Quantifying multiple-site compositional turnover in an Afrotemperate forest, using zeta diversity

摘要: Species turnover is typically measured by partitioning diversity components into alpha and pairwise beta diversity. However, cannot express the full spectrum of multiple-site compositional turnover. To this end, zeta has been proposed as an extended framework to allow complete biodiversity measure species We use a zeta-diversity explore potential community assembly processes African Montane Forest. Using 20 m grid, we in 4.55 ha forest plot located Garden Route National Park South Africa, with 47 27 canopy sub-canopy tree regional pool. first calculate how declines probability retention particular occupancies changes increasing orders (i.e. number sites [grid cells] involved calculation). null models row sums column constrained respectively, whether driven mechanisms ecological differences (species-specific occupancies) or habitat heterogeneity (site-specific thus environmental filters). The decline order followed power law; that is, increased occupancies, suggesting common being more likely be discovered extra sites. model retaining (species’ occupancy) species-by-site matrix recreated perfectly diversity, while (retaining sums) was rejected. This suggests driving species-specific between species) dictate multi-site community. spatial patterns revealed little structuring forces, supporting fine-grain structure these southern Cape forests. large discrepancies occupancy among are behind plot. Future studies could further link distance decay. Environmental filters temporal from landscape demography bring cohesive understanding unique ecosystems.