Cooperative Ecosystem Studies Unit, Piedmont-South Atlantic CESU

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The National Research Program (NRP) of the USGS Water Resources Discipline seeks to provide financial assistance for multidiscipline environmental research to further our understanding on how floodplain forests help to buffer society from water quality degradation and rising atmospheric CO2 when hydrological connections to adjacent streams and rivers remain intact. As depositional sites, floodplains trap material from anthropogenic activities that may drive increases in sediment export upstream and consequent deposition downstream. The main objective of this research is to identify and interpret the biogeochemical relations among elevated sedimentation and key drivers of material trapping (nitrogen and phosphorus dynamics) and C sequestration such as forest net primary productivity (NPP), species composition, and structure. This basic understanding is being used to predict the effects of floodplain sedimentation on ecosystem services. The recipient institution will be responsible for collecting, processing, and analyzing samples necessary to allow for the comparison of the degree of P saturation and N:P balance in soils and vegetation respectively, soil N mineralization, soil porosity, and C storage among forest communities across a range of sedimentation levels on the Congaree Floodplain. Additionally the recipient will assist in the collection of sedimentation information from artificial markers, dendrogeomorphic efforts, and single stage sedimentation samplers. The recipient must have extensive experience measuring biogeochemical properties in floodplain wetland ecosystems, as well as sufficient laboratory instrumentation, field equipment, and personnel to conduct the work. While this research should have applications for forested riparian wetlands throughout the southeastern U.S., emphasis should be placed on the Congaree River (South Carolina) and its floodplain in the vicinity of Congaree National Park. The specific objectives of this funding opportunity include: 1. The measurements of the biogeochemical properties of the soils of forested wetlands in and possibly near Congaree National Park. The recipient will evaluate how N and P biogeochemistry changes across a range of depositional levels are related to C storage. The recipient will assist in the installation and data collection of various monitors of sedimentation dynamics. 2. The assessment of phosphorus status of soils using the ammonium oxalate index of P saturation (DPSox (25%). Estimation of N mineralization will utilize the in –situ buried bag approach. Estimates of soil porosity and an index of aeration. Storage of C, N, and P in sediment will be calculated by combining C, N, and P concentrations in sediment with mass estimates of annual deposition. Analyses of C and N will utilize thermal combustion on a PE-Analyzer 2400. Colorimetric analyses of a Mehlich 3 soil extraction solution will provide estimates of soil extractable (plant available) P. Data analyses will focus upon relationships among NPP, C storage, biogeochemical indices (i.e., mineralization, extractable P, etc.) and sedimentation rates using regression and ANOVA methodologies.

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