A 20-year experiment in the north-central Sierra Nevada recently confirmed what many local, state and federal agencies have been saying for years — that forest management techniques such as prescribed burning, restoration thinning, or a combination of both, effectively reduce risks of catastrophic wildfire in California.
Beginning in 2001, the lead investigator, Scott Stephens, Ph.D, a professor of fire science at the University of California, Berkeley, and a team of other researchers focused on prescribed fire and thinning for two decades in the same location, Blodgett Forest Research Station, a 4,000-acre experimental forest located about 65 miles northeast of Sacramento.
“If you burn a location three times in 20 years you improve it,” Stephens said in a phone interview Tuesday. “When the Forest Service and Cal Fire and other agencies try to do this type of work it’s helpful to have science to rely on. The scale that we need to accomplish the work on is dramatically large. For land managers looking to make forests more resilient, there are a lot of options to be successful.”
Prescribed burning is one of the primary tools local, state and federal agencies have been trying to use in recent years to reduce fire threats in the Mother Lode, at multiple locations in Calaveras and Tuolumne counties, including places in Calaveras Big Trees State Park’s North Grove and South Grove, and in the Stanislaus National Forest’s recently expanded Social and Ecological Resilience Across the Landscape SERAL project, in the South Fork Stanislaus River watershed along the Highway 108 corridor.
In their most recent promotion of Stephens’ Fire and Fire Surrogate Study, UC Berkeley communications staff noted that in March 2022, the governor’s Wildfire and Forest Resilience Task Force announced a strategic plan to expand use of prescribed fire statewide to 400,000 acres annually by 2025.
But the use of beneficial fire continues to be hindered by multiple factors, including the lack of a trained workforce, the need for specific weather conditions for burning, and fears about potential risks, UC Berkeley stated.
“It’s a good statement to think about,” Stephens said. “There are agencies like Cal Fire and the Forest Service that have people capable of doing prescribed burning, but the vast majority of those workforces are employed temporarily during the peak firefighting season.”
The best weather windows for prescribed burning often occur during winter, when those agencies are staffed down for winter and spring.
“Springtime you can have opportunities for burning,” Stephens said. “A lot of fall periods are getting compressed, from dry to wet in a short time. We have to expand to burning at other times of the year, and that’s when we often have no trained workforce available at all.”
That’s already happening in Calaveras and Tuolumne counties, Cal Fire and Forest Service representatives said Tuesday.
Firefighters with the Cal Fire Tuolumne-Calaveras Unit, the Tuolumne County Fire Department and the Groveland Community Services District, through a cooperative agreement with Cal Fire, are all trained in the use of live fire to a basic and intermediate level, and they are well-versed in its application for prescribed fire, Nick Casci, the TCU and County Fire chief, said Tuesday.
The TCU also has employees that serve in leadership positions on both a Prescribed Fire Incident Commander course team, as well as an Intermediate Firing Operations course team. The unit also has multiple chief officers who are qualified prescribed fire incident commanders, filling a key role in the execution of prescribed fire projects, Casci said.
“Lack of trained personnel is not a hindering factor for our local area,” Casci said.
The TCU, County Fire, and Groveland CSD aim to accomplish as many acres of prescribed burning as possible each year, Casci said, working within constraints of weather and available personnel — those who are not committed to emergency incidents or needed coverage for fire response.
Last year, 400 prescribed fire acres were completed in Tuolumne County, not including other treatment methods, Casci said. Cal Fire TCU currently has seven state-sponsored prescribed fire projects in Tuolumne County, not including federally-sponsored projects.
A key to success for local prescribed fire projects is multi-agency collaboration with California State Parks, Stanislaus National Forest, local government cooperators such as Twain Harte Fire Protection District, Tribal Fire Departments such as Tuolumne Rancheria Fire Department, and Cal Fire cooperative agreements with the Tuolumne County Fire Department and Groveland CSD, Casci said.
Benjamin Cossel, a U.S. Forest Service spokesman for the Stanislaus National Forest, reviewed Stephens’ Fire and Fire Surrogate research and said “all of the challenges listed in the UC Berkeley study have impacted the Stanislaus National Forest’s prescribed burning operations to some degree.”
That said, the Stanislaus National Forest and the Forest Service continue to work with federal, state and local partners to identify areas or policies “that prove challenging in achieving state and federal goals and working with our partners to find solutions,” Cossel said.
“We have read the study and feel that it is a confirmation of the work underway with the Stanislaus Wildfire Crisis Strategy Landscape,” Cossel said, referring to plans that include the SERAL project in the South Fork Stanislaus River watershed along the Highway 108 corridor, which is billed as the largest green forest management project in the 127-year history of the Stanislaus National Forest.
“Our treatments are based on a diversity of tools, prescribed fire, machine and hand thinning, that match the treatment area with the right tool or combination of tools,” Cossel said.
Referring to the state goal of expanding prescribed burning to 400,000 acres annually, Cossel said: “When you combine state and federal goals, you’re looking at a goal of 1 million acres per year across both state and federal lands.”
Forest Service contributions to that million acres will vary depending on a variety of factors, Cossel said, “but we will aggressively do everything we can to meet our goals. In addition, working with the Tuolumne Fire Safe Council will help contribute toward that overall goal.”
Stephens’ 20-year study underscores the fact that fire intensity decreases with the decrease in available fuels, and it’s important to note that the combination of thinning and prescribed fire is the key to long term success, Gary Whitson, the TCU unit forester and pre-fire division chief, said Tuesday.
“In areas where dense fuels currently occur, mechanical thinning can be used to safely reduce the fuel loading,” Whitson said. “Prescribed fire can then be used as a long term maintenance tool.”
High vulnerability to wildfire and drought exists at such great scale throughout California forests that action is warranted today, Stephens and his research team concluded.
“We know enough from studies like the Fire and Fire Surrogate Study to move forward competently with large-scale forest restoration treatments,” Stephens said in a summary.
A summary of Stephens’ Fire and Fire Surrogate Study can be found here..