Cryprogamic Soil Crust
What is it?
Cryptogamic soil is a very thin layer of life consisting of a variety composition of living organisms including lichens, bryophytes, algae, fungi, mosses and cryanobacteria Algae are the most common and abundant of them, how ever we more closely associate lichens and moss's due to the fact that we can see them much more clearly with the naked eye. These organism can play a huge part in stabilizing the top layer of soil (Horizon O). This is hugely beneficial in making sure that erosive forces like wind and water don't crumble away this important layer and leave the bedrock barren. Cryptogamic crust also can help maintain moisture levels and distribute it deeper into the soil layers along with other important processes such as nitrogen fixation. Depending on where the soil crust is located and which scholar you ask, soil crust can either help or not help vascular plants from establishing and flourishing.
The fact that its only a thin layer on the surface, does mean its fragile and easily acceptable to being killed. This can be done by some cow in a pasture simply stepping on it or by a silly human child running of the designated path.
Habitat
These types of communities tend to inhabit areas that are arid and semi arid, such as the south western united states. One example of are
lichen's
Algae
Impact
References
Anderson, David C., et al. “Factors Influencing Development of Cryptogamic Soil Crusts in Utah Deserts.” Journal of Range Management, vol. 35, no. 2, 1982, p. 180., doi:10.2307/3898386.
Lesica, et al. “The Effects of Cryptogamic Soil Crust on the Population Dynamics of Arabis Fecunda (Brassicaceae) /.” Details - The Effects of Cryptogamic Soil Crust on the Population Dynamics of Arabis Fecunda (Brassicaceae) /, Helena, Mt. :Montana Natural Heritage Program,[1991], 1 Jan. 1991, www.biodiversitylibrary.org/bibliography/35812.