based on Indiana's Academic Standards, Science,
as adopted by the Indiana State Board of Education, Nov 2000.

numbers refer to the age-appropriate grade-level for the content.

Review

Succession

grades 5: to 6:

• communities may change over short times (decades)
  • abandoned farm fields grow to weedlots, then brush
  • communities recover after forest fires

grades 7: to 8:

• short-term (decade long) changes are succession or community development
  • primary succession
    • site never occupied [no soil development]
  • secondary succession
    • regrowth over site previously supporting a community

grades secondary: to college:

• succession is a series of seral stages
  • pioneeer
  • weedy
  • shrubby
  • sub-climax woods
  • climax forest
  • each stage modifies environment favoring the next seral stage species
  • disturbance returns to earlier seral stage
• Theory of Island Biogeography
  • there is an annual emmigration of individuals from occupied habitats
  • immigrants arrive by chance; first come - first 'served'
  • only current and next seral stage species can become established
  • later immigrants meet competition unless local extinction has occurred
  • or seral changes in environment have occurred
  • composition of community is dynamic
  • short term: succession
  • long-term: adaptation
  • plant populations, once established, may persist for centuries
    therefore animals' habitats/niches persist for centuries also

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© 2004 TwoOldGuys™