Ecosystems are always changing.

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Ecosystems are always changing.
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Populations change over time.

• Limiting factors any factor or condition that
  limits the growth of a population in an ecosystem
• Examples a large population of predators will
  limit the population of prey, a large population
  of prey will limit the population of predators,
  too much or too little of any biotic or abiotic
  factor makes an ecosystem unstable

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Maintaining a balance

• Carrying capacity when a population has reached
  a state where it can no longer grow it has
  reached its carrying capacity
• Living things have certain minimum requirements
  for food, water, and living space
• Different for each population

4
Ecosystems change over time.

• Succession the gradual change in an ecosystem
  in which one biological community is replaced by
  another

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Primary Succession

• After something like a lava flow destroys the
  ecosystem Primary succession occurs which is the
  establishment of a new biological community
• Pioneer species first living things to move
  into a barren environment
• As the pioneers grow, they weaken the rock
  surface and break the rock down, decaying plant
  matter adds nutrients and forms soil allowing
  more plants and shrubs to take root and support
  insects, birds, and small rodents

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Primary Succession
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Secondary Succession

• Takes place after a major disturbance to the
  biological community in a stable ecosystem,
  occurs after a forest fire or other natural event
• Below the surface seeds and plants survive, after
  time grasses and small shrubs grow up and small
  animals return, eventually large trees return
  providing food for more types of animals

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Secondary Succession