Project ID: 2005NY64B

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

Project Type: Research

Focus Categories: Nutrients, Non Point Pollution, Acid Deposition

Keywords: Atmospheric N, forests, soil water

Start Date: 03/01/2005

End Date: 02/28/2006

Federal Funds: $24,981

Non-Federal Matching Funds: $32,100

Congressional District: 22

Principal Investigator:
Christine Goodale

Abstract

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.

Progress/Completion Report PDF