Problems abound for roadside trees |

Problems abound for roadside trees

SUMMIT COUNTY – The thousands of dead and dying trees bordering Summit County’s roadways are caused by a slew of negative influences including de-icers, officials say, and a realistic solution may never be found.

The problem has caught the attention of Colorado’s Department of Transportation, which, with the help of the University of Northern Colorado, will begin this summer to study the impacts of deicers on roadside vegetation, said Stacey Stegman, director of CDOT’s public information department.

“We want to keep the highways safe, but while keeping track of the harmful effects,” Stegman said. “It’s something we hope to get off the ground soon, because we’ve been watching this (issue) develop for some time.”

The local issue deals with brown and wilted lodgepole pines along Interstate 70, Swan Mountain Road, Highway 9 and most other roads that border forest. The trees are signs of humans’ detrimental influence on the natural environment, said Howard Scott of the U.S. Forest Service office in Dillon.

The problem is no secret. As automobile traffic increases in the mountains, more de-icing substances must be used to keep the roads safe. The sand and salt pile on top of the roots of the pines, sucking the moisture from the trees and making them more susceptible to beetle attacks. The beetles, taking advantage of the weakened trees, finish the job by disconnecting a tree’s life support, evidenced by the browning of leaves and the wilting of branches.

John Polhemus, director of the Summit County Road and Bridge Department, said that in the winter of 1973, one truck load of sand-salt mixture per day could cover all the county roads.

“Now, we’re using 20-to-30 truck loads per day,” Polhemus said. “There’s no magic wand out there. I’ve heard of different things being tried, but salt is salt, whether it’s sodium chloride or magnesium chloride.”

The long-term solution, Polhemus said, would be to quit using any solutions on the roads, leaving them slick and snowy for any traffic. That, he said, isn’t going to happen. And the result, according to longtime observers like Polhemus and Scott, is trees dying at a rate rarely seen in the county’s history.

“There’s really no other solution,” Polhemus explained, “unless you keep people from driving or put governors on their cars to keep them from driving fast.”

The level of salt in the mixtures has also increased over the last decade. At one time, the Colorado Department of Transportation’s sand-and-salt mix featured 2 percent salt, but now the mixture includes 5 percent salt.

Other deicing solutions also have negative influences. Magnesium chloride, once believed to be the long-term solution to rock salt, creates a salty mist in the winter that coats the leaves of trees bordering the roads, just as it coats the windshields of cars.

“Often times, if you look at it, only half the tree is browning,” said Rick Herwehe, owner of A Cut Above Forestry and consultant to developers in the community. “I think that is due to spray … the salt from the roads, or the mag chloride on wet roads, being sprayed into the trees. The salt sticks to whatever it touches and dries out the leaves.”

Now, the county is back to using sand and salt, which, unlike liquid sprays, necessitates a huge cleanup effort every spring.

Road crews are working in Breckenridge this week to sweep sand and salt off the roads to use in resurfacing gravel roads in the future. The ditches, some of which are too steep to clean, are having the sand dragged to the surface of the road, where it will be collected and deposited on gravel roads, as well.

“We don’t have to do that on all the roads,” Polhemus said. “But it is very time consuming.”

In the summer, road crews do use magnesium chloride to suppress dust on county-owned dirt roads. The spray is kept to a minimum, Polhemus added, because the liquid is absorbed immediately by the dust.

CDOT’s study, Stegman said, should take a year to complete.

The beetle problem

While there may not be a realistic solution to sand buildup on trees, mountain pine beetles can be stopped, said Tom Estes, owner of Preventive Tree Spraying, a company that services Summit and its bordering counties.

Mountain pine beetles and Ips beetles will begin emerging from the trees in the next month, which has Estes spraying over 25,000 trees on private and public land in Colorado. While the trees might be saved from beetles, foresters like Herwehe say the long-term effects of sand in the soil would kill the trees, eventually.

“Especially since the drought last summer, the salts under the soil have been working their way up into the root zones,” Herwehe said. “Again, there’s no moisture and the tree will die.”

Estes, meanwhile, is using a substance called carbaryl to prevent beetles from making homes in healthy trees. The insects are usually smaller than a quarter-inch long, and will turn a tree reddish-brown in eight-to-10 months after an invasion, according to the Colorado State Forest Service.

While the chemical does work on insects, it also affects the entire food chain.

“There’s certain drawbacks,” Estes said. “We kill a lot of bugs. That’s what carbaryl does. So the birds leave the area when there’s no bugs to eat. We try to take down bird feeders, but it’s a cold-blooded killer, even to fish. It does take a sufficient quantity. A few drops won’t do it.

“But I have noticed the difference,” he continued. “The birds will vacate the area. But, they’ll come back when the bugs do.”

Another chemical, called permethrin, has also been used locally for beetle prevention. Alternatives to chemicals include placing whole trees in a wood chipper, peeling the bark off a tree, and transporting infested trees to areas where the beetles are unable influence large amounts of forest.

Woodpeckers, ironically enough, also help trees by eating the beetles.

Ryan Slabaugh can be contacted at (970) 668-3998 ext. 257 or at

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