Raging Debate Over Burned Trees Could Leave California Vulnerable to Disastrous Fires

Removing burned trees after a wildfire has been standard practice for the U.S. Forest Service for the past century, but an NBC Bay Area Investigation reveals an increasing number of scientists now blame post-fire logging for leaving communities even more vulnerable to hotter, faster fires

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The NBC Bay Area Investigative Unit uncovered a raging battle over how to prevent disastrous forest fires across California, pitting century old practices by the U.S. Forest Service against new data from last year’s Creek Fire. 

As accusations fly about “bogus science” and “profiteering,” California residents, relaxing on a Labor Day weekend, found themselves running from a wall of flames during one of the state’s fastest-moving wildfires ever.  

The Creek Fire was first spotted and reported by a couple riding a motorcycle near Big Creek, California on Sept. 4, 2020 at 6:18pm. By noon the next morning, the fire had ripped through two river canyons to Mammoth Pool Reservoir - traveling 15 miles in less than a day -- that’s high speed for a forest fire. So fast, in fact, that no one managed to warn hundreds of Labor Day weekend campers at the Mammoth Reservoir.

“We’ve seen lots of fires come through here before,” said Amy Wagner, owner of what used to be a general store at Mammoth Pool Reservoir. “But usually we watch them for weeks before they get here.” 

Wagner said by 1 p.m. on Sept. 5, “burning embers were flying over the campground, and the only exit road was blocked by the fire.” Wagner, along with hundreds of people at the campground for the long weekend, scrambled down to the lake as a wall of fire advanced towards them. 

“By 3 p.m. it was like night,“ she said. “ It was black.”

A California Army National Guard helicopter hovers above Mammoth Pool Reservoir before picking up evacuees the night of Sept. 5, 2020 (Courtesy: California Army National Guard)

Into that darkness flew Army National Guard pilot Joe Rosamond and his crew.  Rosamond knew there were serious injuries as he searched for any landmark in the smoke.

“While they're all trying to evacuate to the lake, that's where I think a lot of these injuries happened,” said Rosamond. “It's a panic. It's chaos.”  

Rosamond finally managed to land his Chinook helicopter on a concrete boat launch, and his team began loading the most injured first.

"Some of the people have been burned pretty badly. We're talking like skin coming off of the body,” he said.  

As Rosamond navigated the overloaded helicopter through the smoke, the Creek Fire closed off his escape route. 

“I'm watching our exit path become obscured by the smoke as things are changing," he said. "What was clear, you know, just a couple minutes ago ended up being completely obscured and we had to take a different route in order to get out.” 

Evacuees from Mammoth Pools are flown to safety on a California Army National Guard Chinook helicopter, Sept. 5, 2020, after the Creek Fire left them stranded. (Courtesy: California Army National Guard)

So why did this wildfire spread so quickly?

The answer may have to do with what happened here years before the Creek Fire ever ignited.

Dr. Chad Hanson, a forest and fire ecologist, believes the speed of the fire was driven not only by hot, dry, windy conditions - but also by  a U.S. Forest Service practice called post-fire logging, which means removing burned trees after a wildfire to reduce fuel during future fires.   

"A lot of people think about dead trees and downed logs, dead wood in the forest -- they think of it as fuel, and the science is telling us it's much more complex than that," said Dr. Chad Hanson, a forest and fire ecologist.

“If it wasn't for the logging ... the fire wouldn't have reached the reservoir as quickly,” said Hanson, who has been studying wildfires for more than two decades.  Hanson took the Investigative Unit on a tour of the Creek Fire and provided a first look at his new research that essentially blames the U.S. Forest Service for creating hazardous conditions that allowed the Creek Fire, and other fires across California, to burn faster and spread farther.  

Using the Forest Service’s own data – Hanson found where the Creek Fire burned most intensely.

The flames first erupted at Big Creek Canyon. According to Hanson’s research, the overlap proves areas previously logged after previous past fires later burned most intensely during the Creek Fire. By analyzing the entire perimeter of the Creek Fire, Hanson concluded that logged areas were three times as likely to burn faster and hotter compared to non-logged areas.

The Creek Fire: California's Runaway Blaze

In an upcoming study, Dr. Chad Hanson, a forest and fire ecologist, finds a striking correlation between high intensity, fast-moving forest fires and a practice known as post-fire logging.

Source: Dr. Chad Hanson/John Muir Project
Credit: Sean Myers/NBC Bay Area

“Even though it seems counterintuitive for a lot of people, removing both dead trees and live trees from the forest actually tends to make fires burn faster and hotter,” said Hanson. "That oftentimes occurs near towns and when that happens, you can have tragic consequences.”  

Pointing to a large burned tree on the forest floor, Hanson said, "Not only do they soak up and retain large amounts of soil moisture like giant sponges, but they actually interrupt the flow of the fire across the forest floor," he said. “It actually can slow the flames.”

Burned trees are at the heart of the battle over how best to prevent catastrophic fires that destroy California communities.

“That is entirely bogus,” said Dr. Brandon Collins, a forest research scientist.  "There's nothing in the scientific literature to support that." Collins works with the U.S. Forest Service, but only spoke to the Investigative Unit in his capacity as a Fire Science professor at U.C. Berkeley. He calls Hanson’s study “flawed” and maintains leaving burned logs in the forest will not slow down future fires.

“In fact, it's actually quite the opposite. The Creek Fire, actually, was a great example of that,” said Collins. “We believe that most of what fueled that growth was the dead trees that were killed during the drought that preceded that fire by four or five years.”

Dr. Brandon Collins believes criticism over post-fire logging is unwarranted and misinformed. "Shrubs mixed with the the dead trees, which then become logs on the forest floor, is an incredibly flammable fuel condition," he said.

In 2018, 216 scientists from across the country --- including professors at Harvard, UCLA, and U.C. Davis  – penned a letter asking lawmakers to reduce post-fire logging throughout the west.

“They're misguided when it comes to the scale of the issue,” said Collins. “I think there's absolutely a role for burned trees to be left in the forests as habitat, but that role is not over tens of thousands of acres.” 

Collins is concerned leaving behind burned trees will only lead to more intense fires that natural habitats are unable to withstand. “We're going to keep losing more and more chunks of forests,” he said.

Despite repeated requests, the U.S. Forest Service declined to comment on this story and the increased criticism the agency is facing about its financial stake in post-fire logging, which some view as a conflict of interest. Each year, the U.S. Forest Service collects about $45 million dollars for its budget by selling timber to private lumber companies.

“It's not as though it's going to line someone's pockets,” said Collins.  “That money is being reinvested into reforestation of those areas.”

“They sell public trees to private logging companies after a fire and they keep the revenue,” countered Hanson. "They're financially incentivized to be in the post-fire logging business,” he added.

Hanson stands behind his latest data on the Creek Fire, and says it’s proof that  U.S. Forest Service policy is failing.

"It's making things worse across the board, he said. "We have to change direction."

There are roughly 30 wildfires currently burning more than 2 million acres across California.

"Our fire season is now expanded,” said Rosamond. “Back when I first started, we would probably get called out on our first fire sometime in August and would be done sometime in September. Now, we're starting to see that we're getting called out on fires in June or July and it's lasting all the way through October."

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