Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 2, 2004
Publication Date: November 2, 2004
Citation: McCarty, G.W., Angier, J. 2004. Linkage between evapotranspiration and stream flow within a first-order riparian buffer [abstract]. American Society of Agronomy Abstracts. 2004 CDROM 5797. Technical Abstract: First-order riparian ecosystems are considered to be important buffers for control of agrochemical movement into surface waters. It is important to understand the impact of riparian vegetation, specifically evapotranspiration (ET), on the hydrology of these ecosystems in order to better understand the impact of such vegetation on the transport and fate of agrochemicals within the environment. To determine real-time impacts of ET on the hydrology of a forested riparian buffer, we instrumented a series of trees with thermal dissipation sap flow sensors. The sap flow measurements were obtained in conjunction with continuous monitoring of stream flow (via in-stream weirs) and groundwater (via pressure transducers). The data showed strong diurnal interactions between ET, groundwater levels, and stream flow. ET was predominantly driven by solar radiation and influenced by humidity and wind. The diurnal pattern of ET showed suppressed groundwater levels and stream flows during daylight periods, with recovery occurring overnight. The tight linkage observed between ET and riparian buffer hydrological conditions demonstrates the importance of riparian vegetation on water and solute movement within ecosystems associated with first-order streams. Buffer management strategies for mitigating agrochemical movement into surface water resources should address the impact of these linkages.