Ice storm damage and early recovery in an old-growth forest.

We quantified the damage caused by a major ice storm to individual trees in two 1-ha permanent plots located at Mont St. Hilaire in southwestern Québec, Canada. The storm, which occurred in January 1998, is the worst on record in eastern North America; glaze ice on the order of 80-100 mm accumulated at our study site. All but 3% of the trees (DBH > or = 10 cm) lost at least some crown branches, and 35% lost more than half their crown. Damage to trees increased in the order: Tsuga canadensis, Betula alleghaniensis, Ostrya virginiana, Acer saccharum, Fagus grandifolia, Quercus rubra, Betula papyrifera, Acer rubrum, Tilia americana, and Fraxinus americana. Only 22% of the saplings and small trees (4 cm < DBH < 10 cm) escaped being broken or pinned to the ground by falling material. Levels of damage generally were greater in an exposed ridge top forest than in a cove protected from wind. By August 1999 only 53% of the trees had new shoots developing from the trunk or broken branches; among the more dominant canopy trees, Fagus grandifolia had the least sprouting and Acer saccharum and Quercus rubra the most. We anticipate and will monitor both significant turnover in the tree community and some shift in composition of the canopy dominants.