Editing Ecosystem (section)

===Primary production===
[[File:Seawifs global biosphere.jpg|upright=1.8|thumb|Global oceanic and terrestrial phototroph abundance, from September 1997 to August 2000. As an estimate of [[autotroph]] biomass, it is only a rough indicator of primary production potential and not an actual estimate of it.]]
{{main|Primary production}}
Primary production is the production of [[organic matter]] from inorganic carbon sources. This mainly occurs through [[photosynthesis]]. The energy incorporated through this process supports life on earth, while the carbon makes up much of the organic matter in living and dead biomass, [[soil carbon]] and [[fossil fuel]]s. It also drives the [[carbon cycle]], which influences global [[climate]] via the [[greenhouse effect]].

Through the process of photosynthesis, plants capture energy from light and use it to combine [[carbon dioxide]] and water to produce [[carbohydrate]]s and [[oxygen]]. The photosynthesis carried out by all the plants in an ecosystem is called the gross primary production (GPP).<ref name="Chapin-2011d">{{Cite book|last=Chapin|first=F. Stuart III|title=Principles of terrestrial ecosystem ecology|date=2011|publisher=Springer|others=P. A. Matson, Peter Morrison Vitousek, Melissa C. Chapin|isbn=978-1-4419-9504-9|edition=2nd|location=New York|chapter=Chapter 5: Carbon Inputs to Ecosystems|oclc=755081405}}</ref>{{rp|124}} About half of the gross GPP is respired by plants in order to provide the energy that supports their growth and maintenance.<ref name="Chapin-2011e">{{Cite book|last=Chapin|first=F. Stuart III|title=Principles of terrestrial ecosystem ecology|date=2011|publisher=Springer|others=P. A. Matson, Peter Morrison Vitousek, Melissa C. Chapin|isbn=978-1-4419-9504-9|edition=2nd|location=New York|chapter=Chapter 6: Plant Carbon Budgets|oclc=755081405}}</ref>{{rp|157}} The remainder, that portion of GPP that is not used up by respiration, is known as the [[net primary production]] (NPP).<ref name="Chapin-2011e" />{{rp|157}} Total photosynthesis is limited by a range of environmental factors. These include the amount of light available, the amount of [[leaf]] area a plant has to capture light (shading by other plants is a major limitation of photosynthesis), the rate at which carbon dioxide can be supplied to the [[chloroplast]]s to support photosynthesis, the availability of water, and the availability of suitable temperatures for carrying out photosynthesis.<ref name="Chapin-2011d" />{{rp|155}}