Do Invasive Riparian Woody Plants Affect Hydrology and Ecosystem Processes

Abstract

Political and socioeconomic pressures on riparian areas in semiarid regions of the Great Plains are growing as water resources become more limited. Management along waterways has altered stream ecology and hydrology in ways that encourage the invasion and expansion of native (e.g., Juniperus virginiana) and non-native (e.g., Tamarix sp. and Elaeagnus angustifolia) woody species. One management tool currently implemented to restore the hydrology or increase water yields along waterways in semiarid areas is the removal of vegetation or invasive species. How managers should respond to invasive woody plants to optimize hydrological functions without compromising other riparian ecosystem functions is still debatable. In this manuscript, we provide an overview of the ecological status and hydrological role of riparian vegetation in the northern Great Plains, with examples drawn from the region and other semiarid areas. Additionally, we present information compiled from published studies on water consumption of native and non-native species at both tree and stand levels, and we evaluate the ecohydrological outcomes from removal of invasive woody vegetation. Lastly, we consider the economic costs and benefits of woody species removal, and suggest considerations to help managers make decisions regarding woody species removal.