 1980s. A comparison with survey and historical data for caribou suggested that these fluctuations in this common signal of activity at the three sites resulted mainly from fluctuations in caribou abundance that occurred throughout the 20th century in northeastern Quebec-Labrador. The increase in caribou activity during the 1920-1930s suggested by the frequency of trampling scars is not reported in the historical record. Caribou trampling scars on conifers may offer a new opportunity to assess large-scale spatial and temporal population trends of caribou in subarctic and boreal zones. SN 0008-4301 PD OCT PY 2000 VL 78 IS 10 BP 1784 EP 1790 DI 10.1139/cjz-78-10-1784 UT WOS:000089523900012 ER PT J AU Yokoyama, M Kaji, K Suzuki, M AF Yokoyama, M Kaji, K Suzuki, M TI Food habits of sika deer and nutritional value of sika deer diets in eastern Hokkaido, Japan SO ECOLOGICAL RESEARCH AB Rumen content analysis and field observations were used to investigate the food habits and diet quality of sika deer (Cervus nippon yesoensis Heude) from 1991 to 1993 in eastern Hokkaido, Japan. Diets varied seasonally, with deer consuming graminoids and browse in winter, forbs and agricultural crops in spring and summer and all of these plant foods in autumn. Eighty-four plant species with sika deer bite marks were identified and their use also varied seasonally. The diversity of food resources available provided both critical protein and digestible energy, allowing for physiological maintenance and seasonal growth. With these high-quality diets, deer maintained good body condition in eastern Hokkaido, where the population density was relatively low. RI Kaji, Koichi/C-8355-2013 OI Kaji, Koichi/0000-0001-6578-9995 SN 0912-3814 EI 1440-1703 PD SEP PY 2000 VL 15 IS 3 BP 345 EP 355 DI 10.1046/j.1440-1703.2000.00355.x UT WOS:000089718800010 ER PT J AU Virtanen, R AF Virtanen, R TI Effects of grazing on above-ground biomass on a mountain snowbed, NW Finland SO OIKOS AB The effects of grazing by the Norwegian lemming (Lemmus lemmus) and reindeer (Rangifer tarandus) on biomass and vegetation structure in a mountain snowbed habitat were studied using several grazer-exclosures kept for 5 or 15 yr. During the 5-yr exclusion experiment, the total biomass of mosses in particular, the main winter-food of lemmings, increased within fenced areas as compared to open control areas. In the 15-yr exclosures, Polytrichaceae mosses still dominated, but graminoids (Anthoxanthum odoratum and Carex bigelowii) had also increased. In these longer-term exclosures, dead plant material, consisting of Polytrichaceae moss and graminoid necromass and other plant litter, had increased. By contrast, Kiaeria moss and lichens were absent or had low biomass after 15 yr of grazer exclosure, probably as a result of competitive exclusion. The results suggest that the plant biomass in such low productivity mountain snowbeds can be reduced to a low level by grazing. Grazing also determines the dominance relationships in the plant community and prevents accumulation of plant litter. The observed effects of grazing are inconsistent with hypotheses suggesting that herbivory is of little importance in low productivity environments, but rather support the exploitation ecosystems hypothesis predicting strong grazing impact in such low productivity environments. RI Virtanen, Risto/G-1810-2010 OI Virtanen, Risto/0000-0002-8295-8217 SN 0030-1299 PD AUG PY 2000 VL 90 IS 2 BP 295 EP 300 DI 10.1034/j.1600-0706.2000.900209.x UT WOS:000089031600009 ER PT J AU Stark, S Wardle, DA Ohtonen, R Helle, T Yeates, GW AF Stark, S Wardle, DA Ohtonen, R Helle, T Yeates, GW TI The effect of reindeer grazing on decomposition, mineralization and soil biota in a dry oligotrophic Scots pine forest SO OIKOS AB Reindeer grazing in the Fennoscandian area has a considerable influence on the ground vegetation, and this is likely in turn to have important consequences For the soil biota and decomposition processes. The effects of reindeer grazing on soil biota, decomposition and mineralization processes, and ecosystem properties in a lichen-dominated forest in Finnish Lapland were studied inside and outside a large long term fenced reindeer exclosure area. Decomposition rates of Vaccinium myrtillus leaves in litter bags were retarded in the grazed area relative to the ungrazed area, as well as in subplots from which lichens had been artificially removed to simulate grazing. The effect of reindeer grazing on soil respiration and microbial C was positive in the lichen and lifter layers of the soil profile, but retarded in the humus layer. There was no effect of grazing on gross N mineralization and microbial biomass N in the humus and upper mineral soil layer, but net N mineralization was increased by grazing. In these layers soil respiration was reduced by grazing, indicating that reindeer effects reduce the ratio of C to N mineralized by soil microorganisms. Grazing stimulated populations of all trophic groupings of nematodes in the lichen layer and microbe feeding nematodes in the litter layer, indicating that grazing by reindeer has multitrophic effects on the decomposer food-web. Grazing decreased lichen and dwarf shrub biomasses and increased the mass of litter present in the litter layer on an areal basis, but did not significantly alter total C storage per unit area in the humus and mineral soil layers. The N concentration of lichens was increased by grazing, but the N concentrations of both living and dead Pinus sylvestris needles and Empetrum hermaphroditum leaves were not affected. There was some evidence for each of three mechanisms which could account for the grazing effects that we observed in our study. Firstly, reindeer may have changed the composition and quality of litter input by affecting plant species composition and through addition of N from urine and faeces, resulting in a lack of available C relative to N for decomposer organisms. Secondly, the organic matter in the soil may be older in the grazed area, because of reduction of recent production of lichen litter relative to the ungrazed area. The organic matter in the grazed area may have been in a different phase of decomposition from that in the exclosure. Thirdly, the soil microclimate is likely to be affected by reindeer grazing through physical removal of lichen cover on the ground, and this can have a significant influence on soil microbial processes. This is supported by the strong observed effects of experimental removal of lichens on decomposer processes. The impact of reindeer grazing on soil processes may be a result of complex interactions between different mechanisms, and this could help to explain why the below-ground effects of reindeer grazing have different consequences to those which have been observed in recent investigations on other grazing systems. RI Stark, Sari/L-4440-2013; Wardle, David/F-6031-2011 OI Wardle, David/0000-0002-0476-7335 SN 0030-1299 PD AUG PY 2000 VL 90 IS 2 BP 301 EP 310 DI 10.1034/j.1600-0706.2000.900210.x UT WOS:000089031600010 ER PT J AU Kumpula, J Colpaert, A Nieminen, M AF Kumpula, J Colpaert, A Nieminen, M TI Condition, potential recovery rate, and productivity of lichen (Cladonia spp.) ranges in the Finnish reindeer management area SO ARCTIC AB The focus of the work was to investigate dependency between reindeer density and lichen (Cladonia spp.) ranges in the Finnish semidomesticated reindeer management area. Secondly, we formed a model on the recovery rate of ungrazed woodland lichen ranges (29 sites) after forest fires to evaluate the potential productivity and time needed for Finnish lichen ranges to recover at optimal production. During 1974-95, 59% of the variation in mean semidomesticated reindeer density (range: 0.7-3.0 reindeer/km(2) of the total land area) among the reindeer herding districts in Finland was explained by the proportion of Land area covered by Lichen ranges in these districts. Reindeer densities were highest in the districts where lichen ranges covered 20% to 30% of the area. Reindeer density on the total land area did not explain the condition of Lichen ranges, but 58% of the condition was explained by the reindeer density on the lichen ranges. A condition level for lichen ranges of 1000 kg dry matter per hectare (d.m./ha) of lichen biomass can be considered adequate to ensure survival of reindeer and continued production of lichen. To maintain this level within the sedentary Finnish grazing system, winter reindeer densities on lichen ranges must remain below 5-7 reindeer/km(2). According to our model, the maximum amount of living lichen in the woodland lichen stand at the climax stage is on average about 7000 kg d.m./ha. The maximum annual yield of lichen (175 kg d.m./ha) is produced by lichen stands that contain 2600-2800 kg d.m./ha of living lichen. Using our model and our 1995-96 data, we calculated that the average lichen biomass on lichen ranges in the Finnish reindeer management districts was 13.0% of this optimum, and the average lichen production was 36% of the possible maximum annual yield. Our model indicates that the Finnish lichen ranges would have to remain ungrazed for an average of 18 years to recover to maximum production levels. However, the average time needed for the lichen ranges to recover to the level of 1000 kg lichen d.m./ha, would be only about 7 years. SN 0004-0843 EI 1923-1245 PD JUN PY 2000 VL 53 IS 2 BP 152 EP 160 DI 10.14430/arctic845 UT WOS:000087894200006 ER PT J AU Dumont, A Crete, M Ouellet, JP Huot, J Lamoureux, J AF Dumont, A Crete, M Ouellet, JP Huot, J Lamoureux, J TI Population dynamics of northern white-tailed deer during mild winters: evidence of regulation by food competition SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB We studied white-tailed deer (Odocoileus virginianus borealis) at the northeastern limit of their range after their density had decreased as a result of harsh winters aggravated by coyote predation. We compared two populations wintering in adjacent areas. In the Lac Temiscouata wintering area (LTWA), deer and browse density averaged 10 animals/km(2) and 127 000 deciduous twigs/ha compared with 20 deer/km(2) and 68 000 twigs/ha, respectively, at the Pohenegamook wintering area (PWA). For 75 radio-collared deer, the probability of death was highest during the short spring migration and remained elevated in winter, whereas fewer deaths occurred in summer and none during autumn migration. PWA deer had a higher mortality rate than did LTWA animals and died mostly in winter, from predation, starvation, and collision equally. Based on observed survival rates, we estimated that the finite rate of increase averaged approximately 1.25 and approximately 1.00 for LTWA and PWA populations, respectively. At PWA, we examined 129 carcasses to determine the mortality pattern of deer. Among adults, we did not detect significant differences related to sex. Starvation and predation affected more fawns and old deer than prime animals, whereas collision appeared to be nonselective. Most cases of starvation occurred after the beginning of March, when body reserves dropped to low levels. We conclude that competition for winter forage regulated PWA deer during the study. SN 0008-4301 PD MAY PY 2000 VL 78 IS 5 BP 764 EP 776 DI 10.1139/cjz-78-5-764 UT WOS:000087624400010 ER PT J AU Mathiesen, SD Sormo, W Haga, OE Norbert, HJ Utsi, THA Tyler, NJC AF Mathiesen, SD Sormo, W Haga, OE Norbert, HJ Utsi, THA Tyler, NJC TI The oral anatomy of Arctic ruminants: coping with seasonal changes SO JOURNAL OF ZOOLOGY AB We studied the feeding apparatus of three species of northern ruminants representative of three feeding types: muskoxen Ovibos moschatus, Norwegian reindeer Rangifer tarandus tarandus and high Arctic Svalbard reindeer Rangifer tarandus platyhrynchus and Siberian musk deer Moschus moschiferus. The shape of the muzzle, the incisor arcade, the incisiform and the molariform teeth indicate that these species are selective feeders, irrespective of their body size or their position on the grazer-concentrate selector continuum of feeding types. Narrow muzzles seem well adapted for selective feeding on the diminutive but highly nutritious plants, or parts of plants, on tundra swards and Arctic-alpine meadows and enable the animals to maximize nutrient intake during the short summer. However, their small mouths presumably also restrict reindeer and muskoxen to taking small bites, thereby achieving low rates of dry matter intake when feeding on the very short swards in winter. This is partially obviated by two general strategies; a reduction of energy requirements in winter and, in Norwegian reindeer, migration inland to where foraging conditions are generally more favourable. In Svalbard reindeer, which have little access to lichens or other easy digestible plants in winter, rumen fill increases through the accumulation of slowly fermenting fibrous foods. Despite their narrow muzzles, reindeer and muskoxen are unable to avoid ingesting a certain amount of poor quality forage in winter and cope with this by appropriate modification of digestive function. RI Self, Casey/B-6871-2011 SN 0952-8369 PD MAY PY 2000 VL 251 BP 119 EP 128 DI 10.1017/S0952836900005124 PN 1 UT WOS:000087532600012 ER PT J AU Nellemann, C Jordhoy, P Stoen, OG Strand, O AF Nellemann, C Jordhoy, P Stoen, OG Strand, O TI Cumulative impacts of tourist resorts on wild reindeer (Rangifer tarandus tarandus) during winter SO ARCTIC AB Potential avoidance by wild reindeer (Rangifer tarandus tarandus) of high-altitude tourist resorts during winter was investigated in and near Rondane National Park in Norway. Distribution of reindeer was mapped using systematic snowmobile surveys during 1991-96 and compared with results from investigations of snow and vegetation characteristics. Maternal reindeer avoided a 10 km zone around the resort. Cows and calves increased in density from 0.6 +/- 0.6 reindeer km(-2) at 5-10 km from the resort to 7.6 +/- 2.2 reindeer km(-2) at 15-25 km from the resort. Bulls and yearlings were more tolerant, constituting nearly 92% of all observed animals 5-10 km from the resort. Nearly all animals avoided the zone within 5 km of the resort. There were no significant differences in distribution of lichen heath, hardness of snow, integrated ram hardness index (IRH) values, or snow depths on ridges with increasing distance from the resort. Available biomass of lichens was ca. 1200 g m(-2) 0-5 km from the resort and decreased to a low of ca. 250 g m(-2) at 15-25 km distance, a pattern that probably reflects overgrazing as a result of avoiding the tourist resort. Such avoidance implies reduced forage intake during winter, substantial reduction in available habitat, and lower productivity of the herd. The results suggest that avoidance by wild animals of sources of anthropogenic disturbance may involve long-term impacts, such as reductions in carrying capacity, that are more serious than those expected from direct physiological stress. SN 0004-0843 PD MAR PY 2000 VL 53 IS 1 BP 9 EP 17 UT WOS:000085934000003 ER PT J AU Eilertsen, SM Schjelderup, I Mathiesen, SD AF Eilertsen, SM Schjelderup, I Mathiesen, SD TI Plant quality and harvest in old meadows grazed by reindeer in spring SO JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE AB Dry matter (DM) production and nutritional quality of plants were recorded on an old meadow before, during and after it was grazed by reindeer (Rangifer tarandus tarandus; 15 reindeer ha(-1)) in the spring of 1996 and 1997 in northern Norway. Mean herbage harvest after 54 and 50 days of growth including 25 and 24 days of reindeer grazing was 1217 +/- 320 kg DM ha(-1) in 1996 and 2297 +/- 495 kg DM ha(-1) in 1997 respectively. On ungrazed old meadow, in contrast (P < 0.05), mean herbage harvest after 54 and 50 days of growth was 4159 +/- 1164 kg DM ha(-1) in 1996 and 3791 +/- 275 kg DM ha(-1) in 1997 respectively. In 1997, mean herbage harvest after 50 days of growth including 7 days of grazing by reindeer was as high as 3441 +/- 180 kg DM ha(-1) (P > 0.05). Crude protein content (% of DM) was 25% early in the growing season in both 1996 and 1997. After 54 and 50 days of growth including 25 and 24 days of reindeer grazing, crude protein content was about 17% of DM in both 1996 and 1997 respectively, compared with about 12% of DM in ungrazed old meadow in both years. In 1997, crude protein content was 13.3% of DM after 50 days of growth including 7 days of reindeer grazing. The grazed and ungrazed old meadow contained about 20% (of DM) water-soluble carbohydrates throughout the summer in both years. Mean plant cell wall content in ungrazed plants harvested after about 50 days was higher (51.5 and 49.1% of DM; P > 0.05) compared with plant cell wall content in grazed meadow (49.0 and 46.4% of DM) in 1996 and 1997 respectively. In vitro dry matter digestibility (%) of herbage harvest using rumen fluid from domestic ruminants was about 10% higher (73.4 +/- 0.30 and 75.7 +/- 0.28) in samples from grazed meadow compared with ungrazed meadow (66.2 +/- 0.93 and 65.4 +/- 1.19) in 1996 and 1997 respectively. Reindeer grazing of old meadow in spring maintains the vegetation at a younger phenological stage during the growing season when compared with ungrazed meadow. Therefore grazing increased the quality of the herbage, but decreased herbage harvest under conditions of high grazing intensity. (C) 2000 Society of Chemical Industry. SN 0022-5142 PD FEB PY 2000 VL 80 IS 3 BP 329 EP 334 DI 10.1002/1097-0010(200002)80:3<329::AID-JSFA528>3.0.CO;2-6 UT WOS:000085385100005 ER PT J AU Suominen, O Olofsson, J AF Suominen, O Olofsson, J TI Impacts of semi-domesticated reindeer on structure of tundra and forest communities in Fennoscandia: a review SO ANNALES ZOOLOGICI FENNICI CT Symposium on Northern Dimension to Biodiversity - From Arctic to Boreal Environments CY NOV 20-23, 1999 CL SAARISELKA, FINLAND AB Grazing and trampling by semi-domesticated reindeer are important factors controlling vegetation in northern Fennoscandia. In this article we review Nordic studies on the effects of reindeer on vegetation and animal communities. The studies have shown clear effects on vegetation, especially on Cladina lichen dominated sites. Cladina is the main forage of reindeer during winter and dominates climax vegetation in dry site types in the absence of reindeer. Reindeer can even affect galling and ground-dwelling invertebrates. Due to the special relationship between reindeer and Cladina majority of the research has concentrated on winter grazing on Cladina, but there are some studies of summer grazing which have also shown substantial changes in vegetation. Reindeer grazing increases richness and diversity of vegetation and invertebrate assemblages in most cases, but this influence depends on site type and grazing intensity. The enriching effect seems to be strongest at moderate grazing intensity. RI Olofsson, Johan/A-9362-2009 SN 0003-455X PY 2000 VL 37 IS 4 BP 233 EP 249 UT WOS:000166643700003 ER PT J AU Persson, IL Danell, K Bergstrom, R AF Persson, IL Danell, K Bergstrom, R TI Disturbance by large herbivores in boreal forests with special reference to moose SO ANNALES ZOOLOGICI FENNICI CT Symposium on Northern Dimension to Biodiversity - From Arctic to Boreal Environments CY NOV 20-23, 1999 CL SAARISELKA, FINLAND AB Moose and reindeer occur in large populations in the Fennoscandian boreal forests, and also roe deer occurs in dense populations in Sweden and Norway. These large herbivores affect the structure and function of the forest ecosystems. During periods of high densities discussions arise about the impact of these herbivores on e.g. economic forest trees and preservation of biodiversity. The aim of this study is to review the present knowledge of the disturbance caused by moose in the boreal forest. First, we give a quantitative estimate of the different disturbance factors (feeding, trampling, defecation and urination). Second, we discuss the ecological impact of the different disturbances. SN 0003-455X PY 2000 VL 37 IS 4 BP 251 EP 263 UT WOS:000166643700004 ER PT J AU Kryazhimskii, FV Danilov, AN AF Kryazhimskii, FV Danilov, AN TI Reindeer in tundra ecosystems: the challenges of understanding system complexity SO POLAR RESEARCH CT Human Role in Reindeer/Caribou Systems Workshop CY FEB 10-14, 1999 CL ROVANICMI, FINLAND AB The resilience of tundra ecosystems is limited, with relatively few key biotic components determining the general pattern of the dynamics of these systems. Sustainable use of reindeer pastures, which are natural tundra ecosystems, should take into account interactions within the whole complex of key components. Among the most important are the small herbivorous rodents. For example, during peak densities lemmings may reduce above-ground plant biomass by 50-70%. At the same time, rapid turnover of nutrients in the form of significant amounts of potassium, phosphorus and nitrogen that lemmings excrete in urine promotes vascular plant growth. It is concluded that these kinds of studies are essential for the sustainable management of Russia's grazing lands: 1) comparative studies of productivity, biological diversity and structure of plant communities under the different pressures exerted by the main groups of herbivorous animals (reindeer and small rodents), as well as under varying levels of industrial development; 2) studies of the direct and indirect effects of herbivorous mammals on biological turnover and energy flow within the system; 3) studies of the role of industrial contamination on the turnover of nutrients in tundra ecosystems. SN 0800-0395 PY 2000 VL 19 IS 1 BP 107 EP 110 DI 10.1111/j.1751-8369.2000.tb00334.x UT WOS:000088430500013 ER PT J AU Danell, O AF Danell, O TI Status, directions and priorities of reindeer husbandry research in Sweden SO POLAR RESEARCH CT Human Role in Reindeer/Caribou Systems Workshop CY FEB 10-14, 1999 CL ROVANICMI, FINLAND AB Emerging out of small-scale reindeer farming, large-scale reindeer husbandry in Sweden and Norway was developed to counteract resource scarcity caused by depleted wild reindeer numbers and human population growth above what the former subsistence economy could sustain. Current numbers of reindeer are likely lower and fluctuate less than before wild reindeer were depleted and reindeer husbandry started on a large scale. Productivity is about 7-8 kg of meat per head in winter stock. Current problems arise from a multitude of circumstances, some of them related to the problems of practising a subsistence type of living in close connection with a modern industrialized society. Problems include: low production, typical for harsh conditions and use of an unimproved animal stock; the inability to support a modern standard of living solely from reindeer; the collective access to grazing grounds which makes internal management difficult; unclear legal rights resulting in conflicting interests with other land users and formal owners; and the relatively low number of people directly involved in reindeer husbandry. Possible long-term consequences are marginalization and the loss of land use rights, with negative consequences for the Saami as an indigenous people. Reindeer husbandry research addresses these problems by integrating human-ecological and socio-economic aspects with traditional natural science orientated research on reindeer husbandry problems. This research is funded by a multitude of sources. Independently of this, research is conducted on Saami life and culture in relation to reindeer husbandry at various universities, especially within social sciences and arts. SN 0800-0395 PY 2000 VL 19 IS 1 BP 111 EP 115 DI 10.1111/j.1751-8369.2000.tb00335.x UT WOS:000088430500014 ER PT J AU Bjune, AE AF Bjune, AE TI Pollen analysis of faeces as a method of demonstrating seasonal variations in the diet of Svalbard reindeer (Rangifer tarandus platyrhynchus) SO POLAR RESEARCH AB Analysis of the pollen and spore content of 40 fresh samples of faeces collected from Svalbard reindeer during 1994/5 and 1996 shows variations among acid within seasons, with distinct species/pollen types dominating each season. Winter samples were characterized by high amounts of Salix and moss spores, while spring samples contained decreasing amounts of the plants grazed in winter and increasing values of species grazed in summer, such as Oxyria digyna and Pedicularis spp. Summer samples had a large quantity of pollen and a great number of pollen types. Autumn samples indicated that grasses are the most important forage species in this period. The seasonally varying proportions of pollen types are related to such factors as plant phenology, abundance, palatability and nutritional quality, as well as the preference of reindeers for grazing in low, wet areas in the summer but on higher, wind-blown ridges during the winter. The results mostly confirm other studies of Svalbard reindeer diet and grazing behaviour. The advantages and limitations of the pollen analysis method for such investigations are discussed. OI Bjune, Anne Elisabeth/0000-0002-4509-0148 SN 0800-0395 EI 1751-8369 PY 2000 VL 19 IS 2 BP 183 EP 192 DI 10.1111/j.1751-8369.2000.tb00342.x UT WOS:000166490400004 ER PT J AU Suominen, O AF Suominen, O TI Impact of cervid browsing and grazing on the terrestrial gastropod fauna in the boreal forests of Fennoscandia SO ECOGRAPHY AB Selective foraging by cervids can affect vegetation. and that in turn car far-reaching effects on various components of the boreal forest ecosystem. Since terrestrial gastropods are sensitive to habitat alterations, they can be expected to respond to changes caused by grazing. This study is based on gastropod specimens from two data sets that were collected with pitfall traps in order to study the effects of moose and reindeer on ground-layer invertebrates. Invertebrates were trapped from 23 pairs of plots. where one plot was open to all animals while the other one was fenced to exclude large mammals. Half of the sires were in Finnish Lapland. where reindeer grazing was the main cause of differences between the plots; the rest were located in central Sweden and southern Finland, where moose was the most important cervid grazer. The composition of the gastropod fauna differed between grazed and ungrazed plots in both areas, and the abundance of gastropods in general and that of many species was higher in ungrazed plots (the number of gastropods caught was 17% lower in grazed than in ungrazed plots in moose sites. and 24% smaller in reindeer sites). Species richness differed significantly between grazed and ungrazed plots in the combined data of both sire types, and was 15% higher in ungrazed plots. In moose sites the relative diversity (H'/H'(max)) of gastropods was 17% higher in grazed plots. In reindeer sites, the means of richness and diversity (H') were considerably higher in ungrazed plots (35% and 40% respectively) but the differences were only marginally significant. By indirectly modifying the microclimate within the forest. cervids fulfil the criteria for a 'physical ecosystem engineer'. Since the population density and distribution of terrestrial gastropods depend largely on the physical conditions of the microhabitat, the engineering effects of cervids are the most likely cause of the changes observed in the density and composition of the gastropod fauna in the boreal forest. SN 0906-7590 PD DEC PY 1999 VL 22 IS 6 BP 651 EP 658 DI 10.1111/j.1600-0587.1999.tb00514.x UT WOS:000085437500006 ER PT J AU Landa, A Gudvangen, K Swenson, JE Roskaft, E AF Landa, A Gudvangen, K Swenson, JE Roskaft, E TI Factors associated with wolverine Gulo gulo predation on domestic sheep SO JOURNAL OF APPLIED ECOLOGY AB 1. Following a long history of eradication campaigns against predators, wolverine Gulo gulo distribution and numbers became critically low in Norway in the 1960s. Consequently, wolverines were protected by law during the 1970s and 1980s. This led to an increase in wolverine numbers and re-establishment in some formerly occupied habitats, resulting in increased depredation on domestic reindeer Rangifer tarandus and sheep Ovis aries. Wolverine control and licensed hunting have been used increasingly as tools to reduce the depredation since protection was introduced. However, the factors influencing the level of this depredation have not been studied. We therefore examined losses of domestic sheep grazing unattended on upland summer ranges in the Snohetta plateau of south central Norway during 1979-94, in relation to wolverine population numbers, reproduction and control measures. This area was recently re-occupied by wolverines and reproduction has been recorded regularly from the beginning of the study period. 2. The number of ewes and lambs recorded in organized grazing areas increased more than fivefold during the period, and losses increased proportionally with sheep numbers. The differences in losses among municipalities and grazing co-operatives were probably related to sheep breeds and local variation in wolverine density. 3. The heavy Dala sheep breed was most at risk, whereas losses from the lighter Norwegian short-tailed and Norwegian fur-bearing breeds were lower than expected. 4. Killing of wolverines led to fewer lambs being lost in the same year that the wolverine killing took place, but the effect quickly declined, implying a rapid re-establishment of wolverines in the local area. 5. Lambs were more vulnerable to wolverine predation than ewes, and losses were higher in wolverine cub-rearing areas than in the area as a whole. 6. We conclude that: (i) control programmes for wolverines, as practised today, will have little long-term effect in reducing sheep losses, unless wolverines are eradicated or severely reduced in numbers; (ii) the introduction of more agile sheep breeds will probably reduce losses; (iii) in areas where wolverine control to protect sheep is a threat towards wolverine conservation, the present sheep husbandry system of grazing unguarded sheep in the mountains should be replaced by alternative forms that provide the sheep with more protection. This is particularly important in wolverine denning areas. RI Swenson, Jon/E-2883-2013 SN 0021-8901 PD DEC PY 1999 VL 36 IS 6 BP 963 EP 973 DI 10.1046/j.1365-2664.1999.00451.x UT WOS:000084617900010 ER PT J AU Gerland, S Winther, JG Orbaek, JB Liston, GE Oritsland, NA Blanco, A Ivanov, B AF Gerland, S Winther, JG Orbaek, JB Liston, GE Oritsland, NA Blanco, A Ivanov, B TI Physical and optical properties of snow covering Arctic tundra on Svalbard SO HYDROLOGICAL PROCESSES AB Snow thickness. duration of snow coverage and amount of ice covering the soil are crucial for the development of biota in the Arctic tundra environment. The snow thickness and optical properties control the amount of Photosynthetically Active Radiation (PAR) that is available for vegetation. A late snow cover may prevent birds from nesting on the ground. Furthermore, ice at the snow/soil interface can be an obstacle for grazing of Svalbard reindeer and affect the microfauna population. Snow and ice thickness, and the physical and optical properties of snow covering Arctic tundra were measured on the Broggerhalvoya peninsula on western Svalbard in spring of 1997, Additionally, thicknesses of ground-covering ice were measured in spring of 1998. The initial maximum thickness of snow in the observed areas varied from 0.4 to 0.9 m. The snow around Ny-Alesund began to disappear by the beginning of June, with the entire snow pack disappearing within 2-3 weeks. At the bottom of the snow pack, there was a soil-covering ice layer between 0.05 and 0.1 m thick. We obtained radiation and reflectance parameters (spectral albedo, attenuation of PAR and global radiation) as well as physical properties of snow (e.g. temperature and density) over six weeks from early May to late June. Electrolytic conductivity of melted snow samples from snow pits shows clearly different conductivity for different stratigraphic sections within the snow pack in early June. Later on, these contrasts disappeared as internal ice layers melted and the snow pack underwent percolation. The albedo maximum before melt onset exceeded 0.9, whereas in the later phase of melting snow surfaces exhibited significantly lower albedo due to metamorphosis, thinning, and blackening by soil-particle contamination. However, even an apparently 'clean' snow surface had about 30% lower albedo in mid-June than in mid-May. Observations from under-snow PAR measurements are verified using a physically based radiative transfer model. This comparison indicates that scattering features that an smaller than the bulk-grain size may contribute significantly to the interaction between radiation and snowpack. Copyright (C) 1999 John Wiley & Sons, Ltd. SN 0885-6087 PD OCT PY 1999 VL 13 IS 14-15 BP 2331 EP 2343 DI 10.1002/(SICI)1099-1085(199910)13:14/15<2331::AID-HYP855>3.0.CO;2-W UT WOS:000084002600016 ER PT J AU Hornberg, G Ostlund, L Zackrisson, O Bergman, I AF Hornberg, G Ostlund, L Zackrisson, O Bergman, I TI The genesis of two Picea-Cladina forests in northern Sweden SO JOURNAL OF ECOLOGY AB 1 In northern Fennoscandia a rare forest type, characterized by Cladina species and Picea abies, occurs on dry productive sites outside the range of permafrost but close to the Scandes mountains. 2 We determined the history of vegetation development and disturbance of two Picea-Cladina forests to test the hypothesis that this forest type has a natural origin. 3 We used a combination of several retrospective vegetation history and archaeological methods, i.e. the analysis of pollen, macroscopic charcoal, dendroecological data, written historical sources, maps and ancient remains. 4 The results suggest that the Picea-Cladina forests investigated are-not the products of purely natural factors. 5 Under the influence of harsh climatic conditions and anthropogenic impact, mainly by repeated fires, grazing, trampling and probably also selective cutting of Pinus, mixed coniferous forests, dominated by feather mosses and dwarf shrubs, may have evolved into the. Picea-Cladina type. 6 Repeated anthropogenic use of fire, already established c. 2000 years ago, may have been used to create lichen-dominated areas, initially to attract game but later to improve winter grazing resources for reindeer. This finding contradicts the general view that Saami nomads did not use fire to alter forest vegetation. OI Ostlund, Lars/0000-0002-7902-3672 SN 0022-0477 PD OCT PY 1999 VL 87 IS 5 BP 800 EP 814 DI 10.1046/j.1365-2745.1999.00399.x UT WOS:000083683500006 ER PT J AU Crete, M AF Crete, M TI The distribution of deer biomass in North America supports the hypothesis of exploitation ecosystems SO ECOLOGY LETTERS AB The hypothesis of exploitation ecosystems (EEH) predicts that, along a productivity gradient in terrestrial environments, predators will regulate herbivores at a relatively constant density whenever primary productivity exceeds 700 g m(-2) y(-1); under this threshold, or if predators are absent, forage production determines herbivore density. I tested EEH using the pattern of deer biomass distribution over North America, the dominant family of large herbivores. Deer biomass increased from the High Arctic to the north of the boreal forest and remained in the same range southward within the gray wolf range; for the same latitude, deer biomass increased by a factor of 5 in the absence of wolves. South of the wolf range, there existed a clear relationship between actual evapotranspiration, a proxy of primary productivity, and deer biomass. Highest deer densities occurred in the south-east of the continent where only white-tailed deer are present. The observed pattern lends support to EEH and suggests that the removal of large predators in southern North America may have imposed an unprecedented pressure on plants eaten by deer. RI Michel-Hernandez, Misael Angel/N-2073-2016 SN 1461-023X PD JUL PY 1999 VL 2 IS 4 BP 223 EP 227 UT WOS:000081674700007 ER PT J AU Moen, J Ingvarsson, PK Walton, DWH AF Moen, J Ingvarsson, PK Walton, DWH TI Estimates of structural complexity in clonal plant morphology: comparisons of grazed and ungrazed Acaena magellanica rhizomes SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE AB The aim of this study is to examine the information given by various indices of rhizome morphology that describe grazed and ungrazed rhizome systems of Acaena magellanica (Rosaceae). Internode lengths, branching probabilities, and branching angles were estimated from grazed and ungrazed rhizomes in the field. These parameter values were then used in computer simulations of rhizome growth, and the structural complexity of the simulated rhizomes were described using size, topology, and fractal dimensions. Grazed rhizomes had shorter internodes, higher probabilities of branching, and more open branching angles than ungrazed rhizomes. This resulted in a more directional growth (herring-bone pattern) in the simulated ungrazed rhizomes, whereas the grazed rhizomes had a more space-filling growth pattern. Most indices, even though they are based on different mathematical and theoretical backgrounds, were highly correlated and thus equally good at describing the structural complexity exhibited by the rhizomes. However, indices have different relationships to theories about function, and we suggest that any study of structural complexity of branching systems should use several different indices of shape depending on the questions asked. RI Ingvarsson, Par/G-2748-2010 OI Ingvarsson, Par/0000-0001-9225-7521; Walton, David/0000-0002-7103-4043 SN 0008-4026 PD JUN PY 1999 VL 77 IS 6 BP 869 EP 876 DI 10.1139/b99-047 UT WOS:000083454300011 ER PT J AU Saakkinen, H Timisjarvi, J Eloranta, E Heiskari, U Nieminen, M Puukka, M AF Saakkinen, H Timisjarvi, J Eloranta, E Heiskari, U Nieminen, M Puukka, M TI Nutrition-induced changes in blood chemical parameters of pregnant reindeer hinds (Rangifer tarandus tarandus) SO SMALL RUMINANT RESEARCH AB Twenty-four pregnant reindeer hinds (Rangifer tarandus tarandus) were allocated to three feeding groups during 110 days experiment from January to May. Group 1 was grazing in a 15 km(2) fence, their diet mimicking a good quality winter pasture. Group 2 was fed with lichens. Their energy supply was gradually decreased until it was 30% from the ad libitum amount at the start. Group 3 was fed ad libitum with a pelleted concentrate for reindeer. Lichen fed animals lost 15% of body weight during the experiment. In other groups body weight was either maintained (Group 1) or increased by 18% (Group 3), Serum protein concentration decreased from 77 g/l to 62 g/l in lichen fed animals, accompanied first with a fall in serum urea concentration. When energy supply decreased further, a rise in blood urea occurred. Serum creatinine concentration increased with lichen feeding, and after 2 months it was 61% higher than at the beginning of the experiment. In pellet fed hinds creatinine declined from 190 mu mol/l to 143 mu mol/l. The birth weight of calves reflected the nutritional status of the groups. The average birth weight was 6.3 kg for calves of pellet fed hinds, 5.9 kg in group with mimicked winter diet and 4.0 kg for lichen fed group. Normal winter diet seems to provide enough energy and protein for the maintenance of body weight and for successful calving. Pellet feeding increased body weight, and had a positive effect on birth weights of calves. On poor winter pasture, supplementary feeding can be useful in prevention of malnutrition and in improving of calving success. (C) 1999 Elsevier Science B.V. All rights reserved. SN 0921-4488 PD MAY PY 1999 VL 32 IS 3 BP 211 EP 221 UT WOS:000080385800003 ER PT J AU Kayhko, JA Worsley, P Pye, K Clarke, ML AF Kayhko, JA Worsley, P Pye, K Clarke, ML TI A revised chronology for aeolian activity in subarctic Fennoscandia during the Holocene SO HOLOCENE AB Detailed sedimentological studies and parallel sampling for C-14 and infra-red stimulated luminescence age assays were undertaken at six sites lying beyond and below the tree-line with the objective of establishing the historical development of aeolian landforms in Lapland. The main issues were: (a) the timing of dune activity and processes of stabilization: (b) the specific processes responsible For the past and contemporary activity. New data indicate that many of the primary dunes were active for several millennia after deglaciation. Diachronous stabilization at both local and regional scales appears likely. initial stabilization occurred in local interdune areas and where regional dune fields were colonized by pine (generally before 7 ka). Local large dunes and some regional dunefields only became stable around 4.3 ka, when the regional groundwater table rose and late pine colonization was possible. The latest episode of aeolian activity dates from AD 1100-1650 across the area. A unique deflation triggering Factor was not identifiable, suggesting that several agents acted in combination. Climate-vegetational parameters, especially the 'Little Ice Age' event, together with reindeer trampling, appear responsible Tor the continuing aeolian activity at the tundra sites. At the margin of the pine forest zone, forest fires may be the cause of aeolian reactivation. RI Kayhko, Jukka/D-4849-2010 OI Kayhko, Jukka/0000-0002-3842-7355 SN 0959-6836 EI 1477-0911 PD MAR PY 1999 VL 9 IS 2 BP 195 EP 205 DI 10.1191/095968399668228352 UT WOS:000079599000007 ER PT J AU Sormo, W Haga, OE Gaare, E Langvatn, R Mathiesen, SD AF Sormo, W Haga, OE Gaare, E Langvatn, R Mathiesen, SD TI Forage chemistry and fermentation chambers in Svalbard reindeer (Rangifer tarandus platyrhynchus) SO JOURNAL OF ZOOLOGY AB Seasonal changes in the species composition and fibre content of plant fragments in the rumen and the gross anatomy of the gastrointestinal tract were investigated in Svalbard reindeer Rangifer tarandus platyrhynchus in western parts of Spitsbergen (Nordenskiold Land (NL), 78 degrees N), where the tundra vegetation is relatively abundant, and on the island of Nordaustlandet ((NA) 81 degrees N) where, in the polar desert, plants are scarce. Reindeer were killed while grazing on NL in autumn (n = 19) and in winter (n = 10) and on NA in summer (n = 10) and in winter (n = 3). Rumen contents included mainly mosses and grasses in specimens from NL and mainly Saxifraga spp. in specimens from NA. The plant cell wall content of the dry organic matter in the rumen-reticulum (RR) ranged from 55% to 77% and from 43% to 57% in NL and NA specimens, respectively, and did not vary between seasons. In autumn, the wet weight of the contents of the RR ranged from 13% to 20% of body mass (BM) in females on NL and from 14% to 24% of BM in adult reindeer in winter. On NA, the wet weight of the contents of the RR in adult animals ranged from 15% to 20% of BM in summer and from 15% to 17% of BM in winter in NA. The ratio of the wet weight of the contents of the distal fermentation chamber (DFC) to the wet weight of the contents of the RR was 1:8 in females in autumn, compared to 1:6-1:7 in adult animals on NL in winter. The ratio of the wet weight of the DFC to the wet weight of the RR ranged between 1:8-1:10 in summer, compared to 1:7 and 1:8 in winter. There were no significant differences in the size of plant particles in the RR contents in females from the two areas in any season, indicating that ruminal plant particle size was not influenced by the concentration of plant cell walls in the rumen contents. We conclude that the degree of filling of the gastrointestinal tract of these reindeer was therefore principally a function of plant fibre chemistry. Svalbard reindeer are adaptable intermediate feeders but they have, nevertheless, developed a large DFC similar to that of concentrate selectors. SN 0952-8369 PD FEB PY 1999 VL 247 BP 247 EP 256 DI 10.1017/S0952836999002125 PN 2 UT WOS:000079365500012 ER PT J AU Wada, N AF Wada, N TI Factors affecting the seed-setting success of Dryas octopetala in front of Broggerbreen (Brogger Glacier) in the high Arctic, Ny-Alesund, Svalbard SO POLAR RESEARCH CT International Symposium on Polar Aspects of Global Change CY AUG 24-28, 1998 CL TROMSO, NORWAY SP Int Arctic Sci Comm, Sci Comm Antarctic Res, European Polar Board, Nordic Council Polar Res, Univ Tromso, Commiss Sci Res Greenland, Int Glaciol Soc, Arctic Monitoring & Assessment Programme, World Climate Res Programme, Arctic Climate Syst Study, Int Arctic Res Ctr AB To determine the factors restricting plant reproduction in front of a glacier, the gender expression and seed production of Dryas octopetala L. (Rosaceae) were observed, as well as the grazing pattern of reindeer on flowers, near Broggerbreen (Brogger Glacier), which is near Ny-Alesund (78 degrees 55'N, 11 degrees 56'E), Svalbard. Three hundred shoots with flowers and flower buds were randomly tagged in early July 1996. Between then and the end of flowering in late July, 100 (33%) flowers and buds were grazed by reindeer. Out of the surviving flowers, 145 (76%) shoots had hermaphrodite flowers, while 45 (24%) shoots had male flowers without a developed gynoecium. Male flowers, which appeared later than hermaphrodite flowers in the population, were significantly smaller than hermaphrodite flowers in dry weight. In the hermaphrodite flowers, moreover, smaller flowers showed lower dry-weight allocation to the gynoecium as compared to larger flowers. During the observation, hermaphrodite flowers did not produce any developed seeds under a natural condition (0% seed-set). Cross-pollinated flowers showed 8% seed-set. On the other hand, flowers which were artificially warmed in small greenhouses during the flowering period showed 60% seed-set, regardless of cross-pollination or autodeposition of pollen from anthers to stigma (self-pollination). Thus, it was found that grazing, gender variation in relation to the length of the growing season and the flower size, and - in the flowering period - low temperature rather than pollinator limitation strongly affected the seed production of D. octopetala in the population studied. SN 0800-0395 PY 1999 VL 18 IS 2 BP 261 EP 268 DI 10.1111/j.1751-8369.1999.tb00302.x UT WOS:000085228300023 ER PT J AU Forbes, BC AF Forbes, BC TI Land use and climate change on the Yamal Peninsula of north-west Siberia: some ecological and socio-economic implications SO POLAR RESEARCH CT International Symposium on Polar Aspects of Global Change CY AUG 24-28, 1998 CL TROMSO, NORWAY SP Int Arctic Sci Comm, Sci Comm Antarctic Res, European Polar Board, Nordic Council Polar Res, Univ Tromso, Commiss Sci Res Greenland, Int Glaciol Soc, Arctic Monitoring & Assessment Programme, World Climate Res Programme, Arctic Climate Syst Study, Int Arctic Res Ctr AB Compared to climate, land use change is expected to comprise a more important component of global change in the coming decades. However, climate is anticipated to surpass land use as a factor later in the next century, particularly in the Arctic. Discussed here are the implications of land use and climate change on the Yamal Peninsula of north-west Siberia, homeland of the Yamal Nenets. Since the discovery of super-giant natural gas fields in the 1960s, extensive exploration has resulted in the direct withdrawal of large areas for infrastructure development and associated disturbance regimes have led to cumulative impacts on thousands of additional hectares of land. The land withdrawals have pushed a relatively consistent or increasing number of reindeer onto progressively smaller parcels of pasture. This has led to excessive grazing and trampling of lichens, bryophytes and shrubs and, in many areas, erosion of sandy soils via deflation. The low Arctic tundra lies entirely within the continuous permafrost zone and ice-rich substrates are widespread. One implication of this is that both anthropogenic and zoogenic disturbance regimes may easily initiate thermokarst and aeolian erosion, leading to significant further losses of pastures. Even without industrial disturbance, a slight change of the climate would result in massive thermokarst erosion. This would have negative consequences equal to or greater than the mechanical disturbances described above. The synergistic effects of land use coupled with climate change therefore have profound implications for the ecosystems of Yamal, as well as the future of the Nenets culture, society and economy. RI Forbes, Bruce/L-4431-2013 OI Forbes, Bruce/0000-0002-4593-5083 SN 0800-0395 PY 1999 VL 18 IS 2 BP 367 EP 373 DI 10.1111/j.1751-8369.1999.tb00316.x UT WOS:000085228300037 ER PT J AU Kojola, I AF Kojola, I TI Sex ratio and maternal investment in ungulates SO OIKOS AB Differential maternal investment in sons and daughters can be accomplished by adjusting the sex ratio of offspring or by investing differentially in individual sons and daughters. In polygynous mammals, such as most ungulates, sons are larger than daughters at the end of the lactation period, and the raising of a son can be more expensive than raising a daughter. After weaning, daughters will provide extra maternal investment by sharing their mothers' home range, and local resource competition probably increases the costs associated with producing a daughter. In some species sons seem to benefit from their mothers' phenotypical superiority through heavier maternal investment before weaning. while daughters can share their mothers' high social rank also after weaning. I suggest from the reviewed literature that local resource competition shapes offspring sex ratios at the population level most clearly when the diet type is browse that is a more defendable resource than graze. It is also probable that differential costs, for trample in the form of the subsequent reproductive success and the survival of the mother, are associated with producing sons and daughters are an important selective force modifying sex ratios born to superior and weak females within populations, in addition to a stronger correlation between mothers' quality and the reproductive success of the offspring of one sex. This correlation can be associated also with fitness costs, because the rearing of a weakly competitive offspring may result in the wastage of reproductive effort. SN 0030-1299 PD DEC PY 1998 VL 83 IS 3 BP 567 EP 573 DI 10.2307/3546683 UT WOS:000078350500016 ER PT J AU Choquenot, D AF Choquenot, D TI Testing the relative influence of intrinsic and extrinsic variation in food availability on fetal pig populations in Australia's rangelands SO JOURNAL OF ANIMAL ECOLOGY AB 1. Intrinsic variation in the availability of food to animal populations reflects the influence of foraging by the animals themselves. Intrinsic variation in food availability provides a link between population density, subsequent food availability and variation in the rate of population increase (r), operating through density-dependent food shortage. In contrast, extrinsic variation in food availability is caused by environmental influences on food or animal abundance, which are independent of animal foraging. Extrinsic variation in food availability is random relative to that arising through intrinsic shortage. Intrinsic and extrinsic variation in food availability can influence animal populations simultaneously. Intrinsic variation will impart a tendency towards an equilibrium between animal and food abundance, which will be progressively obscured by density-independent variation as the influence of extrinsic factors increases. 2. This study used a large-scale field experiment, in which the density of food-limited feral pig (Sus scrofa L.) populations was manipulated on six sites, to assess the relative influence of intrinsic and extrinsic variation in food availability. The experiment evaluated the influence of pig population density on r and the abundance of food resources measured as pasture biomass. It was predicted that if intrinsic shortages dominated variation in food availability, pasture biomass and r would decline with increasing pig density. If extrinsic factors dominated variation in food availability, pig density would have no systematic effect on either pasture biomass or r. If intrinsic and extrinsic sources simultaneously affected variation in food availability, higher pig densities would have no systematic effect on r, but would reduce pasture biomass. The simultaneous model predicts reduced pasture biomass because, in the absence of compensatory changes in other sources of variation, the effects of intrinsic and extrinsic factors will be additive. 3. To examine further the degree of interdependence in pig and pasture abundance, a series of stochastic models of the grazing system were estimated and the feedback loop comprising the functional and numerical responses of feral pigs to variation in pasture biomass was manipulated. 4. In the large-scale experiment, neither pasture biomass nor r declined with increasing pig density, suggesting that food availability was dominated by extrinsic factors. However, limitations of the experiment meant that a minor decline in pasture biomass may have gone undetected. Comparison of simulation models, which included and omitted pasture offtake by pigs, indicated that because they were less efficient grazers and persisted at lower average densities relative to other large herbivores, pigs had little influence on variation in pasture biomass. 5. The minor influence pigs appear to exert on pasture biomass suggests that trophic processes, typically invoked to explain herbivore population persistence, have, at best, limited consequences for pig populations. Despite this, simulation models indicate that pigs are able to persist indefinitely under rangelands conditions, because their high intrinsic capacity for increase (r(m) = 0.69) means that they are able to exploit periods when pasture is plentiful more effectively than other large herbivores. 6. The study concludes that intrinsic and extrinsic sources of variation in food availability represent two extremes of a continuum in the strength of interaction between herbivores and their food resources. The position or a grazing system along this hypothetical continuum depends on the relative influence of stochastic, density-independent environmental processes (extrinsic variation) and the efficiency of its vegetation-herbivore feedback loop (intrinsic variation). Feral pig populations in the rangelands appear to occupy a position towards the extrinsic extreme of this continuum. where their dynamics are more influenced by extrinsic than intrinsic sources of variation in pasture availability. RI Choquenot, David/D-8016-2013 SN 0021-8790 PD NOV PY 1998 VL 67 IS 6 BP 887 EP 907 DI 10.1046/j.1365-2656.1998.6760887.x UT WOS:000077670300005 PM 26412369 ER PT J AU Ohtonen, R Vare, H AF Ohtonen, R Vare, H TI Vegetation composition determines microbial activities in a boreal forest soil SO MICROBIAL ECOLOGY AB Forest soil ecology was studied in Fennoscandinavian dry Scots pine forests grazed by reindeer to varying extents (ungrazed, lichen-dominated-sires; grazed sites; and bryophyte-dominated sites). We hypothesized that the productivity parameters of the site (i.e., tree growth and soil nutrient concentrations), the vegetation composition, and the microbial activities are directly correlated. Since the productivity of the lichen-dominated ecosystem is low, microbial activities are assumed to be naturally low. Grazing was expected to decrease both the amount of Scots pine fine roots and the soil microbial activities. Several variables on the characteristics of the soil microbial community, Scots pine fine roots, soil nutrients, and tree growth were studied in relation to vegetation composition by using non-metric multidimensional scaling (NMDS). Basal respiration (Bas), metabolic quotient of the microbial community (qCO(2)), and pine fine root parameters increased toward the ungrazed, nutrient-poor, lichen-dominated sites, which were grouped at one end of the first axis in the NMDS ordination. Soil nutrient and tree growth parameters and thickness of the humus layer increased toward bryophyte-dominated sites, which were grouped at the other end of the first axis in the ordination. The grazed sites fell between them. These were characterized by lower Bas and qCO(2) values and longer lag, compared to ungrazed lichen- or bryophyte-dominated sites, probably due to decreased carbon input and microclimatic change (the soil without lichen carpet is exposed to direct sunlight and wind). Microbial biomass (Cmic), fungal biomass (ergosterol concentration), and the specific growth rare (mu CO2) were not related to vegetation ordination. The high fine root production is the most plausible explanation for the high microbial activities at nutrient-poor, lichen-dominated sites, which produce qualitatively poor and slowly decomposing litter, as fine roots secrete considerable amounts of organic substances. At bryophyte-dominated sites, the higher soil nutrient concentrations and the higher production of easily decomposable substrates are likely to maintain the microbial activities. SN 0095-3628 PD NOV-DEC PY 1998 VL 36 IS 3 BP 328 EP 335 DI 10.1007/s002489900119 UT WOS:000077586800011 ER PT J AU Arseneau, MJ Ouellet, JP Sirois, L AF Arseneau, MJ Ouellet, JP Sirois, L TI Fruticose arboreal lichen biomass accumulation in an old-growth balsam fir forest SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE AB The standing biomass accumulation of Lichens from the genera Alectoria, Bryoria, and Usnea was studied along two environmental gradients, altitude and height along the vertical tree axis, in an old-growth balsam fir (Abies balsamea (L.) Mill.) forest. Lichens were sampled from 50 trees in five sampling sites at an altitude of 720-1068 m asl and encompassing three vegetation belts (mountain, subalpine, and alpine). The lichen biomass accumulation rate was studied at branch and tree levels. The Gompertz equation was used to assess the relationship between time since lichen colonization and standing lichen biomass. The relationship between tree lichen biomass and age was not significant. Colonization delay was assumed to correspond to the age of the youngest branch supporting a given lichen taxon, and our results show that it increased from mountain to alpine belts. Variations in lichen accumulation were related to the branch position along the tree height and altitude. Lichen biomass accumulation rates decreased from tree top to base. We speculate that this reduction reflects a response to microclimatic gradients, aging of thalli, fragmentation, competition, succession, and caribou grazing. The accumulation rate was greater in the mountain belt (r = 0.063) than in the alpine belt (r = 0.027). In the subalpine belt, the relationship between Lichen biomass and time was not significant (p > 0.05). The decrease in accumulation rate along the altitudinal gradient may be primarily explained by climatic conditions. SN 0008-4026 PD OCT PY 1998 VL 76 IS 10 BP 1669 EP 1676 DI 10.1139/b98-144 UT WOS:000079062800001 ER PT J AU Perez-Barberia, FJ Mutuberria, G Nores, C AF Perez-Barberia, FJ Mutuberria, G Nores, C TI Reproductive parameters, kidney fat index, and grazing activity relationships between the sexes in Cantabrian chamois Rupicapra pyrenaica parva SO ACTA THERIOLOGICA AB Reproductive parameters, kidney fat index and grazing activity of both sexes of Cantabrian chamois Rupicapra pyrenaica parva (Cabrera, 1910) in relation to age, season and year are presented and compared with those of other chamois subspecies and cervids. Females younger than three years old had not ovulated. Ovulated ovaries were significantly heavier than non-ovulated ovaries in March-April, and these differences remained until the following rutting season. All pregnant females carried a single foetus. A significant decrease in the percentage of parous females was found in 3-11 years age class (94%) compared with > 11 years (50%). There were no differences in the kidney fat index (KFI) between age classes for either of the sexes throughout the study period. Females showed a significant higher KFI in August-October 1993 than in August-October 1992, coinciding with a significantly greater abundance of grass in 1993. Throughout the year KFI in females showed less fluctuations than in males. Males began the rutting season with a significant KFI three times higher than did females. However, by the spring, the KFI of the males had fallen to half of that of the females. In March-April pregnant females showed a significantly higher KFI than non-pregnant or late-conception adult females. Feeding activity of females and sward height throughout the year were inversely related. Females grazed more actively than males in the summer, rut and spring, except in winter where no differences in feeding activity between sexes were found. The differences in the KFI and feeding activity are discussed in relation to the parental investment and the sexual dimorphism-body size theory. RI Perez-Barberia, Javier/M-9847-2017 OI Perez-Barberia, Javier/0000-0001-7513-5418; Nores-Quesada, Carlos Ignacio/0000-0002-3042-1960 SN 0001-7051 PD SEP PY 1998 VL 43 IS 3 BP 311 EP 324 DI 10.4098/AT.arch.98-26 UT WOS:000076561000010 ER PT J AU Engelmark, O Hofgaard, A Arnborg, T AF Engelmark, O Hofgaard, A Arnborg, T TI Successional trends 219 years after fire in an old Pinus sylvestris stand in northern Sweden SO JOURNAL OF VEGETATION SCIENCE CT IAVS Workshop on Disturbance Dynamics in Boreal Forests CY AUG 26-30, 1996 CL UNIV QUEBEC ABITI TEMISCAAMINGUE, ROUYN-NORANDA, CANADA SP IAVS HO UNIV QUEBEC ABITI TEMISCAAMINGUE AB We present results from repeated analyses (1962, 1993) of a permanent plot established in 1947, combined with retrospective stand age structure data, in an old Pinus sylvestris stand in Muddus National Park, northern Sweden. The study points towards a successional pathway governed by concurrent disturbance effects of climate variability, reindeer grazing and fire. This is intermediate to the two often advocated ideas on dynamics in boreal forests, that is, one of disturbance-related tree regeneration/mortality and one of continuous regeneration. When the plot was established in 1947 the tree layer (> 1.3 m) consisted of 300 individuals/ha of P. sylvestris and 62/ha of Betula pubescens. Subsequently the stand has become more dense and the species dominance has shifted. In 1993, 362 P. sylvestris and 62 Picea abies individuals were present per ha, while no Betula individuals were found. The number of dead trees increased from zero in 1947 to 200/ha (Pinus) in 1993. Pinus was also the most common species in the sapling layer (< 1.3 m) throughout the study period, though the number dropped from 8912/ha in 1947 to 51 % in 1993. Dead saplings decreased from 2650/ha in 1947 to ca. 50 % in 1962, and only 9 % in 1993. Temporal variations in mortality and sapling mean height coincided with variations in snow depth, indicating a critical period in sapling development when saplings are exposed at the snow/atmosphere interface. The number of Living Picea saplings increased slowly until 1993; no dead saplings were found. Most Pinus recruited shortly after the 1774-fire, and during the second half of the 1900s. The major part of the spruce regeneration took place during the later half of the 1900s. No successful Betula recruitment has occurred after the 1930s, and no live Betula were present in 1993, which might be explained as an effect of increased reindeer browsing - the reindeer stock has grown by 50 % since 1961. Although subjected to high mortality, Pinus regenerated and maintained a seedling/sapling bank. In this way Pinus remained dominant in the tree layer after more than 200 postfire years. The importance of the shade-tolerant Picea has slowly increased, while Betula has died off. Thus, even after 219 yr since fire there is an early successional trend in the stand. This suggests that an increased chronic disturbance (grazing/browsing by reindeer) has partly succeeded earlier discrete fire-disturbance events, and maintained a continuous seedbed favouring the shade-intolerant pine recruitment. SN 1100-9233 PD AUG PY 1998 VL 9 IS 4 BP 583 EP 592 DI 10.2307/3237274 UT WOS:000076951800015 ER PT J AU Wegener, C Odasz-Albrigtsen, AM AF Wegener, C Odasz-Albrigtsen, AM TI Do Svalbard reindeer regulate standing crop in the absence of predators? A test of the "exploitation ecosystems" model SO OECOLOGIA AB The Svalbard reindeer is the only mammalian herbivore in Adventdalen (78 degrees N), Svalbard, where it has no natural predators. To test if herbivores in the absence of predators regulate standing crop to a level independent of productivity, which is one of the predictions of the "exploitation ecosystems" model, herbivore exclosures were set up in 1992 in Salix heath, Luzula heath, Cassiope heath, and Alopecurus meadow in Adventdalen. Standing crop of vascular plants was harvested and measured inside and outside the exclosures in 1994, when the reindeer population was at peak density (ca 5.4 animals km(-2)), and in 1996, when the reindeer density was about 30% lower (ca 3.7 animals km(-2)). Standing dead material was reduced by grazing in the Luzula heath in 1994. However, we found no effect of grazing, year, or interactions between grazing and year on live standing crop. Also contrary to the predictions from the model, differences in standing crop between vegetation types were highly significant. Mean biomass of plant material was lowest in the Alopecurus meadow (36 g m(-2)), two fold higher in the Luzula heath, and about threefold higher in the Salix heath and Cassiope heath, indicating that reindeer do not regulate standing crop to the same level on a local scale. The predictive power of the "exploitation ecosystems" model is low due to lack of recognition of the importance of plant chemistry, plant compensation ability, variation in forage availability during the year, parasites functioning as predators: and adverse weather conditions. which may cause density-independent variations in fecundity and mortality of reindeer. SN 0029-8549 PD AUG PY 1998 VL 116 IS 1-2 BP 202 EP 206 DI 10.1007/s004420050580 UT WOS:000075835200024 PM 28308527 ER PT J AU Crete, M Doucet, GJ AF Crete, M Doucet, GJ TI Persistent suppression in dwarf birth after release from heavy summer browsing by caribou SO ARCTIC AND ALPINE RESEARCH AB The Riviere George Caribou Herd (RGCH), in northern Quebec, erupted during a few decades to culminate at approximately 800,000 animals by 1990. The RGCH appeared regulated by competition for summer forage. Repeated browsing and trampling reduced summer range productivity to 50% compared to ungrazed areas, Lichens and dwarf birch having been mostly responsible for this reduction. A reconnaissance flight in 1991 and intensive field work the following two summers suggested that caribou use of dwarf birch leaves was light following the period of peak numbers. We hypothesized that birch stands would show signs of rapid and vigorous recovery in 1993-1994. We surveyed five heavily browsed birch stands, and two inaccessible, lightly browsed ones. Although utilization of birch leaves by caribou ranged between 0 and 6% during the 1994 growing season, heavily browsed stands exhibited no signs of rapid and strong recovery. Young plants did not abound in heavily browsed stands compared to lightly browsed ones, neither was wood accumulation faster in the former than in the latter. Stem density and height were similar in heavily browsed and lightly browsed stands. However, the leaf/wood ratio and the percent dry weight of leaves and wood were higher in lightly browsed than in heavily browsed stands, which resulted in approximately twice as high leaf biomass in lightly browsed than in heavily browsed stands. We hypothesized that previous intense caribou browsing caused a persistent suppression of dwarf birches, and that stems could not accumulate sufficient reserves during a growing season to deploy more leaves in the next spring in order to return the leaf/wood ratio to a normal value. We discuss the consequences of such a reaction of dwarf birch to herbivory on the demography of the RGCH. SN 0004-0851 PD MAY PY 1998 VL 30 IS 2 BP 126 EP 132 DI 10.2307/1552127 UT WOS:000073952600004 ER PT J AU Bowyer, RT Kie, JG Van Ballenberghe, V AF Bowyer, RT Kie, JG Van Ballenberghe, V TI Habitat selection by neonatal black-tailed deer: Climate, forage, or risk of predation? SO JOURNAL OF MAMMALOGY AB We studied habitat selection by neonatal (2-10 days old) black-tailed deer (Odocoileus hemionus columbianus) on Big Flat, Trinity Co., California, during June-August, 1992-1993. Even deer 2-3 days old frequently followed their mothers and occurred in social groups with other adult deer. Neonates used south-facing slopes with gentle terrain and high variability in overstory and concealment cover more often than expected from availability of those habitat variables. Young deer also selected sites with more herbaceous vegetation but avoided areas with more browse. Forage was more digestible at sites with neonates than at random sites, but no difference occurred in nitrogen content of forage between those sites. Variables identified as important components of habitat for young deer more Likely were related to the thermal environment of the neonate and nutritional demands of lactating females than to risk of predation. Alternatively, variation in concealment cover may have been related to predation risk, resulting in a positive relationship between forage availability and risk predation. Minimizing the predation:forage ratio was not a viable model for explaining habitat selection in neonates. SN 0022-2372 PD MAY PY 1998 VL 79 IS 2 BP 415 EP 425 DI 10.2307/1382972 UT WOS:000073776100004 ER PT J AU Kumpula, J Colpaert, A Nieminen, M AF Kumpula, J Colpaert, A Nieminen, M TI Reproduction and productivity of semidomesticated reindeer in northern Finland SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB The increase in the Finnish semidomesticated reindeer (Rangifer tarandus tarandus) stock and the high level of meat production during the 198Os and the beginning of the 1990s were mainly due to reindeer-management practices. However, the continuing deterioration of winter-range quality has now forced reindeer managers to invest increasingly in supplementary feeding. At the same rime, carrying-capacity models for semidomesticated-reindeer ranges have proved difficult to develop. This study deals with reproduction and productivity of the reindeer stock in northern Finland during the period 1987-1995. The results reveal that reproduction and productivity of reindeer in the study area are largely regulated by density-dependent factors related to the quantity and quality of winter ranges. Reindeer densities on total rangeland had the strongest effect on the slaughter body masses of reindeer, which indicates the special importance of summer and autumn pastures for growth and autumn condition of reindeer. Through intensive calf slaughtering, the natural mortality rate was minimised and reproduction rates and reindeer meat production were increased, although winter ranges were heavy grazed. Developing semidomesticated-reindeer husbandry to be more economical in the future by keeping sustainable meat production at a sufficiently high level while maintaining reindeer rangeland in adequate condition and supplementary feeding quite marginal in Finland involves consideration of both ecological and management factors. One way of looking at the economic carrying capacity of Finnish semidomesticated-reindeer ranges is to develop a model based on dependence among the factors presented in this study. Sustainable net incomes from reindeer husbandry could then be optimised by studying and modelling the economy of reindeer management itself with respect to stock density. SN 0008-4301 PD FEB PY 1998 VL 76 IS 2 BP 269 EP 277 DI 10.1139/cjz-76-2-269 UT WOS:000074053500009 ER PT B AU Tommervik, H Hemberg, L Hagner, O Baer, K Stinnerbom, T Umander, G Persson, E AF Tommervik, H Hemberg, L Hagner, O Baer, K Stinnerbom, T Umander, G Persson, E GP ISRSE ISRSE TI Mapping of reindeer grazing areas in the areas of Vilhelmina/Fredrika in Sweden using remote sensing and DGPS technology SO 27TH INTERNATIONAL SYMPOSIUM ON REMOTE SENSING OF ENVIRONMENT, PROCEEDINGS: INFORMATION FOR SUSTAINABILITY CT 27th International Symposium on Remote Sensing of Environment CY JUN 08-12, 1998 CL TROMSO, NORWAY SP Norsk Romsenter (Norwegian Space Ctr), Miljoverndepartementet, CIESIN, USGS, NASA, NOAA, UNEP, ESA, EUMETSAT, Kongsberg Spacetec AS, Space Applicat Inst, Joint Res Ctr European commiss, Tromso Satellite Stn AS, Space Imaging EOSAT, Norwegian Minist Environm AB The intention of the present project was to map the present state of the reindeer ranges especially in the forests by using satellite images,and to extraxt parameters about the grazing capabilities mainly in the forests in the Vilhelmina and Fredrika (Bjurholm) areas in Sweden. The total overall accuracies of the maps produced during the project were estimated to be c. 86%+/-5% for the summer pasture map in Vilhelmina,and about 88.5%+/-8% for the winter pasture map in the Fredrika area. The state of the lichens in the forests was very good, meaning that the reindeer herders within this area of Sweden had a very balanced and sustainable reindeer management practice. Clear cutting activities by large forest companies have reduced the lichen resources (the mean winter diet for the reindeer) in the lichen dominated pine forests within the Fredrika area. BN 82-7542-040-7 PY 1998 BP 530 EP 531 UT WOS:000078443800129 ER PT J AU Morneau, C Payette, S AF Morneau, C Payette, S TI A dendroecological method to evaluate past caribou (Rangifer tarandus L.) activity SO ECOSCIENCE AB Records of population changes of caribou come from various sources (historical accounts, hunting and trading statistics, herd surveys) that are typically incomplete and discontinuous in Lime and space. Here Ne propose a new method for the evaluation of past caribou activity using tree-ring records from boreal and subarctic conifer stands. The age-frequency distributions of trampling scars produced by caribou hooves on surficial roots and low branches of erect and stunted conifers are used as an index of the passage of caribou through stands during the snow-free period. To verify if changes in the age structure of trampling scars correspond to changes in abundance of caribou movement, we analyzed factors influencing production and loss of scars at tyro lichen-woodland sites in northeastern Quebec-Labrador (Canada). The detailed analysis of trampling scars in the first site indicates that the capacity of conifers to produce scars is maintained under a regime of repeated caribou traffic scars were formed at new positions along the exposed roots and scars continued to be produced at a same position in a minimum time of one growing season, even after 15 years of caribou traffic. The influence of repeated caribou trampling on loss of scars was measured by comparing the age structure of scars of three vegetation groups (based on caribou trail network) with different intensities of use. The similarity of the age structures of the three groups showed that scar loss due to trampling was hardly detectable, which indicated that scar loss was low in comparison to the number of scars produced, even in the most used trails. Sampling of trampling scars during two successive years at the second site showed that the stability of the age structure of scars was nor affected by moderate caribou traffic. Our results, therefore, indicate that most of the information deduced from the age structures of trampling scars comes from changes in caribou activity. The method opens the possibility of assessing caribou activity in time (several decades) and space over large areas of the boreal forest and the forest-tundra biomes. SN 1195-6860 PY 1998 VL 5 IS 1 BP 64 EP 76 DI 10.1080/11956860.1998.11682446 UT WOS:000073736000009 ER PT J AU Brouillet, L Hay, S Turcotte, P Bouchard, A AF Brouillet, L Hay, S Turcotte, P Bouchard, A TI The alpine vascular flora of the Big Level Plateau, Gros Morne National Park, Newfoundland. SO GEOGRAPHIE PHYSIQUE ET QUATERNAIRE AB The alpine vascular flora of the Big Level Plateau, Gros Morne National Park, Newfoundland. The alpine flora of northeastern North America is well documented, with the exception of the Long Range Mountains of Newfoundland. The gneissic Big Level plateau is one of the largest high altitude plateaus of the Long Range Mountains. Among the alpine habitats encountered, the numerous snowbed communities contribute the most to vascular plant biodiversity with 73 of the 92 species observed in the alpine zone of the plateau. The 21 rare vascular plant species found on the plateau are all in habitats associated with snowbeds. These species represent about 20% of all rare plants in Gros Morne National Park. Among these, three are southern range extensions from the northern tip of the island: Carer lachenalii, Salix argyrocarpa and Veronica wormskjoldii. The biogeographic composition of the snowbed flora in the Gulf of St. Lawrence New England area, with its circumpolar, cordilleran, northeastern North American and amphi-Atlantic elements, contributes to the exceptional floristic character of the plateau. The intensive grazing of peripheral Carer swards by the large caribou herd of the plateau represents an interesting ecological characteristic of these alpine snowbeds. Also exceptional is the presence of vast areas of hummocky heath with crowberry and Pickering's reedgrass (Empetrum - Calamagrostis pickeringii). These hummocks are caused by frost disturbance on the gentle slopes of the eastern part of the plateau, and to our knowledge, this type of patterned ground has not been reported from the boreal zone of eastern North America; it is a witness of the severity of winters on the plateau. No other granito-gneissic plateau in eastern North America has such extensive or numerous snowbeds. SN 0705-7199 PY 1998 VL 52 IS 2 BP 175 EP 193 DI 10.7202/004774ar UT WOS:000076180200005 ER PT J AU Zobel, K Moora, M Brown, VK Niemela, P Zobel, M AF Zobel, K Moora, M Brown, VK Niemela, P Zobel, M TI Secondary succession and summer herbivory in a subarctic grassland: community structure and diversity SO ECOGRAPHY AB A field experiment was established in a subarctic grassland in the Finnish Lapland to study the role of summer herbivory in plant community succession. Perennial vegetation and moss cover were removed in an area of 324 m(2). The site was divided into four blocks, of which two were fenced to prevent herbivory by large mammals (reindeer, hare). Early successional changes in the vegetation were assessed. Mean species richness per 3 x 3 m plot was consistently higher in the fenced area, indicating that herbivory can suppress small-scale diversity. Herbivory affected the height of several plant species. However, there was no correlation between frequency and height of individual species. There was a weak indication that taller species were more successful in early succession when grazed. Light competition is apparently not a key process determining successional change. Thus, in early stage of succession, summer herbivory has little effect on diversity by limiting light competition, and most species are equally successful in grazed and ungrazed plots. There was some indirect evidence about competitive interactions in the developing community. However, unlike temperate grasslands, large mammal herbivory and competition for light seem not to be important determinants of community change in this subarctic grassland (at least what concernes early successional stages). This may be explained by the harshness of local climate, and abundance of light due to the polar day. RI Zobel, Martin/H-1336-2015; Moora, Mari/D-1961-2009; Zobel, Kristjan/F-2003-2011 OI Zobel, Martin/0000-0001-7957-6704; Moora, Mari/0000-0002-4819-7506; SN 0906-7590 PD DEC PY 1997 VL 20 IS 6 BP 595 EP 604 DI 10.1111/j.1600-0587.1997.tb00428.x UT WOS:000071524800008 ER PT J AU Wegener, C Odasz, AM AF Wegener, C Odasz, AM TI Grazing response strategies along a snow deposition gradient: a laboratory experiment on three grass species from Svalbard SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE AB The objective of this study was to determine whether Arctic grasses from different sites along a snow deposition gradient respond similarly to grazing. The effects of laboratory simulated grazing (two levels of clipping frequency, clipping height, and nutrition) on accumulated biomass of different plant parts and number of tillers were measured in the reindeer forage grasses Poa arctica R. Br. from a dry ridge habitat, Festuca rubra L. from a moist lee-side habitat, and Deschampsia alpina L. from a wet snowbed habitat in Svalbard. Both P. arctica and F. rubra increased the proportion of biomass allocated belowground at the cost of the aboveground structures in response to high clipping frequency combined with high clipping height, leaving total accumulated biomass unchanged. In D. alpina, on the contrary, the percentage of aboveground biomass increased at the cost of belowground structures in response to high clipping frequency and low clipping height. This results in higher vulnerability to clipping and reduced total biomass. These two contrasting response patterns may reflect differences in adaptations in the habitats. Stress tolerance is more important on wind-blown ridges and in lee-side habitats where the grazing season is longer. On the other hand, rapid growth is more important in the snowbed where the growing season is shorter. These strategies may be of great importance in regulating and driving the local foraging patterns of Svalbard reindeer. SN 0008-4026 PD OCT PY 1997 VL 75 IS 10 BP 1685 EP 1691 DI 10.1139/b97-882 UT WOS:A1997YJ56100009 ER PT J AU Wegener, C Odasz, AM AF Wegener, C Odasz, AM TI Effects of laboratory simulated grazing on biomass of the perennial Arctic grass Dupontia fisheri from Svalbard: Evidence of overcompensation SO OIKOS AB The perennial grass Dupontia fisheri is an important forage for reindeer (Rangifer tarandus platyrhynchus) in Svalbard. In a growth chamber experiment, biomass and tillering responses to different clipping frequencies and clipping heights, simulating different reindeer grazing pressures, were measured al two nutrition levels during two growth periods. Total accumulated biomass was reduced by clipping at high frequency, low height, or both in the first growth period, but was unaffected by clipping in the second growth period. Moreover, the reducing effect of clipping on total biomass was present at low nutrition level only; i.e. plants compensated for high simulated grazing pressure when sufficient nutrients were available. Aboveground biomass was reduced 36% by high clipping frequency in the first growth period, but, due to a 61% reduction in aboveground biomass with time in unclipped plants, clipped groups appeared to have higher mean aboveground biomass than unclipped during the second growth period. This observation could be explained by increased self-shading in the unclipped control plants over time. Although the interactions between nutrition and clipping treatments indicate that regrowth of D, fisheri is resource dependent, these results also suggest that grazing by reindeer is important for the maintenance of a high net aboveground production in D. fisheri in Svalbard. SN 0030-1299 PD SEP PY 1997 VL 79 IS 3 BP 496 EP 502 DI 10.2307/3546893 UT WOS:A1997XF18500010 ER PT J AU Nellemann, C Reynolds, PE AF Nellemann, C Reynolds, PE TI Predicting late winter distribution of muskoxen using an index of terrain ruggedness SO ARCTIC AND ALPINE RESEARCH AB We tested the hypothesis that occurrence of rugged terrain would affect distribution patterns of muskoxen (Ovibos moschatus) in late winter through expected higher availability of forage. Indices of terrain ruggedness (TRI) based on contour characteristics from topographical maps were found to be correlated with occurrence of muskoxen in late winter 1982-1990 in northeastern Alaska. Rugged terrain (TRI > 2.5) constituted less than half of the study area, but contained 83% of all muskoxen observed during 1982-1990. Occurrence of rugged terrain partly explained differences in density of muskox among 12 major drainages in the study area. Within 7 of 8 drainages having >30% rugged quadrats, density of muskoxen was correlated to terrain ruggedness. The study corresponds well with studies of snow characteristics, terrain ruggedness and forage availability. The results indicate, that availability of rugged terrain likely affects distribution patterns of muskox by influencing local vegetation and snow characteristics. Analysis of terrain structure may thus in combination with data on snow and vegetation patterns improve bur understanding of distribution patterns of this arctic grazer during winter. SN 0004-0851 PD AUG PY 1997 VL 29 IS 3 BP 334 EP 338 DI 10.2307/1552148 UT WOS:A1997XU11300009 ER PT J AU Nellemann, C AF Nellemann, C TI Grazing strategies of muskoxen (Ovibos moschatus) during winter in Angujaartorfiup Nunaa in western Greenland SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB Terrain and vegetation use by muskoxen (Ovibos moschatus) during winter was examined through surveys of fecal pellet groups in western Greenland in 1994. Being virtually free of snow, Kobresia myosuroides steppe and dry and moist shrub heath were used extensively by muskoxen. Use varied among the three heath vegetation types in relation to the proportion of shrubs to graminoids, with most use being made of K. myosuroides steppe. Density of fecal pellet groups varied from 300 groups/ha at a graminoid biomass of ca. 30 g/m(2) to >2500 groups/ha where biomass exceeded 100 g/m(2). Within K. myosuroides steppe, density of fecal pellet groups was <500 groups/ha on narrow ridges compared with >2000 groups/ha on wider steppe formations. Adaptation by muskoxen to grazing steppe-like vegetation throughout the Late Pleistocene may explain the extraordinarily rapid growth of the population in this grass steppe landscape in western Greenland. SN 0008-4301 PD JUL PY 1997 VL 75 IS 7 BP 1129 EP 1134 DI 10.1139/z97-135 UT WOS:A1997XJ88200015 ER PT J AU Chown, SL Block, W AF Chown, SL Block, W TI Comparative nutritional ecology of grass-feeding in a sub-Antarctic beetle: The impact of introduced species on Hydromedion sparsutum from south Georgia SO OECOLOGIA AB South Georgia has many introduced plant and animal species, a consequence of its long history of human habitation. Introduced reindeer have a strong effect on the vegetation of the Stromness Bay area by causing the replacement of indigenous species by grazing-tolerant grasses such as the exotic Poa annua, and in certain circumstances, the indigenous Festuca contracta. Recently it has been argued that an introduced predatory carabid has contributed to declines in the abundance and an increase in the body size of adults of the indigenous perimylopid beetle Hydromedion sparsutum. However, it also appears that body size of these beetles is smaller in areas where exotic grasses predominate compared to undisturbed areas. Here we test the hypothesis that by causing the spread of poorer quality grasses, especially the exotic Poa annua, reindeer may be having an indirect effect on N. sparsutum. To do this eve examined the nutritional ecology of H. sparsutum larvae on four grass species which form a major part of its diet, viz. the indigenous Parodiochloa flabellata, Phleum alpinum and Festuca contracta, and the exotic Poa annua. Larvae showed the highest growth rate on Parodiochloa flabellata: followed by Phleum alpinum, F. contracta and Poa annua. These differences are due to poorer absorption of the exotic grass, and poorer utilization of the absorbed material in the case of F. contracta. Poor growth of larvae on F, contracta appears to be due to its low water and nitrogen contents, whereas in the case of P. annua a combination elf low water content and high nitrogen content may be responsible for low growth rates. Low growth rates associated with poor quality food may lead either to a prolongation of the life cycle or of the length of feeding bouts of an insect. Neither option appears to be feasible for H. sparsutum, and this means that the outcome of feeding on poorer-quality foods would be a reduction in final adult size. This has fitness consequences for the beetle. Hence it appears that by causing the spread of grasses that are unsuitable for growth of H. sparsutum, reindeer may be hating an indirect effect on this beetle species. RI Chown, Steven/H-3347-2011 OI Chown, Steven/0000-0001-6069-5105 SN 0029-8549 PD JUL PY 1997 VL 111 IS 2 BP 216 EP 224 DI 10.1007/s004420050228 UT WOS:A1997XK99200010 PM 28307997 ER PT J AU Gaston, AJ Ouellet, H AF Gaston, AJ Ouellet, H TI Birds and mammals of Coats Island, NWT SO ARCTIC AB We summarize records of birds and mammals obtained at Coats Island, Northwest Territories during one visit by a National Museum of Natural Sciences expedition and fourteen visits by Canadian Wildlife Service field crews to the northeast corner of the island, as well as records obtained from the journals of the Hudson's Bay Company post active on the island from 1920 to 1924. The terrestrial mammal fauna is very depauperate, lacking any small herbivores. Consequently, predators specializing in small mammals-such as ermine, snowy owl, and long-tailed jaeger, all common on nearby Southampton Island-are rare or absent from Coats Island, except in passage. In addition, there are no snow goose colonies on Coats Island, although good numbers of Canada geese breed there, and some brant may also do so. This means that grazing on the island is mainly confined to the resident caribou population. The absence of small mammals and the relatively low density of geese may have accounted for the poor results of fox trapping during the period when the Hudson's Bay Company post was operating. Numbers of most marine mammals appear to have changed little since the 1920s, although bowhead whales may have become rarer, with only two sightings since 1981, compared to several annually in the 1920s. Winter records from the 1920-24 postjournals suggest that waters off Coats Island are within the wintering range of beluga, walrus, and thick-billed murres. Eighty-four species of birds have been seen since 1975; this number includes many sightings of vagrant birds well outside their normal ranges. This may be accounted for by the comparative lushness of the vegetation surrounding the thick-billed murre colony, which attracts birds from long distances. SN 0004-0843 EI 1923-1245 PD JUN PY 1997 VL 50 IS 2 BP 101 EP 118 UT WOS:A1997XE93600002 ER PT J AU Arseneault, D Villeneuve, N Boismenu, C Leblanc, Y Deshaye, J AF Arseneault, D Villeneuve, N Boismenu, C Leblanc, Y Deshaye, J TI Estimating lichen biomass and caribou grazing on the wintering grounds of northern Quebec: An application of fire history and Landsat data SO JOURNAL OF APPLIED ECOLOGY AB 1. Landsat Thematic Mapper (TM) remote sensing imagery, previously published fire history data (Payette et al. 1989), and field observations were used to examine the influence of caribou grazing in part of their lichen-dominated wintering grounds in northern Quebec, Canada. Lichen biomass and percentage ground cover were measured in 1989 and 1992 over a large area (88 150 km(2)) stratified into five postfire successional stages. 2. Lichen-dominated vegetation covered 55%, moss- or shrub-dominated vegetation 25%, and water bodies 20% of the study area. Lichen biomass increased with postfire stand age, from 530 kg ha(-1) in young stands (<30 years) to 8010 kg ha(-1) in old stands (>90 years). The cumulative amount of lichen cover removed by caribou before 1989 averaged 10% over the study area; by 1992 this value had risen to 21%. Between 1989 and 1992, ground cover of lichens decreased from 55 to 42%. Lichen removal was concentrated in stands >50 years old, where it occurred at a rate of about 5% per year. No significant change in lichen cover was observed in younger stands. 3. The number of caribou grazing in the study area between 1989 and 1992 exceeded the carrying capacity estimated from the annual increment in lichen biomass (approximate to 1% year(-1)); lichens were reduced by both consumption and collateral damage. Lichen cover can be progressively reduced by winter grazing of caribou in large lichen-dominated continental areas in much the same way as in insular ranges. 4. The combination of remote sensed and fire history data may be a helpful tool for managing large herds of wild caribou. SN 0021-8901 PD FEB PY 1997 VL 34 IS 1 BP 65 EP 78 DI 10.2307/2404848 UT WOS:A1997WX89800007 ER PT J AU Virtanen, RJ Lundberg, PA Moen, J Oksanen, L AF Virtanen, RJ Lundberg, PA Moen, J Oksanen, L TI Topographic and altitudinal patterns in plant communities on European arctic islands SO POLAR BIOLOGY AB Vegetation on Bear Island, Jan Mayen and Spitsbergen was investigated along altitudinal and topographic gradients in order to describe the main patterns in plant community distributions and compare them with those on the mainland. In a numerical classification the communities were distinctly differentiated; however, physiognomically similar Racomitrium and Sanionia communities dominated in most habitats on Bear Island and Jan Mayen. On Spitsbergen, moss-dominated communities prevailed in depression sites. High-altitude sites were occupied either by moss-dominated communities or by variable assemblages of fragmented moss cover and scattered vascular plants. Dwarf shrub and grass heaths that were common on the mainland did not occur on grazer-free Bear Island and Jan Mayen, and were confined to the lowest altitudes on Spitsbergen. The lack of grazers on Bear Island and Jan Mayen accounts in part for the differences in vegetation between the mainland and the islands. RI Virtanen, Risto/G-1810-2010; Hamback, Peter/A-8194-2008 OI Virtanen, Risto/0000-0002-8295-8217; Hamback, Peter/0000-0001-6362-6199 SN 0722-4060 EI 1432-2056 PD FEB PY 1997 VL 17 IS 2 BP 95 EP 113 DI 10.1007/s003000050111 UT WOS:A1997WE94900001 ER PT J AU Arseneau, MJ Sirois, L Ouellet, JP AF Arseneau, MJ Sirois, L Ouellet, JP TI Effects of altitude and tree height on the distribution and biomass of fruticose arboreal lichens in an old growth balsam fir forest SO ECOSCIENCE AB Biomass and distribution of arboreal fruticose lichens were studied along two environmental gradients, height along vertical tree axis and altitude, in an old growth balsam fir (Abies balsamea [L.] Mill.) forest in the McGerrigle Range, Gaspe Provincial Park, Quebec. Biomass was estimated by subsampling 53 balsam firs selected from five plots, systematically distributed along an elevational transect. Three vegetation belts (mountain, subalpine, and alpine) located between 720 and 1068 m (above sea level) were sampled. Alectoria sarmentosa, Bryoria spp. and Usnea spp. represented the bulk of epiphytic lichen vegetation. Both gradients influenced lichen biomass and species diversity on balsam fir. The bulk of lichen biomass was found at intermediate heights in trees. In the mountain belt, the number of lichen species was positively correlated with tree height and diameter. Total lichen biomass on trees was predicted by tree diameter and vegetation belt (ln[biomass + 1] = 2.91x + k; R-2 = 0.87; k = -2.07, -3.4, or -5.2 in the mountain, subalpine and alpine belts, respectively). In the same order, estimates of total lichen standing crop were 1306 kg/ha, 150 kg/ha and 11 kg/ha. Decrease in lichen biomass in the alpine and subalpine belts may be related to decrease of tree size, harsh environmental conditions and caribou grazing. SN 1195-6860 PY 1997 VL 4 IS 2 BP 206 EP 213 DI 10.1080/11956860.1997.11682397 UT WOS:A1997XD59900011 ER PT J AU Kullman, L AF Kullman, L TI Tree-limit stress and disturbance - A 25-year survey of geoecological change in the scandes mountains of Sweden SO GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY AB The paper reviews various kinds of geoecological change in the tree-limit ecotone of the Scandes Mountains during the period 1970-95. The focus of the study is a part of a regional network of sites intended for long-term tree-limit monitoring, with special stress on effects of climatic variability. The elevational tree-limits of Betula pubescens ssp, tortuosa, Picea abies and Pinus sylvestris, which rose in response to the climatic amelioration earlier this century, now show clear symptoms of increasing climatic stress and disturbance. This manifests as defoliation, growth recession and reproductive failure, locally leading to some initial elevational tree-limit retraction (unbalanced mortality). Defoliation was preceded by decades of weak summer cooling and an increasingly maritime climate, but recently it correlates significantly with low winter soil temperatures, causing death of needles, shoots and buds. In some habitats, Betula pubescens has suffered from mechanical stress and disturbance by increased snow accumulation. Tree-limit decline is paralleled by analogous responses of high-elevation boreal forests as well as the ground cover, encompassing elevational range-limit retraction of certain plant species, deterioration of alpine/subalpine dwarf-shrub heaths and terricolous lichen mats. These processes coincide with indications of enhanced periglacial activity, chiefly wind deflation of frost-heaved top-soils at exposed sites. Presumably, reindeer trampling and grazing play a certain role in the latter context, although this disturbance interacts with climate cooling and increased storminess. Short-term extreme events, particularly concerning winter climate (e.g, ground frost), represent previously underrated disturbance mechanisms in cold-stressed, high-altitude boreal forest. The results suggest mechanisms of tree-layer regression, which lag behind the most severe stresses and disturbances by decades and make cold-marginal trees increasingly sensitive to climatic extremes and, in addition, unable to respond progressively to later positive weather anomalies, due to major defoliation and hypothetical xylem cavitation. The recorded changes are logical in consequence of the irregular climatic cooling and a more maritime climate since the late 1930s. In a wider perspective, the results fit a current pattern of natural geoecological destabilization and rapid vegetation change in the North Atlantic region. In addition, the results are discussed in the perspective of global climate change and biogeographical records over the past few decades. SN 0435-3676 EI 1468-0459 PY 1997 VL 79A IS 3 BP 139 EP 165 UT WOS:000081067600001 ER PT J AU Ferguson, MAD AF Ferguson, MAD TI Arctic tundra caribou and climatic change: Questions of temporal and spatial scales SO GEOSCIENCE CANADA CT Geological-Association-of-Canada Nuna Meeting - Nunavut Environment Assessment Transect on Looking to the Future: Nunavut Environments, Past and Present CY JUN 14-18, 1996 CL POND INLET, CANADA SP Geol Assoc Canada AB Climatic changes have affected populations of caribou and reindeer (Rangifer tarandus) at scales ranging from a single winter to tens of thousands of years, and from micro-habitats to entire continents. Individuals, populations and the species have adapted to these climatic changes, however, producing complex evolutionary and ecological issues requiring multi-scale, interdisciplinary research. Caribou populations wintering on arctic tundra may be most susceptible to the impacts of anthropogenic climatic change, given the low productivity of their forage, the severity and duration of the winters, and the physical barriers that limit dispersal. Sub-speciation of Rangifer tarandus hypothetically occurred during the Wisconsin glaciation. Recent genetic analyses support the current classification of subspecies, except that Baffin Island caribou may be distinct from barren-ground caribou, R. t. groenlandicus, on mainland Northwest Territories. Baffin caribou may have originated from a small ancestral population in a refugium on Baffin Island during the Wisconsin glaciation; or, they may have originated from immigrants after the Wisconsin glaciation, later experiencing a severe population bottleneck. On a shorter time scale, recent research has suggested that density-independent climatic events occurring over a single winter have caused at least one major population decline among Peary caribou on the Queen Elizabeth islands. Dramatic fluctuations of Greenland populations over the past 200 years have been attributed to climatic changes. However, the onset of some population changes on western Greenland have been inconsistent with the timing of climatic changes. Inuit knowledge of Baffin caribou and studies of tundra caribou on Svalbard, Coats and Southampton islands, South Georgia, and Norway suggest that caribou populations are affected primarily by density-dependent grazing impacts on forage that can last several decades. The discrepancy between these views may be caused by differences in the temporal and spatial scales over which scientific investigations have been conducted, and the measurement of only some ecological factors. Arctic ecological studies require extensive spatial and temporal data before impacts of anthropogenic climate change can be assessed. This will require a longterm interdisciplinary study integrating scientific data from several disciplines, as well as Inuit knowledge. SN 0315-0941 PD DEC PY 1996 VL 23 IS 4 BP 245 EP 252 UT WOS:A1996XB87800011 ER PT J AU Vare, H Ohtonen, R Mikkola, K AF Vare, H Ohtonen, R Mikkola, K TI The effect and extent of heavy grazing by reindeer in oligotrophic pine heaths in northeastern Fennoscandia SO ECOGRAPHY AB Thirty and fifty years old exclosures established in northeastern Fennoscandia in lichen-rich oligotrophic pine Pinus sylvestris forests on podzolised soil were used to study the effect of reindeer grazing on pine fine roots, microbial activity, and on bryophyte, dwarf shrub and lichen biomasses. There were significantly less lichens, especially Cladina stellaris, at grazed than at ungrazed sites. Coverage of other lichens like C. arbuscula and C. rangiferina and bryophytes, especially Dicranum spp., benefitted from grazing. The biomass of vascular plants, mainly Calluna vulgaris, Empetrum nigrum and Vaccinium vitis-idaea, was reduced at grazed sites, although their coverage was not influenced. Microbial activity was significantly lower at grazed sites. The influence of grazing is most obviously mediated by reduced soil moisture during dry periods at grazed sites. Fine root parameters (per soil and stem volumes) were lower at grazed sites (pPCA = 0.072), the first principal component consisting of a number of fine root tips, length and weight. Grazing decreased all exchangeable nutrients by 30-60% in organic layer. Based on PCA the decrease was significant for exchangeable nutrients, although of individual elements only P and S showed statistically significant difference. The extent of heavy grazing in northeastern Fennoscandia coniferous forest was revealed by remote sensing. It revealed extensive area in which reindeer lichens are reduced in northeastern Finland. The Finnish-Russian border can be clearly distinguished in the satellite image composite. SN 0906-7590 EI 1600-0587 PD SEP PY 1996 VL 19 IS 3 BP 245 EP 253 DI 10.1111/j.1600-0587.1996.tb00233.x UT WOS:A1996VD16600005 ER PT J AU Manseau, M Huot, J Crete, M AF Manseau, M Huot, J Crete, M TI Effects of summer grazing by caribou on composition and productivity of vegetation: Community and landscape level SO JOURNAL OF ECOLOGY AB 1 Changes in demography and studies on physical condition of the Riviere George caribou Rangifer tarandus herd have suggested that its size may be primarily regulated by the amount of forage available on the summer range. 2 We therefore document the impact of grazing and trampling on composition and productivity of two plant communities, the shrub tundra and stands of dwarf birch, within this range, Ungrazed sites were rare, but four previously located small areas were used as control sites. 3 For the shrub tundra, the lichen mat was absent in grazed sites and ground previously occupied by lichens was either bare, covered by fragments of dead lichens and mosses or recolonized by early succession lichen species. Ground cover of shrubs not eaten by caribou was lower in grazed sites than in ungrazed sites, and coverage of graminoids, forage shrubs and forbs did not differ significantly between grazed and ungrazed sites. 4 In stands of dwarf birch grazed by caribou, ground cover and leaf biomass of Betula glandulosa was significantly lower than in ungrazed sites. 5 Productivity of forage plant species over the summer range was estimated at 22.5 g m(-2) year(-1) in an ungrazed condition compared to 10.3 g m(-2) year(-1) when grazed. 6 At the landscape level, caribou have fragmented the distribution of their food resource by reducing biomass of shrub tundra and stands of dwarf birch to a very low level. 7 The serious negative impact of migratory ungulates on plant productivity of their summer range may be explained by characteristics of the vegetation and the high carrying capacity of winter compared to summer ranges. Significant factors related to the vegetation are its low resilience and productivity and the absence of a response of vascular plants following removal of lichens. SN 0022-0477 PD AUG PY 1996 VL 84 IS 4 BP 503 EP 513 DI 10.2307/2261473 UT WOS:A1996VH80400002 ER PT J AU Post, ES Klein, DR AF Post, ES Klein, DR TI Relationships between graminoid growth form and levels of grazing by caribou (Rangifer tarandus) in Alaska SO OECOLOGIA AB Herbivores and their forage interact in many ways, in some instances to the benefit or detriment of herbivore and vegetation. Studies of wildebeest (Connochaetes taurinus) in Africa and snow geese (Chen caerulescens) in the Arctic have suggested that these grazers enhance graminoid production in certain sites by repeatedly using them. Other studies have concluded that herbivores are sensitive to local variation in forage quality and quantity, and preferentially use those sites that are intrinsically more productive. In this study, caribou (Rangifer tarandus) were observed foraging at different densities on two adjacent Alaskan ranges, within which particular feeding sites contained predictably high, medium, or low densities of caribou. Vegetation from one high- and one low-use site on each of the high- and low-density ranges was sampled and monitored for productivity, measured as re-growth following clipping, with the objectives of determining which forage characteristics influence usage by grazers and whether the productivity and nature of graminoid growth after clipping were related to grazing history. Forage biomass density (g/m(3)), shoot density (number/m(3)), stand densities of nutrients and minerals (g/m(3)), and forage concentrations of nutrients and minerals (g/100 g tissue) correlated positively with use of sites by caribou. Productivity was independent of previous use by grazers, but consistent within ranges. These results indicate that caribou are sensitive to local variation in forage quality and quantity, preferentially use those sites with higher returns of nutrients and minerals, and have the potential. to enhance graminoid growth on sites that are inherently more productive. SN 0029-8549 EI 1432-1939 PD AUG PY 1996 VL 107 IS 3 BP 364 EP 372 DI 10.1007/BF00328453 UT WOS:A1996VC24600010 PM 28307265 ER PT J AU Moen, J Walton, DWH AF Moen, J Walton, DWH TI Biomass allocation in a subantarctic clonal plant (Acaena magellanica) under grazing by introduced reindeer SO ANTARCTIC SCIENCE AB Biomass allocation and growth by the clonal plant Acaena magellanica were characterized for three populations grazed by introduced reindeer on the subantarctic island of South Georgia. Annual growth markers (internode lengths) were used to divide each rhizome into current year's shoots, one-year-old and two-year-old rhizome segments. Total dry weights were significantly smaller in grazed than in ungrazed populations. Leaf biomass of current year's shoots was very much lower in grazed shoots. Rhizome length and number of leaves were less affected than dry weight by grazing, and the reindeer grazing thus seems to mainly influence biomass accumulation rather than morphology in Acaena. Interactions with Festuca contracta in both grazed and ungrazed areas were also studied in a two-year competition experiment. No apparent release of soil resources (as measured by an increase in plant growth) was apparent in plots where Festuca was removed, but the current year's shoots of Acaena were smaller and more numerous in these plots than in controls, especially in the ungrazed area. OI Walton, David/0000-0002-7103-4043 SN 0954-1020 PD JUN PY 1996 VL 8 IS 2 BP 147 EP 154 UT WOS:A1996UN62900006 ER PT J AU Sand, H Cederlund, G AF Sand, H Cederlund, G TI Individual and geographical variation in age at maturity in female moose (Alces alces) SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB Variation in age at maturity among 2764 female moose (Alces alces) in 14 populations in Sweden was investigated and related to patterns of body growth and characteristics of the environment. Data were collected from animals shot during the hunting season in 1989-1992, and all females were aged and examined for previous pregnancy by inspecting the uterus. Individual variation was large; 10 (1.3%) out of 776 yearlings were classified as previously pregnant, and must have become fertile during their first year of life. Among 2-year-old females 31.2% were mature, while the majority (80.5%) of females became mature at 3 years of age. Age at maturity, calculated as the age at which 50% of the females were mature, was also highly variable among populations and ranged between 2.06 and 3.17 years. Population-specific age at maturity was significantly related to mean yearling carcass mass among populations but not to juvenile, 2-year-old, or adult carcass mass. Approximately 50% of the variation in age at maturity among populations could be explained by the mean rate of body growth between juvenile and yearling stages. High initial rates of body growth and early maturity in a population were strongly associated with low rates of body growth after the yearling stage. No clear relationship was found between age at maturity and population density, amount of browse, latitude, or climatic conditions among populations. This suggests that multiple factors are involved in shaping the geographical pattern of age at maturity and that additional factors such as nutritional quality and age-specific survival must be considered when explaining the mechanisms behind the apparent variation in age at maturity among populations of female moose. SN 0008-4301 PD MAY PY 1996 VL 74 IS 5 BP 954 EP 964 DI 10.1139/z96-108 UT WOS:A1996UN37300020 ER PT J AU SchultzeLam, S Ferris, FG SherwoodLollar, B Gerits, JP AF SchultzeLam, S Ferris, FG SherwoodLollar, B Gerits, JP TI Ultrastructure and seasonal growth patterns of microbial mats in a temperate climate saline alkaline lake: Goodenough Lake, British Columbia, Canada SO CANADIAN JOURNAL OF MICROBIOLOGY AB Goodenough Lake is a small (ca. 1 by 0.6 km) saline-alkaline lake on the Caribou Plateau in British Columbia, Canada, which has a mean depth of <1 m, allowing the growth of substantial prokaryote-dominated benthic microbial mats over the entire lake bottom. Microbial mats were investigated on both a detailed ultrastructural level and at a macroscopic level to determine, on a lakewide scale, the seasonally influenced changes that occurred over the course of a spring to fall growth season. The acceleration of phototrophic activity with warming of the lake water in spring could be followed by increases in dissolved oxygen levels, which quickly reached supersaturation early in the summer. The grazing activity of brine fly larvae (Ephydra hians) was found to have a significant influence on mat growth and development patterns. On an ultrastructural level, several types of filamentous cyanobacteria were the main phototrophic organisms present, even in anaerobic parts of the mats, where they were accompanied by purple bacteria. The dominant cyanobacterium present was a large oscillatoriacean form which, in certain parts of the lake, formed unusual columnar structures that had a very low diversity of microbial species in comparison to mats from other regions of the lake. The microbial community also differed in areas of the lake where less saline groundwater springs emerged from the lake bed. SN 0008-4166 PD FEB PY 1996 VL 42 IS 2 BP 147 EP 161 DI 10.1139/m96-023 UT WOS:A1996TX27600008 ER PT J AU Arneberg, P Folstad, I Karter, AJ AF Arneberg, P Folstad, I Karter, AJ TI Gastrointestinal nematodes depress food intake in naturally infected reindeer SO PARASITOLOGY AB Models have predicted that directly transmitted macroparasites may influence the abundance of forage plants in herbivore grazing systems by reducing the food intake of their host. Evidence of parasite-induced alterations in host food intake is, however, limited mainly to sheep, cattle and laboratory rodents. We estimated the effect of naturally acquired parasite infections on the appetite of reindeer. Food intake was significantly lower in infected reindeer compared to animals in which the parasites had been experimentally removed. Among the infected animals there was a significant negative relationship between intensity of the directly transmitted macroparasites (i.e. gastrointestinal nematodes) and mean food intake, indicating that the lower food intake was caused by these parasites. The time-specific onset of depression in food intake is also consistent with seasonality in the pathogenic effect from gastrointestinal nematodes. This shows that parasite-induced changes in herbivore food intake is not restricted to agricultural systems, and implies that parasites may have impact on the dynamics of a wide range of herbivore plant communities. SN 0031-1820 PD FEB PY 1996 VL 112 BP 213 EP 219 DI 10.1017/S003118200008478X PN 2 UT WOS:A1996UB85000008 PM 8851861 ER PT J AU Crete, M Manseau, M AF Crete, M Manseau, M TI Natural regulation of cervidae along a 1000 km latitudinal gradient: Change in trophic dominance SO EVOLUTIONARY ECOLOGY AB The biomass of forage, herbivores (caribou and moose) and predators (wolf) were estimated for four assemblages of large mammals along a latitudinal gradient in the Quebec-Labrador peninsula and related to predictions made by two types of multitrophic level models. Wolves were present in three study areas, but they had been extirpated in the last one. Annual production of preferred forage exhibited a clear north-south increase for moose, but not for caribou. Neither the herbivore nor predator biomass increased along the latitudinal gradient: the highest herbivore biomass occurred in the wolf-free area and in the northernmost site, while the greatest predator density was observed in the southernmost site. Consequently, the ratio of the herbivore to forage biomass was the highest in the area devoid of wolves and in the northernmost site occupied by migratory caribou. Availability of forage per herbivore was the greatest in the moose-wolf and the caribou-moose-wolf assemblages. The observed data supported the multitrophic level model incorporating classical predator-prey relationships and producing stepwise accrual of trophic level biomass with increasing food chain length. In the northernmost site, the system was limited to two functional trophic levels and caribou were regulated by summer forage. Three functional trophic levels appeared to exist in the central study area where caribou and moose were preyed upon by wolves. Both herbivores were at very low density, the first one due probably to its poor adaptation to predation and the second because of an unproductive range. In the southernmost site, moose were clearly regulated by predation and kept much below the carrying capacity. With the extirpation of wolves in the last study area, moose were regulated by forage and the density exceeded that in the moose-wolf system by seven times even in a less productive range. Caribou, having primarily evolved under resource limitation, is replaced by a cervid better adapted to predation, the moose, in more productive 'three-link' ecosystems. SN 0269-7653 EI 1573-8477 PD JAN PY 1996 VL 10 IS 1 BP 51 EP 62 DI 10.1007/BF01239346 UT WOS:A1996TT49200005 ER PT J AU JALKANEN, R AALTO, T KURKELA, T AF JALKANEN, R AALTO, T KURKELA, T TI DEVELOPMENT OF NEEDLE RETENTION IN SCOTS PINE (PINUS-SYLVESTRIS) IN 1957-1991 IN NORTHERN AND SOUTHERN FINLAND SO TREES-STRUCTURE AND FUNCTION AB The needle trace method was used to study retrospectively the long-term latitudinal variation in needle retention in Scots pine (Pinus sylvestris L.) in Finland. The mean annual summer needle retention (ANR) along the main stem varied from 3.4 to 6.0 needle sets during the period 1957-1991. The lowest values were observed in southern and the highest in northern Finland. The length of the growing season, expressed as the thermal sum (thresh old value +5 degrees C), was negatively correlated with the mean ANR (r = -0.96). The geographical needle retention pattern (NRP) for the period 1957-1991 showed a clearly increasing trend from 1957 to 1969 (southern Finland) and to 1975 (northern Finland); thereafter, the NRP tended to decrease close to its minimum value recorded in 1991. The general level of the NRP was approximately 5.0 needle sets in northern Finland and 3.5-4.0 needle sets in southern Finland. The NRP, with its 6-12 year cycle for southern Finland, was clearly periodical. Differences in the NRP among the ten stands in southern Finland were small, whereas the said periodicity was missing and the differences were high among the stands in northern Finland. The results indicate that variation in the number of needle sets, viz. defoliation of pines, is a normal phenomenon. The role of net carbon assimilation as a regulator of the number of needle sets is discussed. SN 0931-1890 PD DEC PY 1995 VL 10 IS 2 BP 125 EP 133 UT WOS:A1995TJ48100010 ER PT J AU VARE, H OHTONEN, R OKSANEN, J AF VARE, H OHTONEN, R OKSANEN, J TI EFFECTS OF REINDEER GRAZING ON UNDERSTOREY VEGETATION IN DRY PINUS-SYLVESTRIS FORESTS SO JOURNAL OF VEGETATION SCIENCE AB Data on floristic composition and environmental variables were collected in floristically homogeneous oligotrophic pine (Pinus sylvestris) forests with heath-like understorey vegetation in eastern Fennoscandia, and ordinated by non-linear multidimensional scaling (NMDS) in order to study the effect of lichen grazing by reindeer on the understorey vegetation. The study sites included areas with varying grazing pressure, as well as 50-yr old grazing exclosures. Sites rich in respectively bryophytes and lichens were placed at opposite ends of the ordination axes, and heavily grazed sites were placed in between them. Reindeer grazing increased the abundance of bryophytes, especially Dicranum spp. and Pleurozium schreberi. Grazing changed the vegetation to the extent that it resembled more mesotrophic sites, but this did not show any relationship with tree volume or other site productivity indicators. This was observed both in the ordination and, in a more compelling way, when exclosures with adjacent grazed areas were compared. No such signs were evident at ungrazed sites, where especially Cladina spp. spatially replace Cladonia spp. and tiny bryophytes like Barbilophozia spp., Polytrichum spp. and Pohlia nutans during succession. Cladina stellar is had almost disappeared from the most intensively grazed sites. The soil at ungrazed sites was characterized by high Al and Fe concentrations and bryophyte-rich sites by high Mn concentrations. Shannon's diversity index, depth of humus layer and proportion of bare ground also increased in sites getting richer in bryophytes. RI Oksanen, Jari/A-5236-2013 OI Oksanen, Jari/0000-0001-7102-9626 SN 1100-9233 PD SEP PY 1995 VL 6 IS 4 BP 523 EP 530 DI 10.2307/3236351 UT WOS:A1995TD40400009 ER PT J AU SOVERI, T SUKURA, A NIEMINEN, M LINDBERG, LA AF SOVERI, T SUKURA, A NIEMINEN, M LINDBERG, LA TI ULTRASTRUCTURE OF THE LIVER OF REINDEER CALVES UNDER DIFFERENT NUTRITIONAL CONDITIONS SO ANATOMIA HISTOLOGIA EMBRYOLOGIA-JOURNAL OF VETERINARY MEDICINE SERIES C-ZENTRALBLATT FUR VETERINARMEDIZIN REIHE C AB A total of 12 reindeer calves were divided into two groups and the volume densities of liver cytoplasmic structures were counted using TEM. The six animals in group 1 were allowed to graze freely while those in group 2 were kept in pens and fed with lichens. All of them had a negative energy balance and lost weight from November to April, group 1 by 14.9% and group 2 by 24.8%. In spite of the weight losses, no significant changes in volume densities occurred during the winter. Glycogen remained fairly steady and there was no fatty infiltration into the hepatocytes. The very low incidence of Golgi apparatus in the hepatocytes may have been due to the inhibition of protein and lipid synthesis during the winter. These results point to substantial adaptation to extreme environmental conditions. The animals in group 1 apparently moved about more, which may have caused a greater breakdown of glycogen, resulting in turn in a lower volume density of glycogen in January and March. OI Sukura, Antti Kalle Kalervo/0000-0002-8992-1695 SN 0340-2096 PD JUN PY 1995 VL 24 IS 2 BP 91 EP 95 DI 10.1111/j.1439-0264.1995.tb00017.x UT WOS:A1995RH99800006 PM 8588712 ER PT J AU MULDER, CPH HARMSEN, R AF MULDER, CPH HARMSEN, R TI THE EFFECT OF MUSKOX HERBIVORY ON GROWTH AND REPRODUCTION IN AN ARCTIC LEGUME SO ARCTIC AND ALPINE RESEARCH AB The effect of muskox herbivory on growth and reproduction in Oxytropis viscida was examined on Banks Island, N.W.T, during three growth seasons. Two levels of grazing were recognized. ''Chomping,'' which occurs primarily early in the season, affects shoot tips and may include removal of all aboveground biomass. Chomping does not affect survival, but reduces plant diameter and probability of flowering for at least 2 yr following grazing. It also decreases the number of shoot tips during the year of grazing, and decreases the number of inflorescences for at least 1 yr following grazing. Chomping results in a change in plant morphology, including more tightly clustered growth tips and greener more viscid leaves. Chomped plants are less likely to be grazed again in the year following herbivory. ''Nibbling'' refers to the selective removal of inflorescences and seed pods. Nibbling does not affect plant survival, shoot tip number, or number of inflorescences, but does decrease diameter for at least 1 yr following grazing. Results suggest that 0. viscida may not be continually defended and that resistance is induced by chomping but not nibbling. The strategy of this arctic herbaceous dicotyledon appears to be intermediate between that of arctic graminoids which exhibit rapid regrowth and that of slower growing, highly defended arctic shrubs. SN 0004-0851 PD FEB PY 1995 VL 27 IS 1 BP 44 EP 53 DI 10.2307/1552067 UT WOS:A1995QM39200006 ER PT J AU SOVERI, T NIEMINEN, M AF SOVERI, T NIEMINEN, M TI EFFECTS OF WINTER ON THE PAPILLAR MORPHOLOGY OF THE RUMEN IN REINDEER CALVES SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB To study papillar morphology as a nutritional indicator, samples were taken from five areas of the rumen of reindeer calves (Rangifer tarandus tarandus L.) in late April 1986 (group 1, n = 6); early May 1987 (group 2, n = 6); December 1986 (group 3, n = 9); and November 1987 (group 4, n = 6). The reindeer in groups 3 and 4 were allowed to graze freely under natural conditions, mainly feeding on lichens, while those in groups 1 and 2 were kept in pens and fed with lichens. The reindeer had shorter papillae at all five points in the rumen in spring, and the mean and areal papillar volumes and the papillar surface area in the caudal blind sacs were smaller than in the animals studied in early winter. The papillae were shorter in the caudal blind sacs than in the other parts of the rumen. The highest number of papillae was usually found in the atrium or the caudal blind sacs, whereas the mean papillar volume and papillar surface area were greater in the dorsal and ventral walls. Even relatively low amounts of lichens, which are rich in easily soluble carbohydrates, seem to be sufficient to produce volatile fatty acids for the papillae in order to avoid their regression to any great extent. The even, dense distribution of ruminal papillae in the reindeer resembles the pattern found in other ruminants, which are classified as concentrate selectors. SN 0008-4301 PD FEB PY 1995 VL 73 IS 2 BP 228 EP 233 DI 10.1139/z95-026 UT WOS:A1995RC55500002 ER PT J AU Lehtonen, J Heikkinen, RK AF Lehtonen, J Heikkinen, RK TI On the recovery of mountain birch after Epirrita damage in Finnish Lapland, with a particular emphasis on reindeer grazing SO ECOSCIENCE AB The effectiveness of recovery of mountain birch forests defoliated by Epirrita autumnata in 1965 in Inari Lapland, northern Finland, was studied by monitoring seedling and basal sprout formation in eight fenced areas and corresponding control plots, 400 m(2) each. The number of seedlings and the abundance of basal sprouts were measured in 1973, 1979, 1982, 1987 and 1990/1991. The results indicate that tree recovery from seeds is in theory possible in the damaged birch forests almost everywhere in the study area, and that the changes occurring in the undergrowth after the damage may actually support the development of seedlings. However, in practice this process is disturbed by the adverse effect of reindeer grazing on seedling establisment. The formation of sprouts from dormant basal buds in damaged trees is not so greatly affected by reindeer grazing, but sprouting has been successful and the forest will totally recover only in a few areas where sprouting was abundant soon after the Epirrita damage. Sprout formation is disturbed by rot, which spreads from the dead mother tree into the sprouts, and recovery has been rather limited inmost of the damaged areas. Tree density can be expected to decrease greatly in most of these areas. SN 1195-6860 PY 1995 VL 2 IS 4 BP 349 EP 356 DI 10.1080/11956860.1995.11682303 UT WOS:A1995TK48700007 ER PT J AU STAALAND, H GARMO, TH HOVE, K PEDERSEN, O AF STAALAND, H GARMO, TH HOVE, K PEDERSEN, O TI FEED SELECTION AND RADIOCESIUM INTAKE BY REINDEER, SHEEP AND GOATS GRAZING ALPINE SUMMER HABITATS IN SOUTHERN NORWAY SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY AB Radiocaesium concentrations (Cs-137) were measured in extrusa from oesophageally fistulated sheep, goats and reindeer grazing alpine summer vegetation in Griningsdalen, Southern Norway in the period 1987-1989. The experiments with sheep and goats were conducted in different subalpine areas. The reindeer were, in addition, grazed in three areas in the low alpine zone. Glazing bouts lasted for 10-20 min and bite selections were recorded every 15 s through the grazing bout. Reindeer and goats had the most diverse food selection whereas sheep fed mainly on grasses, forbs and to some extent, on leaves of willow. The reindeer extrusa had the highest radiocaesium activity, apparently to a large extent caused by intake of lichens in areas where this type of plants were present. Depending on the type of vegetation in the grazed areas the transfer of radiocaesium from soil to grazed vegetation (Bq kg(-1) dry extrusa/Bq m(-2) soil) was estimated to 0.02-0.04 in sheep, 0.02-0.05 in goats and 0.02-0.43 in reindeer for 1987. SN 0265-931X PY 1995 VL 29 IS 1 BP 39 EP 56 DI 10.1016/0265-931X(95)90936-S UT WOS:A1995TC65100004 ER PT J AU MESSIER, F AF MESSIER, F TI TROPHIC INTERACTIONS IN 2 NORTHERN WOLF-UNGULATE SYSTEMS SO WILDLIFE RESEARCH CT 6th International Theriological Congress (ITC) CY JUL, 1993 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA HO UNIV NEW S WALES AB Four population models for northern ungulates are formulated based on specific regulatory mechanisms: FOOD model, PREDATION-FOOD one-state model, PREDATION-FOOD two-state model and PREDATION model. In this paper I contrast the dynamics of the North American moose (Alces alces), a non-migrant ungulate, with the dynamics of the barren-ground caribou (Rangifer tarandus), a migrant ungulate. Predation by the grey wolf (Canis lupus) and by bears (Ursus arctos and U. americanus) is considered. Moose densities in North America are generally below 0.5 animals km(-2). In most areas, density-dependent food exploitation seems to operate at densities greater than 1.0 moose km(-2) Results from 27 studies were used to assess the functional and numerical responses of wolves to changing moose density. Per capita killing rate and wolf density were related (P = 0.01) to moose density following a Type II response. Wolf predation rate proved to be density dependent from 0 to 0.65 moose km(-2), and inversely density dependent at higher moose densities. An empirical model based on these results suggests that moose would stabilise at high densities in the absence of predators (FOOD model) or in the presence of wolves only (PREDATION-FOOD one-state model). If moose productivity level is diminished through deteriorating habitat quality, or if bear predation is added, then a low-density equilibrium (0.2-0.4 moose km(-2)) is predicted (PREDATION model). The demography of the George River caribou herd in northern Quebec/Labrador is reviewed for the period 1955-93. The herd increased from 5000 animals in 1955 to 644 000 (c. 1.5 animals km(-2)) in 1984, following an exponential growth rate (r) of 0.16. The herd reached a plateau of c. 725 000 animals in early 1990. A decline is predicted for the near future because of severe habitat degradation. In the 1980s, nutritional stress has been documented, especially in summer when caribou used traditional ranges depleted of key forage resources such as lichens and tundra shrubs. Food competition is viewed as the dominant regulatory factor (FOOD model), although the nature of caribou-habitat interactions may generate longterm fluctuations in numbers because of a time-delay effect. Wolf predation does not appear to be an important mortality factor capable of regulating the George River herd. The above case studies can be interpreted within the context of the 'food chain dynamics' theory. For the non-migrant ungulate (moose), a three-link system is proposed where predators hold down grazers, which in turn use only a small fraction of annual forage production. For the migrant ungulate (caribou), a two-link system is proposed where high-density grazers exert a strong regulatory control on plant productivity and where predators have minimal effect on grazers. RI Michel-Hernandez, Misael Angel/N-2073-2016 SN 1035-3712 PY 1995 VL 22 IS 1 BP 131 EP 146 DI 10.1071/WR9950131 UT WOS:A1995RE80600013 ER PT J AU MOEN, J MACALISTER, H AF MOEN, J MACALISTER, H TI CONTINUED RANGE EXPANSION OF INTRODUCED REINDEER ON SOUTH GEORGIA SO POLAR BIOLOGY AB Reindeer were introduced 70 years ago to the Stromness Bay area on the subantarctic island of South Georgia, and the herd is still surviving. Two glaciers confine the heard, and movements are restricted even within the area due to a rugged topography. The Husvik herd has recently expanded its range within this area, and today approximately 88% of the vegetated area is affected by grazing. The grazing effects are described, and the value of the introduction as a natural experiment is discussed. SN 0722-4060 PD OCT PY 1994 VL 14 IS 7 BP 459 EP 462 UT WOS:A1994PL96200005 ER PT J AU OUELLET, JP BOUTIN, S HEARD, DC AF OUELLET, JP BOUTIN, S HEARD, DC TI RESPONSES TO SIMULATED GRAZING AND BROWSING OF VEGETATION AVAILABLE TO CARIBOU IN THE ARCTIC SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB We investigated the consequences of simulated grazing and browsing on net primary production and chemical composition (nutrients, fiber, and total nonstructural carbohydrates) of some plant types available to caribou on Southampton Island, Northwest Territories, Canada. Clipping experiments were conducted in three large exclosures (22 x 22 m) on one deciduous (Salix lanata), one evergreen (Cassiope tetragona), and one semi-evergreen (Dryas integrifolia) shrub species and two types of sedges (Carex scirpoidea and wet-meadow sedges). The impact of various clipping regimes was analyzed in the growing season during which the treatments were applied and at the end of the following growing season. Clipping, for the most part, reduced plant net production. Responses differed among and within plant types according to the timing and intensity of clipping. In some cases maximum net production of plants was not restored during the recovery year, although grazing and browsing pressure was lifted. Clipping modified the chemical composition of S. lanata, D. integrifolia, and the two types of sedges investigated. In clipped sedges, nitrogen, magnesium, potassium, and phosphorus levels in regrowth were above the maximum obtained from controls at any point during the growing season. These chemical changes possibly enhanced the quality of these plants as food for herbivores. Because plant types that showed a high degree of compensatory growth also showed an increase in quality following clipping, herbivores might benefit if they reselect these plants over the course of the growing season. Growth of S. lanata is negatively affected by clipping and represents an important component of the caribou's summer diet, therefore willows are expected to decrease in abundance as the caribou population increases. The decrease in abundance of deciduous shrubs may have important consequences for the caribou's range use and population dynamics. RI Boutin, Stan/A-2619-2014 OI Boutin, Stan/0000-0001-6317-038X SN 0008-4301 PD AUG PY 1994 VL 72 IS 8 BP 1426 EP 1435 DI 10.1139/z94-189 UT WOS:A1994PV94000010 ER PT J AU KAYHKO, J PELLIKKA, P AF KAYHKO, J PELLIKKA, P TI REMOTE-SENSING OF THE IMPACT OF REINDEER GRAZING ON VEGETATION IN NORTHERN FENNOSCANDIA USING SPOT-XS DATA SO POLAR RESEARCH CT 2nd Circumpolar Symposium on Remote Sensing of Arctic Environments CY MAY 04-06, 1992 CL UNIV TROMSO, TROMSO, NORWAY SP UNIV TROMSO, TROMSO SATELLITE STN, AKVAPLAN NIVA A S, FDN APPL RES HO UNIV TROMSO AB Digital image analysis and SPOT XS satellite data recorded on 1 August 1991 were used to monitor vegetation in the border region between Enontekio municipality, Finland, and Kautokeino municipality, Norway. A supervised classification on the red wave length channel was undertaken using training areas for maximum likelihood classifier to produce seven spectral land cover classes. The classification revealed great differences in vegetation between Finland and Norway. The largest difference was the lack of Cladinalichens on the Finnish side of the border. The area on the Finnish side is used for grazing all year round, while the area on the Norwegian side is a winter range only. According to official data for the local reindeer population, the average annual grazing pressure (head/area/time) is higher on the Norwegian side of the reindeer fence. The Finnish grazing practice is believed to have a detrimental impact on the vegetation, and has lead to pasture land degradation. RI Kayhko, Jukka/D-4849-2010 OI Kayhko, Jukka/0000-0002-3842-7355 SN 0800-0395 PD JUN PY 1994 VL 13 IS 1 BP 115 EP 124 DI 10.1111/j.1751-8369.1994.tb00442.x UT WOS:A1994PA90500012 ER PT J AU SOVERI, T AF SOVERI, T TI LIVER HISTOLOGY OF REINDEER CALVES DURING THE WINTER SEASON SO ANATOMIA HISTOLOGIA EMBRYOLOGIA-JOURNAL OF VETERINARY MEDICINE SERIES C-ZENTRALBLATT FUR VETERINARMEDIZIN REIHE C AB Seventeen reindeer calves were divided into three groups and liver biopsies were taken during the winter. Group 1 consisted of 6 animals allowed to graze freely under natural conditions, those in groups 2 (n = 5) and 3 (n = 6) were kept in pens and fed with lichens, the diet being designed to achieve a slight (group 2) or moderate (group 3) weight loss. Weight losses from November to April averaged 14.9 %, 13.2 % and 24.8 % in the three groups respectively. The relative volumes of the different structures in the liver were determined by light microscopic morphometry. The mean size of the hepatocytes was slightly greater in March than in january in groups 1 and 2, and slightly smaller in group 3 (no statistical differences) and then decreased markedly. These changes could also be seen in the sinusoidal lumina. The decrease in the size of the hepatocytes may reflect a shortage of amino acids in the cells or it may be hormone-mediated. Unlike the situation in cows, there was no fatty accumulation in the hepatocytes. This may be a species adaptation to an annual period of starvation. SN 0340-2096 PD DEC PY 1993 VL 22 IS 4 BP 313 EP 318 DI 10.1111/j.1439-0264.1993.tb00225.x UT WOS:A1993MR98100005 PM 8129165 ER PT J AU ENGELMARK, O AF ENGELMARK, O TI EARLY POSTFIRE TREE REGENERATION IN A PICEA-VACCINIUM FOREST IN NORTHERN SWEDEN SO JOURNAL OF VEGETATION SCIENCE CT IAVS Workshop on Disturbance Dynamics in Boreal Forest CY AUG 10-14, 1992 CL UNIV UMEA, UMEA, SWEDEN SP SWEDISH COUNCIL FORESTRY & AGR RES, UNIV QUEBEC HO UNIV UMEA AB Age and size structures of saplings of Picea abies, Pinus sylvestris and Betula pubescens were examined in a 26-yr old forest fire area in a Picea abies-Vaccinium myrtillus forest in northern Sweden. Picea, which is a shade-tolerant species, had its maximum regeneration prior to the shade-intolerant Pinus. The shift from Picea to Pinus regeneration in the late 1970s, did not seem to be related to variations in summer temperature. Instead, it is suggested that Picea established in the shade created by dead trees and, that increased reindeer browsing of Betula in combination with a simultaneous thinning of the tree layer, favoured Pinus recruitment. These regeneration patterns do not confirm conventional views of post-fire succession in Sweden. SN 1100-9233 PD NOV PY 1993 VL 4 IS 6 BP 791 EP 794 DI 10.2307/3235616 UT WOS:A1993MM74700010 ER PT J AU HOVE, K AF HOVE, K TI CHEMICAL METHODS FOR REDUCTION OF THE TRANSFER OF RADIONUCLIDES TO FARM-ANIMALS IN SEMINATURAL ENVIRONMENTS SO SCIENCE OF THE TOTAL ENVIRONMENT AB The same chemicals can be used for reduction of radionuclide transfer to animals whether kept on farms or grazing in semi-natural and natural habitats. However, different techniques are required for administration of the active compounds. Dairy ruminants may be treated effectively by inclusion of chemicals in supplemental concentrates. Practical experience gained after the Chernobyl accident has shown that both clay minerals and hexacyanoferrates are effective in preventing high radiocaesium levels in animal products. Chemicals such as bentonite clays and CaCO3, used for reduction of Cs-137 and Sr-90 transfer respectively, must be fed in hectogram quantities and are only practical for dairy animals in semi-natural ecosystems. Salt licks and sustained release boli with hexacyanoferrates as caesium binders have been developed and used successfully after the Chernobyl accident for meat producing cattle, sheep and. reindeer which graze freely for extended periods. Daily doses of 25-300 mg in sheep and 250-2000 mg in cows reduces Cs-137 accumulation 2-10-fold. Binders for Sr-90 have not been tested in grazing animals. Stable iodine could be provided in salt licks and indwelling rumen boli at rates required to block radioiodine uptake by the thyroid gland. Boli and salt licks are highly cost effective in reducing doses to man when compared to interdiction of food from farm animals. SN 0048-9697 EI 1879-1026 PD SEP 24 PY 1993 VL 137 IS 1-3 BP 235 EP 248 DI 10.1016/0048-9697(93)90391-I UT WOS:A1993MB71900020 PM 8248770 ER PT J AU HANDL, J OLIVER, E JAKOB, D JOHANSON, KJ SCHULLER, P AF HANDL, J OLIVER, E JAKOB, D JOHANSON, KJ SCHULLER, P TI BIOSPHERIC I-129 CONCENTRATIONS IN THE PRE-NUCLEAR AND NUCLEAR-AGE SO HEALTH PHYSICS AB In order to detect characteristic regional differences or temporal changes of I-129 concentrations in the biosphere, thyroids from humans, grazing livestock, and herbivorous wildlife species (reindeer and roedeer) were collected in various areas of the world which are not affected by reprocessing plants. For reasons of comparison, all samples were analyzed for their I-129:I-127 atom ratios. Human and bovine thyroids taken from the 10th region in Southern Chile (39-degrees-41-degrees South) indicated values of the I-129:I-127 atom ratio between 1.1 x 10(-9) and 2.0 x 10(-9) and between 1.2 x 10(-10) and 9 x 10(-9), respectively. They showed no significant increase in the concentration of biospheric I-129 in comparison with that established in the pre-nuclear age. Atom ratios found in human thyroids collected in Lower Saxony (Federal Republic of Germany), which is a region not directly affected by reprocessing plants, exhibited I-129:I-127 values between 8 x 10(-9) and 6 x 10(-8) from February 1988 to September 1990. Thyroid glands of reindeer and roedeer as well as heather, moss, and lichen were taken from the Vilhelmina, Heby, and Gavle communes in Sweden and analyzed for I-129 and I-127. All three communes were found to be seriously contaminated by fallout from the Chernobyl accident. Highest I-129:I-127 atom ratios between 3.5 x 10(-7) and 1 x 10(-6) were found in the Gavle commune (approximately 150 km northwest of Stockholm) where the highest Cs-137 ground deposition (70-80 kBq m-2) was measured. Two soil samples taken from Krasnaya Gora and Mirny locations in Russia (approximately 200 km northeast of Chernobyl) exhibited ratios of about 1 x 10(-6). These locations showed a Cs-137 ground deposition of 370 and 1,300 kBq m-2, respectively. SN 0017-9078 EI 1538-5159 PD SEP PY 1993 VL 65 IS 3 BP 265 EP 271 DI 10.1097/00004032-199309000-00003 UT WOS:A1993LV37100004 PM 8244695 ER PT J AU OUELLET, JP HEARD, DC BOUTIN, S AF OUELLET, JP HEARD, DC BOUTIN, S TI RANGE IMPACTS FOLLOWING THE INTRODUCTION OF CARIBOU ON SOUTHAMPTON-ISLAND, NORTHWEST-TERRITORIES, CANADA SO ARCTIC AND ALPINE RESEARCH AB Changes in the vegetation for various range types subjected to grazing by an introduced caribou population in 1967 on Southampton Island, Northwest Territories, were assesed using a series of exclosures (N = 13; 5.5 m x 5.5 m) in 1990 and in 1991. Changes in the vegetation were related to range use and to prevalent snow conditions. The effect of the exclosures on some factors that are known to influence the production of arctic plant communities (snow condition, timing of snow melt, and soil temperature during the growing season) were also tested. Exclosures had little effect on these physical conditions. Associated with the increase in caribou number there has been a reduction in lichen standing crop; the other plant types were not affected. Under the prevailing snow conditions on the island, winter range appears to be restricted mainly to windswept areas which are nearly free of snow. As a result, some of these areas are showing signs of overgrazing and the past projection of caribou carrying capacity may have been too high. With respect to management, a significant increase in the annual hunting quota is recommended. RI Boutin, Stan/A-2619-2014 OI Boutin, Stan/0000-0001-6317-038X SN 0004-0851 PD MAY PY 1993 VL 25 IS 2 BP 136 EP 141 DI 10.2307/1551550 UT WOS:A1993LC44700007 ER PT J AU HELLE, T MOILANEN, H AF HELLE, T MOILANEN, H TI THE EFFECTS OF REINDEER GRAZING ON THE NATURAL REGENERATION OF PINUS-SYLVESTRIS SO SCANDINAVIAN JOURNAL OF FOREST RESEARCH AB The effects of winter grazing by semi-domesticated reindeer on the natural regeneration of Scots pine were studied in north-eastern Finland. A total of 50 regeneration areas subjected to long-term grazing intensity varying from heavy to none were investigated. During the previous year reindeer had damaged an average of 7.6% of the seedlings; 88% of all mechanical damage were caused by reindeer. The damage frequency was related to the intensity of grazing, and was maximally 60%. Forty-six % of the damaged seedlings were <50 cm in height, and the most common type of damage was branch breakage. Fungal diseases were responsible for the death or poor condition of the seedlings in 80% of the cases, as compared to 12% for reindeer. Grazing slightly increased the incidence of Scleroderris canker, but was associated with a low incidence of snow blight, most probably due to packing of the snow. Grazing had no effect on the number of seedlings capable of developing, whilst plants between the age of 13-24 years grew faster in heavily grazed than in lightly grazed lichen vegetation. SN 0282-7581 PY 1993 VL 8 IS 3 BP 395 EP 407 DI 10.1080/02827589309382786 UT WOS:A1993MH66500009 ER PT J AU ALBON, SD LANGVATN, R AF ALBON, SD LANGVATN, R TI PLANT PHENOLOGY AND THE BENEFITS OF MIGRATION IN A TEMPERATE UNGULATE SO OIKOS AB Seasonal changes in crude protein content of graminoids and herbs grazed by red deer were monitored from 1 May, or as soon as snow melt exposed the vegetation, until 15 October at five sites along an altitudinal gradient from coast to inland. Crude protein declined exponentially with time at all sites, but declined most rapidly from initially higher values at inland locations at high elevations. As a result crude protein was positively correlated with altitude and distance from the coast in early summer and negatively correlated in autumn. The relationships between protein content, date and altitude were used to estimate the quality of the diet of twelve radio-collared female red deer that migrated to summer ranges in the mountains. Individual differences in body weight were significantly related to the estimated, mean crude protein in vegetation available during the summer. Constraints on the timing of migration to exploit the maximal protein concentrations at higher altitudes and the fitness benefits of adaptive ranging behaviour are discussed. RI ALBON, Stephen/C-6304-2011 OI ALBON, Stephen/0000-0002-0811-1333 SN 0030-1299 PD DEC PY 1992 VL 65 IS 3 BP 502 EP 513 DI 10.2307/3545568 UT WOS:A1992KB34700019 ER PT J AU WAIRIMU, S HUDSON, RJ PRICE, MA AF WAIRIMU, S HUDSON, RJ PRICE, MA TI CATCH-UP GROWTH OF YEARLING WAPITI STAGS (CERVUS-ELAPHUS) SO CANADIAN JOURNAL OF ANIMAL SCIENCE AB Ten yearling wapiti stags were used to investigate effects of winter nutrition on subsequent growth on summer pasture. One group of five (LOW) was wintered on medium-quality hay, and the other group of five (HIGH) was wintered on hay and alfalfa-barley pellets (16% crude protein). By the time they grazed spring pasture in mid-April, HIGH wapiti had larger frame dimensions and were 20 kg heavier than those wintered on hay alone, despite their lower pre-winter weights. However, subsequent catch-up growth rapidly narrowed these differences, and both groups attained similar weights and frame measurements by late July. Liveweight gains on summer pasture were 0.30 and 0.15 kg d-1 for LOW and HIGH wapiti, respectively. Although LOW wapiti tended to have higher gut fill (3.3 vs. 2.5 kg dry matter), the difference (corrected for assumed dry-matter content) was insufficient to explain compensatory weight gain. Digestibilities and mean retention times did not differ consistently between the treatment groups but were reciprocally related to one another. Forage intakes rose as pastures flushed but declined sharply in July with overgrazing and resumption of supplemental feeding. LOW wapiti consumed more pasture dry matter than HIGH wapiti in May and June. Efficiencies of forage utilization were unrelated to nutritional history. Using data pooled for the two treatment groups from April to June gave estimates of 878 kJ W-0.75 for maintenance and 33.4 kJ g-1 for liveweight gain. The main factor contributing to compensatory gain on summer pasture was higher forage intakes, particularly in relation to metabolic weight. SN 0008-3984 PD SEP PY 1992 VL 72 IS 3 BP 619 EP 631 DI 10.4141/cjas92-074 UT WOS:A1992JY72900017 ER PT J AU SHIPLEY, LA SPALINGER, DE AF SHIPLEY, LA SPALINGER, DE TI MECHANICS OF BROWSING IN DENSE FOOD PATCHES - EFFECTS OF PLANT AND ANIMAL MORPHOLOGY ON INTAKE RATE SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE AB There appear to be two dominant forms of the functional response of vertebrate herbivores, corresponding to animals foraging in spatially concentrated or spatially dispersed food patches. We examine the factors contributing to the functional response of herbivores feeding on spatially concentrated browses. Specifically, we tested the hypothesis that the instantaneous intake rate of four boreal browsers (moose, Alces alces. woodland caribou, Rangifer tarandus caribou, white-tailed deer, Odocoileus virginianus, and snowshoe hares, Lepus americanus) feeding on red maple (Acer rubrum) browse is an asymptotic function of the size of bite obtainable by the herbivore. Based on this functional response model, we also hypothesized that (i) cropping rate of the herbivores would decline curvilinearly with bite size, (ii) intake rate would decline with increasing fibrousness (measured as the neutral detergent fiber of the foods consumed), and (iii) maximum intake rate would scale as the 2/3 power of herbivore body mass (BM). Intake rates of all animals increased 2- to 10-fold with increasing bite size of stems and leaves, and conformed to the hypothesized asymptotic relation. Similarly, cropping rate declined curvilinearly with increasing bite size, and intake rate declined with increasing fibrousness of foods consumed. Maximum intake rate scaled with BM0.76, not significantly different from the hypothesized exponent of 0.67. These data support the hypothesis that bite size affects intake rate by controlling the ratio of cropping and chewing, and that the asymptotic intake rate of herbivores is related to the food processing capability of the mouth. SN 0008-4301 PD SEP PY 1992 VL 70 IS 9 BP 1743 EP 1752 DI 10.1139/z92-242 UT WOS:A1992JT71200014 ER EF