Regime shifts, resilience, and biodiversity in ecosystem management

Abstract

Key Words alternate states, regime shifts, response diversity, complex adaptive systems, ecosystem services ■ Abstract We review the evidence of regime shifts in terrestrial and aquatic envi-ronments in relation to resilience of complex adaptive ecosystems and the functional roles of biological diversity in this context. The evidence reveals that the likelihood of regime shifts may increase when humans reduce resilience by such actions as re-moving response diversity, removing whole functional groups of species, or removing whole trophic levels; impacting on ecosystems via emissions of waste and pollutants and climate change; and altering the magnitude, frequency, and duration of distur-bance regimes. The combined and often synergistic effects of those pressures can make ecosystems more vulnerable to changes that previously could be absorbed. As a consequence, ecosystems may suddenly shift from desired to less desired states in their capacity to generate ecosystem services. Active adaptive management and gover-nance of resilience will be required to sustain desired ecosystem states and transfor