On Sept. 15, dry pine needles littered the forest floor, forming a beige blanket over charred soil. Insect chatter echoed through the woods while a woodpecker pounded the trunk of a scorched Douglas fir, scattering chips of charcoal. In mid-July, when the Horse Gulch Fire burned at its most intense, firefighters cut a perimeter along the timberline’s edge, just beneath a ridge’s saddle. Now, a narrow lane of overturned soil, evidence of firefighting bulldozers, separated blackened earth from green grass. Verdant sprouts of assorted flora, none more than a foot tall, rose from the churned earth.
The Horse Gulch fire was first reported 10 weeks ago, on July 9. Through the latter half of July, the blaze smothered Helena with smoke as it burned more than 15,000 acres. Blackened grassland, scorched ponderosa pine and charred Douglas fir now decorate the burn scar just north of Canyon Ferry Lake.
Within their brief lifespans, wildfires bring dramatic changes to Montana’s forests and grasslands. But many of the most lasting effects on the landscape appear in the weeks, months and years after the flames are snuffed out. Justin Gude, a research and technical service section chief with the Montana Department of Fish, Wildlife & Parks, says wildfires are a fundamental part of the state’s natural history.
“Everything you see is the product of fire over the years,” Gude said.
More than 350,000 acres of Montana burned over the course of June, July, August and early September this year. Tens of millions of acres have burned across the state over the course of the last century, according to digitized records compiled by the National Interagency Fire Center.
As the National Weather Service reports the onset of cooler temperatures, high humidity and intermittent storms, signs of new life are already returning to burn scars across Montana. The responsibility of post-wildfire recovery falls to the land-owning individual or entity. The U.S. Forest Service, Montana Department of Natural Resources and Conservation and FWP conduct land assessments after wildfires, estimating long-term ecological impacts along with short-term risks, including erosion, landslides and flash floods.
The 200-acre Rising Moon Fire burn scar appears almost indistinguishable from the surrounding terrain.
Credit: Zeke Lloyd / MTFP
The Forest Service released the Horse Gulch Fire Burned Area Emergency Response report in late July, recommending “culvert cleaning, storm inspection and response, and installation of additional drainage features” to mitigate flooding risks. Illustrating those risks, a rainstorm flooded the burn scar on Sept. 12, stranding vehicles and closing Riverside Campground just north of the Canyon Ferry dam.
According to Gude, soil-securing grasses are one of the first types of flora to spread across burned-over landscapes, helping to mitigate floods and landslides. On rangeland, where soil holds critical value to farmers, the U.S. Department of Agriculture has found that grass regrows quickly enough for cattle to resume sustainable grazing one year after a wildfire. But open fields of young grass attract undomesticated large mammals as well. Elk and deer, in particular, reap the benefits of freshly regrowing burn scars.
“There’s more energy there. That translates to higher body fat and higher pregnancy rates,” Gude said.
Big game can suffer, though, when unwelcome plants take up residence on burn scars.
According to Kim Davis, a research ecologist at the Forest Service’s Fire Sciences Laboratory in Missoula, native grasses sometimes lose out to rapidly proliferating invasive species, which often outcompete them for essential resources like sunlight, water, and nutrients.
“Cheatgrass is famous for invading after fire,” Davis said. Cheatgrass, aka Bromus tectorum, a plant native to southwestern Asia, is a major problem in fire-prone states. According to the USDA, reseeding burn scars with native seeds “may help suppress weed invasion after a wildfire.”
A lone deer walks the Remington Fire burn scar. Large mammals are some of the first fauna to return to scorched terrain.
Credit: Zeke Lloyd / MTFP
But no matter the ecological outcomes, Davis stressed the difficulty of comparing wildfire’s impacts on the landscape objectively. Even high-severity fires — blazes hot enough to cause widespread tree and vegetation loss — are part of a healthy process for many high-elevation ecosystems.
“Places that are dominated by lodgepole [pine] will often regenerate really well after a high severity fire,” Davis said. Some lodgepole pines display serotinous traits: their cones contain resin to keep the seeds sealed inside until the heat of wildfire melts the resin, releasing the seeds.
High-intensity timberland fires in areas without serotinous conifer seeds can trigger an ecological battle between sapling species as they compete for newfound access to sunlight. Across Montana, the fight frequently features two familiar groups: deciduous trees and conifers. (Deciduous trees sport broad leaves that fall in the colder months, while conifers usually retain their needle-like leaves year-round.)
While ponderosa pine and Douglas fir are conifers that have evolved to withstand low- and medium-intensity fires, high-intensity fires often usher in a new era of deciduous trees on landscapes where high-intensity fire decimates conifers. Aspens, cottonwoods and poplars usurp formerly coniferous territory by sending up new shoots from their unburnt root systems. Many aspens and some cottonwoods can also resprout from charred stumps.
According to research from Paul Hessburg, a senior research ecologist at the Forest Service’s Pacific Northwest Research Station, some tree populations in the Rocky Mountains have not rebounded at all after “large-scale mortality” events. Hessburg found instead that a lack of conifer seeds on previously timbered areas could shift ecosystems “toward non-forest conditions,” often resulting in grassland where there had previously been forest.
Caitlin Littlefield, who worked as a research fellow at the University of Montana’s Northwest Climate Adaptation Science Center before moving to California-based nonprofit Conservation Science Partners, doesn’t see a meaningful way to compare one ecological outcome to another.
“It is, in some ways, in the eye of the beholder,” Littlefield said, listing an assortment of potential goals for land managers in the wake of wildfire. “Are we talking about the forest recovering to what it looked like before? Are we talking about recovering to conditions that will perhaps be better adapted or more resilient?”
Fallen trunks litter the grassy landscape near the burn scar of the Lakeside Fire, an 800-acre fire that burned north of Canyon Ferry Lake in 2010.
Credit: Zeke Lloyd / MTFP
A vision of the former goal sits just across the Missouri River from the Horse Gulch Fire’s western perimeter. A 200-acre burn scar left by 2022’s Rising Moon Fire appears almost indistinguishable from the surrounding bunchgrass. Only charred bark on surviving conifers, barely visible from a half-built house across a road from the scar’s southern edge, remains testament to the blaze.
A burn scar from the Lakeside Fire, a 2010 blaze that covered 800 acres now abutting the Horse Gulch burn scar, offers an alternative vision of the landscape’s post-fire future. Fallen ponderosa pine and Douglas fir litter grassy ridges dotted by the occasional standing dead trunk with a torched exterior. Young pine trees speckle the terrain, most standing a yard or so above the foliage.
The burn scars around Canyon Ferry Lake highlight the suite of nuanced ecological consequences associated with wildfire, whether an apparent return to status quo or a fundamentally altered landscape. A growing number of agencies, including the National Park Service, have begun utilizing a “resist-accept-direct” framework, selecting one of the three strategies to drive post-wildfire recovery efforts. The RAD framework illustrates a relatively newfound institutional understanding of fire as both a destructive and creative force on Montana’s landscape, creating ecological transformation, Littlefield said, “where forests may no longer be forest, or forests may come back as an entirely different community.”
Land managers, she said, can choose “to resist that transformation, or to accept that it’s going to happen, or to direct it.”
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Publish date : 2024-09-19 08:05:00
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