ENV100Y5 Lecture Notes - Lecture 14: Biogeochemical Cycle, Photic Zone, Transpiration
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ENV100Y5 Full Course Notes
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Document Summary
Energy converted by primary producers: growth, maintenance (respiration) reproduction. Net primary productivity (npp)= gross primary productivity (gpp)- respiration by autotrophs. Npp= energy available to consumers and decomposers. Limits to productivity in terrestrial ecosystems: precipitation, average annual temperature. Limits in aquatic ecosystem: coastlines more productive than open ocean. Biogeochemical cycles: involve biological, geological and atmospheric reservoirs. Substances move among them and can take multiple chemical forms. Residence time in the reservoirs may be seconds days etc. Size and rate of cycling can vary in ecosystems and time and humans can affect them. Generalize biogeochemical cycle: transformation from organic to inorganic, movement through biotic to abiotic reservoirs. Hydrologic cycle influences all other cycles, water is both a participant in and the main transport medium for environmental processes. Major reservoir: oceans 97%, most freshwater: icecaps, ground water, moves between 3 states. Aquifers: underground reservoir, recharged by precipitation and surface water flows. Human impacts on the water cycle: damming rivers= higer evaporation.
