Influence of Stand Thinning on Ice Storm Injury in Maine Hardwood Stands

Abstract

Abstract In January 1998, a severe ice storm struck the northeastern United States, causing widespread injury and, in some areas, substantial damage to forest stands. In Maine, hardwood species were most severely damaged. Landowners have been concerned that thinned stands are more susceptible to ice injury than their unthinned counterparts. The objectives of this study were to investigate injury and recovery from the ice storm in recently thinned (within 5 years) and unthinned hardwood stands. Four field sites were chosen, and individuals in both thinned and unthinned areas were measured to determine damage and recovery values. Species examined included white ash (Fraxinus americana L.), American beech (Fagus grandifolia Ehrh.), red oak Quercus rubra L.), paper birch (Betula papyrifera Marsh.), and red maple (Acer rubrum L.). Damage variables measured included pre- and poststorm crown class, percent crown loss, and number and size of broken branches. Recovery variables included transparency rating, number and location of sprouts, and cambial electrical resistance readings for each individual. Results indicate that thinned stands did not suffer the effects of the 1998 ice storm greater than the unthinned stands, for all stands combined. However, some differences at individual sites were detected. We suggest that landowners should not be overly concerned with continuing to thin their hardwood stands. A thinned stand is not necessarily at greater risk for ice injury. In addition, the thinning may actually accelerate the recovery process by creating individuals that are more vigorous than their unthinned counterparts. Heavily thinned stands, however, may be at a greater risk to ice injury.North. J. Appl. For. 22(4):262–267.