Brian Head • This past summer, a year after 72,000 acres of high-elevation woodlands burned around southwestern Utah’s Markagunt Plateau, residents of the nearby resort town of Brian Head noticed something strange: Tiny white cottony puffs drifted through the air and piled up on the ground like a downy blanket.
It smacked of Christmas in the middle of July, but the fluffy stuff was not snow.
“It looked like cottonwood [seed], but we are at 9,000 feet. We don’t have cottonwoods here,” said Mike Saemisch, a Brian Head resident who has been documenting the fire’s aftermath as a “citizen scientist.”
The mysterious material, which even longtime residents had never seen before, turned out to be seeds exploding off thousands of aspen trees that survived the 2017 fire.
Now tiny plants from those seeds are springing up from the ground, along with millions of aspen shoots suckering off existing roots. Aspen is well-known for rebounding quickly after fires, but some Utah scientists are marveling at the extent of the sudden growth in areas scorched near Brian Head.
Karen Mock, a professor of conservation genetics at Utah State University, learned of the seeding phenomenon from Saemisch and toured the burn region with him in July.
“We found that these little seedlings were everywhere, even in areas where aspen didn’t exist before the fire,” Mock said. “Why is this amazing? ... Because aspen are not thought to reproduce successfully by seed very often in this part of the country.”
The last time a major aspen seedling event was documented in the West was in the late 1980s after the massive Yellowstone fires.
Quaking aspen is a keystone tree species in Western ranges, but these stands, vital to forest health and biodiversity, are in steep decline. Scientists like Mock and USU ecology professor Paul Rogers are searching for answers in hopes of reversing this alarming trend.
The Brian Head burn could provide clues.
Thanks to the flames
“People who study fire ecology get so tired of hearing the media’s negative slant on fire,” said Rogers, who heads the Western Aspen Alliance. “From an ecologist’s point of view, there are a lot of good things. The rejuvenation of aspen stands requires fire.”
Walking around the charred area last summer, Mock was both thrilled and mystified by the tiny seedlings popping from the blackened ground around snags and under downed trunks. Growing flat to the ground, the seedlings don’t even resemble aspen, unlike the year-old suckers that were already 2 feet high.
“Ecologically, these seedlings are so much more important because that’s where you get genetic recombination,” Mock said. “That’s your adaptive potential right there.”
Environmental conditions are morphing unnaturally fast in Western mountains, and a deeper gene pool will help tree species adjust to these changes. But aspen usually propagate through suckered clones that are genetically identical to the mothership root network. The resulting lack of genetic diversity could doom aspen and the ecosystems these trees support. Utah’s famed Pando stand, believed to be the largest organism on Earth, is such a clonal monolith.
Mock and USU colleague Larissa Yocom have set up an experiment to observe how well nursery-raised aspen seedlings grow on ground burned in the Brian Fire blaze. Volunteers planned to plant 2,500 tiny trees inside five fenced-off plots, known as “exclosures," this week, but new snow punted the project to next spring. Once the trees are planted, though, scientists, with the help of locals like Saemisch, will track their progress.
“The question is whether we can use greenhouse-grown seedlings to help regrow aspen in some of these landscape where it has been lost,” Mock said. “Maybe these post-fire environments are a good place to do that because the rodent population will be down, they won’t have competition from weeds, and the water table is going to be up.”
Utah’s state tree, the quaking aspen is in steep decline across its native range due to a combination of factors, including fire suppression, livestock and big game grazing and, of course, climate change. Across Utah, conifers have encroached into aspen stands, often filled with aging trees that aren’t being replaced by younger ones.
Mock hopes the suckers proliferating in the Brian Head burn will provide elk and cattle plenty to eat, giving the seedlings a chance to grow.
“They might provide enough distraction for the herbivores,” Mock said. “If you are an elk, you are going to go to where there is a big wad of suckers, and they may not go picking around for the seedlings. That might help the seedlings survive.”
Fire has long been known to unleash suckering in aspen, but there is no known association between fire and seed production. It could be a coincidence that the Brian Head aspen seeding phenomenon came a year after the big blaze.
Mock theorizes that environmental stressors, like smoke or drought, may have triggered the seed explosion. Last year was Utah’s driest on record, coming on the heels of five consecutive years of below-average precipitation for the state’s southern stretches.
The Brian Head Fire destroyed several homes, contaminated Panguitch’s water supply and wrecked several trout fisheries in tributaries to Panguitch Lake, but some ecologists contend such destruction may be necessary to restore Western forests degraded by past fire-suppression and logging policies.
Western politicians, however, often blame poor forest health on a lack of “active management" and contend logging would restore not only woodlands but rural economies as well.
Forest ecologist Chad Hanson fears a return to rampant logging, or even selective logging, could make national forests less healthy and more prone to destructive blazes in the long run.
“Aspen depends on high-intensity fire to survive and proliferate,” said Hanson, co-founder of the John Muir Project, which advocates for the restoration of fire on forested landscapes. “That’s their ecological niche. Wait for a fire and then grow faster and more prolifically than anything else, taller and faster, so they can have their moment in the sun for 30 or 40 years until the conifers overtop them.”
Hanson contends excluding fire from the landscape has long disrupted the natural rhythms of many Western forests, leading to the loss of millions of acres of aspen and a decline in overall forest health. Aspen stands harbor more biodiversity than any other tree species, help retain water in the ground and fend off flames.
“There are a lot of plants and animals that depend on aspen. If you look at a map of aspen on large landscapes, it’s kind of a map of moisture, especially away form creeks,” Rogers said. “Prolific aspen systems let a lot of light onto the forest floor, so you have a diverse understory with lots of different plants. Most of the animals in our forest ecosystems use aspen at some point each day.”
Aspen are also better at withstanding fire. For evidence of this, walk through the Brian Head burn. Next to conifers killed by flames are stands of aspen that failed to burn completely or at all.
These survivors are now repopulating the terrain stripped of living trees and setting the stage for a richer, if different, forest future.