Forest Establishment and Water Quality Characteristics as Influenced by Spoil Type on a Loose-Graded Surface Mine in Eastern Kentucky

Abstract

Six research plots were established on a surface mine for the purpose of evaluating the forest productivity potential and hydrological and water quality characteristics of three different loose-graded spoil types. The three spoil types were: (1) predominately brown, weathered sandstone (BROWN); (2) predominately gray, un-weathered sandstone (GRAY); and (3) mixed weathered and un-weathered sandstones and shale material (MIXED). The average area of the six plots was approximately 3,658 m 2 . The physical and chemical soil characteristics that gave the BROWN spoil type a predictably higher productivity potential and natural regeneration than the GRAY and MIXED spoil were its finer soil texture, higher CEC and P concentration, and a pH that was more suitable for native hardwood trees. Four species of tree seedlings were planted into the spoils. Growth and survival of the planted trees were evaluated for three years. As an indicator of natural succession potential, percentage ground cover of volunteer vegetation on the three spoil types was also evaluated. By the third year (2007) after planting, the BROWN spoil type had a significantly higher average tree volume index than the MIXED spoil and MIXED was significantly higher than GRAY. Ground cover from natural regeneration was found to be 66.4% on the BROWN spoil (61 different species), 5.8% on the MIXED spoil (35 different species), and less than 2.0% on the GRAY spoil (12 different species). Results showed that the loose-graded spoil in this experiment was characterized by low discharge volumes, small peak discharges, and long durations of discharge and had hydrologic characteristics of a forested watershed, even at this early stage of development. Generally, concentrations of Ca, Mg, and SO 4 2-decreased over time in GRAY and MIXED and increased in BROWN. The pH of the water discharge from all three spoil types has increased from about 7.5 to 8.5. Although the average electrical conductivity (EC) in water discharged from the BROWN spoil remained relatively level during the study period, the GRAY and MIXED appears to be on a downward trajectory from about 1500 µS cm -1 to about 500 µS cm -1 . The latter value of EC has been reported as the apparent threshold at which the benthic invertebrate community returns to drastically disturbed headwater streams of eastern Kentucky and adjacent coal-producing Appalachian states.

Tree Growth on Ripped, Compacted, and Slightly Compacted Gray Sandstone Topsoil Substitute on a Surface Coal Mine in West Virginia

“…Previous studies have shown that average tree height and volume were greater on weathered brown sandstone than unweathered gray sandstone (Showalter et al, 2010;Angel et al, 2008;Emerson et al, 2009). Angel et al (2008) reported that average tree height on brown sandstone (66 cm) was significantly greater than average tree height on gray sandstone (35 cm) after 3 years.…”

“…Angel et al (2008) reported that average tree height on brown sandstone (66 cm) was significantly greater than average tree height on gray sandstone (35 cm) after 3 years. Showalter et al (2010) attributed better tree performance on brown sandstone to lower pH and higher percentage of fines.…”

“…Although there was some variability in average pH values among gray sandstone plots, the mean pH values fell within or slightly below measured unweathered sandstone materials in the Appalachian coal region, as did the mean pH of the brown sandstone plot. Several studies reported that unweathered gray sandstones fell between 7.5 and 8.0 while weathered sandstones ranged from 4.5 to 6.0 (Angel et al, 2008;Haering et al, 2004;Thomas and Skousen, 2011 , 1981;Whiting et al, 2010). The average percent fines on GRP (76%) was statistically similar to the percentage of fines measured on the BSS plot (73%).…”

Quality Change of Mine Soils From Different Sources in Response to Amendments - A Laboratory Study

“…Amine soil material is a structureless agglomeration of fragmented rock, subsoil, and soil that is often less weathered than the original soil profiles that it has replaced (Angel et al, 2008). Minesoils are formed on landscapes altered by mining processes, particularly by the surface mining operations: The original soil profiles have been disrupted to a depth of at least 1 m, and sometimes partially or completely replaced by earth materials from depths below 1 m (Sencindiver & Ammons, 2000).…”

“…The type of parent material and rate of weathering are very important in the development and differentiation of soil properties. Mine soils are classified as either Entiols or Inceptisols (Angel et al, 2008;Sencindiver & Ammons, 2000), and are either without natural genetic horizons or with only weak or moderate development (Soil Survey Staff, 1999). After passage of the Surface Mining Control and Reclamation Act (SMCRA) of 1977, mining companies are required to store the original topsoil during the coal mining phase and then return the original topsoil back to the site after the mining is completed.…”