BIOLOGY 2F03 Lecture 18: Ch. 18 – Disturbance, Succession and Stability
11 Dec 2015
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Document Summary
Natural communities experience a diversity of disturbances, which can have immediate and prolonged impacts of community structure and ecological function. Succession: the gradual changes in plant and animal communities in an area following disturbance or the creation of new substrate. Primary succession: occurs on newly exposed geological substrates not significantly modified by organisms. Secondary succession: occurs in areas where disturbance destroys a community without destroying the soil. Ex. occurring after agricultural lands are abandoned, after a forest fire, after a flood. In other cases, communities may never recover, and instead persist in an alternative state. Pioneer community: the first organisms in a successional sequence (usually. Climax community: when succession ends with a community whose population remains stable until disrupted by subsequent disturbance. The nature of climax communities depends on environmental circumstances. Disclimax community: are maintained only through continual disturbances, plants) such as grazing and drought.
