HR: 0800h
AN: H51H-0878    [Abstracts]
TI: Long-term Ecohydrologic Pattern Optimization at the Hillslope Scale
AU: * Hwang, T
EM: h7666@email.unc.edu
AF: University of North Carolina at Chapel Hill, UNC Department of Geography, Saunders Hall, Campus Box 3220, Chapel Hill, NC 27599-3220, United States
AU: Hales, T
EM: tchales@email.unc.edu
AF: University of North Carolina at Chapel Hill, UNC Department of Geography, Saunders Hall, Campus Box 3220, Chapel Hill, NC 27599-3220, United States
AU: Band, L
EM: lband@email.unc.edu
AF: University of North Carolina at Chapel Hill, UNC Department of Geography, Saunders Hall, Campus Box 3220, Chapel Hill, NC 27599-3220, United States
AB: The optimization of vegetation structure at the plot scale has been reviewed in various terms, including the minimization of water stress and maximization of productivity across the different systems. However, ecosystem patches exist as part of a drainage chain, or catena, that share some degree of dependency on productivity and resource uses with other patches along flowpaths. Especially at a mountainous forest where lateral water fluxes through shallow soil columns are dominant, it will increase the heterogeneity of spatial distribution and the dependence on the topographic gradients. Ecosystem patches linked along hydrologic flowpaths would optimize their vegetation density to local climate, soil and topographic conditions in the absence of significant human manipulation. Therefore, spatial pattern of current vegetation density at the hillslope scale is a good estimator for spatio-temporal dynamics of the root layer moisture. We estimated the spatial distribution of vegetation density from the relationship between point-measured leaf area index information and vegetation indices from the fine- scale remote sensed data. And then, eco-hydrologic model (RHESSys) was deliberately optimized not only with point measurements (e.g. streamflow data, TDR soil moisture data), but also with spatial information (e.g. spatial vegetation density) within the multi-criteria concept. Behavioral parameter spaces related to the spatial distribution of rooting depth were evaluated with rooting depth measurements from soil pits. We tried to examine which hillslope level properties the catenary sequence of patches optimize (e.g. maximizing productivity or water use efficiency, minimizing water stress) and their meaning in terms of susceptibility to the climate fluctuation (e.g. drought) with long-term ecohydrological model simulation.
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 1813 Eco-hydrology
DE: 1855 Remote sensing (1640)
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2007 Fall Meeting