Big Basin Redwoods State Park, about 40 miles south of San Francisco, has been closed since the middle of last week because of the fire, the C.Z.U. Lightning Complex. While most if not all of the park’s structures have been destroyed, little is known yet about damage to the coast redwoods, the species that grows at Big Basin and other parts of California within about 30 miles of the ocean, where they take advantage of the foggy, Mediterranean climate.
But Matt Ritter, a botanist at California Polytechnic State University in San Luis Obispo and director of the school’s plant conservatory, says there is probably little to be worried about.
“They’re ridiculously good at coping with fire,” Dr. Ritter said. Some of the redwoods are a thousand years old or older, he said, “and nothing lives for a thousand years in California without surviving many, many fires.”
Wildfire can sweep through a forest and not kill any of the tissue in a redwood’s trunk, where most of the growth occurs. In a mature redwood this tissue, called the cambium, is protected by up to two feet of bark. The bark is “insanely thick,” Dr. Ritter said, and contains compounds that are naturally fire-resistant.
“California has been burning for about three to five million years,” he said. “Trees have evolved in a fire situation to be protected against it.”
The trees, which can reach 200 feet or higher, also have few limbs within the first 80 to 100 feet. So other trees that catch fire — oaks, madrones or other species, or younger, smaller redwoods — may burn but the flames are unlikely to reach the redwoods’ canopy.
Fire in a redwood grove actually has benefits for reproduction, as the trees that do burn add nutrients to the soil. “Only after a fire do you get really good germination of seeds,” Dr. Ritter said. Over the years at Big Basin and other areas with redwoods, he said, controlled burns have been done for this reason — to encourage growth of new trees.