231 Years of Vegetation Change at Chestnut Ridge Natural Area Preserve, Virginia, USA

Forests in the Appalachian Mountains have experienced shifts in composition and structure over centuries because of modifications to disturbance regimes and introductions of non-native species. To quantify these impacts at Chestnut Ridge Natural Area Preserve (CRNAP) in southwestern Virginia, we compared historical land survey records of witness trees with present-day vegetation sampling of trees and shrubs. In 1794, white oak (Quercus alba; importance value=32%) and black oak (Quercus velutina; importance value=24%) dominated the overstory. By 1923, the overstory had shifted to chestnut oak (Quercus montana; importance value=31%) and American chestnut (Castanea dentata; importance value=21%). At present, northern red oak (Quercus rubra) and chestnut oak dominate the overstory with importance values of 14% and 13%, respectively. Historically, American chestnut was more likely to grow next to other tree species (historical mingling index=0.5); whereas, after the introduction of chestnut blight, American chestnut was more likely to grow next to other American chestnut (present-day mingling index=0.2). Current vegeta- tion in CRNAP provides evidence of mesophication because the oak-dominated overstory co-occurs with a midstory and understory dominated by mesic species including great rhododendron (Rhododendron maximum), red maple (Acer rubrum), and sourwood (Oxydendrum arboreum). The comparison of historical and present-day woody species in CRNAP reveals a dynamic forest with shifts in composition and structure reflecting anthropogenic disturbances and the introduction of chestnut blight.