EVALUATION OF BEST MANAGEMENT PRACTICES FOR CONTROLLING NONPOINT POLLUTION FROM SILVICULTURAL OPERATIONS¹

Abstract

Fifteen years of streamflow and water quality data were evaluated to determine the effectiveness of Best Management Practices (BMP's) in controlling nonpoint source pollution from an 110. acre commercial clearcut located in the Ridge and Valley Province of central Pennsylvania. The analyses addressed both short‐ and long‐term changes in the physical and chemical properties and the hydro‐logic regime of the stream draining this 257‐acre watershed. Overall, the BMP's employed on this commercial clearcut were very effective in preventing serious deterioration of stream quality as a result of forest harvesting. Although statistically significant increases in nitrate and potassium concentrations and temperature and turbidity levels were measured the first two years following harvesting, the increases were relatively small and, with the exception of turbidity, within drinking water standards. Nevertheless, such increases may violate EPA's anti‐degradation policy. Nitrate and potassium concentrations and turbidity levels remained above pre‐harvesting levels for as long as nine years following harvesting. Clearcutting also significantly increased water yield, which in turn initially lowered the concentrations of most solutes because of dilution. Increased water yields returned to pro‐harvesting levels within four years as a result of rapid regrowth. The export of some ions increased; however, the increased export appeared to be insufficient to affect site fertility. Implementation of periodic post‐harvest inspections of harvested areas, increasing the width of the buffer zone, and utilizing buffer zones on all perennial and intermittent channels would reduce further impacts of silvi‐cultural activities on water quality.

Forestry Best Management Practices: Evaluation of Alternate Streamside Management Zones on Stream Water Quality in Pockwock Lake and Five Mile Lake Watersheds in Central Nova Scotia, Canada

“…The land cover changes following timber harvesting can cause alterations in nutrient retention and water discharge mechanisms (Dillon & Kirchner, 1975;Lynch & Corbett, 1990). Silvicultural activities are known to raise the water temperature and increase the release of nutrients and minerals from soil to streams (Campbell & Doeg, 1989;William, Taylor, Warren, & Clingenpeel, 2002).…”

“…Three sub-basins in each lake watershed were selected for clear cut harvesting to approximately 25%-40% of timber up to the buffer zone along each watercourse. Clear cutting or land cover changes can alter the nutrient retention mechanisms in soil that subsequently affect the quality of water in stream and lakes in the watershed (Lynch & Corbett, 1990;Martin & Pierce, 1980;Pomeroy, 2003). Swank, Vose, and Elliott (2001) reported that following clear cutting of mixed hardwoods on a southern Appalachian catchment the on-site impacts were soil and nutrient losses and offsite impacts were on stream water quality, attributed to the altered chemistry and flow rates, sedimentation, and impacts on invertebrate habitat and community structure.…”

Effects of forest management on surface water quality in wetland forests

“…It will not attempt to review the large body of literature that exists on effects of forest management on water quality in uplands. For such information, see Beasley (1979), Martin et al (1984), McClurkin et al (1985), Brown (1989), Lynch and Corbett (1990), and Binkley and Brown (1993). Some of the sites discussed in this review are in the transitional zone between wetlands and uplands, and thus, there is uncertainty whether they would be classified as wetlands by various regulatory guidelines.…”

Relation of water quality to land use in the drainage basins of six tributaries to the lower Delaware River, New Jersey, 2002-07

“…NPSs did not receive significant attention until the implementation of the Federal Clean Water Act, Section 208, in 1970, which includes increased land-use regulations and encourages best-management practices (BMP) for reducing loads of contaminants, such as nitrogen and phosphorus, to streams from nonpoint sources. BMPs are practices that are determined by the State to be practical and effective in achieving and maintaining NPS loads at levels compatible with water-quality goals and may include stormwater management, headwater protection practices, or zoning restrictions on development (Lynch and Corbett, 1990).…”