Experts: Beetle invasion in local forests is ‘getting worse’
TRUCKEE/TAHOE – Fire prevention is a moving target, and this year white firs are in the cross hairs.
As a consequence of years of fire suppression and logging practices that avoided them in the 1800s, white firs have grown bigger, more dense and in places they normally wouldn’t, competing with fire-resistant pines for water and dying off under fir engraver beetle attacks, adding to fuels both deep in the forest and in people’s back yards.
“These trees would normally get cleaned out by fire, and you see them get hit in dry summers by the beetles, but now they’re dying even in the winter,” said Bob Belden, a prevention tech specialist in vegetation management for the Truckee Fire Protection District. “The beetles have always been around but they’re not going away and it seems to be getting worse.”
Jeff Dowling, the Truckee area forester with Calfire, said after the previous three dry winters, there was a large flight of fir engraver beetles last summer, and foresters are seeing the consequences this year.
“The insects get pitched out of healthy trees, they’re part of the system, but when it’s wet they don’t have the opportunity to overcome the trees,” Dowling said.
Unlike the bark beetles hitting area pines that bore a hole bleeding sap around eye level, the fir engraving beetles start from the top of the tree, so often property owners don’t see the damage until the tree is done and the beetles have spread, Belden said.
“This is not just happening out in the national forest, it’s in our backyard,” Belden said.
Firs are shade tolerant and come up under the pines, but are normally burned away during the normal fire cycle, keeping them isolated to higher, cooler climes. Now that they’ve been allowed to grow without fire, they’re competing with pines for moisture in the soil, potentially to the detriment of both species, Belden said.
“People like this tree because it looks like a Christmas tree, but they don’t understand it shouldn’t be growing in these dry climates,” Belden said.
He said unless the dead firs prevent a fire hazard – like multiple downed dead trees on a property – all he can do is suggest the property owner do something about their white firs.
Dowling said the problem is exacerbated by environmental red tape, keeping property owners from harvesting the trees, and by a dying timber market in California.
“Both of those things will contribute to tree mortality,” Dowling said. “When you have too many trees on too few acres this is the scenario we’ll have – large die-offs of firs or pines.”
Belden said he’s found people he has contacted have been cooperative, and said despite not having any big fires this year, property owners have been good about defensible space this summer.
Homeowners associations can enforce work on beetle-infested or dying white firs, he said, and resorts like Tahoe Donner and Northstar have been aggressive on that front.
Belden said any of the area fire districts can help assess a potential problem, like an infested white fir, and give recommendations.
“Call your local fire department and have someone come out and talk to you, it will pay off,” Belden said.
Tahoe Donner’s forestry department and Calfire can also help, he said.