Plant Ecology in Deserts: An Overview

The vulnerability of desert vegetation to off-road vehicle (ORV) impacts, and in particular, the probable longevity of these impacts, is well established for the southwestern deserts of North America. Because of the many similarities of the world’s deserts to those of the United States, consideration of the vegetation of the world’s deserts is also important to management of ORVs. The objective of this chapter is to give the reader an overview of some of the more important aspects of the vegetation ecology and dynamics of the world’s deserts. The emphasis is on the deserts of the southwestern United States since the authors are most familar with this region in both a scientific and practical sense. However, we have no reason to believe that generalizations and concepts gleaned largely from studies of the vegetation of North American deserts will not be applicable to the arid and semiarid regions of other continents, especially when the vegetation types can be considered “matched” (Pielou, 1979) or homologous. In areas with similar climates, similar life forms tend to dominate in the natural vegetation even though such areas may be floristically distinct (Mueller-Dombois and Ellenberg, 1974).