MEASURING SPATIAL AND TEMPORAL SHIFTS IN BEECH GAP FOREST STRUCTURE AND COMPOSITION IN RESPONSE TO BEECH BARK DISEASE IN GREAT SMOKY MOUNTAINS NATIONAL PARK

Abstract

Exotic forest pests and pathogens are among the most serious environmental threats to millions of hectares of forested land worldwide. In Great Smoky Mountains National Park (GRSM), high-elevation beech gaps are dominated by American beech (Fagus grandifolia Ehrh.)—a tree species that has been severely impacted by Beech Bark Disease (BBD), a non-native pathogenic complex first confirmed in the Park in 1986. In 1994, a long-term monitoring protocol was established by Park foresters to document patterns of BBD infestation, progression, and host mortality at 10 beech gap plots established throughout GRSM. The analysis of a 23-year dataset supports that the reduction in F. grandifolia basal area is driving significant shifts in forest structure and composition. The decline of the foundational species, F. grandifolia from high-elevation beech gaps will have broad consequences for associated biota, ecosystem function, and potentially, the long-term persistence of beech gaps in GRSM.