Water Resources Research Act Program

Details for Project ID 2005NY64B

Export of atmospheric nitrogen deposition from forests at the top of the Susquehanna watershed

Institute: New York
Year Established: 2005 Start Date: 2005-03-01 End Date: 2006-02-28
Total Federal Funds: $24,981 Total Non-Federal Funds: $32,100

Principal Investigators: Christine Goodale

Project Summary: The Susquehanna River provides about three quarters of the nitrogen N delivered annually to the Chesapeake Bay. Primary productivey in the Chesapeake Bay is nitrogen limited, and so the added N drives processes of eutrophication and subsequent hypoxia. The majority of the N inputs to the Susquehanna watershed are from agricultural sources, including fertilizer, N-fixing crops and import of animal feed, yet atmospheric deposition of fixed N provides a major contribution (27%) to the watershed total N loading. This proposed research will obtain information on the quantity and immediate source of N exported from forested catchments at the top of the Susquehanna Basin, a region where human activities have increased rates of N deposition to levels 10 times greater than those occurring during pre-industrial conditions. Forested plots adjacent to the Connecticut Hill N deposition long-term monitoring site will be instrumented with lysimeters to collect soil water in and below the rooting zone. Combined with a model of soil water flux, analyses of the N concentration of soil water samples will allow assessment of forest N retention of atmospheric N in this understudied region. Additional surveys of stream N concentrations from nearby forested catchments will allow assessment of landscape variation in N export. Finally, isotopic analyses of the d15N and d18O signal of exported NO3- will allow determination of the direct (short-term) contributions of atmospheric N to forest N export.