Transcript Exponential Growth

POPULATION
GROWTH CURVES
Exponential Growth
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Exponential growth represents growth of
organisms who have an unlimited supply of
food and all limiting factors have been
removed.
The carrying capacity (K) of the ecosystem is
assumed to be unlimited.
It is a J – shaped curve. The steepness of the
J varies with species.
Exponential Growth
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Example: bacteria
produces a J-shaped curve
Number of
individuals
(N)
Time
Logistic Growth
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Logistic Growth - Growth rates are regulated
by internal and external factors until they
come into equilibrium with environmental
resources.
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Growth rate slows as population approaches
carrying capacity.
S-Shaped curve
Environmental Resistance - Any
environmental factor that reduces population
growth.
Logistic Growth
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Example: turtles in a pond
K
produces a S-shaped curve
Number of
individuals
(N)
Time