Directions: Before you start, listen to part of a talk in a biology class.
*Vocabulary is sometimes provided in written form when it may be unfamiliar to the student but essential for understanding the lecture
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disturbance succession |
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primary succession secondary succession |
Community dynamics are the changes in community structure and composition over time, often following environmental disturbances such as volcanoes, earthquakes, storms, fires, and climate change. Communities with a relatively constant number of species are said to be at equilibrium. The equilibrium between species identities and relationships changes over time but maintains a relatively constant number. Following a disturbance, the community may or may not return to the equilibrium state.
Succession describes the sequential appearance and disappearance of species in a community over time after a severe disturbance. In primary succession, newly exposed or newly formed rock is colonized by living organisms; in secondary succession, a part of an ecosystem is disturbed and remnants of the previous community remain. In both cases, there is a sequential change in species until a more or less permanent community develops.