ECOLOGICAL INTERACTIONS

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ECOLOGICAL INTERACTIONS
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ECOLOGICAL INTERACTIONS

• Objectives
• Be able to define each level of ecological
  organization
• Identify 3 ways organisms can interact
• Name and explain the 3 categories or symbiosis
• How do organisms affect the balance of life in
  their ecosystem

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Niche

• Everything an organism does or needs in its
  environment
• Its job or role in the environment

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Competition

• Struggle between organisms to obtain things they
  need for survival (food, water, shelter, light)
• Competition can be within a population or between
  populations of different species using the same
  resource
• i.e. rabbits competing for food in a field or
  rabbits competing with squirrels for suitable
  shelter

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Predation

• To catch, kill, and eat another organism
• The animal being caught is referred to as the
  PREY
• i.e. fox hunts and eats a rabbit

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Symbiosis

• Close relationship between two organisms where at
  least one of them derives some benefit
• 3 categories of symbiosis
• Commensalism
• Mutualism
• Parasitism

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Commensalism

• One organism benefits and the other is NOT harmed
  (, 0)
• i.e. dust mites on your arm
• Nemo and sea
• anemone

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Mutualism

• Both organisms benefit (, )
• i.e. human intestinal bacteria. They get food
  from us and give us vitamins

Bee collects pollen to make honey. Flower uses
bee to spread pollen to other flowers
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Parasitism

• One organism benefits and the other is harmed (,
  -)
• i.e. athletes foot, tapeworm

Tapeworms live in the intestines and steal
nutrients from the host
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Life in Balance

• Maintaining a stable environment is HOMEOSTASIS
• As organisms use resources in their environment
  and interact with other organisms, they upset the
  natural balance and must continually adapt to
  survive
• Over time this leads to permanent changes in the
  species ? EVOLUTION