Oregon forests face drought stress despite lower tree mortality

A new report from the Oregon Department of Forestry and the USDA Forest Service indicates that drought remains a primary stressor for Oregon’s forests, weakening trees' ability to resist insect pests and disease. While 2025 saw a return to typical precipitation levels, the spring season was recorded as the fourth driest on record.

Total tree death or damage affected 181,500 acres, a figure significantly lower than the 10-year average and less than half of the peak damage seen in 2022. In 2022, 1.8 percent of Oregon’s 30 million forested acres showed signs of damage, compared to 0.7 percent in 2025.

Geographically, the highest rates of tree mortality were concentrated in eastern Oregon. Union County reported the highest impact at 2.4 percent of forested acres, followed by Umatilla County at 1.24 percent and Harney County at 1.12 percent. Coastal regions reported the lowest levels of damage. Approximately 78 percent of the damage observed via aerial survey resulted from the combination of drought and opportunistic beetles targeting Douglas-fir, true fir, and pine species.