BIOB50H3 Lecture 3: BIOB50 Lecture 3
13 Feb 2017
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Document Summary
Between the lithosphere (earth"s crust & mantle) and the troposphere (lower layer of the atmosphere) Biomes are large-scale biological communities shaped by the physical environment in which they are found. Relies on morphological responses of organisms to the physical environment. Terrestrial biomes are classified by the growth form of the dominant plants and their leaf characteristics(ex. deciduousness, succulence) Selection pressures - aridity, high and subfreezing temps, intense solar radiation, nutrient poor soils, grazing by animals, and crowding by neighbours. The evolution of similar growth forms among distantly related species in response to similar selection pressures is called convergence. Terrestrial biomes reflect global patterns of precipitation and temperature. The association b/w climate variation and terrestrial biome distribution can be visualized using a graph of avg annual precipitation and temperature. This approach fails to incorporate seasonal variation in temp and precipitation. The potential distributions of terrestrial biomes differ from their actual distributions due to human activities.
