Editing Fen (section)

== Threats ==
One of the many threats that fens face is conversion to agricultural lands.<ref name=":42">{{Cite journal |last1=van Diggelen |first1=Rudy |last2=Middleton |first2=Beth |last3=Bakker |first3=Jan |last4=Grootjans |first4=Ab |last5=Wassen |first5=Martin |date=November 2006 |title=Fens and floodplains of the temperate zone: Present status, threats, conservation and restoration |journal=Applied Vegetation Science |volume=9 |issue=2 |pages=157–162 |doi=10.1111/j.1654-109x.2006.tb00664.x |bibcode=2006AppVS...9..157V |hdl=11370/f76f9817-87e7-4764-837d-ef51703e21c8 |issn=1402-2001 |url=https://research.rug.nl/en/publications/fens-and-floodplains-of-the-temperate-zone(f76f9817-87e7-4764-837d-ef51703e21c8).html |hdl-access=free |access-date=2021-04-07 |archive-date=2022-01-12 |archive-url=https://web.archive.org/web/20220112234338/https://research.rug.nl/en/publications/fens-and-floodplains-of-the-temperate-zone-present-status-threats |url-status=live }}</ref> Where climates are suitable, fens have been drained for agricultural use alongside crop production, [[grazing]], and [[Haymaking|hay making]].<ref name=":15">{{Cite web|title=Threats to Fens|url=https://www.canr.msu.edu/nativeplants/restoration/threats_to_fens|access-date=2021-04-01|website=Native Plants and Ecosystem Services|language=en|archive-date=2021-04-18|archive-url=https://web.archive.org/web/20210418164455/https://www.canr.msu.edu/nativeplants/restoration/threats_to_fens|url-status=live}}</ref> Draining a fen directly is particularly damaging because it lowers the water table.<ref name=":6" /> A lower water table can increase [[aeration]] and dry out peat, allowing for aerobic decomposition or burning of the organic matter in peat.<ref name=":23"/><ref name=":6" /> Draining a fen indirectly by decreasing its water supply can be just as damaging. Disrupting groundwater flow into the fen with nearby human activities such as [[quarrying]] or residential development changes how much water and nutrients enter the fen.<ref name=":15" /> This can make the fen more ombrotrophic (dependent on precipitation), which results in acidification and a change in water chemistry.<ref name=":42" /> This directly impacts the habitat of these species, and many signature fen species disappear.<ref name=":42" />

Fens are also threatened by [[invasive species]], [[Habitat fragmentation|fragmentation]], peat cutting, and pollution.<ref name=":15" /> Non-native invasive species, such as the [[Rhamnus cathartica|common buckthorn]] in North America, can invade fens and outcompete rare fen species, reducing biodiversity.<ref name=":15" /> [[Habitat fragmentation]] threatens fen species, especially rare or endangered species that are unable to move to nearby fens due to fragmentation.<ref name=":15" /> Peat cutting, while much more common in bogs, does happen in fens. Peat cut from fens has many uses, including burning as a fuel.<ref name=":15" /> Pollutants can alter the chemistry of fens and facilitate invasion by [[invasive species]].<ref name=":15" /> Common pollutants of fens include road salts, nutrients from [[septic tank]]s, and runoff of agricultural fertilizers and pesticides.<ref name=":15" />