Aspen Public Radio: Climate change kindles bigger, hotter wildfires ... - The Aspen Times

Aspen Public Radio: Climate change kindles bigger, hotter wildfires; older prescribed burn stopped Lake Christine Fire’s progress in 2018 | AspenTimes.com

Aspen Public Radio: Climate change kindles bigger, hotter wildfires; older prescribed burn stopped Lake Christine Fire’s progress in 2018

Aspen Public Radio
Halle Zander/Aspen Public Radio

Editor’s note: This is the last of Aspen Public Radio’s four-part series, “ Adaptation: Responding to Climate Change in the Roaring Fork Valley.”

On July 3, 2018, the Lake Christine Fire ignited near Basalt and burned more than 12,000 acres.

The fire northeast of El Jebel, Willits, and historic downtown Basalt burned a total of three structures and temporarily displaced hundreds.

Now Adam McCurdy, the forest and climate director for the Aspen Center for Environmental Studies (ACES), often leads tours in a section of the burn scar near Missouri Heights, discussing recovery processes with fellow hikers.

During an interview at Rock Bottom Ranch in April, he said the fire burned at different severities in different places.

At higher elevations, Engelmann spruce, subalpine fir, and lodgepole pine trees had a lot of damage.

“When they burn, they burn hot,” he said. “We did see some soil damage where we had soils that were mineralized, where the heat actually broke down the molecules.”

But he added that aspen trees in mid-elevation areas were doing well, growing thousands of shoots per acre in some places.

And at lower elevations, where the burn scar can be seen from Highway 82, there were a lot of pinyon junipers before the fire. Now there’s a lot of grassland.

“I think it’s a reasonable expectation to think that shrubs are going to move in there,” McCurdy said. “But I doubt that hillside is going to look like it did in any of our lifetimes.”

He said these different recovery timelines represent typical rates of forest succession and create a “mosaic” in the burn scar.

Future concerns

Many of Colorado’s forests have evolved with fire and mature trees can survive harsh conditions, but seeds are more fragile and may need cooler and wetter conditions to take root.

“So you might have a forest on the landscape that’s able to survive these new conditions that we’ve created through climate change, but once that forest is disturbed, whether it’s from a fire or logging event, the seeds might not be able to establish,” McCurdy said.

In a 2019 study, scientists found warmer and drier conditions around the West are making it harder for certain tree species to bounce back after fire — specifically at lower elevations.

Tom Veblen is a retired professor of geography at the University of Colorado Boulder. He co-authored the study and found a decline in post-fire regeneration of ponderosa pine and Douglas fir trees at lower elevations.

Some areas in the West are converting to non-forests, such as grass and shrubland. He said that can have further impacts down the line.

“From my perspective, our most important concern should be the carbon storage provided by large, long-lived trees,” he said.

When large swaths of these low-elevation forests disappear, the carbon storage they provided disappears, exacerbating the warming climate that impacted those forests in the first place.

He has not studied the Lake Christine Fire burn scar, but he said that with warm and dry conditions getting more extreme, high elevation places like the Roaring Fork Valley could see forests struggling to rebound after a fire, if they haven’t already.

It’s just a matter of time.

“It’s not at all surprising that under continued warming conditions — which, unfortunately, that’s going to continue, there’s no doubt about that — we are seeing a change in the extent of forest from low elevations to high elevations,” Veblen said. “And everybody who’s been studying this across the Western U.S. is finding a similar pattern.”

Climate advocates and world leaders say weaning communities off fossil-fuel dependency is necessary to prevent or elongate the time it takes to reach these kinds of thresholds, but there are some techniques that can be carried out now to limit the spread and impact of future wildfires.

Prescribed fire

Jim Genung has been a firefighter for over 20 years and seen the changes in fire behavior over time.

“These fires are just getting bigger and bigger and bigger, and fires are moving faster, hotter,” he said.

He’s a fire-management officer for the Upper Colorado River Interagency Fire Management Unit and works among public agencies to fight fires and mitigate fire risks in parts of western Colorado.

He does this in part with prescribed burns set intentionally in the spring and fall, when temperatures are low and winds are slow. Prescribed burns can eliminate brush and downed trees that could dry up later in the summer and fuel a higher-intensity wildfire.

And studies have found that fires that burn at a lower intensity result in higher rates of tree regeneration.

Genung said firefighters were able to manage the Lake Christine Fire’s perimeter and its damage because fire managers had conducted a prescribed burn outside of Basalt a few years before.

“The Lake Christine Fire burned right up to the edge of the last prescribed fire we did,” he said. “And it really changed the homogenous structure of the oak brush. We kept it out of Missouri Heights with that.”

He added that it’s one of the best mitigation tools he has.

“We can get a lot of area covered in a short amount of time,” he said. “We can treat a lot of acres relatively safely.”

There’s always a risk when putting fire on the ground, but many fire managers use prescribed burns to protect forested communities as climate change worsens.

McCurdy remembered how a dry heat characterized the summer of 2018 in Basalt when the Lake Christine Fire ignited.

“2018, by some measures of drought, was the driest year in the Roaring Fork Valley in 120 years,” he said. “It was a lower-than-average ‘precip’ year (during) the hottest year on record at the time.” he said. “And that’s what we’re seeing more and more across the state and across the West.”

He said a cooler summer would have changed how that fire burned and how far it reached.

“Climate change set the stage for that fire igniting and for that fire growing as quickly as it did,” he said.

The series is supported by a grant from the Aspen Skiing Company’s Environment Foundation. If you have a story idea for our ongoing climate coverage, please reach out to news@aspenpublicradio.org.
See more