The unimodal relationship between species richness and biomass in herbaceous plant communities

FRASER, L.; HERBDIVNET; ENRICO, L.

Perth

Simposio; 57th Symposium of the International Association for Vegetation Science; 2014

IAVS (International Association for Vegetation Science)

One of the central problems of ecology is the prediction of species diversity across environmental gradients. The humped-back model (HBM) suggests that plant diversity peaks at intermediate productivity; at low productivity few species can tolerate the environmental stresses and at high productivity a few highly competitive species dominate. Over time the HBM is has become increasingly controversial, and recent studies claim to have refuted it. Here, using data from coordinated surveys conducted throughout grasslands worldwide, and comprising an unparalleled range of site productivities and more relevant measures of primary productivity, we provide strong evidence in support of the HBM pattern, at both global and regional extents. By providing strong evidence for a unimodal relationship between diversity and productivity these findings have important implications for the direction of future research into the drivers of plant diversity.