HR: 1330h
AN: H32C-0584    [PDF]
TI: Impact of Fire on Recharge at a Semiarid Site
AU: * Seyfried, M S
EM: mseyfrie@nwrc.ars.usda.gov
AF: USDA-ARS, 800 Park Blvd Paza IV, Boise, ID 83712 United States
AU: Murdock, M D
EM: mmurdock@nwrc.ars.usda.gov
AF: USDA-ARS, 800 Park Blvd Paza IV, Boise, ID 83712 United States
AB: The potential hazards and benefits of fire are critical issues in semiarid parts of the Western USA. The hydrologic impacts of fire, in terms of recharge, are poorly understood in the region. These impacts depend largely on the transpiration of the newly established, post-fire vegetation relative to that of the pre-fire vegetation. In this study we focus on two impacts of fire on vegetation, the reduction of leaf area index, which influences the rate of transpiration, and the potential reduction in effective rooting depth, which influences the amount of water transpired. The study site has a mean annual precipitation of about 550 mm with a native vegetation dominated by semiarid shrubs. For one season prior and one season following a prescribed fire we monitored leaf are index, soil water content, and soil water potential in adjacent burned and unburned plots. One year after the fire we have documented a substantial reduction in leaf area index and effective rooting depth. Simulations indicate that potential recharge after the fire increased by more than 50 mm per unit area. This result will vary considerably with location depending on environmental factors such as the soil depth and amount and season of precipitation.
DE: 1655 Water cycles (1836)
DE: 1818 Evapotranspiration
DE: 1836 Hydrologic budget (1655)
DE: 1875 Unsaturated zone
SC: Hydrology [H]
MN: 2003 Fall Meeting