BEND, Ore. (AP) - The U.S. Forest Service is planning to cut down hundreds of ponderosa pines that were killed by an herbicide applied along a highway in central Oregon.
The federal agency is taking public comment on a plan to remove the trees along a 12-mile (19-kilometer) stretch of U.S. Highway 20 near the city of Sisters, The Bulletin reported Thursday.
The Deschutes National Forest trees were likely killed by an unhealthy dose of the weed-killer Perspective, which contractors working for the Oregon Department of Transportation first applied around 2013, forestry officials said.
The herbicide was administered to kill broad-leaf weeds and other plants that pose fire dangers. The state agency has an agreement with the Forest Service to manage vegetation along roads that cross through lands managed by the federal agency, said Peter Murphy, a spokesman for the state Department of Transportation.
When the herbicide was first used in the area, it was approved to treat forestland. It was not listed as harmful to ponderosa pines, said Brent Oblinger, forest pathologist for the Forest Service. The herbicide is no longer used by the federal agency in Washington and Oregon.
The Forest Service started to notice browning foliage and other indicators that something was wrong in 2014, Oblinger said. The affected trees, estimated to be more than 1,000, absorbed the herbicide through their root system, resulting in no available remedies, he said.
Many of the dead trees are mature ponderosa pines, which become more likely to fall after they have been dead for five years, Oblinger said.
The state agency can cut down trees that are hazardous to roadways, but an extensive removal requires the Forest Service, Murphy said.
A full-scale effort would likely occur next spring.
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Information from: The Bulletin, http://www.bendbulletin.com
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