AWR Blog

by Eve Byron, Independent Record

Aerial application of herbicides including clopyralid and picloram is planned to take place next week on 1,200 acres in the Ogden Mountain and Nevada Mountain areas to try to knock back spotted knapweed infestations, but it may be subject to a lawsuit.

Treatment of lands on the Helena National Forest, as well as on private property in the area, is part of an ongoing effort, according to Shawn Heinert, the Lincoln Ranger District’s rangeland specialist. It should only take a few days at the most, but they hope to conclude aerial operations by Oct. 14.

“If the weather doesn’t work for us, we’ll be delayed until the spring or early summer,” Heinert said. “Fall treatments can be really effective . . . because of the translocation of the herbicide into the plant’s roots, but it’s a small window of opportunity.”

The spraying was examined under a previous Environmental Impact Statement, Heinert said, and this is the second round of treatment; the first took place in 2008.

“The areas in which we are using them are high, upland dry sites, and we are staying away from streams,” Heinert said. “We’re doing this based on following the label requirements on the herbicides and the EIS Record of Decision, which was signed specifically for the northwest portion of the Helena National Forest.”

The plan calls for using low-flying helicopters to spray the two herbicides, which use synthetic growth hormones “to cause uncontrolled and disorganized growth in susceptible plants,” according to the website

While the two herbicides are similar, clopyralid kills a more limited range of plants than picloram and is a little gentler on grasses. Clopyralid also has a shorter half-life, is more water-soluble and has lower adsorption capacity than picloram, according to the website.

Some damage can be possible if clopyralid is splashed into the eyes during application, but otherwise it’s nontoxic to fish, birds and other animals.

Picloram also can cause eye damage and can be highly toxic if inhaled. While it’s not toxic to birds, mammals and aquatic species, chronic exposure to wildlife is a concern, and studies have found weight loss and liver damage in mammals following long term exposure to high concentrations.

Application will occur on weekdays to minimize sportsman and recreation conflicts, and the area of aerial application and roads will be signed to inform the public.

“We will have a person stationed on the roads, there will be signs and a contact person to let people know it’s taking place,” Heinert said.

But Michael Garrity, executive director of the Helena-based Alliance for the Wild Rockies, on Tuesday filed a 60-day notice of intent to sue over the spraying. He cited a recent case the nonprofit organization won in April 2010 on the Kootenai National Forest because the spraying didn’t take into consideration impacts of low-flying helicopters to grizzly bears, which are protected under the Endangered Species Act.

In that ruling, U.S. District Judge Donald Molloy decided that the Forest Service had to stop aerial spraying until it addressed how often the flights would be allowed and what the effect would be on the endangered bears. Garrity’s group said multiple low flights would cause bears to permanently abandon habitat subjected to weed spraying.

The notice of intent to sue says that helicopters cause grizzly bears to panic and flee “in nearly all cases” and that grizzly bears never become tolerant of helicopters, even with frequent exposure.

“They need to follow the U.S. District Court decision when it comes to the Endangered Species Act,” Garrity said. “The agencies’ actions in this matter represent an unlawful departure from their legally binding mandate to protect and recover imperiled species and their habitats.”

Originally published here.



Learn about our track record in fighting to protect the Northern Rockies, what we use donations for, and other actions you can take.

Join our community on Facebook.


Share This