Growth in Economic Losses Due to Forest Disturbances in the Eastern United States

Climate change projections suggest growth in the rate and intensity of forest disturbances such as wildfire and hurricanes. This study compares observed forest mortality and infers economic losses associated with forest disturbance events in eight ecoregions of the eastern United States for the first two decades of the twenty-first century. For each ecoregion, we estimate disturbance rates and their impacts on tree mortality and timber values based on multiple remeasurements of forest inventory plots for two decadal periods ending in 2015 (“period 1”) and 2024 (“period 2”). Using an excess mortality approach, we attribute mortality to either normal stand development or disturbance events in these two periods. We then estimate the losses that would be anticipated in period 2 based on period 1 disturbance patterns and compare them with realized losses. Area disturbed and forest mortality increased between the two periods and in all ecoregions; major drivers were hurricanes in the southeast and insects in the northeast. Total losses from disturbances in the eastern United States grew from $30.8 billion per year in period 1 to $49.5 billion per year in period 2, with substantial variation across ecoregions. In period 2, about 40 percent of disturbance-related losses (~$20 billion per year) were unanticipated based on period 1 disturbance regimes applied to exposed resources. Area disturbance rates and biomass mortality rates are poor proxies for timber value losses that depend on the species/size mix of timber.