In 2019, the Tahoe National Forest alone had 1.5 million tree deaths. It was the second-highest tree mortality count across the state of California for that year — Klamath National Forest had nearly 1.9 million.

The numbers are startling, particularly in comparison to the relatively mild years of 2006 through 2008, said Nic Enstice, regional scientist with the Sierra Nevada Conservancy, when 600,000 trees were lost each year across the entire state. 

Fire risk increases after significant tree mortality and in a year that has seen numerous wildfire-related records broken statewidefive of the top 20 largest wildfires in state history happened this year — this trend is troubling to say the least. Yet here in Tahoe/Truckee, there wages a valiant battle to lessen the risk of wildfire. It’s happening on multiple fronts and while it’s admittedly not happening “fast enough,” the wheels are in motion and great results can already be seen.

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Our shrinking forest

Our region is reverently known as the Green Bubble, or the “last green forest in the Sierra Nevada.” While tree mortality numbers aren’t in yet for 2020, Tahoe’s living forests — trees that have not yet succumbed to massive tree mortality — are known to be in peril, for a multitude of reasons. 

“Historically, these forests … evolved in a manner so [fire, beetles, drought] couldn’t crash over a large area like a tidal wave,” Enstice explained. “It more ebbed and flowed, sped up, slowed down as there were patches of trees here and gaps there. The fire couldn’t behave uniformly across large areas.”

Fire suppression by humans, however, has shifted dynamics. Extensive logging efforts (which replaced healthy mixed-size trees with tightly-packed uniformly-sized ones) and putting out fires as soon as possible didn’t flush out unhealthy trees, yielding forests of matchsticks ripe for bark beetles to feast upon.

To give an idea of recent loss, an SNC annual report in 2017 noted that since 2014, approximately 110 million trees died from drought, beetle, or fire. The Tahoe National Forest is currently seeing about 140 dead trees per acre.

Bark beetles, the cause behind so much death, are running amok. In 2019, the vast majority of tree mortality in the TNF was due to the fir engraver beetle, partial to red fir trees. Bark beetles in general respond to chemicals emitted from dead and dying trees, where they bore inside and lay eggs, and eat the tree from the inside out. The deadened trunks and flammable needles provide plenty of combustible material, leading to today’s catastrophic wildfires.

“It is my understanding that one to two years after significant mortality … fire risk increases because of the highly flammable dead needles still on the trees,” Enstice said. “But after year two, the needles should mostly be on the ground — yes, still flammable, but with less airflow and less material available for combustion at once. Fire risk is expected to go down a bit. Then, years 11 to 20, risk goes back up as the big trees start to fall and all of that fuel becomes available to burn.”

These fir beetles seem to have come from down south. During the 2014 to 2017 drought, about 60 million trees in the Southern Sierra Nevada suffered from bark beetles, primarily in mixed conifer, ponderosa pine, and sugar pine species. 

The drought ended, and beetles shifted to higher elevations … and completely different trees, primarily white and red fir. Enstice says at this point in time there haven’t been any drastic fires due to mortality in the Central Sierra, the mountains from Auburn east to the Tahoe Basin, though the Creek Fire’s spread and size (still active at over 380,000 acres northeast of Fresno) caught him off-guard. 

Enstice doesn’t have an answer for the beetles’ shift in tree species, but he has colleagues looking into why beetles weren’t as prominent during the drought in the Central Sierra and what caused things to kick into gear here.

(Bark beetles aren’t all bad, by the way. They’re native species, part of the natural ecosystem, and provide tree regulation under normal circumstances.)

Holistic thinking

The northerly trajectory of the bark beetles helped drive the creation of what is essentially a forest health think tank. A consortium of agencies and organizations came together in 2017 to create the Tahoe Central Sierra Initiative. The goal is to achieve forest restoration across 2.4 million acres of Sierra Nevada land, exploring why this region might differ from certain management preferences in other parts of the state. The strategy is to develop a cohesive landscape plan that is unique to the Central Sierra.

“We believe our best chance at moving forward is to restore the health of these forests and to control the one dynamic in the fire, the creation of fire that we can control,” Enstice said. “… The fuel is the one place we can really step in and have a say in this.”

TCSI is heavily grounded in science. Angie Avery, executive officer of the SNC, described the process as taking scientific knowledge and applying it to the collaboration’s landscape, which covers the Tahoe National Forest, Lake Tahoe Basin Management Unit, Eldorado National Forest, and small parts of the Plumas and Humboldt-Toiyabe national forests. She says TCSI stands out because of its scientific and regional approach.

TCSI was intended to think about game changers as it relates to how you plan and implement forest management across a larger region, and then how do you think about funding that and investing in the type and kind of work that needs to happen,” Avery said. “All with the goal of saying okay, we’ve got some time before us before it gets here and has the same impact as it did in Southern California. How do we make a difference on those landscapes? That was definitely a driving factor of pulling together this group of people.”

The TCSI crew (which includes the SNC, The Nature Conservancy, California Tahoe Conservancy, U.S. Forest Service, and others) is currently finishing up the modeling of various management scenarios, including mechanical treatment, hand thinning, and/or prescribed burns. From there, a blueprint will be created for action across the landscape.

For Avery, the urgency of the situation is underscored by this record-breaking wildfire season. “From my perspective, this year drives to the heart of the issue and says we have to be thinking big, we have to be thinking quick; we have to be thinking, we need to be moving, we need to be acting,” she said. … The situations on the ground strike me as urgent and needing an all-hands-on-deck, all-tools-in-the-toolbox response now.”

A NORTHWARD TRAJECTORY: The central portion of the Sierra Nevada mostly escaped the 2014 to 2017 extreme drought, but bark beetles headed north nonetheless, and the region has experienced vast amounts of tree mortality in recent years, making a future local wildfire all the more deadly. Photo courtesy Sierra Nevada Conservancy

Putting wood to good use

One tool is experiencing a revival and it serves a dual purpose. Last summer, the Tahoe Fund launched The Smartest Forest Fund — a program to help fuel innovative forest management ideas. During the program’s build-up, Amy Berry, executive director of the Tahoe Fund, was told by numerous parties that the most helpful thing the forest fund could do was to get the Carson City biomass facility up and running.

When in operation, the facility can convert biomass (think plant material) to a renewable energy source in the form of heat or energy, while simultaneously providing an efficient outlet for wood and fuel pulled from local forests during wildfire management projects.

Efforts at the Carson facility, however, have been stalled with COVID-19’s havoc, Berry told Moonshine. “The next step for us was to have a meeting with the [Nevada] governor’s office,” she said. “… Unfortunately, it’s very hard to get in front of the governor these days.”

Hope isn’t completely lost, though. Cogen is a biomass facility in Loyalton, just under an hour from Truckee, and was operated by American Renewable Power until the group went bankrupt earlier this year. Cogen was quickly purchased by Sierra Valley Enterprises.

Tom Beam, CEO of Sierra Valley Enterprises, said his staff is in a planning and development phase for Cogen, which will remain as a biomass facility. More information, he continued, is to come.

Candid camera

Another tool in the fighting-fire toolbox is already saving the day. On the morning of Aug. 24, a plume of smoke rose from the trees of Prosser Hill — yet another lightning-caused ignition in California during 2020.

The smoke was quickly recognized by an ALERT Tahoe camera in Tahoe Donner, one that had been installed only a few weeks before.

The ALERT Tahoe program has erected14 wildfire-detecting cameras that utilize smoke awareness technology and send alerts to local fire dispatch centers.

“The system is working,” said Heidi Hill Drum, CEO of the Tahoe Prosperity Center. “It’s not the cameras that put out the fire … but the information the cameras give [firefighters] early and quickly is so important so they’re able to get in there and put [the fires] out.”

TECHNOLOGY ON WATCH: On Oct. 30, smoke appeared on Diamond Peak and was picked up by two different ALERT Tahoe cameras. No information on how the fire started is available at this time. Photo courtesy ALERT Wildfire

Since cameras were first being installed five years ago in the Tahoe Basin, 65 fires have been extinguished before they reached 1 acre in size.

The next camera, number 15,will be put up at Northstar California Resort.

“We feel that Lake Tahoe is pretty well covered right now,” Hill Drum said. “… Our original goal was 11 [cameras], but if there’s any area that folks feel is missing protection, we’re happy to look at it. They can reach out to us at tahoeprosperity.org.”

Continued maintenance is the biggest concern moving forward, as lenses and software need to be updated and improved every few years. Parasol Community Foundation has set up an ongoing endowment for such work and plans to match any donations made.

Even with the wildfire season officially (and hopefully) winding down this month, the threat looms large over the entire western U.S. Here in our region, it is of some comfort that innovation and collaboration are being implemented in full force to help combat this ever-present danger.

“We’re tracking a lot of work that’s happening across the Sierra Nevada,” said Brittany Covich, policy and outreach branch manager with the SNC. “… We know that prescribed fire or managed fire can help. We know that doing treatment in the right place at the right scale can help. That kind of work is happening across the Sierra Nevada. It’s not happening at the scale that we want yet, it’s not happening as fast as we would like yet, and we don’t necessarily have the funding that we need to do it at that pace and scale, but signs are good that we’re moving that direction.” 

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