Effects of biodiversity strengthen over time as ecosystem functioning declines at low and increases at high biodiversity

Human‐caused declines in biodiversity have stimulated intensive research on the consequences of biodiversity loss for ecosystem services and policy initiatives to preserve the functioning of ecosystems. Short‐term biodiversity experiments have documented positive effects of plant species richness on many ecosystem functions, and longer‐term studies indicate, for some ecosystem functions, that biodiversity effects can become stronger over time....