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Community: group of interacting
populations in a certain area at same time
Communities can be different, they can be
different species (plant or animal)
They can be difficult to live in too
 Too much of something, too little
Limiting factors: any biotic or abiotic factor
that restricts the existence, numbers, or
reproduction of an organism
 they control what lives in a environment
 Ex:
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Temperature
Precipitation (water)
Disease
Space
Food/predators
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Tolerance: the ability of an organism to
withstand (tolerate) changes in an
environment
what are your ranges of tolerance?
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Succession: natural changes in an
environment that occur over time
Refers to natural growth of plants/trees/etc
2 types
 Primary
 Secondary
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Primary succession: the colonization of
barren land by communities of organisms
Done by “pioneer species”
 Moss
 Lichen
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No animals present, no soil present
Occurs on rock
 Lichen breaks down rock to form soil so other
plants and shrubs can grow
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Primary succession leads to a climax
community
 a stable, mature, community that undergoes little
to no change
 Plant life has reached it’s peak in growth
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Secondary succession: occurs after some
sort of natural disaster or human caused
interruption
 Forest fire
 Habitat destruction
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Soil and animal life already existed there
Does not involve pioneer species
Will also lead to a climax community