| M.E. O'Dea and D. Phillip Guertin |
| Authors are Research Hydrologist, UDSA, Forest Service, Pacific Southwest Station, Riverside, Calif. 92507 and Associate Professor, School of Renewable Natural Resources, University of Arizona, Tucson, Ariz. 85721. At the time of the research, the senior author was a graduate student, School of Renewable Natural Resources, University of Arizona, Tucson, Ariz. 85721. |
Abstract |
| A 2-year field experiment was undertaken to quantify the interacting effects of a late-spring prescribed burn and summer rainfall on seasonal runoff and erosion in a southern Arizona grassland. Six blocks with walled subplots (n = 24) were installed on a hillslope to measure changes to plant, soil, and hydrologic variables in response to treatments. Increased bulk density, erosion, and runoff volumes; and lowered plant cover and water intake rates were observed within the burned plots following the first summer season. In the second year, higher bulk density, runoff volumes, and erosion measures were again observed within the burned plots, as well as lower plant cover, aggregate stability, and water intake rates. The results of this study indicate that following late-spring burning, semi-desert grasslands are susceptible to greater summer runoff and erosion compared to unburned grasslands. |
| Key Words: Arizona, sediment yield, summer rainfall |