The latest report from the Washington State Department of Natural Resources isn't mincing words when it comes to the state of forest health in Washington. Data from a 2023 aerial detection survey, detailed in their annual Forest Health Highlights, paints a sobering picture, mapping a sprawling 517,000 acres of forest affected by tree mortality, defoliation, or diseases. The survey crowned a 55-year high in damage attributed to the Douglas-fir engraver, a bark beetle turned forest felon amidst escalating climate stresses. DNR and the USDA Forest Service took to the skies for an expansive view across approximately 22 million acres, marking the largest operation since the annual surveys kicked off in 1947, excluding a pandemic-induced hiatus in 2020.
Despite the survey revealing the least affected acreage since 2018, officials are far from relieved, with Commissioner of Public Lands Hilary Franz declaring the report "one of the most comprehensive resources" in flagging the gravity of forest health dilemmas. "I encourage all landowners and land managers," Franz told the public, encouraging the use of the report's findings to preserve Washington’s iconic evergreens. Yet, the Douglas-fir engravers' assault on 25,600 acres stands stark, nearly a fifth more than the 20,300 acres recorded four years prior.
The report points fingers at secondary bark beetles, including the Douglas-fir engraver, that exploit trees weakened by other pests or climate-induced stressors like excessive heat and drought. Reinforcing these findings, DNR entomologist Glenn Kohler highlighted the connection between the health of the forests and the climatic adversaries they face. "We know that heat and drought are two of the most prominent areas of concern for forest health throughout Washington," Kohler revealed, lingering on the suspected ill effects the 2021 heat dome had on forest vitality.
As though adapting to a warmer world, the California Fivespined Ips beetle, historically a stranger to the more temperate Puget Sound environs, was pinned for ponderosa pine deaths as far north as western Washington's King County. Beetle traps, once capturing fewer than ten Ips beetles, are now brimming with hundreds, as insects previously hunkered down near the Columbia River Gorge spread their wings and expanded their territory. This worrying trend mirrors the dry conditions spanning the state's western and eastern forests, which by late September last year teetered between moderate and severe drought levels, the U.S. Drought Monitor reported.
With summer's traditional drought stress symptoms potentially amplified by wayward rainfall and scorching heat, chances of recovery for the injured trees are slim, setting the stage for a possible uptick in tree mortality this year. The annual survey offers an unsettling glimpse of the impacts such extreme weather events may have wrought on Washington's forests, where each data point adds depth to the story of a complex environmental crisis unfolding in the Evergreen State.
