Years of drought causing tree die-off in Oregon forests

MEDFORD, Ore. – Douglas firs and other trees are dying in southern Oregon forests, where three years of drought have taken a toll.

Pines, oaks and madrone do better in drought conditions than Douglas firs, but even more drought-tolerant trees like ponderosa pines have lost out in southern Oregon’s competition for water, experts told the Mail Tribune. The recent winter brought wet weather, but it was too late for many of the trees after prolonged drought conditions and beetle attacks.

The die-off in Applegate Valley, up the west Cascades and into the Willamette Valley appears to be even worse than the tree deaths caused by drought in the mid-1990s and early 2000s. The scale of the die-off will be quantified during aerial mapping surveys next month.

“It’s quite striking,” said Ellen Goheen, a plant pathologist with the Rogue River-Siskiyou National Forest. “I never remember seeing it quite this dramatic in the 22 years I’ve been here.”

Oregon Department of Forestry spokesman Brian Ballou said officials had been expecting tree deaths, but they “just didn’t know what it would look like.”

South-facing slopes and areas with dry soil have more dead trees, as do densely wooded areas with more competition, Goheen said.

“They’re struggling against each other for water, and some are better at getting water than others,” she said. “Some of the smaller trees are flat-out dying for a lack of water.”

For other trees, it’s a slow struggle against pests like the flat-headed fir borer and pine bark beetles. The insects attack trees stressed by lack of water and eat away at them, cutting off their ability to funnel moisture up their trunks.

“The tree dies from the top down,” said Matthew Krunglevich, a district protection planner with the forest department. Private landowners should stay on top of how their trees are doing, either by hiring a forest contractor or calling the forest department for consultation, he said.

Pitch oozing from pines is a sign that the tree is fighting an infestation, Krunglevich said. Dead pines, meanwhile, should be cut into pieces no larger than 3 inches in diameter to interrupt the bugs’ reproduction cycle and keep the infestation from spreading to other trees.

“If not, you’re just making a buffet for more bugs,” Krunglevich said.