Press release today from Oregon State University. The first few paragraphs:
As more of the Pacific Northwest burns, severe fires change forest ecology
CORVALLIS, Ore. — Over the last 30 years, the landscape annually affected by forest fires has slowly increased across the Pacific Northwest, and in some regions, severe blazes account for a higher proportion of the area burned than in the past.
As a result, the ecology of some of the region’s forests is changing in unprecedented ways.
Scientists calculated that less than one-half of 1 percent of the region’s forest is subject to fire in any given year. But in a project using satellite imagery and ground-based tree inventories, they also found that, in areas historically dominated by low- and mixed-severity fires, nearly a quarter of the burned landscape was subject to patches of high-severity fires that often exceeded 250 acres in size.
Studies of fires prior to 1900 suggest that severe fires occurred over smaller patches of forest and accounted for a much smaller proportion of the total burned area than they do today.