Several Basic Controls Govern Population Siz1

Several Basic Controls Govern Population Siz1 - niche...

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Several Basic Controls Govern Population Size The environment is the ultimate cause of population stabilization. Two categories of factors are commonly used: physical environment and biological environment. Three subdivisions of the biological environment are competition , predation, and symbiosis. Physical environment factors include food, shelter, water supply, space availability, and (for plants) soil and light. One of these factors may severely limit population size, even if the others are not as constrained. The Law of the Minimum states that population growth is limited by the resource in the shortest supply. The biological role played by a species in the environment is called a niche . Organisms/populations in competition have a
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Unformatted text preview: niche overlap of a scarce resource for which they compete. Competitive exclusion occurs between two species when competition is so intense that one species completely eliminates the second species from an area. In nature this is rather rare. While owls and foxes may compete for a common food source, there are alternate sources of food available. Niche overlap is said to be minimal. Paramecium aurelia has a population nearly twice as large when it does not have to share its food source with a competing species. Competitive release occurs when the competing species is no longer present and its constraint on the winner's population size is removed....
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Several Basic Controls Govern Population Siz1 - niche...

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