The changes caused by fires in California’s forests will take centuries

The single-engine Cessna buzzed 1,000 feet above a burnt scar in northern California, while UC Berkeley scientist Scott Stephens moved enthusiastically in his chair and looked out the window to get a better view.

Downstairs, heavy cars raised clouds of dust, while commercial lumberjacks tried to save any wood they could, while a vast canopy of green, gold, and brown rolled under the plane. Occasionally, this bright autumn blanket would be affected by burn spots.

“It’s fantastic, just fantastic,” Stephens said. “It’s a real mosaic!”

But as the flight continued, the colors of autumn gave way to a deserted sea of ​​gray and black. The trees now looked like charred toothpicks coming out of a pile of ash.

This was the way, Stephens explained, that the fire in the northern complex took place on September 8 in Berry Creek, a rural hamlet in Butte County, about nine miles north of the Oroville Dam.

As California takes stock of the worst fire season, experts say the growing and devastating fires have already altered the state’s iconic forests over the coming centuries. Exacerbated by the warm climate and decades of aggressive fire suppression efforts – which have left large areas of wilderness covered – these fires will continue to alter the landscape and, in some cases, make it more susceptible to fires than ever before, they say. They. In other cases, the flames were likely to restore the patches of wild land to their original state.

California’s diverse ecosystem – its lush mountain ranges in the north; its flat and fertile valleys in its midst; and the snow-capped backbone of the Sierra casting a shadow of rain over the Mojave Greenhouse desert — they have evolved over the eons. However, this evolution has not stopped and today it is greatly influenced by drought, fire and rising temperatures, experts say.

During the summer, hundreds of fire-adapted Sequoias were destroyed in the Sierra along with conifers, and rangers speculating that many trees might never return. In Bigwood Redwoods State Park, west of San Jose, environmentalists are wondering about the long-term prospects of forest behemoths as the cold, foggy environment they develop heats up and dries up.

In Los Padres National Forest, years of repeated fires have already changed the vegetation that covers the hills, increasing the risk of fire for the inhabitants around them.

And now, after the northern complex fire, the area around Berry Creek can be added to that list, said Ryan Bauer, who drives hazardous fuels and has prescribed the fire program for Plumas National Forest.

“This was to the point where, as you drove through that forest, there were not even large logs left on the ground, it cleaned up quite a bit of surface fuel and left a large bed of ash with sticks sticking out. from it, ”Bauer said. “It will repair itself, nature is strikingly resilient, but it will certainly not return to a forest.”

The fire in the northern complex began on August 17 as separate fires that spread to each other until the morning of September 8, when they merged and jumped a picturesque river and out of the national forest and rural county Butte. By the time the fire was completely engulfed on December 3, it had burned 318,935 acres, killed 16 people and destroyed or destroyed 2,455 buildings, many of them homes.

The roar of such fires was compared to a jet engine or an approaching freight train. Bauer said these comparisons don’t quite fit.

“I’m thinking more of an avalanche of fire,” he said. “It doesn’t just roll down the hill, it gets worse and worse and gets stronger as it goes, triggering more fire and then this cloud of fire igniting extra fire.”

In the early and late parts of the fire, it burned moderately and slowly mostly to the north and east, creating that “mosaic” of patches of three to five acres of coal that Stephens was so excited about.

The California owl appreciates the variety of a quasi-burned forest, where it can prey on small animals that are attracted to the new vegetation for food, Stephens said. Fully developed trees, such as mosaic, also burn, as they reduce competition for resources and burn the dead and dying garbage that the flames climb to reach the tops of the trees.

But this type of burn accounted for only about 25 percent of the entire fire footprint, officials said.

Most of the fire in the northern complex – like the other large flames that blackened more than 4 million acres in California this year – burned too much surface area too intensely to be seen as a general benefit to California’s greater forest ecology. , he said.

“The problem is that there are no small patches of forest, but large, continuous spots that have burned under high severity, completely out of scale with what is desired,” said Stephens.

The first vegetation to return to extremely burned areas will be grass and invasive shrub species, such as the French broom and the Scottish broom, which, despite their bright yellow flowers, pose a threat to nearby residents due to how hot burn and how close they develop together, turning them into a potential connection to a fire that turns into an urban conflagration.

“You don’t want to leave it around,” said David Derby, a forester in the Butte unit of the California Department of Forestry and Fire Protection. “That’s what we have around Paradise. It’s a little green and cute, but it’s thick and flammable and it’s scary if it catches fire. “

Over time, some oaks will grow from their root systems, Derby said, but huge areas of conifers will not do so because they rely on their leaves and cones to spread, and the fire was too intense for any of them. they can survive. The area was so thick with conifers, just because of a century of fire suppression, anyway, so burning an entire stand of them and entrusting the oaks could bring the area back to its prehuman settlement, Derby said.

“It could be hundreds of years in some places,” Derby said. “You will have a big opening and things will start to sow from the edges and eventually it will be completed.”

In the short term, there are lessons from both the Nordic complex fire and Paradise 2018, which could be applied to the lands around Berry Creek and Feather Falls, among other areas, to ensure that if and when it will return the fire, it is less severe, experts say.

Along the edge of the impressive September 8 firefight, what the fire did not destroy was evidence that fuel treatment – including removing dead fuel from the ground and cutting down the lower third of tall trees – slowed the fire and saved homes, officials said.

In Quincy, the seat of Plumas County, years of work by federal foresters and the local fire safety council made it possible to fight the fire there, Bauer said.

“If these treatments had not been completed, we would have lost more homes,” Bauer said. “None of them worked 100%, but with the combination of several of them, we managed to stop the fire spread there.”

Residents of Berry Creek were in a hurry to carry out similar projects since the campfire, but could not find support. Windfires are virtually impossible to stop because of their speed and unpredictability, firefighters say, but they can pose a lesser threat to a community if a healthy, well-managed forest slows their approach.

This was a lesson hard to learn in Paradise, which had been visited by fire only 10 years earlier.

The campfire exploded in part because logs and dead trees from the 2008 Humboldt fire were allowed to dry and rot where they died and fell, providing a fuel jackpot to sustain a fire as it burn through bushes and fast-burning grass that are the first to return, officials said.

Foresters should ensure that as many trees around these rural communities as possible are recovered, Bauer and Derby said, with responsibility for the various federal, state and local agencies, depending on the location.

“Even with the major increase in wildfires that climate change patterns predict for us, there is a way we can see forests persist in California in the future,” Bauer said. “He tells me that we know how to solve the problem and that we have the tools. It’s just that the scale is so amazingly large … we’ll only see if we can be effective at the scale we want to be effective if we want to stay in the forests of California. “