Biodiversity–stability relationships strengthen over time in a long-term grassland experiment

Abstract Numerous studies have demonstrated that biodiversity drives ecosystem functioning, yet there is a lack of knowledge about how biodiversity loss alters ecosystems functioning and stability in the long-term. We report on temporal changes in the species richness–productivity, –stability, –species asynchrony, and –complementarity relationships over 17 years in a grassland biodiversity experiment. Richness–productivity and richness–complementarity relationships strengthened because productivity declined more rapidly in less than in more diverse communities. Using five-year rolling windows, we found that richness–stability relationships became stronger over time because more diverse communities maintained greater productivity. In later years asynchrony increased temporal complementarity among species, thus providing an insurance effect of species richness on stability. These results show how mechanisms stabilizing ecosystem functioning can change with community age. They demonstrate the importance of preserving diversity in natural systems as the role of diversity for ecosystem stability may take decades to realize the full potential.