The mission of the Arid Lands Resource Sciences (ALRS) program is to provide an academic environment in which to examine the economic, ecological and social factors which determine the long-term sustainable use of arid and semiarid lands. Because of its multifaceted nature, sustainable use cannot be adequately defined nor understood through the tools available in any single discipline. Rather, it must be considered from several disciplinary perspectives. Thus, students in the ALRS program are trained in two or more of the physical, biological, resource, agricultural and social sciences, as they relate specifically to the sustainable use and management of arid and semiarid lands.