Editing Ecosystem (section)

===Energy flow===

{{main|Energy flow (ecology)}}
{{See also|Food web|Trophic level}}
[[Energy]] and [[carbon]] enter ecosystems through photosynthesis, are incorporated into living tissue, transferred to other organisms that feed on the living and dead plant matter, and eventually released through respiration.<ref name="Chapin-2011e" />{{rp|157}} The carbon and energy incorporated into plant tissues (net primary production) is either consumed by animals while the plant is alive, or it remains uneaten when the plant tissue dies and becomes [[detritus]]. In [[terrestrial ecosystem]]s, the vast majority of the net primary production ends up being broken down by [[decomposition|decomposers]]. The remainder is consumed by animals while still alive and enters the plant-based trophic system. After plants and animals die, the organic matter contained in them enters the detritus-based trophic system.<ref name="Chapin-2011i">{{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 10: Trophic Dynamics|oclc=755081405}}</ref>

[[Ecosystem respiration]] is the sum of [[Cellular respiration|respiration]] by all living organisms (plants, animals, and decomposers) in the ecosystem.<ref>{{Cite journal|last1=Yvon-Durocher|first1=Gabriel|last2=Caffrey|first2=Jane M.|last3=Cescatti|first3=Alessandro|last4=Dossena|first4=Matteo|last5=Giorgio|first5=Paul del|last6=Gasol|first6=Josep M.|last7=Montoya|first7=José M.|last8=Pumpanen|first8=Jukka|last9=Staehr|first9=Peter A.|date=2012|title=Reconciling the temperature dependence of respiration across timescales and ecosystem types|journal=Nature|language=En|volume=487|issue=7408|pages=472–476|bibcode=2012Natur.487..472Y|doi=10.1038/nature11205|issn=0028-0836|pmid=22722862|s2cid=4422427}}</ref> [[Net ecosystem production]] is the difference between [[Primary production|gross primary production]] (GPP) and ecosystem respiration.<ref name="Lovett-2006">{{Cite journal|last1=Lovett|first1=Gary M.|last2=Cole|first2=Jonathan J.|last3=Pace|first3=Michael L.|date=2006|title=Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation?|journal=Ecosystems|language=en|volume=9|issue=1|pages=152–155|doi=10.1007/s10021-005-0036-3|bibcode=2006Ecosy...9..152L |issn=1435-0629|s2cid=5890190}}</ref> In the absence of disturbance, net ecosystem production is equivalent to the net carbon accumulation in the ecosystem.

Energy can also be released from an ecosystem through disturbances such as [[wildfire]] or transferred to other ecosystems (e.g., from a forest to a stream to a lake) by [[erosion]].

In [[aquatic ecosystem|aquatic systems]], the proportion of plant biomass that gets consumed by [[herbivore]]s is much higher than in terrestrial systems.<ref name="Chapin-2011i" /> In trophic systems, photosynthetic organisms are the primary producers. The organisms that consume their tissues are called primary consumers or [[secondary production|secondary producers]]—[[herbivores]]. Organisms which feed on [[microbe]]s ([[bacteria]] and [[fungi]]) are termed [[microbivore]]s. Animals that feed on primary consumers—[[carnivore]]s—are secondary consumers. Each of these constitutes a trophic level.<ref name="Chapin-2011i" />

The sequence of consumption—from plant to herbivore, to carnivore—forms a [[food chain]]. Real systems are much more complex than this—organisms will generally feed on more than one form of food, and may feed at more than one trophic level. Carnivores may capture some prey that is part of a plant-based trophic system and others that are part of a detritus-based trophic system (a bird that feeds both on herbivorous grasshoppers and earthworms, which consume detritus). Real systems, with all these complexities, form [[food web]]s rather than food chains which present a number of common, non random properties in the topology of their network.<ref>{{cite journal |last1=Briand |first1=F. |last2=Cohen |first2=J.E. |title=Community food webs have scale-invariant structure |journal=Nature |date=19 January 1984 |volume=307 |issue=5948 |pages=264–267|doi=10.1038/307264a0 |bibcode=1984Natur.307..264B |s2cid=4319708 }}</ref>