HR: 1330h
AN: H32C-0586    [PDF]
TI: Impacts of Prescribed Burning in Upland Meadows on Understory Evapotranspiration
AU: * Mullen, R M
EM: Gina.Mullen@nau.edu
AF: Environmental Science and Policy Program, Northern Arizona University Box 5694, Flagstaff, AZ 86011 United States
AU: Springer, A E
EM: Abe.Springer@nau.edu
AF: Department of Geology, Northern Arizona University Box 4099, Flagstaff, AZ 86011 United States
AU: Kolb, T E
EM: Tom.Kolb@nau.edu
AF: School of Forestry, Northern Arizona University Box 15018, Flagstaff, AZ 86011 United States
AB: The frequency and extent of prescribed burning is increasing in Southwestern forest and meadow ecosystems. This management action has the potential to impact groundwater recharge. We are studying the impacts of prescribed burning on evapotranspiration of the herbaceous understory in an upland wet meadow at Hart Prairie, Arizona. Three treatments (non-burned control, burned during the early-summer pre-monsoon season, burned during the late-summer monsoon season) were randomly applied to replicated circular plots (2 m radius) in each of two herbaceous communities (grass dominated, fern dominated) in 2001. Treatment effects on herbaceous evapotranspiration were assessed by soil-water budgets based on repeated soil-moisture measurements with time-domain reflectometry. In 2001, the pre-monsoon burn increased soil-water content in the grass-dominated community, and to a lesser degree in the fern-dominated community, compared with the control. In 2002, one summer after treatment, both pre- and post-monsoon burns decreased soil-water content compared with the control, with a larger decrease occurring in the fern-dominated community. These trends in soil-water content continued in 2003, two summers after burning. Reduction of evapotranspiration caused by the pre-monsoon burn increased soil water available for groundwater recharge for several weeks following treatment. However, the beneficial effect of burning on groundwater recharge was short-lived as herbaceous evapotranspiration was higher in burned compared with non-burned plots one and two years after treatment.
DE: 1818 Evapotranspiration
DE: 1836 Hydrologic budget (1655)
SC: Hydrology [H]
MN: 2003 Fall Meeting