Catastrophic shifts in ecosystems

All ecosystems are exposed to gradual changes in climate, nutrient loading, habitat fragmentation or biotic exploitation. Nature is usually assumed to respond to gradual change in a smooth way. However, studies on lakes, cora l reefs, oceans, forests and arid lands have shown that smooth change can b e interrupted by sudden drastic switches to a contrasting state. Although d iverse events can trigger such shifts, recent studies show that a loss of r esilience usually paves the way for a switch to an alternative state. This suggests that strategies for sustainable management of such ecosystems shou ld focus on maintaining resilience.