HR: 09:45h
AN: B51F-08 INVITED     [Abstracts]
TI: Coupling of Hydrologic and Ecosystem Nutrient Cycling in Forest and Suburban Catchments
AU: * Band, L E
EM: lband@email.unc.edu
AF: Lawrence Band, Department of Geography University of North Carolina CB#3220, Chapel Hill, NC 27599 United States
AU: Tague, C
EM: ctague@mail.sdsu.edu
AF: Christina Tague, Department of Geography San Diego State University, San Diego, CA 92182-4493 United States
AU: Groffman, P
EM: groffmanp@ecostudies.org
AF: Peter Groffman, Institute for Ecosystem Studies Box AB 65 Sharon Turnpike, Millbrook, NY 12545 United States
AU: Kaushal, S
EM: skaushal@al.umces.edu
AF: Sujay Kaushal, University of Maryland Center for Environmental Science Appalachian Laboratory, Frostberg, MD 21532 United States
AU: Kenworthy, S
EM: kenworthy@wku.edu
AF: Steven Kenworthy, University of Western Kentucky 1906 College Heights Blvd. #31066, Bowling Green, KY 42101-1066 United States
AB: This paper discusses the coupling of hydrologic and biogeochemical cycles in forested and suburban catchments of the Baltimore Ecosystem Study. Suburban development produces important changes in land cover, surface and subsurface hydrologic flowpaths and the water and nutrient balances of watersheds. The built environment is characterized by increased spatial heterogeneity of surface cover and more rapid convergence of surface flowpaths. This results in alterations of stream channel geomorphology and the characteristics and coupling of riparian areas with drainage lines. The presence of sanitary infrastructure (sanitary sewers and septic systems) in the moderate and low density suburban catchments introduces new nutrient sources and altered subsurface flowpaths. We combine detailed sampling of distributed soil water, stream discharge and water quality, with high resolution digital land cover, lidar derived elevation data and household surveys of lawn management practices to develop a spatial dataset characterizing hydrologic and ecosystem dynamics of suburban and control forest catchments. A conceptual model is developed based on hydrologic controls of nitrogen transformations and transport within forested catchments, augmented by anthropogenic sources of nitrogen and altered flowpaths within developed sites. The altered geomorphic structure and built drainage systems of the watershed produces significant modification of catchment scale soil moisture and potential nutrient retention. We also modify and apply an ecohydrologic catchment model that simulates the interaction of spatially distributed water, carbon and nutrient cycling. Numerical experiments with the simulation model are used to explore coupling and nonlinear response of water and nutrient cycling within each catchment. Opposite trends are seen in the response of nutrient export to a major drought in our forest and low density suburban catchments, that appears to be explained by spatial location of nutrient sources and the interaction between hillslope and riparian flowpaths.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 1813 Eco-hydrology
SC: Biogeosciences [B]
MN: Fall Meeting 2005