Evaluating Soil Genesis and Reforestation Success on a Surface Coal Mine in Appalachia

Abstract

m Surface mining poses a significant threat to the Appalachian region via forest loss and fragmentation. Reclamation methods that utilize heavy grading to prevent landslides and erosion create a compacted landscape that is not suitable for forest establishment or growth. Overburden materials derived from differing geologic strata can exhibit large variation in physical, chemical, and mineralogical properties. Determining whicb strata should be used for creating a rooting medium for successful reforestation is not well established. Twelve 0.2-ha plots composed of either segregated brown sandstone, gray sandstone, sbale, or a sandstone-shale mixture (four treatments; n = 3) were created on a surface mine in eastern Kentucky using a low-compaction reclamation method. Each plot was planted with native hardwood tree seedlings following the Forestry Reclamation Approach. After two growing seasons, brown sandstone treatments had four times greater extractable P (Mehlich III) and five times greater total N than the other treatments. This helped contribute to greater tree growth on brown sandstone treatments. Spoil settling was faster in the shale treatments due to the loss of carbonate cements. Clay contents and 2:1 minerals were also greater in the whole soil of the shale treatments, leading to greater plant-available water and a greater cation exchange capacity. Gray sandstone treatments exhibited alkaline conditions (pH :: 8.8) that suppressed tree growth. The mixing of brown sandstone and shale overburdens may produce a suitable combination of higher fertility, water holding capacity, and faster settling in reclaimed mine environments.Abbreviations: CEC, cation exchange capacity; FRA, Forestry Reclamation Approach.T he Surface Mining Control and Reclamation Act of 1977 (SMCRA) requires the restoration of post-mining land use capability to a level "equal to or better than" that which preceded mining. Surface-mined lands in Appalachia were forested before mining but are often reclaimed to pasture. One reason for this change in land use is that the reclamation practices under SMCRA tend to inhibit tree growth. Impediments to forest growth under SMCRA includes: (i) excessive compaction of the spoil, (ii) unsuitable or sometimes toxic rooting material, and (iii) competition for nutrients and water by aggressive and often invasive herbaceous species that are planted to establish ground cover (Angel et al., 2005;Burger et al., 2005a;Rodrigue and Burger, 2004). The spoil medium effects on tree growth, tree species not suited to site conditions, and improper tree planting techniques are often problems associated with reclaimed lands. Realizing the significance of these problems, regulatory, mining, and research groups coordinated efforts to restore forests across the region. As a result, a five-step system to reforest coal-mined land, called the Forestry Reclamation Approach (FRA), was developed based on 80 yr of research. The steps of FRA are: (i) create a suitable 1.2-m-deep rooting medium for Soil Sei. Soc.

Soil biochemical properties in brown and gray mine soils with and without hydroseeding

“…Miller et al (2010) found that gray sandstone rocks exhibited a higher durability in a slakedurability test and were highly resistant to weathering during the freeze-thaw test. Zipper et al (2011) reported that mine soils derived from gray sandstone would continue to have higher coarse fragments and lower percent fines than brown sandstone mine soils as they age because of resistance to degradation.…”

Evaluating the Use of Tree Shelters for Direct Seeding of Castanea on a Surface Mine in Appalachia

“…The West Virginia site was constructed using a mixture of brown and gray spoils, while the plots in our study were constructed using predominately brown spoils [14]. A series of recent studies have indicated that brown spoils tend to provide a better growing medium for native hardwoods than gray, less weathered spoils [8,10,36,37]. Soil pH in West Virginia (5.8) was within the preferred range of the American chestnut (5.5-6.5 [38]).…”

Forest restoration following surface mining disturbance: challenges and solutions

“…Sorenson et al (2011) found that coniferous stands were linked with fungal presence, whereas aspen stands had a stronger bacterial component. The type of soil replacement or substrate amendment can be clearly linked with differences in both vegetation (Angel et al 2008;Miller et al 2012;Wilson-Kokes et al 2013a) and microbial biomass and composition (Machulla et al 2005;Palumbo et al 2004;Chodak and Niklinska 2010). Vegetation affects soil microbial communities by the quantity and quality of litter while microbes, in turn, influence re-vegetation success (Jasper 2007).…”

“…Siltstone and shale materials weather rapidly but the resulting soils have finer textures and can thus be prone to compaction or settling (Casselman et al 2006). Unweathered gray sandstone, siltstone and shale materials result in soils with slightly higher pH (from 6.5 to 8.5), in which trees can survive but grow slowly (Angel et al 2008;Miller et al 2012). Soluble salts, which are detrimental to tree growth, are higher in fine textured soils derived from unweathered, shale and siltstone overburden as compared to soils derived from weathered sandstone (Torbert et al 1990;Rodrigue and Burger 2004).…”