Jurien Bay leaf nutrient data
2016-11-02T08:03:57Z (GMT) by
Description Leaf nutrient concentration and C/N stable isotope data for 18 plant species across five dune chronosequence stages along the Jurien Bay chronosequence. Format A data frame with 508 observations on the following 22 variables: plot factor with names of 50 10x10-m plots stage factor indicating chronosequence stage (1 = youngest, 5 = oldest) species factor with full plant species names state factor with leaf state: mature or senesced date sampling date ICP factor stating whether nutrients other than C and N were analysed with a radial or axial ICP equipment for each sample C leaf carbon concentration (%) Ca leaf calcium concentration (microg g^-1) Cd leaf boron concentration (microg g^-1) Cu leaf copper concentration (microg g^-1) Fe leaf iron concentration (microg g^-1) K leaf potassium concentration (microg g^-1) Mg leaf magnesium concentration (microg g^-1) Mn leaf manganese concentration (microg g^-1) Mo leaf molybdenum concentration (microg g^-1) Na leaf sodium concentration (microg g^-1) P leaf phosphorus concentration (microg g^-1) S leaf sulfur concentration (microg g^-1) Zn leaf zinc concentration (microg g^-1) N leaf nitrogen concentration (microg g^-1) d15N delta-N-15 (permil Air) d13C delta-C-13 (permil VPDB) Details For leaf sampling, we used 50 plots (10 m x 10 m each) from five chronosequence stages where vegetation had been characterised previously. Using the vegetation survey data, we ranked species in each of the five chronosequence stages from the most to the least abundant, based on canopy cover estimates. We then selected 5–7 species from each stage, targeting the most abundant species for each of four contrasting nutrient-acquisition strategies: arbuscular mycorrhizal (AM), ectomycorrhizal (EM), N-fixing (NF) and non-mycorrhizal (NM) (see juriensp for strategies). Ericoid mycorrhizal species were not considered because they were not among the most abundant species. We note that N-fixing species are generally AM and/or EM, but we considered them as a separate group because they often show high foliar [N]. Species were selected from the ten most-abundant species per stage, with the exception of stage 4 where the 18 most-abundant species were considered. The selected species accounted for between 38% (stage 5) and 65% (stage 1) of the total canopy cover of each stage. A total of 18 species were selected for leaf sampling. All leaf material was collected over a two-month period between late March and early May 2012, near the end of the dry summer season. In each of the 50 plots, only healthy mature individuals were selected for sampling. In general, mature and senesced leaves were sampled from one individual plant per species in each plot. A species was considered absent from a plot if it could not be found within ~30 m of its centre. The number of individual collections (one collection = both mature and senesced leaves) per species in each chronosequence stage ranged from five to ten. In each case, representative samples of mature and senesced leaves were collected using nitrile gloves in order to minimise sample contamination. Leaves were not washed prior to nutrient analyses but we consider dust contamination to be highly unlikely, given the sandy nature of the soils. Mature leaves were undamaged, fully expanded and exposed to full sunlight. In most cases, senesced leaves were collected directly from the plant by gently shaking the plant and collecting fallen leaves. Senesced leaves were easily distinguished from green leaves, since they were yellow or brown and detached easily from the plant. However, for a few species it was not possible to collect senesced leaves from live plants, in which case senesced leaves were collected directly beneath the plant from recently fallen litter. In all cases, there was no visible degradation of senesced leaves collected from this litter, which had predominantly fallen during the summer and had not been exposed to any significant rain between litter fall and collection. Therefore, we assumed that losses of nutrients through leaching or decomposition were minimal, although some photodegradation may have occurred. A total of 508 leaf samples (mature and senesced) were collected for nutrient analyses. Each leaf sample was oven-dried (70 degrees C, 48 h) and finely ground using a Teflon-coated stainless steel ball mill. A subsample was analysed for carbon (C) and nitrogen (N) concentrations using a continuous-flow system consisting of a SERCON 20-22 mass spectrometer connected with an automated nitrogen/carbon analyser (Sercon, Crewe, UK). Stable isotopes of C and N were analysed using a continuous flow system consisting of a SERCON 20-22 mass spectrometer connected with an automated N/C analyser (Sercon, Crewe, UK). These analyses were done at the Western Australian Biogeochemistry Centre, located at the University of Western Australia. A second subsample was acid-digested using concentrated HNO3:HClO4 (3:1) and analysed for Ca, Cd, Cu, Fe, K, Mg, Mn, Mo, Na, P, S and Zn concentrations using inductively coupled plasma-atomic emission spectrometry (ICP-AES; ChemCentre, Perth, Australia). All digests were first analysed using a simultaneous Varian Vista Pro (Australia), radially configured ICP-AES equipment fitted with a charge-coupled device (CCD) detection system and an A.I. Scientific AIM-3600 auto-sampler. Samples with P concentrations close to minimum reporting limit were re-run on more sensitive axially-configured ICP-AES equipment. The ICP analyses were done at the WA Chemcentre.