Plant Succession (Seral Stages) and Climax Communities

• plant communities generally regenerate themselves after a disturbance depending on climate and other factors
  
  

  tropical island Krakatoa and its fiery volcano (1883) extinction, colonization, and equilibrium devoid of life; completely devastated landscape 1900 - 13 species of birds and many plants had comeback 1921 - 31 species of birds; approaching full recovery 1934 - 31 species of birds (some left, other came); 270 plant species plant communities reached equilibrium

  
  
  
• After a disturbance (such as a clear-cut, landslides, volcanic eruption, crown fire)
  

1) region reverts to its pioneer stage

• environment favors certain species (grasses)
• characterized by rapid growth and simplified ecosystem
• most biomass per square inch
• most vulnerable to pests and disease
  

2) evolves into more shrubby and woody plants (chaparral)

• begins to diversify
• soils develop
• shade and moisture retention
  

3) matures with trees and underbrush; more species and biodiversity

• more shade, developed soils, and diversification
• environment allows certain species to return
  

4) ultimately returns to a mature plant community and equilibrium

• also known climax stage as transformation ends
• characterized by slow growth and diverse ecosystem
• as a whole - system more stable
  • least vulnerable to pest and disease
  • stable habitat for many species
  • spotted owl, marbled murrelet, amphibians, fungi, lichens, insects, etc.
    
    

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