Low snowpack kindles more severe wildfires, western study finds
“It’s only March, and a wet spring could still make a lot of difference”
Across much of the Rocky Mountain West, a winter of record-breaking high temperatures and historically low snowfall has forced people to think about having less water this spring. But it could also mean more severe wildfires this summer, according to new research from Western Colorado University.
In a paper published in the journal Environmental Research Letters, researchers from Western’s Clark School of Environment and Sustainability found that declining snowpack not only extends the fire season but also increases the severity of forest fires.
Analyzing 36 years of snowpack and wildfire data across forests in the western United States, the researchers identified two related but distinct patterns. Early snowmelt was strongly associated with earlier fire seasons and greater total area burned. But low snow water content – the amount of water stored in winter snowpack – was linked to more severe fires, leading to higher tree mortality, greater impacts to ecosystem functions, and increased likelihood of long-term forest loss.
“Snowpack acts as a kind of seasonal water savings account for forests,” the study’s lead author, Dr. Jared Balik, a Western research scientist, said. “When that account runs low, soils dry out earlier, vegetation loses moisture, and forests become more vulnerable to severe fire.”
While previous research has connected warming temperatures and earlier snowmelt to longer fire seasons, this new research shows that reduced snow storage also influences how destructively forests burn.
Years with low snowpack were consistently associated with higher burn severity across watersheds studied from 1985 to 2021. This year, nearly every river basin in the West is experiencing low snowpack.
The findings carry particular weight for southwestern watersheds, including the Rio Grande and Colorado River basin, where long-term snowpack declines have been most pronounced.
The research also highlights the role of global climate patterns like El Niño and La Niña. Depending on the region, such phenomena can increase or decrease winter snowpack and influence the severity of the fire seasons that follow.
However, the long-term trend points toward warming winters and reduced snowpack, leading to earlier melt and more high-severity forest fires.
High-severity fires can trigger cascading ecological effects, according to the paper, such as post-fire flooding and debris flows, and may increase the likelihood that forests convert to shrubland or grassland under warmer, drier conditions.
The researchers, including Balik, Western professor Dr. Jonathan Coop, and Dr. Sean Parks of Ariel Re, say snowpack conditions could serve as an early indicator of fire severity risk, helping land managers adjust thinning, prescribed fire, and preparedness strategies based on winter conditions.
“As snowpack continues its long-term decline, we should expect not just more fire, but more severe fire,” Coop said. “Understanding those connections not only allows us to plan ahead in years like this one but also compels forest management interventions like prescribed fire that can reduce wildfire impacts.”
Despite a gloomy outlook for the upcoming wildfire season, there is still reason to be hopeful. “It’s only March, and a wet spring could still make a lot of difference,” Balik said.
To read the full study, visit https://iopscience.iop.org/article/10.1088/1748-9326/ae4e4a. For more information about studying the science of wildfires at Western, visit western.edu.
END
In a paper published in the journal Environmental Research Letters, researchers from Western’s Clark School of Environment and Sustainability found that declining snowpack not only extends the fire season but also increases the severity of forest fires.
Analyzing 36 years of snowpack and wildfire data across forests in the western United States, the researchers identified two related but distinct patterns. Early snowmelt was strongly associated with earlier fire seasons and greater total area burned. But low snow water content – the amount of water stored in winter snowpack – was linked to more severe fires, leading to higher tree mortality, greater impacts to ecosystem functions, and increased likelihood of long-term forest loss.
“Snowpack acts as a kind of seasonal water savings account for forests,” the study’s lead author, Dr. Jared Balik, a Western research scientist, said. “When that account runs low, soils dry out earlier, vegetation loses moisture, and forests become more vulnerable to severe fire.”
While previous research has connected warming temperatures and earlier snowmelt to longer fire seasons, this new research shows that reduced snow storage also influences how destructively forests burn.
Years with low snowpack were consistently associated with higher burn severity across watersheds studied from 1985 to 2021. This year, nearly every river basin in the West is experiencing low snowpack.
The findings carry particular weight for southwestern watersheds, including the Rio Grande and Colorado River basin, where long-term snowpack declines have been most pronounced.
The research also highlights the role of global climate patterns like El Niño and La Niña. Depending on the region, such phenomena can increase or decrease winter snowpack and influence the severity of the fire seasons that follow.
However, the long-term trend points toward warming winters and reduced snowpack, leading to earlier melt and more high-severity forest fires.
High-severity fires can trigger cascading ecological effects, according to the paper, such as post-fire flooding and debris flows, and may increase the likelihood that forests convert to shrubland or grassland under warmer, drier conditions.
The researchers, including Balik, Western professor Dr. Jonathan Coop, and Dr. Sean Parks of Ariel Re, say snowpack conditions could serve as an early indicator of fire severity risk, helping land managers adjust thinning, prescribed fire, and preparedness strategies based on winter conditions.
“As snowpack continues its long-term decline, we should expect not just more fire, but more severe fire,” Coop said. “Understanding those connections not only allows us to plan ahead in years like this one but also compels forest management interventions like prescribed fire that can reduce wildfire impacts.”
Despite a gloomy outlook for the upcoming wildfire season, there is still reason to be hopeful. “It’s only March, and a wet spring could still make a lot of difference,” Balik said.
To read the full study, visit https://iopscience.iop.org/article/10.1088/1748-9326/ae4e4a. For more information about studying the science of wildfires at Western, visit western.edu.
END