Regime shifts in social-ecological systems

Regime shifts entail a large, persistent reorganization of the structure and function of complex systems, and often occur abruptly and unexpectedly. Regime shifts are associated with changes in the resilience of a system and have been documented in ecosystems, social systems, economic systems, and coupled socio-technical and social-ecological systems. This chapter focuses on regime shifts in social-ecological systems, which often have substantial impacts on ecosystem services, such as crop production or flood regulation, that directly impact human well-being. The frequency of social-ecological regime shifts is increasing with ever more human pressures on the environment. At the same time, such regime shifts are usually difficult to detect and costly to reverse if they occur. Observations of abrupt change in time series data provides empirical evidence of regime shifts that can be analyzed using a variety of methods including bifurcation theory, principal component analysis (PCA), chronological clustering and sequential t-tests. Modeling may be used to understand causal relationships and the strength of feedback mechanisms. Managing the resilience of social-ecological systems in ways that support long-term sustainability relies on a deeper understanding of the mechanisms and drivers that lead to regime shifts, and the capacity to deal with such shifts when they occur.