Biological Soil Crust (IMAGE)
Caption
This looks like ordinary dirt but it is a biological soil crust (BSC), a living mantle of soil particles bound together by microbes and their by-products. BSCs are common to the arid and semiarid lands that make up about 40-percent of Earth's total land mass.
Credit
(Photo from Ferran Garcia-Pichel, Arizona State University)
Usage Restrictions
with permission of Ferran Garcia-Pichel, Arizona State University
License
Licensed content