The smooth white trunks of what were once towering conifers stand like twisted tombstones at the top of Mount Elden. Standing tall on grass-covered slopes, the trees serve as stark markers of the Radio Fire, a blaze that started from an abandoned campfire, then raced up and over the mountain 40 years ago.
Terri Fortier was 23 years old at the time and was working at the Purina plant. She climbed to the top of the tower to watch as the wind propelled the fire up Elden’s south-facing slope.
“It was beautiful but it was so sad,” Fortier said. “Trees were going up like torches.”
Soon, helicopters and planes began flying over her apartment on Fourth Street, making it “like a war zone,” she said.
The fire was even more devastating to Fortier and her soon-to-be husband, though. The two had just bought property along Little Elden Springs Road where they were planning to build a home. The fire completely torched it.
“It was like walking in hell,” she said about visiting the property after the fire.
As it produced plumes of smoke that towered over Flagstaff and meant bombers flying above residents’ heads to drop slurry on the flames, the nearly 5,000-acre Radio Fire jolted people, said Andrew Sánchez Meador, who works in forest management, ecology and applied statistics at Northern Arizona University and the Ecological Restoration Institute.
“It was the beginning of northern Arizona and Flagstaff being aware of larger fires,” he said. “This was not the type of fire we should have been seeing in this system.”
Post-fire recovery is one of the areas Sánchez Meador studies.
Four decades later, Sánchez Meador and other experts in fire ecology and forest management say the outlook for how the Radio Fire burn scar will recover is still murky, complicated by washed away soils, a harsh environment and the prospect of a hotter, drier climate in the future.
BARRIERS TO GROWTH
While aspen and gambel oak regrowth is creeping up the slopes of Mount Elden, Sánchez Meador said it will probably be 200 to 500 years before pine trees cover the mountaintop as they once did -- if that ever happens at all.
Although many people focus on trees and plant cover, it’s really the soil that is the key variable for vegetation to reestablish after a fire, said Peter Fulé, a professor in NAU’s School of Forestry.
After the Radio Fire, large amounts of soil got washed down the mountain, forming large fans of deposited material at its base but making for a harsher growing environment on the top and slopes, Fulé said. It won’t be decades or generations but hundreds to thousands of years to add back as little as a centimeter of soil to those areas, he said.
An additional challenge is the fact that the basalt soil on Elden is already difficult for trees establishment, Sánchez Meador said.
While aspen have filled in across the north-facing slope of Elden, they too are stunted, Fulé said. Loss of soil could be at play as could the loss of vegetation and litter cover, making the ground more exposed to the elements of wind and sun, he said.
“It’s a microclimate that can make it difficult for things to grow,” he said. “It’s a steep, dry, harsh environment that got even harsher and drier because of loss of vegetation and soil.”
As for the question of whether the area will ever look the same as it did before the flames, Fule said there isn’t a clear answer on what happens to ecosystems in the Southwest after severe fires. The range of responses is drastic.
In the area burned by the 1996 Horseshoe Fire about 14 miles north of Flagstaff, hardly any new trees are sprouting, he said. Conversely, the areas burned by the Rodeo-Chediski and Wallow fires in the White Mountains have seen “abundant regeneration,” likely due to different soils and monsoon precipitation, Fulé said.
Then there are other places in the Southwest where severe fires have basically turned coniferous forests into oak shrublands, if not permanently then for a “really long time,” he said.
“We kind of have examples of all these extremes and it’s not clear why,” Fulé said.
Variation in regeneration is found even across the Coconino National Forest due to differences in soil depths and moisture patterns, said Dick Fleishman, who is now the operations coordinator on the Four Forest Restoration Initiative and tracked post-Radio Fire recovery when he joined the Coconino National Forest in 1980. Ponderosa pines and Douglas firs that were planted after the fire on the northeast side of Elden, for example, have reached only about half the size of trees planted the same year after the Huffer Fire that started south of Clints Well, near the Mogollon Rim, Fleishman said.
Climate change may also shift which types of trees come back where, he said. Ponderosa pines that grow back on Elden’s slopes may creep higher than they once were and the line where the higher elevation mixed conifer forest begins may get pushed up as well, he said. There’s also the possibility that the area will stay in an oak, aspen, shrub state as the climate continues to warm, Fulé said.
POSITIVE SIGNS OF RECOVERY
All things considered, though, including the severity of the fire and the arid conditions of the Southwest, Mount Elden’s post-fire recovery is going well, Sánchez Meador said.
Grasses quickly filled in across the burn footprint, stabilizing the soil and reducing flooding dangers, Fleishman said. The fire also created somewhat of a blank slate, which is an opportunity for the forest to reestablish with a density and tree pattern closer to historical, pre-settlement norms, Fleishman said.
The area at the base of Elden’s east side, where there are flatter slopes and deeper soils, is making good progress in returning to a ponderosa pine forest thanks to natural regeneration and replanting efforts in the area of Sandys Seep Trail and Little Elden Springs Road, Fulé said.
While the Mount Elden ecosystem was one generally adapted to more frequent, lower severity fires, some places where aspen are now growing back did do better with higher severity stand-replacing fires, Sánchez Meador said. Douglas and white firs will likely be shooting up beneath the aspen canopy, he said.
Also worth noting is that even the bare top of Elden serves ecosystem purposes, with grasses and dead trees providing food and habitat areas for small mammals and the wide open spaces making good hunting for raptors, Sánchez Meador said.
“There is a lot going on still,” he said. “It just may not be ideal for what we want.”