Author(s): Kumud Acharya, Sachiko Sueki, John Healey, Yiping Li
Linked Author(s): Kumud Acharya
Keywords: Eddy covariance, white method, Tamarix, saltcedar, leaf beetle
Abstract: The Virgin River is a tributary of the Colorado River System and flows through the Tri-State area of Arizona, Utah and Nevada. The river's relevance to each state is an important issue as rising population growth results in greater demands on a depleting, limited water supply. One of the ways to manage the water supply of the Colorado River System is vegetation management which includes invasive Tamarisk (Tamarixspp). Tamarisk is the most prolific invasive plant spreading along many riparian corridors of the Southwestern United States. A tamarisk thicket, during a single growth cycle, transpires water at rates that can approach the evaporation rate of an open body of water. Because of the mixed results of traditional control of tamarisk via chemical, mechanical and fire-based methods, biological control using Diorhabdacarinulata (leaf beetle) begins in 2001. The successful release at the banks of Virgin River in St George, UT in 2006 leads to the large-scale establishment of the beetles along the Lower Virgin River. The objective of this study is to determine the effect of beetles' defoliation on tamarisk water consumption based on long-term ET and groundwater data. An eddy covariance tower is installed along the corridor of the Lower Virgin River in 2010. The site is surrounded mostly by tamarisk. Beetles arrive at the site at the end of 2010 and large scale defoliations occurring in 2011 and 2012. However, extent of defoliation in subsequent years is not consistent. The ET and groundwater data from 2010 to 2016 suggest that the effect of beetles' defoliation on tamarisk water consumption is short-lived
Year: 2017