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Cryptobiotic soils are known by a number of names:
- Cryptogamic soils
- Microbiotic soils
- Microphytic soils
- Biological soil crusts
*We will refer to them as Cryptobiotic soils throughout this section:
What are cryptobiotic soils?
Cryptobiotic soils is defined as meaning “hidden life” at the desert surface. These soils are compromised of living organisms that are intertwined 1-4 mm above the surface. They are composed mainly of cyanobacteria (formerly blue-green algae). They are also composed of liverworts, fungi, lichens, mosses, green and brown algae, and bacteria. The soils consist of filaments that become active when moistened and move throughout the soil. In the process of moving they leave behind a trail of mucilaginous sheath that binds loose soil particles together forming an intricate web of organic material.
What's the big deal about these soils?Cryptobiotic soils are the primary nitrogen fixers in the Basin and Range community and aid in preventing large amounts of ablation (wind erosion) and surface water runoff. They also provide nutrients to nearby plants and provide an area for seed germination. The soils account for nearly 70% of the available surface area of the Basin and Range and are capable of absorbing 10 times their volume of water!
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What happens if you walk on them?The weight of your own body and the compressional force will literally destroy the soil sheath and severely damage the filaments. This effect can decrease nitrogen fixation by nearly 80% and cause surface water runoff to increase by half the amount. Soil loss can increase to as much as six times as compared to undisturbed soils. During dry periods, sandy soil overlain by trampled crusts can become moving sand dunes in only a few years!
What is the long term prognosis?Broken soils can take 5-7 years to recover under normal weather conditions. Unfortunately soil thickness may take up to 50 years to fully recover and mosses and Lichens will need 250 years to recover, all from being stepped on!
What else damages these soils?
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Fire can also severely damage the soil, but slow recovery is possible if the intensity of the fire was low enough. The main causes for damage against cryptobiotic soils are from heavy livestock grazing, tourist activities (biking, hiking, motored vehicles) and also military activities.
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I just want a place to graze! |
Livestock poses the greatest threat to these soils. During their wandering while on range land, livestock can trample and destroy cryptobiotic soils. Because of the large amount of area that cattle cover while grazing they damage these types of soils faster than anything other mechanism. |
