On a dark August night pulsing with heat, the skies over Northern California erupted in a rare lightning storm jumpstarting a wildfire season that was still technically weeks away. The next morning, the chaos began. It wouldn’t stop for another three months.
Between those first CZU, SCU and LNU Complex Fires in August and October’s Silverado and Blue Ridge Fires, more than four million acres burned in California this year. It's the biggest fire season in modern history, and it more than thirty lives and thousands of buildings.
But while the fires’ effects on populated areas were profound, by sheer square mileage, it’s California’s parklands, forests and open spaces that have borne the brunt of the damage. Within days of the storm that launched the fire season, flames had enveloped Big Basin State Park, a land of ancient redwood groves in the Santa Cruz Mountains.
Nearby, both Butano State Park and Little Basin suffered severe damage. Nearly all of the San Vicente Redwoods, a more than 8,000 acre old-growth forest co-managed by the Peninsula Open Space Trust (POST), burned. With trails blocked by debris and the high risk of falling branches from affected trees, it was mid-October before it was safe enough for even officials to visit the property.
It will take months, in some cases years, for park officials to clear out the most dangerous tree-falls, address high-risk landslide and mudflow areas, and repair enough of the trails and facilities for hiking and backpacking to safely resume in parts of the Santa Cruz Mountains and other recreation areas hit hard by this year’s fires. And when they do, things will be different. Repeated fire events could even turn once forested sections of the state’s iconic Pacific Crest and the John Muir into hot, sunny shrub fields.
“All these hikes we take for granted, that forest is going to be big-time changed,” says Scott Stephens, professor of fire science at University of California Berkeley.
Fires, even large ones, aren’t new to California. According to Kristen Shive, director of science at Save the Redwoods League, prior to the violent removal of indigenous communities in the 19th century and Forest Service policies which put an end to controlled burns and fire rotations in the early 20th century, low-grade, restorative wildfires—some of which sparked from lightning and heat events, others of which were intentionally set to refresh the forest—burned around 4.5 million acres annually in the state.
The fire, itself, is not the problem. In fact, explains Noelle Chambers Thurlow, vice president of conservation at POST, “in some cases we may see actual benefits from the fire such as the activation of fire-dependent seedbanks, the creation of new animal habitat, reduced competition among trees for water and nutrients and other regenerative effects.”
The problem is the intensity of today’s wildfires compared with those in the past. Over the last several decades, a build-up of flammable materials has caused wildfires to burn hot enough to reach the fragile upper forest canopies instead of just scorching their more fire-resistant trunks. In any wildfire, individual trees die, but the more severe the fire, the more damaging it is to the forest as a whole, including keystone species like the California redwood and giant sequoia. And because forests can take decades, if not centuries, to recover from intense fires, they have a greater effect on the entire ecosystem.
Simultaneously, climate change is turning California from a Mediterranean climate marked by wet winters and dry summers to something more desert-like. Droughts, like the one that lasted from 2011-2019, are now longer and more frequent than in the past, and warmer winter temperatures have decreased snowfall in the mountains, choking out a key source of water for the state. With less moisture all around, the length of the fire season has increased exponentially, with wildfires sparking earlier and burning later into the year.
There’s not yet a means of measuring which regions are likely to suffer more extreme damage prior to a wildfire, but looking at changes in near-infrared and shortwave-infrared data over time with a technique known as a normalized burn ratio can indicate the severity of a wildfire after the fact. A study conducted by NASA’s Ames Research Center on the complex fires sparked by lightning in August showed that CZU fire in the Santa Cruz Mountains burned at such a high intensity that in significant swaths of the forest, all that remained was soot, ash and charred stumps.
Like the forests, those of us who are drawn to backpacking and hiking California’s famed coastal redwoods and granite peaks will experience effects from ever longer, more intense fire seasons. In August in the Bay Area, “the air quality alone was responsible for significant recreational limitations for a nearly three week stretch where it was unhealthy to go outdoors,” says Chambers Thurlow. At 7,000 feet of elevation in the Sierra Nevada, that kind of wildfire smoke would make backpacking virtually impossible.
And then there are the standing snags, the charred remains of trees damaged in wildfires that remain upright for five to 15 years before crashing to the ground. “They’re very dangerous,” says Stephens. “You do not want to have to camp when you’re in a snag field.” A ranger told me the same thing last summer at Lassen Volcanic National Park in the southern reaches of the Cascade Range, when my planned route took me through a swath of snags that had burned about ten years before.
It’s true that wildfires will change when and where we backpack in California. Fire closures will leave us clamoring for smaller slices of forest in summer and fall. But the state’s rugged, rich beauty will survive. The wildfires will change how we backpack in California, but it won’t change why.