September 23, 2021
General Sherman, Other Giant Sequoias, Threatened by Fire, Saved for Now
As the KNP Complex fire grew in Sequoia and King Canyon National Parks, thoughts immediately turned to protecting the groves of giant sequoias in the parks, one of which includes the General Sherman tree, the largest tree on the planet. The General Sherman is roughly 275 feet tall, and about 2,000 years old. It’s been through fires, and is indeed, evolved to be exposed to low-level burning from time to time. But the uniquely dry, overloaded fuels in many Western forests mean wildfires that burn hotter and faster than in decades past; hot and fast enough to consume a giant like the Sherman, or his similarly ancient friends.
Firefights and NPS officials moved quickly to protect the Sherman, wrapping its base in reflective blankets to prevent ground fire from climbing its bark. But the trees had another, deeper level of protection: relatively recent prescribed burns in the nearby forests cleared a lot of the fuels that could have escalated the fire’s growth near the ancient behemoths.
As of today, September 23, the trees are safe.
How do those blankets work you ask? By preventing embers from accessing the internal bark of the tree through scars from fires past. The bark of these giant trees can withstand flame to a degree, and will often be left with burn scars that are vulnerable points. Crews wrap the trees, and, as they move through the forest looking for spot fires to extinguish, douse burn scars with water to keep embers from taking hold.
The KNP Complex fire has chewed through nearly 30,000 acres of forest and is still 0% contained. The General Sherman and the Four Horseman trees that share its grove survived a low intensity fire that burned across their bases in recent days, which should protect them should the fire reverse its course, but if it grows again in intensity, the trees might again be threatened.