Rethinking Ecosystem Resilience in the Face of Climate Change

Resilience is usually defined as the capacity of an ecosystem to absorb disturbance without shifting to an alternative state and losing function and services 1–3. The concept therefore encompasses two separate processes: resistance—the magnitude of disturbance that causes a change in structure—and recovery—the speed of return to the original structure 4,5—which are fundamentally different but rarely distinguished. Yet, resilience has become a central concept in the management of natural ecosystems 6,7. Many current management actions aim to alleviate local stressors in an effort to increase ecosystem resilience to global climate change 8,9. Such a management philosophy is premised on the belief that eliminating local drivers of ecological change will increase the ability of an ecosystem to resist future climate disturbances, its ability to recover from such disturbances, or both 2,6. Measuring resilience is fraught with difficulties 1,3. Nevertheless, assessing changes in resilience as a result of management action is critical because there is general agreement for the existence of a strong link between resilience and sustainability 10. Successfully increasing the resilience of natural systems may therefore have important implications for human welfare in the face of global climate change. In this Perspective, we will argue that the expectation of increased resilience of natural communities to climate change through the reduction of local stressors may be fundamentally incorrect, and that resilience-focused management may, in fact, result in greater vulnerability to climate impacts. We illustrate our argument using coral reefs as a model. Coral reefs are in an ecological crisis due to climate change and the ever-increasing magnitude of human impacts on these biodiverse habitats 11,12. These impacts stem from a multiplicity of local stressors, such as fishing, eutrophication, and sedimentation. It is therefore not surprising that the concept of resilience—to climate change in particular—is perhaps more strongly advocated as an underpinning of management for coral reefs than for any other ecosystem 9,. Marine reserves or no-take areas, the most popular form of spatial management for coral reef conservation, are widely thought to have the potential to increase coral reef resilience 11,13,14,17. But do they really?