Forest health conditions on the Allegheny National Forest (1989-1999): Analysis of forest health monitoring surveys

This publication describes the forest vegetation and health conditions of the Allegheny National Forest (ANF). During the past 15 years, the ANF has experienced four severe droughts, several outbreaks of exotic and native insect defoliators, and the effects of other disturbance agents. An increase in tree mortality has raised concerns about forest health. Historical aerial surveys (1984-98), the 1989 Forest Inventory and Analysis plot data, and the 1998/1999 Forest Health Monitoring plot data were analyzed to compare disturbed and undisturbed areas. Tree mortality and crown dieback levels were compared between undefoliated areas and areas defoliated by cherry scallopshell moth, elm spanworm, and gypsy moth. American beech mortality was compared inside and outside the beech bark disease killing front. This study illustrates the value of an intensified grid of Forest Health Monitoring plots and demonstrates the integration of aerial survey and plot data.