Poster Details
SPATIALLY-EXTENSIVE SAMPLING REVEALS CONSISTENT HYPORHEIC-ZONE EFFECTS ON DISSOLVED ORGANIC MATTER QUANTITY AND QUALITY AT THE WATERSHED SCALE.
Dissolved organic matter (DOM) regulates energy flow, nutrient cycling, and water quality in surface waters. As DOM passes through directional stream networks, the stream-groundwater interface, known as the hyporheic zone (HZ), exerts a strong effect on DOM quantity (i.e., concentration) and quality (e.g., aromaticity, molecular weight). Because of methodological challenges of sampling the HZ, most of our current understanding of DOM dynamics in the HZ is based on site-level studies, and it is unknown how land use and land cover influence HZ DOM processing at larger spatial scales. In this study, we performed large-scale, high-resolution HZ sampling to test how landscape patterns influenced DOM quantity and quality at 39 sites throughout a third-order watershed with diverse land patterns, encompassing first-, second-, and third-order locations. We found a strong correlation between land use and surface water DOM quantity and quality, but this relationship broke down with HZ depth. This homogenization of sub-surface DOM quantity and quality indicates common HZ functioning across spatial scales, providing a potential pathway for scaling HZ functioning determined at the site level to the watershed level.
Joseph Lee-Cullin (Primary Presenter/Author), Department of Earth and Environmental Sciences, Michigan State University, USA, cullinjo@msu.edu;
Jay Zarnetske ( Co-Presenter/Co-Author), Department of Earth and Environmental Sciences, Michigan State University, jpz@msu.edu;
Evan Wiewiora ( Co-Presenter/Co-Author), Department of Earth and Environmental Sciences, Michigan State University, USA, wiewiora@msu.edu;
Benjamin Abbott ( Co-Presenter/Co-Author), Department of Earth and Environmental Sciences, Michigan State University, USA, benabbo@gmail.com;
Sydney Ruhala ( Co-Presenter/Co-Author), Department of Earth and Environmental Sciences, Michigan State University, USA, ruhalasy@msu.edu;
Tyler Hampton ( Co-Presenter/Co-Author), Department of Earth and Environmental Sciences, Michigan State University, USA, thampton@msu.edu;