Topic Progress:

Community Dynamics

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

Vocabulary
disturbance
succession
primary succession
secondary succession

TRANSCRIPT

Community Dynamics

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.

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