A growing understanding of the importance of riparian ecosystems in the semiarid and arid west has sparked interest in the growth and distribution of riparian vegetation. Disturbances and stresses caused by changes in streamflow patterns from dams have profoundly affected riparian vegetation species composition and structure. In the Southwestern United States, riparian forests historically dominated by the native Populus Fermontii (Cottonwood) and Salix Gooddingii (Willow) have been inundated by the exotic species Tamarix Ramosissima (Salt Cedar). This study presents a method for reservoir release management to enhance downstream vegetation recruitment of native species. The focus is on the Bill Williams River (BWR) in Western Arizona which is regulated by Alamo Dam. Through literature review, expert knowledge, and computational modeling, more informed decisions can be made regarding recruitment strategies for riparian vegetation. Modeling in this study employs the U.S. Army Corps of Engineer Hydrologic Engineering Center’s Ecosystems Functions Model (EFM) and River Analysis System (RAS), ESRI’s ArcMap, and Applied Imagery’s Quick Terrain

doi:10.1111/j.1365-2427.2009.02206.x Theory, methods and tools for determining environmental flows for riparian vegetation: riparian vegetation-flow response guilds