Communities and interdependence

• Interdependence

  • when each species in a community depend on one another for: 


  -food

  -pollination

  -shelter

  -seed dispersal

  -etc
• Community

  • a group of interdependent species living in an ecosystem
• Population

  • all organisms of one species living in a habitat
• Ecosystem

  • the interaction of a community of living organisms with the non living parts of their environment
• Abiotic factor

  • non-living factors which can affect a community 


  E.g.

  • temperature
  • light intensity
  • CO2 levels
  • O2 levels
  • wind intensity
  • mineral availability
  • moisture levels
• Biotic factors

  • new predators
  • competition
  • new pathogens/parasites
  • food availability
• Stable community

  • when the abiotic and biotic factors rarely change
  • all population numbers stay fairly constant 


  E.g.

  • tropical rainforests
  • ancient oak woodlands