An executive summary released by the National Park Service details the impacts of wildfires in 2020 and 2021 on one of California’s most iconic trees.
Forestry professionals are surveying the damage done to the Sierra Nevada’s sequoia trees this year by the Kings National Park Complex and Windy fires. The preliminary findings, disclosed in an NPS executive summary this week, show that the KNP Complex and Windy wildfires killed or terminally damaged 2,261-3,637 sequoias measuring 4 feet or larger in diameter. To be considered a terminal loss, a tree must succumb to fire damage within 3 to 5 years.
A study conducted in 2020 showed that the Castle Fire decimated up to 14% of the Sierra Nevadas’ giant sequoia population. So, officials were particularly concerned about what wildfires in 2021 would mean for the trees that remained.
Together, the KNP Complex and Windy wildfires resulted in 3-5% total giant sequoia loss. Twenty-seven of the 70 sequoia groves within the western Sierra range were determined to be fully or partially within the fire perimeters.
When combined with the 10-14% hit to the same tree population in 2020, the region’s total loss lands somewhere between 13% and 19%, according to the NPS report: “[T]hese fire impacts represent a significant threat to large sequoia persistence.”
Potential for New Growth
But there’s cause for optimism, too, the report states. First, analysis has shown that prescribed firework, including prescribed burns, mechanical thinning, and improvements to response team logistics, is proving effective in decreasing burn severity.
And, although some giant sequoia groves experienced moderate to high burn severity in 2021, most within the KNP Complex burned at a low severity. Low-severity burns are expected to translate to long-term benefits for the affected groves, the NPS says: “These beneficial effects include fuel reduction, small canopy openings ideal for regeneration, and removal of litter and generation of ash — also ideal conditions for giant sequoia seedlings.”
Read the full executive summary at NPS.gov.