ENV100Y5 Lecture Notes - Lecture 13: Primary Production, Consumers Energy, Cyanobacteria
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ENV100Y5 Full Course Notes
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Document Summary
Net primary productivity (npp) = gross primary productivity (gpp) - respiration by autotrophs. Npp = energy available to consumers & decomposers. There"s chemical energy that gets into ecosystems but the bottom-line is if there"s energy coming in, there"s only one class of organisms that is in the position to do something for that energy (autotrophs; meaning the self-feeders) Examples of autotrophs include plants, multicellular algae, unicellular protist, purple sulphur bacteria and cyanobacteria. Some energy is sometimes loss thus we make a difference between npp (net primary productivity) and gpp (gross primary productivity) Solar energy comes in, it"s fixed through photosynthesis then it"s lost (some energy) but some of it is stored in the plant which then gets eaten by a herbivore and that"s available to consumers. Energy is the currency that moves around in the ecosystem. Primary production is how we get energy and it"s the basis for the engine of productivity but it"s exactly where we see significant threat.
