Grantee Research Project Results
Impacts of Flow Diversion and Regulation on Successional Processes in Cottonwood and Willow Dominated Riparian Forests, Verde River, ArizonaEPA Grant Number: U915369
Title: Impacts of Flow Diversion and Regulation on Successional Processes in Cottonwood and Willow Dominated Riparian Forests, Verde River, Arizona
Investigators: Beauchamp, Vanessa B.
Institution: Arizona State University - Main Campus
EPA Project Officer: Broadway, Virginia
Project Period: August 1, 1998 through August 1, 2001
Project Amount: $88,209
RFA: STAR Graduate Fellowships (1998)
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Ecology and Ecosystems
The objective of this research project is to determine how flow diversion and regulation alter natural successional processes in cottonwood forests in a southwestern arid-riparian ecosystem. Findings from this study project will be used to develop restoration strategies and monitoring programs for cottonwood forests, to predict impacts of water diversions on riparian forests, and to help dam managers develop water -release schedules that will enhance the quality of cottonwood forests downstream from dams.Approach:
Because there is an age gradient of cottonwoods away from the active channel, a space-for-time substitution approach will be used to investigate the changes in under story vegetation, soil texture, chemistry, and mycorrhizae populations that occur along this gradient. A chronosequence of cottonwood stands ranging from saplings to senescent trees will be used to examine these successional processes and assess how flow diversion and regulation impact these processes. Seven reaches along the Verde River have been selected for this project study. Three reaches are free flowing: one is subject to minimal surface water diversions, another is below a significant diversion, and a third lies above the first reservoir on the Verde River. The next reach is below this reservoir, and the fifth reach is below a second water storage reservoir. The remaining two study reaches are located above and below a large unregulated tributary that may dampen some of the effects of flow regulation on the main stem of the river.Supplemental Keywords:
fellowship, riparian, Salix, Populus, dams, succession.