Catastrophic wind disturbance in an old-growth hemlock–hardwood forest, Wisconsin

Abstract

On 4 July 1977, the Flambeau River Hemlock–Hardwood Scientific Area (Sawyer County, WI) was leveled by a downburst of hurricane-force winds. This paper documents preblowdown and postblowdown composition in a 61-ha portion of a state Scientific Area. Total stand basal area after the blowdown was reduced to 6% of prestorm levels. Total seedling density increased greatly following the blowdown, especially that of Betula alleghaniensis Britt. Acer saccharum Marsh, continued to dominate the relatively unaffected sapling layer. A dense shrub layer of Sambucus pubens Michx. developed. Such massive blowdowns do not appear uncommon in northern Wisconsin. Implications for forest regeneration and structure are discussed.