Print PageSurface mining is the dominant driver of land-use change in Appalachia. In some watersheds, more than 15% of the land area has been converted to reclaimed mineland. Since the implementation of the Surface Mining Control and Reclamation Act of 1977 (SMCRA), most surface mines in Appalachia have been reclaimed to pasture or wildlife habitat. In this mode of reclamation, topsoil is replaced, fertilized and limed, and compacted with multiple passes of heavy machinery. Aggressive, often non-native, ground cover plants are then seeded. While effective at controlling erosion and establishing an aesthetically pleasing continuous groundcover, biological succession appears to be arrested on many of these sites, and it is unclear how nutrient cycling develops over time. To elucidate the development of the ecological structure of pasture-reclaimed minelands, we investigated a chronosequence of surface mines in northern West Virginia that were reclaimed over the last 12 years and a managed pasture site that served as a reference. Soil chemical and physical properties, plant diversity, and arbuscular mycorrhizal fungi were assessed.
Results/Conclusions
Bulk density of soil was initially greater than 150% that of the reference pasture site, and while significant recovery was observed over time, soil on the 12 year old mine site was still significantly more compacted than the reference site. The water holding capacity of all mined sites was dramatically less than that of the reference site, and little recovery was observed over 12 years. Soil carbon and nitrogen were initially less than one-third and one-quarter, respectively, of the reference site; however, by seven years, there was no significant difference in either soil C or N relative to the reference pasture site. Plant diversity was extremely limited on the zero and three year old mine sites, and while some recovery of diversity was observed by 12 years, both species richness and diversity (as measured by the Shannon Index) were significantly less on the mine sites than the reference pasture site. Reclaimed mineland is cumulative and represents a substantial area of Central Appalachia. Reclamation practices are driven by regulation and will have lasting influence on these ecosystems; it is therefore critical ongoing regulation be informed by ecological outcomes. Our results suggest that while nutrient cycling may recover quickly, the physical properties of soil and the presence of aggressive groundcover plants may stunt the ecological development of reclaimed surface mines.
