HR: 08:45h
AN: B31E-04 INVITED     [Abstracts]
TI: Woody Plants and the Water Cycle on Semiarid Shrublands-Observations from the Field
AU: * Wilcox, B P
EM: bwilcox@tamu.edu
AF: Rangeland Ecology and Management, Texas A&M University, College Station, TX 77840
AU: Munster, C
EM: c-munster@tamu.edu
AF: Biological and Agricultural Engineering, Texas A&M University, College Station, TX 77840
AU: Owens, M K
EM: kowens@ag.tamu.edu
AF: Texas Agricultural Experiment Station, 1619 Garner Field Road, Uvalde, TX 78801
AU: Mohanty, B
EM: bmohanty@tamu.edu
AF: Rangeland Ecology and Management, Texas A&M University, College Station, TX 77840
AU: Jackson, R B
EM: jackson@duke.edu
AF: Department of Biology, Duke University, Durham, NC 27708
AB: The density and coverage of woody plants on semiarid landscapes has increased markedly during the last 150 years-a phenomena ecologists have named woody plant encroachment. This presentation will summarize results from field studies evaluating the relationship between juniper and the water cycle on karst rangelands in Central Texas. Field studies include measurements of interception and transpiration at the tree scale, rainfall simulation at the large plot and hillslope scale, and long-term monitoring of springs and evaluating changes in streamflow from large rivers during the last 100 years. We are finding that runoff from these rangelands occurs as a combination of surface flow and shallow subsurface flow. Shallow subsurface flow is especially high in the juniper forests. Multi year monitoring of springs in the region prior to and after shrub control do suggest that spring flow increases by about 50 mm/year following shrub control. However an analysis streamflow during the last century would suggest that streamflow has not changed in spite of a general increase in shrub cover. These results are put in context with other work across the globe. Our work, combined with that conducted in other locations allows us to develop some generalizations about the linkage between woody plants and water yield on the basis of climate, physiography, and runoff generation.
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 1813 Eco-hydrology
DE: 1834 Human impacts
DE: 1879 Watershed
SC: Biogeosciences [B]
MN: Fall Meeting 2005