Key questions for understanding drivers of biodiversity-ecosystem service relationships across spatial scales

Context Biodiversity loss is predicted to have significant impacts on ecosystem services based on previous ecological work at small spatial and temporal scales. However, scaling up understanding of biodiversity-ecosystem service (BES) relationships to broader scales is difficult since ecosystem services emerge from complex interactions between ecosystems, people, and technology. Objectives In order to inform and direct future BES research, identify and categorise the ecological and social-ecological drivers operating at different spatial scales that could strengthen or weaken BES relationships. Methods We developed a conceptual framework to understand the potential drivers across spatial scales that could affect BES relationships and then categorized these drivers to synthesize the current state of knowledge. Results Our conceptual framework identifies ecological/supply-side and social-ecological/demand-side drivers, and cross-scale interactions that influence BES relationships at different scales. Different combinations of these drivers in different contexts will lead to a variety of strengths, shape, and directionality in BES relationships across spatial scales. Conclusions We put forward four predictions about the spatial scales that the effects of biodiversity, ecosystem service management, ecosystem co-production, and abiotic linkages or effects will be most evident on BES relationships and use these to propose future directions to best advance BES research across scales.