Biology 1225 Chapter Notes - Chapter 17: Keystone Species, Mount St. Helens, Climax Community
5 Feb 2014
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Document Summary
Ecology is the study of the interactions of organisms with one another and with their physical environment. Some other definitions are commonly used by ecologists: Biosphere the zone of the earth"s crust, atmosphere, and water that supports life. Habitat the place where a species lives; it is characterized by distinctive physical features and vegetation. Population all of the members of the same species living in the same place at the same time. Community - all of the populations in a given place at the same time. One of the axioms of ecology is that no two different organisms can occupy exactly the same niche, if this was to happen, one would out-compete and eliminate the other. Ecosystems consist of one or more communities interacting with one another, and their physical environment. Energy flows in an ecosystem, and materials are cycled. Organisms can be categorized within ecosystems according to the manner in which they obtain energy and matter.
