The Combined Effects of Defoliation and Modified Timber Stand Improvement on Hardwoods in the Tug Hill Region of New York

A 2×2 factorial analysis of variance was used to assess the combined effects of defoliation by forest tent caterpillar, Malacosoma disstria (Hub.), that occurred from 1991 through 1993 and concurrent modified timber stand improvement (TSI) treatments on sugar maple [Acersaccharum (Marsh.)] and black cherry [Prunus serotina (Erhr.)] in the Tug Hill region of New York state. Defoliation significantly reduced growth of both overstory sugar maple and black cherry. Defoliation significantly increased both mortality and crown dieback ofoverstory sugar maple. TSI treatments made during the outbreak significantly increased mortality and crown dieback of suppressed sugar maple. Defoliated stands where TSI occurred had lower mortality of overstory sugar maple, and residual overstory sugar maple recovered more rapidly from defoliationcompared with untreated defoliated stands. For the first time, red maple (Acer rubrum L.) is reported as a host for forest tent caterpillar.