UW researches impact of 2024 wildfire season
During the Wyoming Weed and Pest Council’s (WWPC) 80th Annual Conference, held on Oct. 29-31 at the Ramkota Hotel and Conference Center in Casper, individuals gathered to hear about the latest research being conducted at the University of Wyoming (UW) on reclaiming the state’s grasslands.
Wildfires swept across the Cowboy State in 2024, resulting in more than 810,000 acres of burned range.
Dr. Brian Mealor, director of the UW Sheridan Research and Extension Center and Institute for Managing Annual Grasses Invading Natural Ecosystems, addressed the destruction of Wyoming’s native lands, including the big sagebrush plant species.
“We have been tracking wildfire here in Wyoming for over 80 years, and the thing that really struck me when I started looking at historic fire data was our ecosystem is a lot more fire prone than we want to think. I think there are several reasons for it,” he mentioned.
Big sagebrush
Big sagebrush is perhaps the most important shrubby plant in the Western grasslands, and according to the Sagebrush Conservation Design, it’s been reported 1.3 million acres per year of intact sagebrush rangelands are being degraded by large-scale threats like invasive annual grasses, conifer encroachment, wildfire and development.
Across the West’s sagebrush biome, a 175-million-acre area stretches from New Mexico to southern Canada, according to the U.S Department of Agriculture.
However, a large portion of northern Wyoming’s rangeland was destroyed by wildfires this year, including Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis).
Big sagebrush usually stands two to four feet tall, but can reach heights of 13 feet and creates a canopy which provides a healthy growing environment and protects several other plants growing underneath.
Ranchers have viewed the plant as a woody weed, but experts say it is an important plant in keeping a balanced ecosystem.
“It brings up water and nutrients, which is a huge deal,” Mealor mentioned. “Often, the surface soil is pretty depleted, and on a dry year, big sagebrush is what’s wicking up water from deep below the ground.”
Destruction
Studies show complete elimination of big sagebrush has a significant effect on biodiversity and forage production is actually diminished, including grasses and forbs livestock rely on.
Mealor said, “We need to primarily look at soil characteristics following a fire. If it’s a low severity fire, the soil is still intact and the roots are still there, but if its high-level intensity, we will see things like a hydrophobic layer which prevents water from moving into the soil causing serious problems.”
Recovery of big sagebrush populations after fire is inhibited by the loss of adult plants and the limited ability of new seedlings to survive or reproduce, a limitation with negative population consequences which can last for decades after post-fire seeding restoration efforts, according to recent research.
“It takes a long time for big sagebrush to grow, and it depends on a number of factors including whether it’s growing from seed or from a transplant and the elevation of the area. It may take decades to reestablish the species here,” Mealor noted.
Reestablishing big sagebrush
Big sagebrush does not typically send out new shoots from its roots after a fire and must rely on seed dispersal to repopulate.
According to recent research, there is pretty clear data if there was a decent amount of sagebrush prior to the fire, the likelihood of reestablishing is higher as it may relate to mycorrhizal association or soil condition.
“One of the biggest challenges we will face in reestablishing big sagebrush is precipitation at the right time of the year,” Mealor said. “Perennial grass competition is another factor in the success of reestablishing big sagebrush.”
There is a possibility to take big sagebrush cuttings from other areas to help reestablish it in burn areas, but there are limitations.
“We are talking thousands of acres of burn scars from this year’s fires,” he added. “It’s a great place to start and to get a core area started. It is like reestablishing little islands in hopes there will be natural recruitment which comes from the seed sources.”
The recovery of big sagebrush habitat is one of the largest – if not the largest – ecosystem restoration challenges in the U.S.
“Big sagebrush seeds are incredibly small, and their longevity is very short in terms of viability. It would be fall when they would be setting seed,” Mealor said. “Unfortunately, this year’s seed crop was destroyed before it was able to disperse.”
A full recovery of big sagebrush canopy cover can take up to 100 years, and finding ecologically and economically effective ways to establish the species is often critical for restoration success.
Melissa Anderson is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
