What drives abrupt ecological change, and how does it connect environment and society? Abrupt ecological change is often both a cause and a consequence of change in the broader social-ecological system (SES). It can arise from both past and current interactions and feedbacks between social and ecological systems. Spatial patterns in geomorphology and ecosystems across a landscape strongly influence social and economic systems (e.g., via accessibility, the distribution of available resources, and the technologies that emerge). The degree to which the dynamics of a human society or economy are dominated by lateral exchanges (networks) or top-down regulation (hierarchies) can thus be heavily conditioned by the biophysical environment. Different social structures (e.g., kinds of management institution or tenure regime) in turn become drivers of ecological patterns across landscapes. Ecosystems are structured in different ways and may be more or less vulnerable to particular kinds of impact. For example, aquatic systems are vulnerable to trophic cascades; and stable environments provide the potential for the evolution of co-adaptations that can either enhance or reduce system resilience to change. Ecological and social systems are spatially structured, interacting heterarchies, each composed of a combination of networked and hierarchical flows and drivers
Results/Conclusions
Societies develop particular governance structures to manage particular kinds of resource, leading to the co-development of social and ecological heterarchies. The interactions between a socioeconomic system and the ecosystems it relies upon create structures that influence societal responses to environmental change, affecting the ability of societies to manage social-ecological feedbacks. Analysis of 17 well-documented historical cases suggests that social structure influences both the likelihood of change and the nature of the feedbacks between ecosystems and societies. Ecology has models of change, but lacks compelling theories to support and direct their development; the adaptive cycle is one of the few contenders for a theory of change, but it is a general description of a pattern that can be generated by at least 14 quite different underlying mechanisms. Case studies and data suggest that we need a new kind of social-ecological theory in order to deal with abrupt change; that there are different kinds of vulnerability/resilience to abrupt change, and that differently-structured SESs will need to develop different coping structures and strategies; and that understanding the spatial nature of abrupt ecological change is vital to predicting and proactively managing it.