The CZU fire transformed California’s oldest state park in a matter of hours. Its effects will linger for hundreds of years. The forest is expected to rebound, eventually, more or less-but when? How long until the forest looks, feels, sounds, and smells like the place I knew?<\/p>\n
\n\t\tWhen Will the Forest Rebound?\n\t<\/h2>\n\t
To find out, I called up Zane Moore, a redwood ecologist who’s pursuing a PhD at UC Davis. Since 2012, his search for the tallest trees in the Santa Cruz Mountains has taken him on foot up every creek and along almost every ridge within the 18,000-acre state park, which is within the ancestral territory of the Cotoni and Quiroste\u00a0people, among others. Since the CZU fires died down enough to make it-if not safe, exactly, then at least not obviously lethally dangerous-to return, Moore has been among the dozens of researchers who’ve driven and hiked through the burn, recording the damage, and bearing early witness to the recovery.<\/p>\n\t
Based on data from tree rings and analyzing fire damage in other old growth stands throughout the redwoods’ range, Moore estimates that the CZU fire was a once-in-a-millennium event. “I don’t think this fire is unprecedented for California’s redwoods-and there’s evidence of fires even worse than this,” he says. “But I think it’s been very rare.” Still, from what he’s seen in the forest since last August, and what he knows about the trees’ abilities to withstand fire, he estimates 98 percent of Big Basin’s redwoods will survive.<\/p>\n\t\t\t\t![\"Fire](\"https:\/\/sempervirens.org\/wp-content\/uploads\/2021\/08\/Redwood-Fire-Scars-by-R-Thomas.jpg\" "\\"Redwood")
\n\t\tA redwood scarred before the CZU fire. by R. Thomas\n\t
Thinking of those charred trunks I’d seen in the news, the first thing I wanted to know was: how long until Big Basin’s redwoods are, well, red<\/i> again? “As the tree grows, those black parts will get sloughed off,” Moore said. In 20 years, he reckons the trunks will be about half red again. In 40 years, just a few scarred furrows will remain. “Anytime you’re in an old growth stand, you’ll see scars from past fires. They never necessarily get rid of all of it,” Moore says.<\/p>\n
Moore is sanguine about the forest’s future-but for California’s human residents there’s not much cause for optimism in the wake of the CZU fires, which claimed one life,<\/a> caused one injury<\/a>, and forced 77,000 people to evacuate<\/a>.<\/p>\n\t Before firefighters contained the blaze on September 22, it burned 86,000 acres and destroyed 1,500 buildings. The fire also burned 73 percent of the old growth redwoods remaining in the Santa Cruz Mountains, including much of Big Basin’s 4,400 acres of old growth. Fanned by strong winds on the third day of the blaze, fueled by hot air and drought-dried timber, the flames leapt to the tops of some of the park’s tallest redwoods. Almost every building, dozens of bridges, and hundreds of miles of roads and trails with Big Basin were destroyed or severely damaged. On August 20, Sempervirens Fund issued a statement that read, in part, “We are devastated to report that Big Basin, as we have known it, loved it, and cherished it for generations, is gone.”<\/p>\n\t That’s true enough. It’ll be the work of years, and the spending of many millions of dollars, to rebuild the infrastructure that makes this place accessible to its adoring public. And several of the park’s biggest and most beloved trees were killed by the fire and have fallen, or likely will soon. In a talk for the Santa Cruz Museum of Natural History<\/a> in May, Moore ran through a partial roll call of possible casualties, including the Washington, Santa Clara, and Father of the Forest trees. Subsequent visits bring mixed news: “The Washington and Santa Clara Trees-could go either way … the Father of the Forest, I think has a chance.” The top 100 feet of the region’s largest tree has since snapped off, “so it’s no longer the largest.” The fire also toppled the widest tree in the Santa Cruz Mountains, “and it took out a few trees next to it, which is a bummer,” Moore said. Meanwhile much of Big Basin is still a fantastically hazardous place to be-partly because fire-damaged trees could come crashing down at any time, and partly because some areas are still on fire<\/a>. Much of the park is closed to the public indefinitely<\/a>. (The coastal portion at Rancho del Oso<\/a> reopened in late May.)<\/p>\n\t Today just five percent of California’s old growth redwood forests remain. I think that’s partly why so many trees in Big Basin are named, known, and loved in the first place: Thousand-year-old trees are rare enough that each one felled by fire can seem like an unbearable loss. So it was heartening to spend an hour on the phone with Joanne Kerbavaz, an environmental scientist with California State Parks. “What I’ve been telling people is that we expect 90 percent of the redwoods to survive,” she said right off the bat. The figure comes in part from a 2014 paper <\/a> in the journal Fire Ecology <\/i>that studied tree mortality in the Santa Cruz Mountains following fires in 2008. She’s also taking clues from the fire scars that marked most of the park’s oldest trees, even before last August. “When you look at how much damage the old growth trees already had, and they’re still standing after a thousand or two thousand years,” she says. “Last year’s fires were, for most of them, another round of what they experienced before, rather than being something that’s more than they can withstand.”<\/p>\n\t\t\t\t And when it comes to fire, redwoods can withstand a lot. Their thick, spongy bark insulates the wood, and even their eponymous hue is an adaptation to fire, the result of tannins in their bark. When the bark burns, Moore says, the tannins char quickly, but resist combustion-basically forming a shield that prevents the fire from burning into the tree’s more fragile interior.<\/p>\n And unlike most other West Coast conifers, a redwood can survive even if most of its canopy burns off. Following a fire, a surviving redwood will shoot out a fuzz of electric green sprouts along much of its blackened trunk, aiming to “quickly rebuild its crown and regain photosynthetic surface area that was lost,” Moore said.<\/p>\n\t In the days and weeks following the CZU fires, Sempervirens Fund asked people to share their memories of Big Basin State Park<\/a> on social media. “That ask was geared to what we thought was our community: our neighbors, people who’d had to evacuate their homes, people who live, work, and play in the Santa Cruz Mountains,” says Matt Shaffer, communications director at Sempervirens Fund. But within days, the post had millions of views, and memories streamed in from people all over the world. Shaffer says the global outpouring that followed news of the park’s fate is just one signal of Big Basin’s enduring importance.<\/p>\n\t And it gives you an inkling of the flavor and number of questions that Kerbavaz and her colleagues have been fielding for months. “Now everyone wants to know: how long will it take until Big Basin looks like it used to look?” she says. “Those are questions we just don’t have a good guideline on.”<\/p>\n For one thing, last August’s fire-while it wasn’t a knockout punch-was the biggest and hottest to burn through old growth redwoods since scientists have been keeping track. Across their present range and throughout much of their recent adaptation, redwood forests are estimated<\/a> to have burned on average every 6 to 25 years. But in the era of fire suppression the so-called fire return interval in redwood forests has grown<\/a>. So Kerbavaz and her fellow scientists don’t have much in the way of analogs to feed into their recovery models. Instead, they’re extrapolating from findings in timber industry research, from intense fires in other ecosystems, and from studies of smaller burns like the 2003 Canoe Creek fire <\/a> in Humboldt Redwoods State Park, and fires in second-growth stands, like the lightning-caused fires in Big Sur<\/a> and the Santa Cruz Mountains<\/a> in 2008. Meanwhile, nobody can be sure how the ongoing drought and our ever-warmer climate are affecting how the forest is already recovering, let alone its long-term prospects. “A lot of these are changes that may impact the timelines for recovery,” Kerbavaz says.<\/p>\n\t![\"Green](\"https:\/\/sempervirens.org\/wp-content\/uploads\/2021\/08\/CZU-Fire-Redwoods-Green-Sprouts-Orange-Leaves-11-29-20-by-D-Mulvaney.jpg\" "\\"CZU")
\n\t\tGreen sprouts from redwoods after the CZU fire. by D. Mulvaney\n\t