Publications

Many current theories of community function are based on the assumption that disturbances such as herbivory act to reduce the importance of neighbor interactions among plants. In this study, we examined the effects of herbivory (primarily by nutria, Myocastor coypus) on neighbor interactions between three dominant grasses in three coastal marsh communities, fresh, oligohaline, and...

A spatial data base of 1609 landslides was analysed using a geographic information system to determine landslide frequency in relation to highways. A 126 km long transportation network in a 201km2 area of humid-tropical, mountainous, forested terrain in Puerto Rico was used in conjunction with a series of 20 buffer (disturbance) zones varying from 5 to 400m in length, measured...

Abstract not supplied at this time

No abstract available.

Trends in nutrient concentration and load are computed for 40 stations on 24 streams in the Mississippi River Basin. The drainage area of the Mississippi Basin covers about 42 percent of the conterminous United States, and the Mississippi River discharges about 420 billion gallons per day of freshwater to the Gulf of Mexico. The period for which trends are analyzed varies for each...

Instream nutrient loads of the Altamaha, Suwannee, St. Johns, Satilla, Ogeechee, Withlacoochee, and Ochlockonee River Basins were computed and compared with nutrient inputs for each basin for the period 1986-90. Nutrient constituents that were considered included nitrate, ammonia, organic nitrogen, and total phosphorus. Sources of nutrients considered for this analysis included...

A hydrographic survey of Sabine Lake, a broad, shallow estuary lying on the Texas-Louisiana border, was conducted in June 1996 to help address questions relating to potential environmental effects of future water demands in Texas. The use of a variety of new instruments in this study is one means by which automation is improving efficiency and effectiveness of these efforts by increasing...

Approximately 30 percent of the water used in Guilford County, North Carolina, is from ground-water sources. All rural supplies are from ground water; approximately 65,000 residents used ground water for their domestic water supplies in 1990. The U.S. Geological Survey (USGS), in cooperation with the Guilford County Soil and Water Conservation District and the Guilford County Department...

No abstract available.

The U.S. Geological Survey National Water-Quality Assessment Program (NAWQA) is designed to provide long-term, consistent information on water quality that can be used to describe local, regional, and national conditions. The full-scale NAWQA Program, initiated in 1991, includes both study-unit and national synthesis activities. Study-unit investigations provide scientific data and...

Historically, cypress-tupelo swamps covered much of the low-lying coastal regions of the Southeast. However, saltwater intrusion and increased flooding over the past 30 years, combined with past logging, have depleted the numbers and decreased the survival and growth of baldcypress (Taxodium distichum) in coastal areas along the Gulf of Mexico.

No abstract available.