Showing papers by "Carl E. Zipper published in 2003"

Impacts of Mine Drainage and Other Nonpoint Source Pollutants on Aquatic Biota in the Upper Powell River System, Virginia

Abstract: The Clinch-Powell River system of Virginia and Tennessee, USA, is among the most biologically diverse ecosystems in the world, and has been identified as a conservation priority of national importance. Other researchers have attributed declines in Powell River freshwater mussel populations to coal mining-related activities. The objectives of this paper are to synthesize the results of several studies aimed at assessing acid mine drainage (AMD) impacts in the Powell River watershed, and to describe the relative roles of AMD, nutrient loading, and urban runoff in structuring the benthic macroinvertebrate communities of the Powell River. Impacts ranged from acute toxicity due to the combination of acid and metals, acute aluminum toxicity in circumneutral pH waters, and physical impacts from solid ferrihydrite, to decreased clam growth due to urban runoff. These findings support the concern that AMD negatively impacts aquatic biota in the Powell River watershed in a variety of ways, and emphasize the importan...

Using Public Domain Data to Aid in Field Identification of Hydric Soils

Abstract: Hydric soil field identification is a common activity for natural resource professionals and planners, but it can be time consuming and labor intensive. This study used Soil Survey Geographic Database (SSURGO), National Wetlands Inventory (NWI), National Land Cover Data (NLCD), and other public domain data to make digital hydric soil predictive maps of two study areas in western Virginia. Soil scientists used the predictive maps as guides to conduct hydric soil field surveys and compared the results to delineations of SSURGO map units dominated by hydric soils and NWI and NLCD wetlands. At Stuarts Draft, 15% of the 1296-ha study area was composed of hydric soils compared with 14% estimated by SSURGO. At Blacksburg, 3% of the 828-ha study area was composed of hydric soils compared with 1% estimated by SSURGO. Both NWI and NLCD estimated 1% wetlands at each area. Locational correspondence was higher between the field survey and SSURGO than between the field survey and the NWI and NLCD wetlands at both study areas. The predictive maps were useful because the SSURGO delineations were closely aligned with field survey delineations, had 13% for NWI and NLCD at Stuarts Draft, and had ≤ 2% false positive identifications. Overlaying NWI and NLCD onto SSURGO polygons resulted in ≤ 1% improvement of predictive map utility, but all indicators of hydric soils were useful in narrowing the specific location of hydric soils within large SSURGO delineations.