Species in variable environments

Species and communities may exist in a dynamic state of change in response to environmental variation and disturbance. This chapter explores the consequences of variable environments and disturbance to species interactions and community structure. In particular, it examines how disturbance can result in the succession of ecological communities, how disturbance may promote (or hinder) species coexistence, how a varying environment can promote species coexistence through a mechanism called the “storage effect”, and how communities may shift between alternative states in response to environmental change. The latter topic is particularly relevant to the management of biotic resources and the restoration of degraded ecosystems, as systems may respond to environmental change abruptly at a “tipping point”, leading to alternative community states that can be difficult to reverse.