Lecture 25 - Primary productivity - the amount of light...

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BIOLOGY 1001: LECTURE 25 ECOSYSTEMS Ecosystem - all the organisms in a given area as well as the non-living ("abiotic") factors with which they interact. Biome - one of the world's major communities, classified according to the predominant vegetation and characterized by adaptations to the local environment. Trophic structure - the different feeding relationships in an ecosystem that determine the route of energy flow and the pattern of chemical cycling. Nutrient cycling - movement of vital chemicals between the physical environment and living organisms Carbon cycle - the conversion of atmospheric CO 2 to carbohydrates by the process of photosynthesis, and the return of CO 2 back into the atmosphere by respiration and decomposition Nitrogen fixation - conversion of atmospheric nitrogen into ammonia and nitrates by bacteria
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Unformatted text preview: Primary productivity - the amount of light energy converted to chemical energy by the autotrophs of an ecosystem. Trophic levels: Producers - organisms capable of producing organic energy from sunlight = autotrophs Consumers - organisms that acquire organic energy from food = heterotrophs Primary consumers - organisms that eat plants Seconday consumers - organisms that eat primary consumers Detritovores - organisms that eat dead organic matter Energy flow: Food chain - the pathway along which food is transferred from trophic level to trophic level. Food web - the interconnected feeding relationships in an ecosystem...
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This note was uploaded on 01/20/2010 for the course BIOL 1001 taught by Professor Fall during the Fall '08 term at Minnesota.

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