English

Abstract

During the past five years, a forestry reclamation approach has been adopted by some coal companies. To ensure adequate tree survival and growth, competition from erosion control groundcovers must be reduced. The purpose of this study was to test the effect of herbaceous groundcover on reforestation success after five years for Phase III bond release. An herbaceous ground cover mix consisting of orchard grass, redtop, birdsfoot trefoil, and red clover was hydroseeded on reclaimed mined land in Wise County, Virginia. The mine soil was a mix of weathered sandstone and unweathered siltstone that was lightly graded and left uncompacted. The following winter, 100 each of white oak, red oak, sugar maple, white ash, and tulip poplar (crop trees) were mixed and planted per acre. An additional wildlife mix of crab apple, dogwood, white pine, and bristly locust was planted at a combined rate of 100 trees/ac. Three half-acre treatment plots were spot-sprayed with Roundup herbicide (3-ft circle around each tree, achieving 70% groundcover (reduced cover) for three years, and three half-acre treatments were left untreated (full cover). After five years, average crop-tree survival rates were 58% and 69% on the untreated plots (full cover) and sprayed (reduced cover) plots, respectively. The actual numbers of trees planted by the professional tree planting crew were 687 and 663 per acre for the full cover and reduced cover plots, respectively. After five years, 415 and 419 surviving trees per acre remained which exceeded the minimum number needed for bond release in Virginia. Tree growth on the full cover plots was suppressed, but growth was excellent on reduced cover plots compared to that expected for these species on undisturbed sites. Reduced cover doubled the growth rate for most species except for red oak, which grew three times faster, and white ash, which grew four times faster when released from some of the ground cover competition. All species in this mix appeared to be compatible and should grow into a valuable tree stand. This study shows that this reforestation approach is quite viable for restoring native hardwoods, except that commonly used ground cover could compromise reforestation success.