Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 9/4/2004
Publication Date: 12/8/2004
Citation: Seyfried, M.S. 2003. Impact of fire on recharge in semiarid regions. Eos Transactions American Geophysical Union, 84(46), Fall Meeting Supplement, CD-ROM abstract H32C-05.
Technical Abstract: 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 unvurned 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.