Linking biodiversity and ecosystem services: Current uncertainties and the necessary next steps

Understanding when biodiversity conservation and ecosystem-service maintenance are compatible is needed within the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Here, we evaluate current understanding and uncertainties of the effects of biodiversity change on selected ecosystem services and suggest ways to further understand the links between biodiversity change and ecosystem services. We reviewed experiments, observations, and syntheses on the effects of species richness on six ecosystem services: forage, timber, fisheries, climate regulation, agricultural pest control, and water quality. Establishing a direct link from biodiversity to ecosystem-service provision has often been precluded by limited data (i.e., the amount, consistency, or generality of the data) and a mismatch between the variables measured and the final ecosystem service that is relevant to stakeholders. We suggest that encompassing syntheses and a network of interdisciplinary experiments under realistic conditions could fill these gaps and could inform the outcomes of alternative management and policy scenarios within IPBES.