Study: Insect outbreaks actually reduce wildfire severity

BURLINGTON, Vt., April 28 (UPI) -- Insect outbreaks and wildfires have grown in severity in recent years, leading some scientists -- and wildfire policy makers -- to draw a correlation between the two.

It turns out there is a link between the two, but the correlation is a negative one. New research shows outbreaks of insects like the mountain pine beetle and western spruce budworm have helped reduce fire severity.

"There is huge concern that insect outbreaks and forest fires will continue to increase with climate change," Bill Keeton, a forest ecologist at the University of Vermont, said in a news release. "These threats remain significant, but our study suggests that major insect outbreaks, contrary to current thinking, can dampen future fire impacts -- and we can use that knowledge to improve forest management."

Keeton and his colleagues found that insect outbreaks result in forest thinning, killing some trees -- presumably the weakest ones -- and leaving others alive. This process leaves a forest less dense and with less flammable mass.

Man-made forest thinning is already a strategy employed by forest managers. The latest findings, published in the journal Environmental Research Letters, suggest management plans account for thinning already accomplished by insect outbreaks.

Not all insects outbreaks are the same, however. Researchers say forest managers need to approach each forest and each outbreak differently.

"These findings will help forest managers to better prioritize restoration efforts designed to reduce fire risks," concluded Keeton.