Water repellent soils following prescribed burning treatments and a wildfire in the oak savannas of the Malpai Borderlands Region

Abstract

Water repellent (hydrophobic) soils impact the infiltration process of a water budget by restricting the movement of water into and through a soil body. The infiltration of water into a water repellent soil can be inhibited or completely impeded in which case much of the incoming precipitation reaching the soil surface becomes overland flow. One mechanism causing the formation of water repellent soils is the distillation of organic compounds in the litter and duff layers during combustion in a fire (DeBano 1981, 1999, 2003, Doerr et al. 2000). This mechanism resulted in the formation of water repellant soils following prescribed cool and warm season burning treatments and a wildfire on the Cascabel Watersheds in the oak savannas of the Malpai Borderlands Region in the eastern part of the Coronado National Forest. This paper complements the findings of an earlier study on the formation of water repellency on selected sites locations classified by accumulations of litter and other organic debris or dominant tree species on the watersheds before the fires (Neary et al. 2008) by reporting on the occurrences and levels of water repellency on a watershed-basis. An attempt to correlate the occurrences and levels of water repellency to the severity of the prescribed burning treatments and the wildfire is also presented.

Citation

Stropki, Cody L.; Ffolliott, Peter F.; Gottfried, Gerald J. 2009. Water repellent soils following prescribed burning treatments and a wildfire in the oak savannas of the Malpai Borderlands Region. Hydrology and Water Resources in Arizona and the Southwest. 39: 5-8.