Recent theoretical and experimental work provides clear evidence that biodiversity loss can have profound impacts on functioning of natural and managed ecosystems and their ability to deliver ecological services to human societies. Work on simplified ecosystems in which the diversity of a single trophic level is manipulated shows that diversity can enhance ecosystem processes such as primary productivity and nutrient retention. Theory also strongly suggests that biodiversity can act as biological insurance against potential disruptions caused by environmental changes.
One of the major current challenges, however, is to extend this knowledge to multitrophic systems that more closely mimic complex natural ecosystems. Our theoretical work shows clearly that trophic interactions have a strong impact on the relationships between diversity and ecosystem functioning, whether the ecosystem property considered be total biomass or temporal variability of biomass at the various trophic levels. In both cases, food-web structure and trade-offs that affect interaction strength have major effects on these relationships. Multitrophic interactions are expected to make biodiversity-ecosystem functioning relationships more complex and nonlinear, in contrast to the monotonic changes predicted for simplified systems with a single trophic level. Merging food-web and biodiversity-ecosystem functioning approaches is an exciting challenge which offers promising perspectives.