Unburned trees left after Oregon’s Labor Day Fires are dying — a potential blow to future forests

Five years ago, the Labor Day Fires burned more than a million acres across Oregon and Washington.

Since then, researchers at Portland State University have been tracking the post-fire changes to the forests. What they’ve found reveals an evolving landscape, where unburned trees in the fire scars have succumbed to the delayed effects of the fires and will likely continue to die off.

During the 2020 fire event , dozens of fires were burning all at once, driven by unusually high winds . Five of the fires grew into “megafires,” each burning more than 100,000 acres on the west side of the Cascades.

But wildfires don’t burn uniformly across the forest. Wind, geography and forest management play a huge role in how severely the fires burn. And fires often leave behind large islands o