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'{{short description|Organism that breaks down dead or decaying organisms}} {{For|The Matches album of the same name|Decomposer (album)}} [[File:Fungi on fallen Birch Branch - geograph.org.uk - 239255.jpg|thumb|Fungi acting as decomposers of a fallen tree branch]] '''Decomposers''' are [[Organism|organisms]] that break down dead or decaying organisms; they carry out [[decomposition]], a process possible by only certain kingdoms, such as [[fungi]].<ref name=ACE>{{Cite web |url=http://nerrs.noaa.gov/doc.htm |title=NOAA. ACE Basin National Estuarine Research Reserve: Decomposers. |access-date=2012-09-17 |archive-url=https://web.archive.org/web/20141009000003/http://www.nerrs.noaa.gov/doc/siteprofile/acebasin/html/biores/decomp/dctext.htm |archive-date=2014-10-09 |url-status=dead }}</ref> Like [[herbivore]]s and [[predator]]s, decomposers are [[heterotrophic]], meaning that they use [[organic material|organic substrates]] to get their [[energy]], [[carbon]] and [[nutrients]] for growth and development. While the terms decomposer and [[detritivore]] are often interchangeably used, detritivores ''ingest'' and digest dead matter internally, while decomposers ''directly absorb'' nutrients through external chemical and biological processes.<ref>[http://www.eoearth.org/article/Trophic_level?topic=58074 ''Trophic level''. Eds. M.McGinley & C.J.cleveland. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC]</ref> Thus, [[Invertebrate|invertebrates]] such as [[earthworm]]s, [[woodlice]], and [[sea cucumbers]] are technically detritivores, not decomposers, since they must ingest nutrients - they are unable to absorb them externally.<ref>{{Cite web|url=http://citadel.sjfc.edu/students/naa07113/e-port/decomposers.html|title=Decomposers|website=citadel.sjfc.edu|access-date=2019-05-09}}</ref> == Fungi == The primary decomposer of litter in many [[ecosystem]]s is [[fungi]].<ref>{{Cite journal|last=Godbold|first=Douglas L.|last2=Hoosbeek|first2=Marcel R.|last3=Lukac|first3=Martin|last4=Cotrufo|first4=M. Francesca|author-link4=M. Francesca Cotrufo|last5=Janssens|first5=Ivan A.|last6=Ceulemans|first6=Reinhart|last7=Polle|first7=Andrea|last8=Velthorst|first8=Eef J.|last9=Scarascia-Mugnozza|first9=Giuseppe|last10=De Angelis|first10=Paolo|last11=Miglietta|first11=Franco|date=2006-03-01|title=Mycorrhizal Hyphal Turnover as a Dominant Process for Carbon Input into Soil Organic Matter|url=https://doi.org/10.1007/s11104-005-3701-6|journal=Plant and Soil|language=en|volume=281|issue=1|pages=15–24|doi=10.1007/s11104-005-3701-6|issn=1573-5036}}</ref><ref>{{Cite journal|last=Talbot|first=J. M.|last2=Allison|first2=S. D.|last3=Treseder|first3=K. K.|date=2008|title=Decomposers in disguise: mycorrhizal fungi as regulators of soil C dynamics in ecosystems under global change|url=https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2435.2008.01402.x|journal=Functional Ecology|language=en|volume=22|issue=6|pages=955–963|doi=10.1111/j.1365-2435.2008.01402.x|issn=1365-2435|doi-access=free}}</ref> Unlike [[bacteria]], which are unicellular organisms and are decomposers as well, most [[saprotroph]]ic fungi grow as a branching network of [[hypha]]e. While bacteria are restricted to growing and feeding on the exposed surfaces of organic matter, fungi can use their hyphae to penetrate larger pieces of organic matter, below the surface. Additionally, only [[wood-decay fungus|wood-decay fungi]] have evolved the [[enzyme]]s necessary to decompose [[lignin]], a chemically complex substance found in wood.<ref>{{cite journal|last1=Blanchette|first1=Robert|title=Delignification by Wood-Decay Fungi|journal=Annual Review of Phytopathology|date=September 1991|volume=29|pages=281–403|doi=10.1146/annurev.py.29.090191.002121}}</ref> These two factors make fungi the primary decomposers in [[forest]]s, where litter has high concentrations of lignin and often occurs in [[coarse woody debris|large pieces]]. Fungi decompose organic matter by releasing enzymes to break down the decaying material, after which they absorb the nutrients in the decaying material.<ref name=berkeley>{{cite web |url=http://www.ucmp.berkeley.edu/fungi/fungilh.html |title=Fungi: Life History and Ecology |first1=Ben |last1=Waggoner |first2=Brian |last2=Speer |work=Introduction to the Funge=24 January 2014}}</ref> Hyphae used to break down matter and absorb nutrients are also used in reproduction. When two compatible fungi hyphae grow close to each other, they will then fuse together for reproduction, and form another fungus.<ref name=berkeley /> == See also == *[[Chemotroph]] *[[Micro-animals]] *[[Microorganism]] == References == {{reflist}} {{Refbegin}} == Further reading == * {{cite journal | last1 = Bear | first1 = MH | last2 = Hendrix | first2 = PF | last3 = Cheng | first3 = W | s2cid = 86031411 | year = 1992 | title = Microbial and faunal interactions and effects on litter nitrogen and decomposition in agroecosystems | journal = Ecological Monographs | volume = 62 | issue = 4| pages = 569–591 | doi=10.2307/2937317| jstor = 2937317 }} * Hunt HW, Coleman DC, Ingham ER, Ingham RE, Elliot ET, Moore JC, Rose SL, Reid CPP, Morley CR (1987) "The detrital food web in a shortgrass prairie". ''Biology and Fertility of Soils 3'': 57-68 * Smith TM, Smith RL (2006) ''Elements of Ecology''. Sixth edition. Benjamin Cummings, San Francisco, CA. {{Refend}} {{Feeding}} {{Modelling ecosystems}} [[Category:Microbiology]]'