HR: 10:45h
AN: H22A-02    [Abstracts]
TI: Comparison of Different Approaches for Relating Ecology and Hydrology in Semiarid Regions
AU: * Scanlon, B R
EM: Bridget.Scanlon@beg.utexas.edu
AF: University of Texas at Austin, Bureau of Economic Geology 10100 Burnet Rd. BLDG 130, Austin, TX 78758 United States
AU: Reedy, R C
EM: Bob.Reedy@beg.utexas.edu
AF: University of Texas at Austin, Bureau of Economic Geology 10100 Burnet Rd. BLDG 130, Austin, TX 78758 United States
AU: Keese, K E
EM: keese@mail.utexas.edu
AF: University of Texas at Austin, Bureau of Economic Geology 10100 Burnet Rd. BLDG 130, Austin, TX 78758 United States
AB: A variety of approaches can be used to assess the impact of linkages between ecology and hydrology on the water cycle in semiarid regions. We present a range of techniques from point to regional scales that document ecological controls on the water cycle. Nonvegetated and vegetated precision weighing lysimeters showed the importance of variations in biomass productivity in dampening the impact of elevated El Nino winter precipitation on subsurface water storage in the Mojave Desert, Nevada. Soil water storage data were compared with ground-based and satellite-based biomass productivity to regionalize the results from the lysimeter data. Soil water potential monitoring in various desert basins throughout the southwestern US shows dramatic differences in the soil water balance between winter when vegetation is dormant and spring when vegetation reactivates. Vertical profiles of soil water potential sensors also provide indirect evidence of the depth and timing of root water uptake. Soil water potential and chloride profiles in the Southern High Plains also show strong relationship between land use and subsurface water movement. Higher recharge beneath dryland (nonirrigated) relative to rangeland settings is shown by high soil water potentials and low chloride concentrations. The point unsaturated zone data are regionalized using decadal variations in groundwater levels. Combining various approaches that range in space and time scales provides a more comprehensive understanding of linkages between ecology and hydrology in these water-limited systems.
DE: 1851 Plant ecology
DE: 1875 Unsaturated zone
DE: 1894 Instruments and techniques
SC: Hydrology [H]
MN: 2005 Joint Assembly