Jurien Bay Dune Chronosequence Floristics and Soil Dataset

The dataset accompanies the paper by Zemunik et al. (2016), which used the Jurien Bay dune chronosequence to investigate the changes in the plant community diversity and turnover in response to long-term soil development. The Jurien Bay chronosequence is located in the Southwest Australian biodiversity hotspot, in an area with an extremely rich regional flora. The dataset consists of both flora and soil data that allows all analyses presented in the paper (Zemunik et al. 2016) to be independently investigated. The dataset is an update to that previously supplied for a prior study (Zemunik et al. 2015; DOI 10.4227/05/551A3DDE8BAF8). The study used a randomised stratified design, stratifying the dune system of the chronosequence into six stages, the first three spanning the Holocene (to ~6.5 ka) and oldest spanning soil development from the Early to Middle Pleistocene (to ~2 Ma). Floristic surveys were conducted in 60 permanent 10 m × 10 m plots (10 plots in each of six chronosequence stages). Each plot was surveyed at least once between August 2011 and March 2012, and September 2012. To estimate canopy cover and number of individuals for each plant species within the 10 m × 10 m plots, seven randomly-located 2 m × 2 m subplots were surveyed within each plot. Within each subplot, all vascular plant species were identified, the corresponding number of individuals was counted and the vertically projected vegetation canopy cover was estimated. Surface (0-20 cm) soil from each of the 420 subplots was collected, air dried and analysed at the Smithsonian Tropical Research Institute in Panama, for a range of chemical and physical properties: total and resin soil phosphorus; total nitrogen and dissolved organic nitrogen; soil total and organic carbon; exchangeable calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn) and sodium (Na); Mehlich-III extractable iron, magnesium, copper (Cu) and zinc (Zn); and pH (measured in H20 and CaCl2). Nutrient-acquisition strategies were determined from the literature, where known, and from mycorrhizal analyses of root samples from species with poorly known strategies. Most of the currently known nutrient-acqusition strategies were found in the species of the chronosequence. Previous studies in the Jurien Bay chronosequence have established that its soil development conforms to models of long-term soil development first presented by Walker and Syers (1976); the youngest soils are N-limiting and the oldest are P-limiting (Laliberté et al. 2012). However, filtering of the regional flora by high soil pH on the youngest soils has the strongest effect on local plant species diversity (Laliberté et al. 2014). The update involved modification to species names due to taxonomic changes and the inclusion of additional soil analyses, not present in Zemunik et al. (2015). The additional soil variables (additional to DOI 10.4227/05/551A3DDE8BAF8) were exchangeable Ca, K, Al, Mg, Mn and Na, measured for all 420 subplots; and Cu, Fe, Mn and Zn, extracted in Mehlich III solution, for each of the 60 plots. References Laliberté, E., Turner, B.L., Costes, T., Pearse, S.J., Wyrwoll, K.H., Zemunik, G. & Lambers, H. (2012) Experimental assessment of nutrient limitation along a 2-million-year dune chronosequence in the south-western Australia biodiversity hotspot. Journal of Ecology, 100, 631-642. Walker, T.W. & Syers, J.K. (1976) The fate of phosphorus during pedogenesis. Geoderma, 15, 1-19. Zemunik, G., Turner, B.L., Lambers, H. & Laliberté, E. (2015) Diversity of plant nutrient-acquisition strategies increases during long-term ecosystem development. Nature Plants 1, Article number: 15050, 1-4. Zemunik, G., Turner, B.L., Lambers, H. & Laliberté, E. (2016) Increasing plant species diversity and extreme species turnover accompany declining soil fertility along a long-term chronosequence in a biodiversity hotspot. Journal of Ecology.