Sequoia National Forest officials state the Giant Sequoia National Monument could still have an uncertain future as a result of the Castle Fire which is part of the Sequoia Complex.
The Castle Fire burned an estimated 13,600 acres in 10 giant sequoia groves in the Giant Sequoia National Monument, which has a total of 33 groves. Forest Service groves burned were Alder Creek (shared with a private landowner); Mountain Home (shared with the state); Belknap Complex (McIntyre, Wheel Meadow, Belknap; shared with a private landowner); Dillonwood (shared with the National Park Service); Middle Tule (shared with the state); and Burro Creek, Freeman Creek, Silver Creek, Upper Tule, and Wishon groves.
About 35 percent of the giant sequoia groves, 9,800 acres, out of the Monument's total 27,830 acres were burned. About 62 percent, 6,000 acres, were burned at high-severity.
Forest officials stated where the fire burned at lower-severity or high-severity in small patches, it's expected to work like a prescribed burn to help restore the grows by activating Sequoia seedling growth, reducing fuel loads that may influence future fires and clearing out small trees, leaving more water and sun available for remaining plants and Sequoia seedlings.
“Giant sequoias are a fire-adapted species and need localized high-severity fire to regenerate,” Forest service officials stated.
Fire officials added because of the lack of prescribed burns and trees being killed by drought and species in the forest, forest fuels in many groves have dramatically changed which influences how severely a wildfire moves through them.
“Patches of high-severity fire in the 2020 Castle Fire were likely much larger than they would have been historically and this could mean an uncertain future for portions of the groves,” forest service officials stated.
Forest service officials added the forest service won't be able to assess the impact on the groves until a thorough survey can be conducted.
Preliminary satellite data indicate the highest losses of mature giant Sequoia trees are in the Belknap Complex and the Freeman Creek groves. Of the recently burned groves, the U.S. Forest Service Burned Area Emergency Response Team found Alder Creek, Belknap Complex, Dillonwood, and Freeman Creek groves burned at the highest severity, which implies there were also higher losses of trees in those groves.
Protection measures around the Stagg Tree in the Alder Creek Grove and the Bush Tree in Freeman Creek Grove resulted in minimal damage, forest service officials stated.
In 2017, the Pier fire burned through the Black Mountain Grove on the Sequoia National Forest and the Railroad fire burned through the Nelder Grove on the Sierra National Forest. In both places, there were significant losses of mature giant Sequoia trees.
The Save the Redwoods League and the U.S. Forest Service Ecology Program teamed up to monitor giant Sequoia losses. They found in the Nelder Grove, 39 out of the 104 mature Sequoias died. In the areas burned at higher severity sampled in the Black Mountain Grove, 52 of the 183 mature Sequoias surveyed died.
“These events raised awareness that even the oldest, largest giant Sequoias are vulnerable to high-severity fire,” forest officials stated. “Large areas of high-severity fire within giant Sequoia groves are concerning because most of these ancient trees lived through hundreds of fires, yet modern wildfires are killing them.”
Forest officials state shrubs also tend to flourish in high-severity fire conditions making it difficult for new Giant Sequoia seedlings to grow. “However, with careful monitoring of giant Sequoia seedlings, the Forest Service may be able to intervene by manually reducing competing shrubs and planting giant Sequoias if necessary,” forest service officials stated. “Recent fires highlight the need for restoration in the giant Sequoia groves.”
Forest officials state such measures as prescribed burning can reduce the likelihood of future large forest fires.
“The Giant Sequoia National Monument Management Plan requires protection, preservation, and restoration of giant Squoias through management activities,” forest service officials stated.
Forest service officials added The Forest Service partners with Tule River Tribe, the National Park Service, Save the Redwoods League, and CAL FIRE on the best way to manage the forest.
As of Thursday afternoon the Sequoia Complex had still burned 171,032 acres and was still 80 percent contained. There 206 firefighting personnel working the fire. The estimated date for full containment is still November 20.