Reforestation practice for enhancement of ecosystem services on a compacted surface mine: Path toward ecosystem recovery

Abstract

Re-establishment of trees on surface mine-lands is difficult and their growth is often slow. Compacted spoil and existing vegetation may hinder forest restoration and reduce or delay ecosystem service delivery. We used brush removal, deep tillage, planting native trees, fertilizer, and herbicide applications to speed restoration of 35ha of previously reclaimed and abandoned surface mine-lands in southwestern Virginia, USA. Intermediate measures of success (tree stocking and volume, species richness and evenness) were assessed 2, 3, and 4 years after planting. After two plantings and 3 years of herbicide application, survival of planted trees was 31% (639treesha−1). Volunteer trees such as black locust (Robinia pseudoacacia), sourwood (Oxydendrum arboretum), ash (Fraxinus sp.), and red maple (Acer rubrum) provide additional stocking (539treesha−1), 65% of the total tree volume, and contribute to species richness, indicating that they aid in the recovery of ecosystem services such as carbon sequestration and biodiversity support. Annual volume growth rates are increasing for planted and volunteer trees. However, autumn olive (Elaeagnus umbellata), an exotic invasive shrub, covered 27% (±5.6) of the sampled area and produced greater volume than native trees. Autumn olive and herbaceous vegetation had potentially antagonistic relationships with planted and volunteer trees. Results indicate that the re-establishment of forest cover, comprised of a mix of planted and volunteer trees, is likely across much of the site. Early-successional species will likely dominate in the near term but planted, mid-successional species such as tulip poplar (Liriodendron tulipifera) and oaks (Quercus spp.) will likely remain as components of the new forest.