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We hypothesize that county scale geospatial data (1:5000 to 1:24,000) can depict critical hydrologic and geomorphic attributes of stream reach ecosystem nitrogen (N) sinks in lower order watersheds.<P> Our objectives are to: <OL> <LI>Develop a ranking system for the N sink capacity of lower order stream reach ecosystems. The evaluation will reflect N retention resulting from both the individual and cumulative effects of each N sink within drainage networks. Key watershed N sinks include: the zero order network of seasonally saturated swales and ephemeral flowages constituting the expanded stream network in wet weather conditions; the riparian zone; the stream and its sediments (e.g., the hyporheic zone that exchanges water with the stream); lakes; and reservoirs. Water residence time may be the controlling factor for reducing N loading in all these settings; hydrology and geomorphology strongly influences residence time.<LI>Translate our insights into an environmental spatial decision support system (ESDSS) to improve the capacity of local decision makers in targeting best management practices (BMPs) and planning efforts to areas with the greatest potential to affect watershed N export. <LI> Transmit our ESDSS to Extension (e.g., Nonpoint Education of Municipal Officials (NEMO) and eXtension) and NRCS (Natural Resources Conservation Service) professionals to enhance their capacity to train local decision makers. <LI>Create new curricula and training opportunities for graduate and undergraduate students that provide new insights into watershed N dynamics and expand their understanding of the rigor required to develop accessible decision support tools for coastal decision makers. Our evaluation tool will be tailored to the geographic and political conditions prevailing within most rural communities in coastal New England and New York; however, the tool will be built in modular format and easily adaptable to other regions if they possess critical differences in ecosystem structure influencing N sinks along drainage networks. Because our approach focuses on sink areas that enhance retention times and biogeochemical processing, the tool will have additional value for stakeholders concerned with other water quality issues.
Non-Technical Summary: Local decision makers and landowners can affect a number of watershed processes that control nitrogen (N) export from coastal watersheds to estuaries where N exerts profound effects on its functions and values. Certain areas of the landscape have a capacity to function as sinks for N u in these N sink areas (for instance riparian zones, streams and its sediments, and reservoirs under certain conditions) N is bound up or removed via biological processes. We will develop an environmental spatial decision support system (ESDSS) for local watershed managers to evaluate the extent and location of N sinks within specific stream reach ecosystems. Our ESDSS will permit decision makers and landowners to target best management practices (BMPs; e.g., intensive source controls or stream reach ecosystem restoration) in subwatersheds that lack stream reach ecosystem N sinks and will provide guidance to protect critical areas in subwatersheds with important N sinks. <P> Approach: To develop a ranking system of the N sink capacity of lower order stream reach ecosystems (Objective 1) we will focus on several watersheds in Southern New England that have high resolution spatial data on soils, geomorphology, land cover and land surface elevation as well as water quality data. We will engage in an iterative process that starts with published relationships between landscape attributes and N sink function. We will strengthen our ranking system through mass balance assessments and core studies on stream, hyporheic and reservoir function. The classification will focus on individual N sinks and the cumulative stream reach ecosystem. Sensitivity analysis and other approaches will be used to assign levels of certainty (high and low) to each estimate. Drawing on our experience with developing graphical user interfaces (GUIs) and visualization formats for local decision makers, our environmental spatial decision support system (ESDSS) will be developed (Objective 2) in a modular format for each of the N sinks as well as for the whole stream network. Our ESDSS will display the different tiers of N sink capacity and will visually represent uncertainty in specific stream reach ecosystems. We will assess and refine the GUI and visualization format through an iterative process with sequential feedback from four different audiences: GIS students, NEMO Extension professionals, NRCS staff and local decision makers. Our ESDSS and related educational materials will be disseminated (Objective 3) to NEMO (Nonpoint Education of Municipal Officials) Network participants via train the trainer Extension programs with individuals versed in the range of effectiveness of different GIS platforms for addressing the constraints and capacities of local decision makers. NRCS staff will receive targeted training. We will also make our work available to the Map@Syst Community of Practice in eXtension. We will focus our educational efforts (Objective 4) on: i) curriculum development and engagement the NSF-funded IGERT (Integrative Graduate Education and Research Traineeship) Ph.D. training grant at the University of Rhode Island (URI); ii) doctoral level research training at Arizona State University; and iii) involvement of undergraduate URI Coastal Fellows in experiential learning. Both the IGERT and Coastal Fellows programs have outcome assessment structures that we will use to assess educational value from these efforts.