Comparison of windthrow damage among thinned and unthinned hardwoods and adjacent pine stands following a late winter tornado on the Cumberland Plateau near Sewanee, TNThis article is part of a larger document. View the larger document here.
In March, 2004, prior to spring leaf-out, an F0 tornado snapped or uprooted 672 trees across 25 ha of the western margin of the Cumberland Plateau near Sewanee, TN. A ridgeline separated the impacted area into two parts: westward-facing slopes of mature hardwoods and eastward-facing slopes with thinned and unthinned hardwoods, pine stands, and clearcuts. Greatest damage (29 to 30 percent of damaged stems and basal area) occurred in the pine stands. Among hardwood stands, damage was greater in the mature hardwoods west of the ridgeline than in either thinned or unthinned hardwoods east of the ridge. Damage was intensified on the windward shoulders of ridges and along the margins of clearcuts. Canopy trees were impacted more than lower crown positions, with scarlet oak damaged more severely and white oak less severely than other oak species. Overall, 84 percent of damaged trees were uprooted rather than broken, upturning approximately 0.5 percent of the ground surface.