|Blank, Robert - Bob|
Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2005
Publication Date: 11/1/2005
Citation: Rau, B.M., Chambers, J.C., Blank, R.R., Miller, W.W. 2005. Hydrologic response of a central Nevada Pinyon-Juniper woodland to prescribed fire. Rangeland Ecology and Management. 58:614-622. Interpretive Summary: Heat-induced soil water repellency and consequential danger of soil erosion during precipitation events is a potential concern following landscape fires. We investigated the influence of prescribed fire in Pinyon-juniper woodlands in central Nevada on soil water infiltration. In general, prescribed fire increased water repellency and water infiltration rates relative to control sites. Our data suggests that inherently high natural water infiltration rates of this ecosystem mitigate against the possibility of erosive events following prescribed burning.
Technical Abstract: This study was conducted to further determine the effect of prescribed fire on surface hydrology in Great Basin Pinyon-juniper woodlands. The study was conducted 35 miles south of Austin, Nevada. in the Shoshone mountain range. Infiltration rates were measured using a single ring infiltrometer over an elevation (low, mid, and high) gradient, at three microsites (under tree, under shrub, and interspace) before a prescribed burn in Aug. 2001 and then following the prescribed burn in Aug. 2002. Data collected from infiltration experiments were used to calculate saturated hydraulic conductivity (K(qs)). Soil was collected from the burn location and water drop penetration times were performed in order to determine the development of water repellent soils. Final infiltration rates before the burn were higher at the low elevation than at the mid and high elevation sites although the data could not be numerically analyzed due to the inability to pond water on the soil surface at the low elevation. Before burning, the final infiltration and saturated hydraulic conductivity K(qs) rates measured on the interspace and under shrub canopy microsites were lower than on those microsites located beneath tree canopies at the mid-elevation study site (2225m). Following burning, no significant differences in the final infiltration or K(qs) rates were found among the three microsites. On the higher elevation study site before the burn, however, the microsites located in interspace and under shrubs had lower final infiltration and K(qs) rates than those located under the tree canopy, and burning caused no significant deviation from this trend. Saturated hydraulic conductivity rates at the high elevation did not differ by microsite before the burn, however, after burning interspace microsites had lower K(qs) rates than under tree microsites. Burning increased water repellency of surface soils (0-3 cm) by 300% under shrubs and 196% under trees.