Work is set to begin Friday in Sequoia and Kings Canyon national parks to reduce forest fuels around 11 giant sequoia groves/NPS file shot of the Board Camp Grove that burned in the 2020 Castle Fire

Building on past practices to protect sequoia groves in Sequoia and Kings Canyon national parks from damaging wildfires, crews at the adjoining parks are beginning to reduce forest fuels around 11 giant sequoia groves across the two parks.

The work scheduled to begin Friday comes in the wake of last year's KNP Fire Complex that burned more than 88,000 acres in the two parks from September through October of 2021.

It also comes two years after the Castle Fire roared through 22 giant sequoia groves and burned 9.7 percent of the entire range of giant sequoias at high severity, according to the National Park Service. In particular, three giant sequoia groves within Sequoia National Park [Board Camp, Upper Dillonwood, and Homer’s Nose] sustained contiguous acres of high severity fire that removed 75-100 percent of the overstory tree cover and killed a significant amount of monarch sequoia trees.

The grove most heavily impacted was Board Camp Grove, a 48-acre-tract of giant sequoia and mixed conifer forest in steep remote wilderness within Sequoia National Park. Due to the loss of mature overstory sequoia trees in this grove and the short dispersal distance of sequoia seeds (600 feet), the Park Service believes Board Camp Grove has a very low likelihood of recovering giant sequoia tree cover without management intervention.

As the KNP complex was burning into Sequoia, Park Service crews successfully worked to protect the park's front-country sequoia groves, installing sprinkler systems, removing forest fuels, and even wrapping some sequoia trunks in a fire retardent fabric. As for the damage done by the Castle Fire, the Park Service is studying whether to plant sequoia seedlings in Board Camp Grove.

The urgency to protect the 11 groves stems from the loss of perhaps 19 percent of the world's large giant sequoias between 2020 and 2021 to three large wildfires (the Castle, Windy, and KNP Complex Fires), including several thousand trees in Sequoia and Kings Canyon.

While giant sequoias require frequent low- to moderate-intensity fire for healthy growth and regeneration, these fires burned so intensely that they overwhelmed even the iconic species' natural defenses. Some areas [eg. Board Camp Grove] were so affected that no mature living trees remained to reseed the ground. Most of these catastrophically burned areas had not experienced fire in recent years, and because of that, carried heavy fuel loads that caused fires to burn more intensely.  

Beginning Friday, park staff will remove and reduce dense vegetation and other potential fire fuel sources in and around the 11 giant sequoia groves that have been identified as especially at risk. The work will include manual thinning by hand, and later burning piles of cut vegetation and dead wood, and later using prescribed fire in areas that were initially thinned by hand. 

What's different from past fuel-reduction work at the two parks this time is that even remote backcountry groves are being addressed, Sequoia spokesperson Rebecca Paterson said Thursday.

"This work focuses specifically on giant sequoias wherever they are found in the parks," Paterson said during a phone call. "You're absolutely right, that a lot of our fuels reduction work focuses around giant sequoias, but it has typically been mostly around those more front-country groves, like your Giant Forest or Grant Grove. And those places where there's also a human safety and infrastructure protection component, because, of course, in a great big wildfire, human safety is going to be our top priority, always. So that's typically been where we focus most of our fuel reduction efforts.

"But in this particular situation, it's a little bit different, because the massive wildfires of the last couple of years made us acutely aware of how vulnerable those more remote groves that have no fire history, no, recorded fire history, are. So this work is focused on trying to start to reduce the fuel loads in those places as well."

With the 11 groves of giant sequoia spread across the two sprawling High Sierra parks, the work won't quickly or easily be done. In some cases crews will be flown into remote groves to begin reducing fuel loads with chainsaws and other hand tools, the spokesperson said.

"This is the beginning of a project. The work that we're starting [Friday], for example, is starting in Redwood Meadow, which is in a remote part of Sequoia," said Paterson. "And there's going to be some supplies that are hiked in and some personnel and supplies that are flown in because we're looking at probably a 10-plus-mile hike out to that location. That's just the first phase of the work that is starting tomorrow. In practicality, you know, we are treating this as an emergency and we're acting on it as quickly as we can. ... We anticipate that this work is going to be ongoing for quite a long time."

In a press release, Park Service Director Chuck Sams said that, "[I]n the midst of a new era of extreme fire behavior fueled by climate change, this work is an important step towards ensuring the long term viability of the ancient giant sequoias and protecting them from future losses. We have the tools to protect this iconic species and will deploy them as needed.”  

Most of the work this fall will include manual thinning of excess vegetation. The trimmings from thinning will be burned on site in piles, or as part of a prescribed burn, or a combination of the two, the park release said. As the project continues, park staff will provide more details for individual components of the project, including when smoke impacts are anticipated. Additional work may include possible replanting of six sequoia groves that burned at high severity in 2020 or 2021 and have been determined to be at risk for total failure of natural regeneration. The earliest that work might begin is fall of 2023.  

The two national parks have a prescribed burning program that dates back more than 50 years. Most of this work has been focused on medium- to high-use areas, including 10 sequoia groves, to protect the spectacular natural ecosystems as well as human safety and infrastructure. These decades of work have proven to be effective in areas such as the Giant Forest in Sequoia National Park and Grant Grove in Kings Canyon National Park. The new phase of fuels reduction work is expected to help protect many of the more remote giant sequoias by reducing the amount of hazardous fuel in thus-far untreated groves.