PARENT SESSION
Poster Session #39: Disturbance Ecology.
Thursday, August 9, 2001. Presentation from 3:30 PM to 5:00 PM. Exhibition Hall

Assessing the impact of the ice storm of 1998 on an old-growth forest.

ARII, KEN¹, HOOPER, MICHAEL¹, DUGUAY, STEPHANIE¹, LECHOWICZ, MARTIN¹, ¹

ABSTRACT- The ice storm of January 1998, is the worst on record in eastern North America. We summarize our efforts to assess the impact of this storm on an old-growth forest at Mont St. Hilaire (Quebec), where over 100 mm of glaze ice accumulated. We investigated the impacts from three perspectives: 1) qualitative assessment of damage to individual trees, 2) quantitative estimate of the woody debris produced, and 3) amount of gap opening created in the canopy. Tilia americana and Fraxinus americana were the most damaged by the storm, Tsuga canadensis and Betula alleghaniensis the least damaged. The storm generated 19.5 tons of woody macro-litter per hectare. The storm destroyed much of the forest canopy, but gap formation was spatially heterogeneous. The range of pre-storm gap fraction values was 8-22% at a 120 sampling locations, while the post-storm range was 12-47%. Canopy loss in this old growth forest was greater for locations that had; 1) less open canopy prior to the storm and 2) greater presence of Fagus grandifolia in the canopy.

KEY WORDS: disturbance, ice storm, old-growth forest, canopy