diversity-function debate

Functional diversity, composition, and species richness affect the biogeochemical processes of ecosystems. However, the degree to which these factors influence ecosystems and whether that influence is significant is much debated. In the article The Influence of Functional Diversity and Composition on Ecosystem Processes, scientists reported on an experiment in which they studied the effects of plant species diversity, functional diversity, and functional composition on ecosystem processes, as measured in six response variables (productivity, plant % N, plant tot. N, soil NH4, soil NO3, and light penetration). 289 plots were designed with varying amounts of the three controlled factors. Each plot contained up to 32 perennial savannah-grassland species representing up to five plant functional groups. These species were not equal in their functional impact to the ecosystem.