Forest outlines weed management options
by JOEL GALLOB - Ravalli Republic
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With non-native plants a growing concern in the 1.35 million-acre Selway Bitterroot Wilderness, the Bitterroot National Forest and three other forests plan to use chemical, biological and mechanical controls to reduce the impact of existing invasive plants and work to prevent establishment of new ones.
With 13 weeds of concern, spotted knapweed tops the list, said Gil Gale, Invasive Plant Program Leader at the Bitterroot National Forest. Also of concern are ox eye daisy, dalmation toadflax and sulfur cinquefoil, but knapweed represents more than 90 percent of the infestation, he said.
The weed-fighting effort will include chemical, biological and mechanical treatments, re-seeding and replanting, and education and prevention designed to reduce the unintended human transport of invasive plants into the wilderness.
It would not be the first fairly large use of herbicides in a wilderness area, as there have been such programs in the Bob Marshall and Frank Church wildernesses.
The Forest Service has developed a Draft Environmental Impact Statement describing the alternatives analyzed and the one selected as preferred.
“Non-native invasive plants are a growing concern in the Selway Bitterroot Wilderness and surrounding areas,” the DEIS summary states. “Without efforts to control these weeds, they will continue to expand into new areas and the number of new weed species will increase.”
The project also involves the Nez Perce, Clearwater and Lolo National Forests, for a total area of 1.4 million acres including the wilderness, 31,000 acres of roadless area, and general forest lands.
The goal, said Gale, is first to prevent the establishment of new invasive species and second, to prevent the expansion of existing invasive species.
The biological controls are aimed at containing infestations, while the chemicals are hoped to eradicate infestations. The chief bio-control is the root miner weevil, an insect that eats knapweed roots.
All the chemical treatments are to be ground-based, and in the wilderness the treatments would be “selective, hand-operated, spray applications using backpack and stock-mounted sprayers,” the document states.
The Draft EIS looked at five alternatives.
The alternatives include:
• A no action alternative (actually a no new actions alternative).
• An alternative emphasizing herbicides (the “confined treatment” alternative).
• One that emphasizes biological methods (the bio-control alternative).
• And two others where both biological and chemical approaches would be used.
The no action alternative would continue the use of current anti-weed methods. These include removal by hand and mechanical means (specifically at airstrips and administrative sites), limited use of herbicides at administrative sites, plus continued use of approved bio-control agents inside and outside the wilderness. This alternative would involve about 100 acres per year of herbicide use. Historically, less than 20 wilderness acres per year have received herbicides.
The “proposed action” alternative that began the discussion would utilize all currently approved weed control methods, plus herbicides, and new releases of bio-control agents. Designated areas include all trails, camps, trailheads, administrative sites, airstrips, private land buffers and dam sites located in infested wilderness areas, plus roads outside the wilderness but within the project area. The chemically treated area would be under 1,500 acres per year. There would also be up to 10,000 acres of biological control over the 10- to 15-year life of the project.
Alternative three is called the “confined treatment” option. It would introduce no new biological controls, but use herbicides at all trails, associated camps, trailheads, administrative sites, airstrips and private buffers in currently infested areas. No herbicides would be used within 50 feet of live water. It would involve 1,806 acres of herbicide treatment per year.
Alternative four would emphasize bio-controls. Inside the wilderness, it would manage weeds without herbicides, and biological agents would be introduced in all currently infested areas. This would treat 996 acres annually with herbicide, and up to 50,000 acres with bio-controls over the project’s life.
Alternative five is the “preferred” one. Like the “proposed alternative” it would employ all currently used methods, but would expand areas for treatment beyond those in the “proposed” alternative. Designated treatment areas would include all trails, camps, trailheads, administrative sites, airstrips, private land buffers and dam sites currently in infested wilderness areas. It would also include roads outside the wilderness but within the project area.
This preferred alternative would allow for “more aggressive chemical treatment of new invaders and new colonies of established invasive plant species,” and for future treatment in areas now weed-free or in the early infestation stage. And it would include stock grooming stations at Race Track, Gateway and Paradise trailheads.
It would involve the largest amount of chemicals, 4,125 acres of herbicide treatment per year, and up to 50,000 acres of bio-control treatment over the project’s life.
It is the only alternative identified as likely to have a “high” level of effectiveness.
All of the action plans include an updated public education program and the requirement that stock be fed weed-free feed for 48 hours before entering the wilderness.
Reporter Joel Gallob can be reached at jgallob@ravallirepublic.com or at 363-3300.
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Gracene Long wrote on May 13, 2008 4:03 PM: