Monument staff working to combat noxious weeds


As invasive weeds spread throughout Dinosaur National Monument, the monument staff is working on a plan to counter the attack.

Approximately 685 species of flora have been identified at the monument. Seventy-three of those plants are classified as nonnative, meaning they have been transported to the monument from elsewhere. Twenty of the nonnative plants are invasive, meaning they are taking over the park's ecosystem.

The monument has never before had a formal plan to manage weeds. But recent inventories have identified invasive plants in more than 1,000 of the monument's 211,000 acres. Plants such as tamarisk, a shrub that grows on riverbanks, have been found in more than 500 acres.

"The National Park Service spends millions each year combating invasive plants in an effort to preserve park resources," Emily Spencer, weed management planning specialist at the monument, wrote in a briefing statement on the management plan. "Farmers and ranchers lose millions more trying to control nonnative plants that drastically reduce land use and productivity."

Until now, the monument has managed weeds through chemical means, such as pesticides, cultural techniques, such as crop rotation, and mechanical strategies, such as cutting, mowing and burning, Spencer said.

"But we'd prefer to use all the available tools in the toolbox," she said during a phone interview.

Other available tools include education, prevention and biological controls. Through educational programs, newsletters and press releases, Spencer said the monument would teach visitors about the way in which seeds spread. Park visitors, landowners and outdoor enthusiasts would learn if they are indirectly contributing to the spread non-native plants, simply by not removing some seeds from their sweater before leaving a particular ecosystem.

Education also works as a form of prevention, as do irrigation canals and range management.

Biological control includes grazing livestock in invaded areas. But grazing on public lands tends to cause controversy among the environmental community. Even more controversial is the introduction of insects to feed on an invasive plant community, Spencer said.

These are all techniques Moffat County has used in its weed management plan for the last 12 years. On Feb. 9, the Moffat County Board of Commissioners sent a letter to the monument explaining their plant management policy and encouraging the monument to develop a plan that would be integrated with the county's.

"We want them to have a truly integrated plan that leaves all the options there," said Gary Brannan, director of pest management for Moffat County.

Spencer indicated that the management plan might have less emphasis on pesticides and biological controls than other strategies, because those controls are controversial.

Brannan said the county wouldn't agree with that, because they wouldn't want to see any of the tools taken off the table.

Spencer described her working relationship with the county as good. She has been working with the county on the plan, and she wants to coordinate the plan with surrounding landowners, as well.

"You coordinate the same plan of attack," she said. "If both do X, Y, Z, you work together to take care of certain problems."

Spencer's goal is to have the plan done by mid-June. But before beginning that work, the monument is accepting public comment until Feb. 20. Interested individuals can call Spencer at and describe what they would

(970) 374-2501, Ext. 3 like to

see included or excluded from

the plan.

If the Moffat County weed management plan is any indication of what the monument's plan will be like, it will focus on mechanical and chemical controls. Through the Weed Bounty Program, a program that contracts laborers to pull weeds by hand, 47,000 pounds of invasive weeds were pulled last year. On top of that, Brannan said county employees harvested at least half that amount.

Many factors come into play when eradicating invasive plants from an area, including the size of the area, the qualities of the plant species, and the location of the infestation. Brannan said pulling weeds by hand works well on bi-annuals. He has seen good results from grazing and experimented with insect release, but finds he uses chemical pesticides most often.

"Economics dictate we use chemicals," he said.

Chemicals are one of the only solutions for eradicating perennials, he said. Chemical controls work quicker and cost less than other strategies.

Rob Gebhart can be reached at 824-7031 or by e-mail at

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