Below is a news release from the Wyoming Game and Fish Department.
The Wyoming Game and Fish Department has been closely monitoring the area burned in the 2020 Mullen Fire for signs of cheatgrass. Cheatgrass is an invasive noxious weed with the ability to take over landscapes and reduce growth of other beneficial native plants. An aerial herbicide treatment was applied to parts of the burned area after the fire, and Game and Fish has been happy to see minimal cheatgrass and the recovery of many native plants in the treated area this spring.
“In 2021 and 2022 Game and Fish worked alongside the U.S. Forest Service to apply the herbicide Rejuvra, which prevents cheatgrass from germinating but allows growth of native plants,” said Ryan Amundson, Game and Fish terrestrial habitat biologist in Laramie. “It was amazing to return to those areas this year and see native species recovering in landscapes with little to no cheatgrass.”
The treated areas have been surveyed each year since the Mullen Fire, and results show a steady recovery. In 2021, the first spring after the fire and prior to herbicide treatment, there was a high density of cheatgrass and a lack of native grasses. In 2022, after the herbicide treatment, there was little to no cheatgrass and native grasses began to fill in the area. This year, native grasses and forbs (wildflowers) continue to recover and expand throughout the area, and little cheatgrass is present.
“We are very pleased with the overall recovery of native plants in the burn scar,” said Britt Burdett, Game and Fish terrestrial habitat biologist in Saratoga. “We are also now finding more shrub seedlings throughout our survey locations, which is promising for the continued recovery of native species.”
The recovery of native plants will better support wildlife. When cheatgrass overtakes areas, it suppresses overall biodiversity. Animals rely on different plants for food and shelter, so when one plant dominates the landscape, it often supports fewer animal species. Game and Fish has been encouraged to see a variety of wildlife return to the Mullen Fire scar, including deer, elk, moose, and pronghorn. Interestingly, some of those animals are selecting habitats differently than expected.
“We’re seeing a shift where elk and deer are wintering at higher elevations in the burn scar,” said Lee Knox, Game and Fish wildlife biologist in Laramie. “We are used to seeing these animals head to lower elevations in large herds over winter. Now, they are staying up at higher elevations and in smaller groups, taking advantage of aspen and willow habitats that were enhanced by the Mullen Fire and provide shelter and forage.”
This habitat selection continued even through periods of deep snow last winter, contradicting the expected pattern where snow pushes animals down to lower elevations. In addition to visual surveys, Game and Fish has fitted elk, deer, and moose in this area with GPS collars. The detailed movement data from collars will allow biologists to better understand the response of big game to wildfire.
Game and Fish will continue to monitor recovery in the Mullen Fire scar for years to come. If the last three years serve as an indicator of what is to come, the area will continue to heal and provide great habitat for Wyoming’s wildlife.
The cheatgrass spraying project cost 1.2 million dollars and more than 16,000 acres were treated. This large effort could not have been accomplished without the funding support from the following partners: The Wyoming Wild Sheep Foundation, Rocky Mountain Elk Foundation, Sheep Mountain Mule Deer Initiative, Platte Valley Habitat Partnership, Secretarial Order 362 (migration corridor funding), U.S. Forest Service, WY Governor’s Big Game License Coalition, and the Wyoming Wildlife Natural Resource Trust Account.
(Photo credit: Wyoming Game and Fish Department)