Trees continue to pay price for wildfires

Another wave of die-offs is under way in the area of the Columbia Complex Fire.



The South Touchet home of Randy and Debbie Lewis is a defensible space, Columbia County Fire District 3 Chief Rick Turner said during a tour Tuesday. Lots of green grass, trees removed from the area surrounding the house, and a composition roof all contribute to the fire resistance of the site.

DAYTON -- Dead tops. Random dead branches. Pitch blobs on the bark. Pale needles.
Dead trees.

Forest pest experts and forest land management specialists recently joined local landowners in a tour of sites where trees are dead or dying.
Debbie Fortner of the Natural Resource Conservation Service and Lisa Naylor of Blue Mountain Resource Conservation and Development organized the tour.

Naylor and Fortner said they have been receiving calls regarding dead trees, including mature ponderosa pines on the slope south of the Touchet River east of Waitsburg. The trees are visible from U.S. Highway 12.

The culprit in this case is black pine leaf scale, according to Mike Johnson, state Department of Natural Resources forest health specialist for the northeast region.

This insect is a native species, and unless something occurs to weaken the tree's immune system, it is not a problem, Johnson said.

Conditions that can make the tree susceptible to an outbreak include dust from roads or construction; drift from pesticides, which kill a parasitic wasp that keeps the scale in check; and overcrowding of trees.

Overcrowding contributes in two ways, Johnson said. It allows the larvae of the scale to disperse to other trees by wind. It also causes trees to beweaker, and less able to resist insects.

Symptoms of scale include faded-appearing foliage, and "lion's tail" tufting of foliage at ends of branches. Close inspection will reveal black scales.
Scale insects are just one of a number of insects taking advantage of the stress trees are experiencing as the result of drought and the aftermath of the Columbia Complex Fire.

There are other conditions that can cause a tree to weaken or die.

Landowner Randy Lewis led the tour group to a young grand fir at the edge of a pond.

The species has a long list of insect and diseases that can kill it, entomologist Craig Schmitt said.

The fir had a number of symptoms, including pitching (pitch extruded in an attempt to evict an insect), dead branches, and different-colored foliage on part of the tree.

The changing color could be due to sun scald, Schmitt said.

The tree has also been disturbed when a berm was constructed around the pond, and part of the berm has been pushed against the tree. The activity would also cause soil compaction that affects root growth and function.

While fire stress allows beetle populations to build up, then spread to healthy trees, the resulting dead trees create fuel for another fire.

Lewis' home is defensible in a wildfire, Columbia County Fire District 3 Chief Rick Turner observed. Lewis has removed trees near his home, planted a wide expanse of grass, which he keeps irrigated and green.

Firefighters make their choices of what to defend based on three priorities, Turner said. Those are life of firefighters and citizens, property, including homes, and resources, such as trees and grassland.

If a home is surrounded by trees and shrubs, has a wood shake roof and poor access, firefighters might not choose to protect it, Turner said.
At a site near Lewis' home, the entomologists and Johnson removed chunks of bark from several dead pine trees.

Lia Spiegel and Schmitt, who work at the U.S. Forest Service Forestry and Range Sciences Laboratory in La Grande, examined what they found inside the bark.

The western pine beetle or the mountain pine beetle is the most likely culprit when pine trees die. The beetles make their way into the trees, where they lay eggs that hatch into larvae that eats its way to adulthood by munching along the cambium, or growth layer, just under the bark. In the process the beetles make distinctive trails, or galleries, that are species-specific.

Western pine beetles create a spaghetti-type gallery pattern, while mountain pine beetles' galleries are more straight-lined.

Another deadly insect is the ips beetle, which thrives in logging slash. Two mistakes landowners can make will facilitate an ips outbreak. Thinning at the wrong time of the year is one mistake.

The other is piling cut wood and brush between live trees, inviting the insects to the piles, and providing them ready access to the healthy trees.
Fighting the insects with pesticides is almost futile, as most of their life is spent under cover of bark.

"The best thing you folks can do on private land is keep the stands thinned out," Schmitt said.

Giving individual trees enough room to flourish also gives them the ability to withstand insect invasions. Spacing also makes it more difficult for beetles to migrate from tree to tree.

Thinning and vegetation control has another benefit, Fire Chief Turner said. When lightning strikes a live tree, it blows the bark off. When it strikes a dead tree, it blows flaming debris away from the tree, igniting available fuels.

"Those things are like a bomb going off," Turner said.

WSU Cooperative Extension

Columbia County, 382-4741
Garfield County, 843-3701
Walla Walla County, 524-2645

Natural Resoures Conservation Services, 202 S. Second St. (Post Office Building), Dayton, 382-4773, Ext. 3.


Use the comment form below to begin a discussion about this content.

Sign in to comment

Click here to sign in