Quantifying disturbance effects on ecosystem services in a changing climate.

Disturbances, such as hurricanes, fires, droughts and pest outbreaks, can cause major changes in ecosystem conditions that threaten Nature's contributions to people (ecosystem services). Climate change is intensifying disturbances, posing risks to ecosystem services. To assess those risks, we develop a flexible, functional trait-based approach to quantify ecological, ecosystem service and economic impacts from disturbance regimes. Our broadly applicable approach integrates knowledge from disturbance ecology and ecosystem service valuation, and we highlight the pitfalls of using either perspective in isolation. We demonstrate our approach by quantifying impacts to timber and recreational enjoyment from extreme windstorms in a midlatitude forest. While we predict large potential losses to these services under historical and future disturbance regimes, common ecological metrics of compositional and biomass stability are inadequate for predicting these impacts. We then provide a roadmap for applying our approach across different social-ecological systems, illustrating the approach for crop pollination, flood hazard mitigation and cultural values from coral reefs-which all face intensifying disturbances. This study highlights and provides tools to address the pressing need to consider disturbances in future ecosystem service assessments.