Winter/Spring 2002

The Federal Water Pollution Control Act of 1972, the Clean Water Act of 1977 and the Water Quality Act of 1987 collectively provide federal legislation designed to control nonpoint source (NPS) water pollution. In response, states in the southern United States have designed Best Management Practices (BMPs) to minimize the impacts of forestry practices on water quality. Forestry practices such as harvesting may result in soil erosion, nutrient loss and resultant NPS pollution in the form of sediment and nutrient delivery to streams that not only produce potential degradation of water quality, but also can potentially alter aquatic habitat and endanger aquatic biota.

Silvicultural BMPs are designed to maintain streamwater quality, aquatic habitat and aquatic biota by minimizing streamwater temperature changes and the transport of sediments, nutrients and pesticides into surface waters. However, scientifically-based assessment of effectiveness of these measures, particularly in relation to protection of aquatic habitat and maintenance of aquatic communities, has been lacking because monitoring programs have not been widely implemented. If landowners are expected to enthusiastically incorporate BMPs into their forest management protocols, then it is necessary to quantify the benefits of this practice in forested watersheds of the southern United States.

The overall objective of the study is to evaluate effectiveness of BMPs currently used on intensively managed loblolly pine (Pinus taeda) plantations in the East Gulf Coastal Plain of Mississippi. This study experimentally investigates relationships among degrees of BMP compliance and responses of physicochemical, habitat and biotic stream properties. We coordinate our efforts with private industry to apply appropriate logging operations for manipulative treatments at each stream study site.

Fifteen study streams located in the coastal plain middle section and sand-clay hills subsection of Mississippi (Calhoun, Choctaw and Webster Counties) are used in the experimental. Water quality and biological communities are measured, and current, as well as historical data on being collected upstream from all stream sites to thoroughly characterize each stream drainage. This characterization identifies land use, plant communities, timber age and soil surface coverage, help delineate differential impacts among drainage parameters and instream measurements below experimental manipulations. Outcomes of this research will enable forest managers to modify ineffective BMPs and promote BMPs which are meeting management goals.

The co-investigator of this research, which is being conducted by Eric D. Dibble, Ph.D., Associate Professor, Department of Wildlife and Fisheries, Mississippi State University, is Dr. Stephen Schoenholtz, Soil Hydrologist, Oregon State University. Weyerhaeuser Corporation and The Timber Company have provided management records and study sites for the research. Collaboration with the U.S. Environmental Protection Agency, the Mississippi Water Resources Research Institute, the Mississippi Department of Environmental Quality, the National Council of the Paper Industry for Stream and Air Improvement, the University of Mississippi and the University of Georgia has been ongoing in this research of BMP effectiveness. We also have coordinated with scientists at the Army Corps of Engineers Waterways Experiment Station and the Mississippi Natural Science Museum for taxonomic confirmation of aquatic macroinvertebrates and fishes.