Impact of Gypsy Moth Defoliation in Stands Containing White Pine

Abstract

Abstract Heavy infestations of gypsy moth in Rhode Island forests in 1981 and 1982 caused the greatest defoliation and mortality of white pines in stands where pines were mixed with oaks. White pine basal area losses were greatest (33.7%) in oak stands where white pine occurs as an understory (oak-pine). In stands where pines shared the canopy with oaks (pine-oak), white pine basal area losses were 12.7%, and in pure pine stands, losses were 7.3%. Losses were nearly 5, 4 and 9 times those observed in control stands for oak-pine, pine-oak, and pine stands, respectively. Results indicate that in oak-pine stands, cutting practices that encourage the growth of understory white pines to canopy positions where trees are less vulnerable to defoliation should be a first priority of management. North. J. Appl. For. 5:108-111, June 1988.