Storm runoff and sediment losses from forest clearcutting and stand re‐establishment with best management practices in East Texas, USA

Abstract

Abstract:Nine small (2Ð5 ha) and four large (70-135 ha) watersheds were instrumented in 1999 to evaluate the effects of intensive silvicultural practices with best management practices (BMPs) on runoff and stream water quality in the Western Gulf Coastal Plain of East Texas, USA. Two treatments were implemented in 2002: a conventional treatment with clearcutting and herbicide site preparation, and an intensive treatment that added subsoiling, fertilization and a release herbicide application. Watershed effects were compared with results from a previously conducted study on the same watersheds in 1981, in which two combinations of harvesting and mechanical site preparation without BMPs were evaluated. Due to the reduction in evapotranspirational demand, total storm runoff increased on all six treated small watersheds following harvest by 0Ð94 to 13Ð73 cm in 2003. Runoff increases were not statistically significant on the treated large watersheds. Total first-year sediment loss was significantly greater on two of the conventional and one of the intensive small watersheds. The greatest first-year increase was 540Ð1 kg ha 1 , only one-fifth of that observed on these watersheds from shearing and windrowing without BMPs in 1981. First-year sediment loss was significantly greater on the intensive large watershed following harvest, but not on the conventional large watershed. These data suggest that BMPs are very effective in reducing potential water quality impacts from intensive silvicultural practices.

Soil Erosion and Surface Water Quality Impacts of Natural Gas Development in East Texas, USA

“…For undisturbed forestlands, sediment yield averaged about 42 kg ha , though these differences were not found to be statistically significant [17]. In that study, a streamside management zone (SMZ) with a minimum total width of 30 m was retained around all stream channels.…”

“…This was comparable to runoff measured at F2 in the 2009 water year of 9.58 cm. However, the clearcut reported by McBroom et al [17] covered an average of 75% of the total watershed area, where the well location at F2 only occupied about 10% of the total watershed area. Even when the gas well pad was offset by 15 m from the stream, it still had a proportionally greater impact on runoff than forest management.…”

“…In addition, the significantly higher bulk density on the well locations resulted in less infiltration. McBroom et al [17] found that for nearby undisturbed forests, annual runoff ranged between 0.64 and 10.32 cm, depending on rainfall. Following clearcutting of the watersheds reported by McBroom et al [17], annual runoff ranged between 7.82 and 9.79 cm.…”

“…McBroom et al [17] found that for nearby undisturbed forests, annual runoff ranged between 0.64 and 10.32 cm, depending on rainfall. Following clearcutting of the watersheds reported by McBroom et al [17], annual runoff ranged between 7.82 and 9.79 cm. This was comparable to runoff measured at F2 in the 2009 water year of 9.58 cm.…”

Economic Valuation of Watershed Services for Sustainable Forest Management: Insights from Mexico

“…Conventional forest management practices, that include logging and grazing, affect tree density, canopy cover, and tree composition and structure (Brown et al, 2005). Hydrologic studies in the United States have demonstrated that selective harvesting and clear-cutting promotes increased discharge because of a reduction of stand density and canopy cover that demand less water for transpiration (Swank et al, 1988;McBroom et al, 2008). Nonconventional forest disturbances that cause tree mortality include forests fires, pests and diseases, strong winds, etc.…”