Temporal Structure: Perturbation, Colonization, Succession
No assemblage of organisms remains unchanged for long; the often-quoted “balance of nature” is largely a fiction; natural assemblages are seldom in stasis nor is any one current state a lasting condition. Daily, seasonal, and decadal shifts in weather and climate impart changing patterns to living assemblages, with differing time scales. Perturbations of many kinds—asteroid strikes, fires, storms, habitat loss, pollution, sea level rise, geological subsidence, and many others—change conditions and species assemblages on specific parcels of environments, and the parcels can then be colonized by organisms, and a succession of species may occur. Recovery to earlier conditions and assemblages may or may not take place (cf. Chap. 18).