• View of Grand Canyon National Park at sunset from the South Rim

    Grand Canyon

    National Park Arizona

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    Beginning Sunday, temperatures will increase before another passing weather system causes a period of strong gusty winds Tuesday and Wednesday. (Source NOAA) More »

Biological Soil Crusts

Cryptogamic crusts, N. Herbert NPS

Cryptogamic crusts

NPS Photo by N. Herbert

Biological crusts (also known as cryptogamic, microbiotic, crytobiotic and microphytic crusts) are microscopic non-vascular assemblages composed of blue-green algae, diatoms, golden brown algae, lichens, mosses and a few xerophytic (adapted for growth with a limited water supply) liverworts on more mesic (moderate amount of moisture) sites.
 
Don't bust the cryptogamic crust logo
Blue-green algae contribute to the bulk of the algal tissue. Biological crusts grow on and within soils and other substrates, modifying these surfaces in significant ways. The blue-green algae fix atmospheric nitrogen and thus enhance the nutrient status of the soil.

Cryptogamic crusts retard erosion by wind and water, help retain soil moisture during dry periods, slow evaporation rates, and enhance seedling establishment. These living crusts are extremely fragile and one footprint can set back development for decades.

For more information on Biological Soil Crusts visit this USGS Soilcrust website.

Did You Know?

KOLB STUDIO GRAND CANYON N.P.

Kolb Studio was once the home and business of the Kolb brothers, pioneering photographers at Grand Canyon. Today you can visit free art exhibits in the auditorium and shop in the bookstore. The studio is located in the Village Historic District, at the Bright Angel Trailhead. Open daily. More...