ANCHORAGE (KTUU) - Firefighters in the Matanuska-Susitna Borough have noticed a change in spruce trees along river corridors, the destructive effects of the spruce beetle.
A 2016 aerial survey conducted by the Alaska Division of Forestry and the U.S. Forest Service looked at 30 million acres across the state and found more than 193,000 acres had damage attributed to spruce beetles. The Forest Service says that’s a six-fold increase over 2015.
“They’re a big concern, certainly one of our top concerns,” said Jason Moan, a DOF Forest Health Program Manager. “We have seen a slight increase over the last couple of years and then a pretty substantial increase last year and we’ll be actively looking into things that might be behind that this year.”
Norm McDonald, a DOF fire management officer, says the dead spruce trees can be a major source of fuel for wildfires.
“Recently after they’re killed they are a dangerous fuel type. They can torch and spot and then really the problem is after they’ve been dead for a few years and the needles are gone you get more sunlight that hits the ground and then the grass comes up behind that,” McDonald said.
Another implication for firefighters is land that is more difficult to fight fires on because of “dead and down” trees and thick grass.
“It’s difficult to cut line through it’s difficult for dozers to get through. The retardant from the tankers doesn’t penetrate that thick grass very well so it’s probably one of the more challenging fuels types,” McDonald Said.
Moan advises against harvesting spruce trees this time of year because the beetles are attracted to freshly cut spruce left on the ground. He says the insects fly between mid-May and mid-July.