Vegetation and soil development in planted pine and naturally regenerated hardwood stands decades after mining
Frouz, J., and J. A. Franklin.  2015.  Journal of the American Society of Mining and Reclamation.

Reclamation activities including planting of tree and grass species can have lasting effects on forest stand composition and soil properties. In this study we compared soil properties and forest development on mined land, planted with pine or left un-planted, after approximately 48 years. These parameters were also compared to the adjacent forest, to test the hypothesis that the development of forests and minesoils differ between planted and unplanted sites. Areas planted to pine had lower basal area, and lower soil and microbial respiration rates than did un-planted areas. Basal area of un-planted sites was comparable or higher than that of adjacent forest stands, suggesting that natural succession of hardwoods leads to better long-term recovery than pine planting. Differences in root biomass, along with corresponding differences in soil respiration, indicate that below-ground biomass production recovered more slowly than did above-ground productivity. Mined sites had a greater stock of phosphorus than adjacent sites. The greater presence of earthworms on mined sites accelerated cellulose decomposition, which may speed up nutrient cycling.