Effects of Groundwater Decline on Riparian Vegetation on Semiarid Regions: The San Pedro, Arizona

Groundwater depletion threatens many riparian ecosystems in arid and semi-arid regions of the world. The aquifer that sustains Arizona's San Pedro riparian ecosystem, for example, is threatened by regional goundwater declines and localized pumping from the alluvial aquifer. This paper demonstrates the important role of shallow groundwater in structuring the San Pedro River plant community, portions of which function as reference areas that indicate site potential for a globally rare forest type (Sonoran riparian Populus-Salix forests).