Editing Lichen (section)

===Lichens and soils===
In addition to distinct physical mechanisms by which lichens break down raw stone, studies indicate lichens attack stone chemically, entering newly chelated minerals into the ecology. The substances exuded by lichens, known for their strong ability to bind and sequester metals, along with the common formation of new minerals, especially metal [[oxalate]]s, and the traits of the substrates they alter, all highlight the important role lichens play in the process of chemical [[weathering]].<ref name=catena>{{cite journal |doi=10.1016/S0341-8162(99)00085-5 |title=Weathering of rocks induced by lichen colonization – a review |journal=CATENA |volume=39 |issue=2 |page=121 |year=2000 |last1=Chen |first1=Jie |last2=Blume |first2=Hans-Peter |last3=Beyer |first3=Lothar |bibcode=2000Caten..39..121C |url=http://www.geo.mtu.edu/~raman/papers2/ChenetalCatena.pdf |access-date=21 March 2015 |archive-url=https://web.archive.org/web/20150402091727/http://www.geo.mtu.edu/~raman/papers2/ChenetalCatena.pdf |archive-date=2 April 2015 |url-status=live }}</ref> Over time, this activity creates new fertile soil from stone.

Lichens may be [[Lichens and nitrogen cycling|important in contributing nitrogen]] to soils in some deserts through being eaten, along with their rock substrate, by snails, which then defecate, putting the nitrogen into the soils.<ref>{{cite journal |doi=10.1038/346839a0 |bibcode=1990Natur.346..839J |title=Fertilization of the desert soil by rock-eating snails |journal=Nature |volume=346 |issue=6287 |page=839 |year=1990 |last1=Jones |first1=Clive G. |last2=Shachak |first2=Moshe|s2cid=4311333 }}</ref> Lichens help bind and stabilize soil sand in dunes.<ref name="WIL"/> In deserts and semi-arid areas, lichens are part of extensive, living [[biological soil crust]]s, essential for maintaining the soil structure.<ref name="WIL"/>