GEV 1050 Lecture Notes - Lecture 4: Heterotroph, Chemosynthesis, Trophic State Index
28 Nov 2016
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Document Summary
Net primary productivity (npp), or the production of plant biomass, is equal to all of the carbon taken up by the vegetation through photosynthesis (called gross primary production or gpp) minus the carbon that is lost to respiration. Graph represents the total npp (global) notice the red stretched of high levels of productivity. Average net primary productivity (g c m-2 yr-1) Least productive: extreme deserts, most productive swamps and marshes. Npp is natural, but through human activities we manipulate it to sustain us. Altering ecosystems: i. e. farming, land use change, aquaculture, lumber for shelter, biofuel, landscaping, clothing (cotton) Lakes: swamping a eutrophic lake with nutrients (limiting) brings up the production to a level that reflects human manipulation (algal blooms that use up o2, starve other organisms, decrease diversity of the lake) Oligotrophic, not a lot of production, capped b/c no nutrients entering the system eut(cid:396)ophi(cid:272) (well fed; outside nutrients) nutrients often limit npp.
