Concurrent establishment of ground cover and hardwood trees on reclaimed mined land and unmined reference sites

Abstract

A reclaimed mined site and an unmined reference site were compared to assess the effectiveness of reclaiming land according to United States Public Law 95-87, The Surface Mining Control and Reclamation Act of 1977, for forest land use. Red oak ( Quercus rubra L.) and black walnut ( Juglans nigra L.) seedlings were planted concurrently with K-31 fescue ( Festuca arundinacea Schreb.) and red clover ( Trifolium pratense L.), and maintained under the same levels of management on mined and unmined sites in Sullivan County, Indiana. Soil chemical and physical properties were evaluated, and ground-cover productivity was assessed for 4 years. Survival and growth of bareroot and container seedlings as influenced by chemical control of competing ground cover was followed for 7 years. After liming and fertilization, mine soil physical properties rather than chemical properties were apparent factors affecting survival of tree seedlings and productivity of both tree species and ground-cover vegetation. Survival percentage of black walnut and red oak seedlings on the mine site was adequate to meet the 450 trees acre −1 (≈ 1112 trees ha −1) stocking level specified by current laws only when ground cover vegetation was controlled. Survival and height growth of both tree species was greater on the reference site than on the mine site, especially when ground-cover vegetation was controlled. The poorer growth on the mine site was due to severe stem dieback on plots with no ground-cover control. The results show the importance of controlling the competing ground-cover vegetation during seedling establishment on reclaimed mine soils, particularly during the first 4 years following outplanting.