In the so-called balance of nature, large herbivores are held in check by predators, disease, and sporadic failures of food sources. Although perhaps this didn't really work as well as our mythology suggests, often man has upset whatever balance there ever was. Exploitation, rather than sustainability, has been the usual rule in the arid and semi-arid Southwest.
For economic reasons, excess numbers of livestock were pushed onto the desert grasslands, leaving far too many animals on the range once drought hit. Desperate for food, domestic animals over-harvested grasses, injuring plants already under stress from drought.
The large area necessary under desert conditions for collection of
moisture to support a limited plant body results in plants separated by bare areas. As
sharp hooves trampled these dry areas of bare soil, the erosive forces of wind and
water had free hand, damaging the soil beyond recovery. Too much of our Chihuahuan
Desert, as we see it today, has been shaped not by nature, but by a too optimistic view
of the ability of the land to support the activities of mankind.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
<<p class="three">Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.