HR: 0800h
AN: GC41A-0113    [Abstracts]
TI: Hydrological and Ecological Sensitivities to Climate Change for Four Western U.S. Mountain Ecosystems.
AU: * Christensen, L
EM: lindsey@nrel.colostate.edu
AF: Natural Resource Ecology Laboratory, CSU, Colorado State University, Fort Collins, CO 80523,
AU: Tague, C L
AF: Donald Bren School of Environmental Science and Management, UCSB, University of California, Santa Barbara, Santa Barbara, CA 93106,
AU: Baron, J S
AF: U.S. Geological Survey, Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523,
AB: National Parks in Western U.S. mountain ecosystems are rapidly changing as a result of the direct and indirect effects of climate change. With warming temperatures, these systems are expected to experience earlier melt and reductions in snow accumulation. The impact of these changes on other hydrologic patterns, such as summer streamflow, and ecosystem structure and function maybe significant, but is likely to vary across the Western U.S. Park managers need quantitative estimates of these potential changes for development of long- term management strategies. A systematic approach can be used to define where and why these mountain ecosystems are affected by climate, focusing on net ecosystem exchange, net primary production, evapotranspiration, and streamflow trends. We used RHESSys, a spatially distributed, dynamic process model of water, carbon, and nitrogen fluxes, to examine the interplay between ecological and hydrological sensitivities to climate in four National Parks across the Western U.S., including watersheds in the North Cascades (WA), Glacier (MT), Rocky Mountain (CO), and Yosemite (CA) National Park. Analyses show while some systems are more hydrologically sensitive to climate variations, others are more ecologically sensitive. For example, with warm temperatures, the greatest reduction of summer streamflow is likely to occur in Glacier, while greatest sensitivities of vegetation responses, e.g. transpiration, net primary productivity, are predicted for the Cascades. Understanding the degree to which these watersheds are sensitive to climate variability and change will help to predict site specific vulnerabilities and allow park managers to tailor climate change management plans to individual locations.
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1630 Impacts of global change (1225)
DE: 1637 Regional climate change
DE: 1655 Water cycles (1836)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting