PCB 3044 Lecture Notes - Lecture 3: Alpine Tundra, Pelagic Zone, Littoral Zone
9 Nov 2017
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Document Summary
Biosphere: part of earth (e) where living organism r found. Most living occur w/in thin layer of e surface. Lies btw lithosphere (e crust & mantle) & troposphere (lowest layer of atmosphere: terrestrial biomes r characterized by growth forms of dominant vegetation. Biomes: large-scale terrestrial communities shaped by physical environment. + categorized by dominant plant forms & characteristics. Plants: good indicators of climatic conditions & disturbances. Plants have taken many forms in response to selection pressure (p) (eg: aridity, extreme to, solar radiation, grazing, crowding) Convergence: evolution of similar growth forms occurs in similar climates on different continents, even if not b genetically related, in response to similar selection. Distribution of terrestrial biomes is determined to e climate zones. Topography, ocean currents & other factors also help determine biome distribution. High biomass, high diversity: ab 50% of e species. Light: key factor: plants must grow above others/ adjust to low light levels.
