How fuel reductions fueled the ‘Christmas Valley miracle’

Eli Ramos, Tahoe Daily Tribune

MEYERS, Calif. – When the Caldor Fire swept through Christmas Valley and Meyers in 2021, many expected to return to a smoking, blackened wreck—and were surprised by the fire leaving the areas largely unharmed. What’s now known as the “Christmas Valley miracle” was supported through years of fuel reduction treatment.

In a study accepted by the journal of Forest Ecology and Management earlier this month, researchers Hugh Safford and Saba Saberi found that trees in treated areas were three times more likely to survive than those in untreated areas.

Safford, who lives in Meyers for part of the year, said he was familiar with the work that the Lake Tahoe Basin Management Unit (LTBMU) and the U.S. Forest Service (USFS) conduct in the area. He was interested in studying an area he was familiar with, and when he walked the area after the fire was put out, said he saw obvious patterns tied to fuel treatment.

“When there are unmitigated fuel piles, there was more severity there,” said Safford. “There’s a lot of variance in management, but what we saw was this unorthodox treatment, without prescribed fire, was what had helped.”

Safford and Saberi found that the most effective fuel treatment was mechanical and hand thinning of areas over several years, followed by mastication, which processes trees into chips and mulch. Safford compared the masticated trees to carnitas, though he said he wouldn’t top his tacos with it anytime soon.

Safford praised the LTBMU’s specifications to only place masticated material on bare ground, as well as the stipulation to limit the thickness to less than 6 inches, or 15 centimeters. That foresight helped make the mastication treatment more effective and limited tree death from thicker mastication layers, which can smolder for a long time after a fire has spread and kill the roots of trees.

He hoped that their findings would help inform decisions made by the USFS and LTBMU in treating the environment and preventing the spread of fire.

However, Safford and Saberi agreed that while prescribed fire wasn’t in the most effective treatments for their study, it didn’t mean it wasn’t important.

“There’s nothing in this study to suggest that prescribed fire doesn’t work. There weren’t that many samples that had prescribed burns, so that was just part of our dataset,” said Saberi. “One of the main takeaways of this study is that with any type of forest treatment, doing it in a repeated fashion, not a one and done, is what’s really important.”

Indeed, the thinning and mastication represented many years of work into fuel treatment. “The science basically is united on this understanding that you really need to mix mechanical, hand, and fire as treatments in order to properly treat the fuels, the canopy fuels, the ladder fuels and the service fuels,” said Safford. He called the backlog of unburned fuel piles in Tahoe a “major hiccup” in increasing forest resistance to fire and forest health.

And in the Sierra Nevada, more trees doesn’t necessarily mean healthier forests. In fact, fewer trees in a stand is actually better for our forests.

The Jeffrey pine, which dominates the forests of Tahoe, are highly fire-tolerant trees with flammable needles that grow best in open stands. These all suggest that their niche in nature was adapted to regular fires.

But when they’re paired with denser forests, the trees compete more for water and can sometimes pass infections or infestations to other nearby trees. When paired with fire-sensitive trees, Jeffrey pines unfortunately help fire easily escape into the canopy, where it’s harder to fight and often very destructive.

“The biggest ecological problem in Sierra Nevada is the lack of fire,” said Safford. “We’ve had a period of 125 years or more where we’ve barely had any fire at all. We stopped fire as an ecological force,” said Safford. “There are all sorts of benefits to reintroducing fire and the kind of conditions that fire would create—open stands, less canopy cover, more sun hitting the ground.”

Safford’s lab, among others, have shown positive effects to water and carbon outcomes, less erosion, increased biodiversity and fire safety for people living in these areas.

“The beauty of these particular forest types and the luck of where we live is that the same work that reduces fuels and fire impacts is also largely restorative,” said Safford. It creates better species diversity, healthier ecological function, and tree survival through droughts, insect outbreaks and wildfires. “They’re very parallel, which is not the case in all ecosystem types. This kind of work really ought to be done in much more than the Tahoe Basin.”

“It’s really cool to do a study like this and see the positive benefits happening on the scale that it does, but it’s such a drop in the bucket,” agreed Saberi. “If it can get people to think about doing this restorative work on a larger scale and to have future resilience, that would be great.”

The study concluded that the LTBMU and other landholding agencies should consider forest thinning to forested areas outside the wildland urban interface in order to restore forests. “Some of this work can be accomplished using a judicious mix of hand and mechanical thinning, but we cannot avoid the simple truth that fire will ultimately treat most of the landscape. The choice we have is whether we use fire or fire surrogates proactively… or whether we allow severe and uncontrolled burning to define our future.”