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Each
population has a range of tolerance to variations in
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its
physical and chemical environment. The largest number
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of
individuals in a population will be in the optimum level
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or
range, While a few can survive above or below that
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range
(possibly in stress), but no individuals can survive
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outside
of the range of tolerance.
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The law
of tolerance: the existence, abundance, and
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distribution
of a species in an ecosystem are determined by
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whether
the levels of one or more physical or chemical
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factors
fall within the range tolerated by that species.
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Tolerance
limits are the minimum and maximum limits
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for
physical conditions beyond which no members of a
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species can
survive.
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