10.6084/m9.figshare.3315961.v1
Diego Sotomayor
Diego
Sotomayor
cj lortie
cj
lortie
Direct and indirect consequences of dominant plants in arid environments
figshare
2016
Indirect effects
Direct Effects
community ecology research
desert ecosystem
Atacama Desert
Coexistence theory
Ecology
Physical Geography
Conservation and Biodiversity
Community Ecology (excl. Invasive Species Ecology)
Evolutionary Biology
Terrestrial Ecology
2016-05-06 17:19:47
Figure
https://figshare.com/articles/figure/Direct_and_indirect_consequences_of_dominant_plants_in_arid_environments/3315961
This Figure belongs to the Synthesis chapter of Diego Sotomayor's PhD dissertation: "Direct and indirect consequences of dominant plants in arid environments". This dissertation was presented at the Department of Geography at York University.<br><br>The numbers in the Figure correspond to the dissertation chapters were each concept was covered:<br><br>1) Indirect interactions in terrestrial plant communities<br>2) Dominant plant effects across large spatial and temporal gradients<br>3) Dominant plant effects at micro-scales and within seasons<br>4) Plant-plant direct and indirect interactions by dominant plant canopies<br>5) Dominant plant effects on ecotypic differentiation<br><br>This is the abstract of the dissertation:<br>
In arid environments, dominant woody plants such
as shrubs or trees, usually facilitate a high density of species in their
understories. This phenomemon is composed by a series of direct and indirect
effects from the dominant plant to the understory species, and among understory
species. The aim of this project was to determine these direct and indirect
consequences of dominant plant-plant facilitation in a collection of field
sites along the coastal Atacama Desert. The following objectives and hypotheses
were examined in this project: (1) to summarize and contextualize the breadth
of research on indirect interactions in terrestrial plant communities; (2) that
the positive effects of dominant plants on understory communities are
spatiotemporally scale dependent, from micro- to broad-scale spatial effects,
and from within-seasonal to among-year temporal effects; (3) that dominant
plants via their different traits determine the outcome of plant-plant
interactions; (4) that dominant plants determine the outcome of interactions
amongst understory species and that their responses are species-specific; and (5)
that facilitation by dominant plants generates sufficiently different
micro-environmental conditions that lead to consistent differences in seeds
traits of understory plants. Overall, we found that multiple
factors determine the outcome of plant-plant interactions along the field sites
studied in this project. These factors impact both the direct and indirect
effects of dominant woody plants on their understory communities and include
species-specific traits of both the dominant and understory species, and the
spatial and temporal environmental gradients that manifest their effects at
different scales. Dominant plants usually facilitate increased species richness
and density of plants in their understory, that in turn mediates effects
amongst these species. However, these direct effects seem to have a limit given
that at extremely stressful environmental conditions they tend to change to
neutral and even competitive effects of canopies on their understories. This
provides evidence that positive effects of dominant plants collapse under
extreme spatiotemporal stress. Although we did not find evidence of
evolutionary effects of top-down facilitation, the methodology proposed here
represents a contribution to test the conditions under which these results
hold. Overall, this project illustrates the importance of understanding the
multiple drivers that determine the outcome of biotic interactions.
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