Impact of Humans and Natural Disasters in Ecosystems

• Removal of all biotic life
  • How? Removal with clearcutting, fire, tornado, volcano, recovery?
  • Primary Succession:
    • the ecosystem lacksoil and vegetation
    • pioneer species come, create soil and provide nutrients for greater organisms to move in
  • Secondary Succession:
    • has soil remaining/maybe plants
    • this is much faster than primary succession. Smaller plants invade, larger ones come later.
• Toxins
  • toxins can accumulate in lower food chain however this concentration not always bad
  • in tertiary consumers this toxin concentrates, can kill or harm species
• Overhunting endangers populations
  • upset balance of matter cycle
• Pollution
  • The Pepper Moth Story:
    • During industrial revolution pollution (soot) coated trees resulted in a change in the ratio of colors of pepper moths.