Community Interactions

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Community Interactions Ecological Succession
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Community Interactions

• SYMBIOSIS any relationship where 2 species live
  closely together
• 3 main types of Symbiotic Relationships
• 1) Mutualism both species benefit from the
  relationship (, )
• In this picture, the aphids
• benefit as the ants protect
• them the ants benefit
• because they feed on the
• sugary fluid secreted by
• the aphids.

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Commmunity Interactions

• Types of Symbiosis
• 2) Commensalism one organism benefits the
  other remains unaffected.(, ?)
• This clownfish can survive the sea
  anemones stings, so the fish can benefit
  from having a home while the sea anemone is
  unaffected by its inhabitants.
• Remember Nemo, look once, look twiceand
  look several more timesbecause the ocean is
  a DANGEROUS place to be!

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Community Interactions

• Types of Symbiosis
• 3) Parasitism one organism benefits the other
  is harmed (, -)
• A jar of tapeworms,
• types of flatworms
• that must live in
• another organisms
• digestive tract for
• survival. They can
• grow up to 20 meters!

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Community Interactions

• Competition results when organisms attempt to
  use ecological resources (i.e. water, food,
  light, space) in the same place at the same time
• NO 2 SPECIES CAN OCCUPY THE SAME NICHE DUE TO
  COMPETITION (this is called the Competitive
  Exclusion Principle.

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Community Interactions

• Predation when one organism feeds on another
  (,-)
• Predator-Prey Relationships

Population Density ( organisms)
Time (years)
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Ecological Succession

• Succession The continual maturing of a
  particular habitat through predictable changes
  over time
• Primary Successionwhen succession begins from an
  area where no soil exists
• In Primary Succession, the first species to grow
  (usually lichens) is called the pioneer
  species.
• Example land naturally developing after a
  glacier

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Ecological Succession

• Secondary Succession when
• succession must start over after some
• sort of disturbance (the community does
• not lose its soil)
• Example land naturally developing after a
• forest fire OR farmland after agriculture is
• abandoned
• The final stage in succession is called
• a climax community, the most stable,
• diversified, and complex stage.
• (usually has many hardwood trees)