Primary production is formation of organic material from inorganic carbon, powered by light or chemical free energy. Photosynthetic plants, algae and cyanobacteria supply familiar examples. The product supports consumers directly or enters a detritus-based food web.
Gross primary production counts total carbon fixation, whereas net primary production subtracts the producers' own autotrophic respiration. A standing stock of biomass is therefore different from either rate: a small stock can turn over rapidly.
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