In particular, the Sonoran Desert in Southern Arizona is a delicate ecosystem. The native plants and animals that live there are uniquely adapted to a lifestyle in an arid region. Cows are not. When cattle are introduced into this finely tuned ecosystem, the results are predictable: ecological disaster. As the southwest endures a prolonged drought, the capacity of this land to support native forms of life is pushed to the limit. Once poorly managed herds of cattle are overgrazing these areas, the only possible result is catastrophe.
Consider these two photographs of a typical area before and after the advent of ranching and cattle grazing:
Tom's hiking pages / tom@mmto.org