Greater scientific understanding is needed of how semi-arid landscapes and other dry environments function, particularly from the ecohydrologic perspective. This need is driven by the growing urgency of finding answers for such troublesome issues as the sustainability of ecosystems, inadequacy of water supplies, degradation of water quality and the effects of environmental change at local, regional, and global scales. Because of the tight coupling between ecologic and hydrologic processes in semi-arid landscapes, these issues must be addressed from an ecohydrologic perspective.
Ecohydrology has been defined as “the sub-discipline shared by the ecological and hydrological sciences that is concerned with the effects of hydrological processes on the distribution, structure, and function of ecosystems, and with the effects of biotic processes on elements of the water cycle” [Nuttle, 2002]. While not a new term, ecohydrology is receiving increased attention, largely because of the recognition that more interdisciplinary or holistic approaches are required to adequately address applied and basic environmental research problems [e.g.,Baird and Wilby, 1999; Gupta, 2000; Gurnell et al., 2000;Horton, 1998; May et al., 1999;Nuttle, 1999, 2002; and Rodriguez-Iturbe, 2000].