A new forest study reveals an unexpected silver lining for forests attacked by insects like the mountain pine beetle.
Researchers from the University of Vermont and Oregon State University studied fires in forests with outbreaks of both mountain pine beetles and western spruce budworms in the past 25 years. The new report shows that forests eaten up by insects had less severe wildfires than those that were insect-free.
Lead researcher Garrett Meigs said bugs like the pine beetle act like a thinning agent for a forest.
“When the insect outbreaks affect forests, there’s less fuel available or less live vegetation available to be affected by wildfire,” said Meigs, a post doctoral research associate at University of Vermont.
Researchers looked at 81 fires over 25 years in Oregon and Washington forests.
The insects change forest structure and composition, albeit in different ways. Meigs’ prior research has also shown that insect outbreaks don’t increase the likelihood that a forest will burn.
“Overall, both insects reduce the severity of wildfires,” said Meigs, although the effects of each insect are different.
This is the largest study to date of this kind, said Meigs.
“Moving forward, our forests in the Pacific Northwest will continue to be affected by these insect outbreaks and wildfires. And it’s important to consider how they interact,” Meigs said. “It’s one piece of a more complex puzzle.”