English

Abstract

Poor growth and survival has been noted in tree seedlings planted into an existing ground cover. Such observations are ascribed to competition between root systems of ground cover and trees for water and nutrients. During drought, competition for water becomes intense and could result in mortality. Seedlings of shortleaf pine, green ash, northern red oak, and shagbark hickory were planted on twelve plots on a loosely graded ridge-top in eastern Tennessee that had been reclaimed and planted with native warm season grasses in 2006. Plots were planted in spring of 2007 with pine alone, hardwoods (ash, oak and hickory) alone, or alternating pine and hardwood seedlings. Planting was followed by an extreme and extended drought. In December of 2007, survival of shortleaf pine averaged 35%, while northern red oak averaged 95%, green ash 87%, and hickory 88%. Seedling size at time of planting was related to the probability of survival, with larger seedlings showing low mortality rates. Survival was greater on the northwestern facing slope, while seedlings on the southeastern slope had the greatest growth. Cover of native grasses at the time of planting ranged from 8 to 44%, but there was no clear relationship between ground cover density and seedling survival. Additional