Replanting Giant Sequoias After the Castle and KNP Complex Fires

Cones collected from the few surviving trees in Board Camp Grove. NPS / A. Bishop.

Unprecedented losses

Giant sequoias are among the most fire-adapted trees on Earth. But in 2020 and 2021, two major wildfires burned through twenty-eight sequoia groves in Sequoia and Kings Canyon National Parks. Where they burned at low and moderate severity, they likely did the forest good. Where they burned hot, they killed the giants.

Counting satellite imagery and field surveys — including adjoining lands and a third fire, the 2021 Windy Fire on national forest land — the fires killed an estimated up to 14,000 large sequoias: about 19% of all the large sequoias on Earth.

Board Camp Grove after the fire: no living overstory trees and large areas of bare soil. NPS / C. Brigham.

No seedlings

Emergency post-fire planning (BAER) found areas where sequoias would struggle to regenerate: the parent trees were dead, and erosion threatened to wash away any surviving seeds. Surveys funded by the NPS Inventory Program found large areas of two groves with little to no sequoia regeneration; four more groves are to be surveyed.

Getting ready to replant

Burned Area Rehabilitation funding after the 2020 Castle Fire and the 2021 KNP Complex Fire let park managers start planning reforestation. In fiscal year 2022, park staff and partners:

• collected cones from two of the six groves that burned at high severity;
• paid for cultural resource surveys to inform planting plans;
• began planning and analysis for all six damaged groves.

Timing matters. Sequoias regenerate naturally only in a short window after fire, using the fresh soil and small canopy gaps. So seed and seedlings must be ready to plant the moment environmental analysis is complete. The work draws together park divisions, NPS programs, the U.S. Geological Survey and the Forest Service.

Why it matters

The damage stems from more than a century of fire suppression, which let fuels build up, and hotter droughts in the southern Sierra Nevada driven by climate change. As the projects continue into 2023, park staff hope the groves will recover and keep awing visitors for generations.

Sources

Based on "Burned Area Rehabilitation projects help save sequoias," National Park Service Fire and Aviation Management; a work of the United States government in the public domain. The source dates the Board Camp Grove photograph April 2020, before the 2020 fire that burned the grove; no date is given here.