• Ecological succession is the progression of life from an uninhabited state to a fully functional and healthy ecosystem.
    • Ex: one community with certain species is gradually and predictably replaced by another community of diff species
      • As succession progresses, species diversity and total biomass increases
    • Succession can occur over long periods as climate changes and shorter periods when species alter habitat
      • Both times, characteristics of an ecosystem that supported resident species no longer exist and habitat become favorable to new species
  • Pioneer species: plants and animals that are first to colonize new habitat
  • Usually opportunistic, r-selected species & those that can tolerate harsh conditions like nutrient-deficient soil
  • As physical characteristics change, r-selected species gradually replaced by more stable k-selected species
    • Live longer so environmental effects slow down rate of succession
  • Climax community: Final successional stage where organisms remain stable

Two Kinds of Succession

  1. Primary succession: in habitats that never previously supported living things
  • Start with protists and prokaryotes and end with grass
  1. Secondary Succession: in habitats where communities destroyed by disturbance