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, and mosses. Algae are the most common and abundant of them all due to their adaptive ability, how ever we more closely associate lichens and moss's due to the fact that we can see them much more clearly with out the assistance of a microscope. 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 animal walking over it in a pasture. Humans hiking up in the mountains has also had a detrimental impact on the population of Soil Crust communities.
Sign In the Utah telling hikers to stay on the path
Habitat
These types of communities tend to inhabit areas that are arid and semi arid, such as the south western united states, Australia and Antartica.. Soil Crust communities are highly specialized community of cyanobacteria, mosses, and lichens that along with their biomass and wastre products creat the Soild crust that cover the surface of otherwise barren landscapes.
They perform ecological functions that benifit the surrounding evnironment.
Soil Stability:
Water Infiltration: Cryptogramic Soil Crust communities can affect he regions hydrologic cylce, depening in which type, in a positive or negative way. Including absorbuance and retention abilities of the soil, along with soil porosity itseelf by changes how the rain and runnoff water interacts at the surface.
Effects on Plant Germination and Growth (Positive and Negative):
[Lichens]
Lichens are a composite organism, the consist of many different types on individuals working together for a common goal, survival. Lichen arise from cyanobacteria and/or algae which are all ready living among a fungus in a symbiotic lifestyle. Thus creating a new organism that looks and behaves very different then its "parent" organisms.
They are distinguished by their growth patterns and because of this they can be used to age past events. This is done by measuring their radial size and then based on this we can infer how long that lichen has been growing on that barren rock. Which we can then determine how long that barren rock has been barren and exposed. [[File:|border\200px]]
Lichens are one of the firs living things to start colonizing on barren rock after an event that stripped it of its soil. It starts the process of forming new soil. It does this by releasing acids that break down the rock as it grows over time. This releases rock material and when the lichen dies it is turned into a small layer of soil for the next stage of restoration to occur in. Lichens can also do Nitrogen and carbon fixation, as well as producing a array of different colors due to different pigments they release.
Styles of Lichens
Crustose: These Lichens form a close bond with the surface upon which it is growing on. Forming a biological adhesive layer with the abiotic surface
Foliose: These lichen have the unquie ability to change their repodructive habits based purely on environemntal stresses. The more disturbances their are, the more they use sexual repoduction. While the more stable the enviroment is the more they use asexual reproduction.
foliose:
Squamulose:
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.
Ahmadjian, V. The nature of lichens:31-36.