Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: July 13, 2002
Publication Date: N/A
Technical Abstract: Riparian buffer zones have the potential to intrinsically remediate agricultural contaminants, but their true effectiveness remains largely unevaluated. Most riparian zone studies to date have focused on one or two aspects such as hydrology, biology, or geochemistry) of a riparian system, with conclusions based on inherently limited research. It is the interactions between these components of a riparian system, however, that ultimately determine the overall effectiveness of the system at contaminant mitigation. The OPE3 study includes research to evaluate riparian zone function within an agricultural setting, in an attempt to more fully understand the complex interactions between hydrology, biogeochemistry, vegetation, and climate that affect the fate of agrochemicals. The riparian study site consists of a first-order stream surrounded by (primarily obligate wetland) vegetation. The site has been instrumented with five permanent stream sampling/monitoring stations fitted with weirs, so that continuous stream flow, and water quality, data can be obtained. This configuration also allows changes between stations to be assessed. Approximately 170 piezometers have been instrumented throughout the riparian zone to measure groundwater movement and composition. Numerous riparian soil cores have been extracted and evaluated. Twelve tree sap flow sensors have been placed into five trees in the riparian zone to measure sap flow (and ultimately to establish evapotranspiration rates). Vegetation surveys have also been performed at the site. Research conducted at the site over the past three years indicates that variations in hydrologic conditions (largely driven by climate and local stratigraphy) exert a substantial influence on stream contaminant loads. Information gleaned from this study should help establish guidelines for predicting riparian zone function in similar settings, and for implementing best management practices to minimize contamination from agriculture in the larger ecosystems.