Herbicides in Southern Forestry

Environmental interest groups have traditionally equated herbicide use with degradation of water quality. If the entire water quality picture is rationally analyzed. the conclusions are quite the contrary. Use of herbicides compared to mechanical site preparation improves or maintains water quality. Short-duration pulses of residues may appear in streamflow. but data from forest ecosystem studies indicates that these residues are generally not significant to aquatic ecosystems. The herbicides currently being used in southern forestry are low in toxicity and do not persist in the environment. Herbicide use significantly reduces the major, but frequently ignored, water quality problem, sediment. Site preparation with herbicides maintains watershed hydrologic conditions close to that of undisturbed stands and does not aggravate storm runoff, which can transport large amounts of sedimeni into streams. In addition, herbicide use does not produce adverse soil disturbance. which can lead to compaction and markedly increased soil erosion. Sediment displaced in streams produces significant and long-term changes in aquatic systems and can adversely affect stream biota and water quality large distances downstream.