Pop psychology says a crusty demeanor only disguises a sensitive person beneath. Personal idiosyncrasies aren't something we explore here, but a crusty desert definitely conceals a sensitive land beneath. In undisturbed desert, much of the seemingly bare ground is not soil surface. Instead, it's a mat of numerous microscopic organisms—bacteria, algae, fungi, lichens.
Although highly variable from place to place, it serves a variety of ecological functions. Cyanobacteria (often called blue-green algae) take nitrogen from the air and combine it into forms usable by itself and other organisms, and the entire mat protects the soil from erosion. Moreover, harmful exotic plants have a difficulty obtaining a foothold, a problem not shared by most natives.
Destruction of this crusty, but sensitive, surface on a large scale is
ecologic disaster, whether by trampling, fire, or other means. Wind and water erosion
quickly commences, and other community services disappear. Huge tracts of desert have
been trampled by livestock, and off-road vehicles compound the damage. Today's
desert landscape has been sorely despoiled by such destruction of our crusty
neighbor.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.