BIOL 180 Chapter Notes - Chapter 55: Silt, Ecology, Secondary Succession

• School: UW
• Department: Biology
• Course: BIOL 180
• Professor: Freeman Scott

Document Summary

Frederick clements hypothesis: biological communities are stable and orderly entities with highly predictable composition: reasoning: species interactions are so extensive - and coevolution so important - that communities have become highly integrated and interdependent units in nature. Species within a community cannot live without each other. Communities develop over time by passing through series of predictable stages dictated by extensive interactions among species. Climax community - final stage where developmental progression culminates. Is stable, doesn"t change over time: determined by area"s climate. Henry gleason in contrast contends that community found in particular area is neither stable nor predictable: plant and animal communities are ephemeral associations of species that just happen to share similar climatic requirements. Communities-are-predictable hypothesis: group of species present at a particular site is highly predictable: prediction: identical plankton communities will develop in all 12 ponds. Communities-are-unpredictable hypothesis: group of species present at a particular site is highly unpredictable: different plankton communities will develop in different ponds.