Hemlock Stands Prior to Hemlock Woolly Adelgid Infestation: Baseline Conditions at the Western Range Limit from Two Surveys a Decade Apart

Keywords: eastern hemlock, hemlock woolly adelgid, invasive species, forest dynamics
Abstract Type: Paper Abstract

Abstract

The Hocking Hills of southeastern Ohio are situated at the western range boundary of eastern hemlock; here, this foundation species occurs in isolated pockets in ravines and on steep slopes. The goal of this study is to characterize these hemlock stands prior to infestation by Hemlock Woolly Adelgid (HWA), which recently entered the State and will cause high mortality if untreated. Thirty plots established roughly a decade ago were resurveyed, and paired with transects to record non-Hemlock species likely to seed in from above. Hemlock remains the dominant species in all plots; storm damage and competitive thinning appeared to account for most mortality across all species. Hemlock growth rates were comparable to deciduous species. Following future hemlock mortality, tulip poplar, chestnut oak, white oak, sweet birch and red maple may be among the first species to dominate the canopy; Japanese stiltgrass appears to be the invasive species of greatest concern. The results of this study can inform management and conservation efforts in the unique Hemlock stands of southeast Ohio.