Last week, the Forest Service used aerial spraying of herbicides to treat approximately 410 acres of open grasslands at Blue Mountain for noxious weeds.
The area sprayed is one of 26 projects that were identified by the Lolo National Forest in an environmental impact statement completed two years ago, according to Andy Kula, weed program leader for the Lolo forest.
"We've been trying to use ground application for weed control on Blue Mountain for about 10 years," Kula said. "But the terrain is too rough and we were losing ground."
The rugged terrain was also damaging equipment, he said.
Four additional areas close to Missoula are scheduled for aerial herbicide treatment this spring, according to Kula.
Those areas are Mormon Ridge in the Lolo Creek drainage; Babcock Mountain in the Rock Creek drainage, an area recently acquired by the Forest Service from Plum Creek; follow-up treatment in the Ninemile area that was burned in the wildfires of 2000; and follow-up treatment in the Flat Creek area near Superior that was burned in the fires of 2000.
"Last year," Kula added, "we successfully treated 10 project areas that were identified in our Winter Range and Burned Area EIS. We are using an integrated three-pronged approach to weed management: aerial and ground-applied herbicides, bio-control agents - insects, and prevention and education."
The goals, he said, are to restore wildlife habitat, keep new weeds from being established, reduce existing invasive weeds, restore native and desirable vegetation and protect adjacent uninfested lands.
The Blue Mountain herbicide treatment was designed to control eight different noxious weeds, Kula said. The area is infested with spotted knapweed, sulfur cinquefoil, houndstongue, morning glory, Canada thistle, leafy spurge, St. Johnswort and Dalmatian toadflax.
Biological control efforts will continue on areas that were not sprayed, according to Kula.
Those weeds are very invasive, he said, and can be spread rapidly by attaching seed heads to shoes, clothing, pets, horses and tires. Areas of concentrated public recreation, such as Blue Mountain, are at particularly high risk of weed invasion.
"It's well-documented that these weeds reduce native grasses and forbs," Kula said. "Over time, the results are devastating for wildlife habitat and recreation values. Neighboring landowners had requested the Forest Service control weeds on Blue Mountain."
The Blue Mountain Recreation Area was posted with yellow signs before the spraying to alert recreationists that it would be done this spring, according to Kula. Neighboring homeowners were notified to expect a low-flying helicopter.
"We were out long before dawn on Wednesday morning to ensure that early walkers didn't get into the project area," said Kula. "The support of the neighbors and people who use Blue Mountain was tremendous. Everything went perfectly, as expected."
Kula said that some of the pine trees in the area of the spraying might be affected. But he said the trees often recover from the damage in a year or two.
"Since we're already removing small trees for fuel reduction and to maintain an open grassland setting, some tree damage is acceptable," he said.
Because wildflowers and weeds are both forbs, Kula said, some wildflowers, such as lupine, will also be affected by the herbicide.
"I wish there was a perfect solution," he said. "But there isn't. If you don't control the weeds, they will eventually eliminate both native grasses and wildflowers, spread to adjacent uninfested lands, and Blue Mountain would be one big leafy spurge, St. Johnswort and Dalmatian toadflax seed orchard. If you go ahead and treat the weeds, you will reduce some wildflowers, but protect the native grasses and uninfested lands."
Reporter Daryl Gadbow can be reached at 523-5264 or at email@example.com