Unifying Research on Social–Ecological Resilience and Collapse
Ecosystems influence human societies, leading people to manage ecosystems for human benefit. Poor environmental management can lead to reduced ecological resilience and social–ecological collapse. We review research on resilience and collapse across different systems and propose a unifying social–ecological framework based on (i) a clear definition of system identity; (ii) the use of quantitative thresholds to define collapse; (iii) relating collapse processes to system structure; and (iv) explicit comparison of alternative hypotheses and models of collapse. Analysis of 17 representative cases identified 14 mechanisms, in five classes, that explain social–ecological collapse. System structure influences the kind of collapse a system may experience. Mechanistic theories of collapse that unite structure and process can make fundamental contributions to solving global environmental problems.
As social–ecological systems enter a period of rapid global change, science must predict and explain ‘unthinkable’ social, ecological, and social–ecological collapses.
Existing theories of collapse are weakly integrated with resilience theory and ideas about vulnerability and sustainability.
Mechanisms of collapse are poorly understood and often heavily contested. Progress in understanding collapse requires greater clarity on system identity and alternative causes of collapse.
Archaeological theories have focused on a limited range of reasons for system collapse. In resilience theory, the adaptive cycle has been used to describe collapse but offers little insight into the mechanisms that cause it.
Theories of collapse should connect structure and process. Mechanistic, structure–process–function theories of collapse suggest new avenues for understanding and improving resilience.