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intrinsic rate of increase (r)
how fast a population would grow under ideal conditions with no limiting factors or environmental resistance acting upon it
any factor (limiting factor) that can limit a populations growth; ex: amount of space, temperature, precipitation, disease, food availability
capacity for growth; how well an organism can reproduce and get offspring out into the environment; ex: high biotic potential = fish, insects, small mammals like mice, etc.; low biotic potential = large mammals like the panda, elephants, rhinos, etc.
carrying capacity (K)
maximum number of individuals an ecosystem can support for an extended period of time or indefinitely; determined by biotic potential of the organism and the environmental resistance factors that population faces
rapid growth; doubling of population each generation; usually associated with intrinsic rate of increase (r); happens when organisms have very little environmental resistance factors or limiting factors acting upon them
exponential growth demonstrated by a population when it has few limiting factors or little environmental resistance acting upon it
rapid explosive growth followed by decrease in population growth until population levels off
density-dependent population controls
Limiting factors have a greater effect as density increases
Mostly Biotic Factors
Competition for resources
density-independent population controls
Limiting factor effects are not dependent on the size of the herd
Mostly Abiotic Factors
population size fluctuates above and below carrying capacity
Ex: undisturbed tropical rain forest
boom and bust cycles
Ex: lynx and snowshoe hare; wolf-moose interactions
Top-down population regulation
Bottom-up population regulation
no recurring pattern; often caused by catastrophic events like natural disasters or major habitat destruction that cannot be predicted
Offspring are exact genetic copies (clones) of a single parent
Examples: single-celled bacteria, corals, yeast, vegetative in plants
reproduce quickly, high biotic potential, many offspring, little care to offspring; ex: insects (roaches), small mammals (mice, rats, rabbits), etc.
reproduce slowly, low biotic potential, few offspring, a lot of care to offspring; ex: large mammals like elephants, panda, kangaroo
late loss population survivorship curve
organisms in population live long life and often have few offspring but give offspring a lot of care; ex: large mammals
constant loss population survivorship curve
organisms die off evenly at all ages throughout lifespan; ex: song birds
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