Influence of spoil type on afforestation success and natural vegetative recolonization on a surface coal mine in Appalachia, United States

Abstract

Surface mining has altered a vast land area in the Appalachian Region, threatening highly biodiverse native forest, contributing to habitat fragmentation, and generating severely disturbed sites that are unsuitable for succession to native ecosystems. Although there are many factors that influence species colonization and establishment on these sites, selection of topsoil substitutes suitable for native species is of particular concern. A series of experimental plots was installed in 2005 on a reclaimed mine site in eastern Kentucky, United States, to examine the suitability of three spoil types (unweathered GRAY sandstone, weathered BROWN sandstone, and MIXED sandstone/shale) as topsoil substitutes. Bareroot 1:0 seedlings of four native hardwood species (Fraxinus pennsylvanica, Quercus rubra, Q. alba, and Liriodendron tulipifera) were planted in the spoil. Seed required for ground cover was not applied so that natural colonization could be evaluated. Two years after installation, researchers concluded that tree growth was highest on BROWN; in addition, species richness and ground cover of volunteer vegetation were higher on BROWN. In 2013, tree volume was over 50 times higher in BROWN than GRAY. In addition to planted hardwoods, naturally colonizing vegetation provided nearly 100% cover on BROWN compared to 20% on MIXED and less than 10% on GRAY plots. Species richness of volunteer vegetation continued to be higher on BROWN (41) than GRAY (30) or MIXED (30), with native species comprising 65–70% of total species richness on all plots. Findings suggest that when topsoil substitutes are used, weathered spoils are more favorable to reforestation than unweathered spoil.

Establishing Pine Monocultures and Mixed Pine-Hardwood Stands on Reclaimed Surface Mined Land in Eastern Kentucky: Implications for Forest Resilience in a Changing Climate

“…Large portions of the project site exhibited poor drainage and even standing water (which can frequently be the case on these sites [52,53]), suggesting that overall soil moisture conditions may be more favorable for loblolly pine than shortleaf pine. Chemically, soils were favorable across treatments, with pH, particle size distribution, nutrient levels, and CEC similar to those observed on soils favorable for tree growth and survival in another eastern Kentucky study [6]. However, the soils in loblolly pine plots in this study were chemically more favorable than the soils in shortleaf pine plots, with higher total N and exchangeable Mg.…”

“…Shortleaf pine survival (42%) was similar to that of planted hardwoods, but lower than that of loblolly pine (85%) (p < 0.05). Survival of shortleaf pine was lower than first-year survival reported by Angel (2008) of mixed hardwoods planted into mixed mine spoils with no vegetative competition in eastern Kentucky (69-98%) [6,45], lower than survival (65-75%) of seedlings planted into spoils seeded with groundcover species [46], and lower than first-year chestnut survival in legacy mined land in eastern Kentucky (72-97%) [9]. However, shortleaf pine survival was similar to survival of seedlings planted into mine spoil seeded with groundcover species (56%) [47], and greater than survival of shagbark hickory (Carya ovata) reported in the same study (24%) [47].…”

“…Browse was observed on this site, as on many other similar plantings, and can significantly affect growth and survival [9,50,51]. Regardless of browse, hardwood growth tends to be low during the first 2-3 years after planting [45], with growth rates increasing after this 2-3 yr establishment period [6].…”

Mining Site Reclamation Planning Based on Land Suitability Analysis and Ecosystem Services Evaluation: A Case Study in Liaoning Province, China

“…In many surface mining sites, the topsoil soils are completely destroyed by mine exploitation. The related research has indicated that the mine soils composed of crushed overburden can provide a suitable soil substitute when native soil is unavailable for use in mine reclamation practice [69]. The suitable soil substitutes, such as weathered mine spoils, should be selected carefully by analyzing the characteristics of mine spoil.…”

Reclamation of a Degraded Coal-Mining Area with Perennial Cover Crops

“…A constructed minesoil is usually compacted by excessive machine traffic, which results in inadequate physical conditions for plant growth and development (Lunardi Neto et al, 2008;Sheoran et al, 2010;Borůvka et al, 2012;Stumpf et al, 2014;Sena et al, 2015), as well as a decrease in the biodiversity of soil fauna (Oliveira Filho et al, 2014) and carbon losses due to mechanical mixing of soil horizons (A, B, and/or C) during the operations of removal, transport, and placement of the soil (Ussiri and Lal, 2005;Leal et al, 2015). In addition to these impacts, in mine waste piles derived from coal processing (usually enriched in pyrite), the process of soil aggregation and structuring by the root system of cover crops can promote input of oxygen and water and increase the development of acid mine drainage in the reclaimed area (Quiñones et al, 2008;Campaner and Luiz-Silva, 2009;Costa and Zocche, 2009;Inda et al, 2010;Daniels and Zipper, 2010;Moura, 2014) Reclamation of a mined area should return a degraded ecosystem to a non-degraded condition, which may be different from the original environment (Ibama, 2011).…”