Effects of silvicultural treatments on survival and growth of trees planted on reclaimed mine lands in the Appalachians

Abstract

Reforestation of reclaimed surface mined lands in the Appalachian coal producing region is difficult because most sites have dense ground covers, compacted soils, and unfavorable soil chemical properties. This study evaluated the effects of a range of silvicultural treatments on the survival and growth of different tree species planted on reclaimed coal mines in the Appalachians. Three sites were selected for study, one each in Ohio (OH), West Virginia (WV), and Virginia (VA). At each site, plots were planted with three species: (1) hybrid poplar; (2) white pine; and (3) a native hardwood mix. A gradient of silvicultural treatments designed to improve survival and growth of seedlings was applied: (1) weed control only; (2) weed control plus tillage; and (3) weed control plus tillage plus fertilization. First year survival and growth varied among the three sites and the species planted. In Virginia where the minesoil was developed from oxidized sandstone, survival and growth was better than at the sites in West Virginia and Ohio where siltstone and shale derived minesoils dominated the sites. Hardwood survival across treatments was 80%, 85% and 50% for the sites in Virginia, West Virginia, and Ohio, while white pine survival was 27%, 41%, and 58%, and hybrid poplar survival was 37%, 41%, and 72%, respectively. Growth of hybrid poplar increased in response to increasing silvicultural inputs while growth of white pine and the native hardwoods were generally not affected by the silvicultural treatments applied. Hybrid poplar height and diameter growth were superior to the other species. Height growth of this species was 127 cm during the first year in the most intensive treatment at the site in Virginia. In comparison, the greatest height growth of white pine and hardwood was 9 cm and 8 cm, respectively. Detailed measurements of above- and below-ground biomass and tissue nutrient concentrations were made on the hybrid poplar at the site in West Virginia. Hybrid poplar biomass increased from 16 g to 104 g from the least intensive to the most intensive silvicultural treatment for this site. The weed control + tillage + fertilization treatment improved the foliar nutrition compared to the other treatments. The survival and growth of hybrid poplar on these sites suggest that this species may be well suited for reforesting reclaimed mined land in the Appalachians.