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California’s Iconic Redwoods, Sequoias and Joshua Threatened by Climate Change


California’s iconic coastal sequoias, some standing since before Julius Caesar ruled Rome, are fighting for their lives. They are increasingly threatened by Forest fires which are bigger and more intense due to the impact of man-made climate change.

And it’s not just the redwoods – giant redwoods and Joshua trees are in trouble too. These majestic trees are unique to the West Coast and are an integral part of the fabric of the historic California landscape. But the experts who know and love these trees are genuinely worried about their future.

Last year 4.2 million acres burned in California worst fire season checked in. Scientists say the the climate is warming up these fires will get bigger at an accelerated pace. And although redwoods and giant sequoias have historically been resistant to natural forest fires, these unusually intense fires are beginning to overwhelm their defenses, with fires reaching higher into their peaks.

It is estimated that 10% of the old redwoods that burned during the 2020 fire season in places like Big Basin Redwood State Park, 50 miles south of San Francisco, will die.

A few hundred miles east in the Sierra Nevada mountain range, 350 giant sequoias were killed as flames shot hundreds of feet high, burning far into the canopy. To the south, in the Mojave Desert, an estimated 1.3 million Joshua trees burned down as firenadoes tore up the invading grass.

California’s Iconic Redwoods, Sequoias and Joshua Threatened by Climate Change
Charred Joshua trees are seen during the Bobcat fire in Valyermo, Calif., September 18, 2020.

KYLE GRILLOT / AFP via Getty Images


CBS News visited Big Basin State Park earlier this month and met with two longtime forest scientists, Todd Keeler-Wolf, a vegetation ecologist, and Joanne Kerbavaz, Big Basin’s senior scientist.

“This fire was of such magnitude and intensity that there are no traces of such large fires in this neighborhood,” Kerbavaz said of the August fire that raged in almost the entire park, swallowing up 18,000 acres.

It started as part of a lightning seat 14,000 strikes that sparked 350 fires statewide. Lightning events like this are almost unheard of in California; this was the result of a moisture surge from a decaying tropical system off Baja California.

Although this lightning event could be considered a mere meteorological chance, it coincided with a sultry summer heatwave which has undoubtedly been made worse by climate change. This heat, in addition to a long-term climate-induced drought, has dried up vegetation, turning it into a powder keg just waiting for lightning to start fires.

During his 22 years at Big Basin, Kerbavaz says he has witnessed a change: a once nurturing climate has undergone significant change.

“There is a consensus that things are getting drier and drier, and most of us who lived in this region can feel it,” she said. “And there is a consensus that the fog patterns have changed, and that we know that in the redwood forest, the fog patterns are critical to sustaining the redwood forests in this climate.

She fears that in the decades to come, if the fog continues to shrink, the habitat suitable for redwoods that live farther from the ocean will shrink as well.

California’s Iconic Redwoods, Sequoias and Joshua Threatened by Climate Change
Big Basin Redwoods State Park in California was hit by a wildfire in August 2020 that burned about 97% of the park’s 18,224 acres. National Parks Safety Officer and Ranger Gabe McKenna, center, examines the damage. The park contains 4,400 acres of old-growth redwood forest and 11,300 acres of secondary growth.

Carolyn Cole / Los Angeles Times via Getty Images


Since 2000, the western United States has experienced a megadrought, one of its worst droughts in 1,200 years. On top of that, since 1970, summers in California have warmed by 2-3 degrees Fahrenheit. These types of climatic conditions, hotter and drier, set the stage for a longer fire season with larger and more intense fires.

For redwoods – despite their extensive root system, 12-inch thick bark, and having survived repeated fires over their thousands of years of existence – these recent intense fires are overwhelming their natural defenses.

Keeler-Wolf has a duty to watch the wreckage of the August fires. Pointing to a huge ancient sequoia, he talks about the immensity of the fire.

“It affected the whole tree all the way to the top. This one is a candidate to be declared dead, but we have yet to pronounce it,” he said.

Both scientists agree that these coastal redwoods are very hardy. Even when heavily damaged by fires, they can push new trees from their trunks and even their roots.

Kerbavaz explained, “There are also dormant buds at the base that can re-germinate and form new trees. Even before the flames were out, the plants were starting to come back. The redwoods were growing back along with the areas. adjacent rooms were still burning. ”

Although about 1 in 10 burnt redwoods fail to do so, historically, Kerbavaz says 90% should survive. But the loss of so many ancient trees, some of which have been around for thousands of years, means things will never be the same again.

“I hope for a long lifespan, but realistically, in the next 40 years it might not look like it was in the previous 40 years. Many trees were burnt. So we expect the trees to come back, but in some cases they will look very different, ”Kerbavaz said.

California’s Iconic Redwoods, Sequoias and Joshua Threatened by Climate Change
Burnt trees smolder in the Alder Creek Grove of the Giant Sequoia National Monument in Springville, Calif., October 28, 2020. Castle fire burned through portions of about 20 giant sequoia groves on the western slopes of the Sierra , the only place on the planet they grow naturally.

Al Seib / Los Angeles Times via Getty Images


Redwoods have many of the resilient qualities of redwoods, but unlike redwoods, they cannot grow back easily. This, combined with the fact that they live much further inland, away from the humid marine layer of the Pacific Ocean, makes them even more vulnerable to forest fires.

Park Williams is a Columbia University scientist and an expert on the link between fires and climate change. Through his research, he observed an unprecedented difference in climate and its impact on forests. At a meeting in New York City in mid-January, I asked Park what his research had revealed.

Jeff Berardelli: It seems to happen to Joshua trees, redwoods, and redwoods. And these are all different microclimates. So what’s up?

Park Williams: Well, there’s a lot going on, but the one thing all the forests of the western United States are experiencing is warming. And as we warm the atmosphere, these forests are more likely to burn.

Jeff Berardelli: These fires can burn higher up on these trees, causing those trees to die where they would not have died years ago. Is it correct?

Park Williams: We know that fires were very frequent in these forests during the last millennia. These trees are designed to be able to tolerate fire, but they can only tolerate fire if these fires are not giant catastrophic events. These giant fires with flames several hundred meters high have managed to kill several hundred of these ancient majestic trees.

As giant as these fires are, Williams says this might just be the beginning. As the region continues to warm, forest fires will worsen at an accelerating rate.

“The really important connection between heat and fire is that it’s actually exponential. And that means for every degree of warming you have in California, the amount of additional wildfire you get increases more than it did in the previous degree of warming. “

All of the scientists interviewed for this story agree that if we don’t stop warming the planet, these majestic trees will face a losing battle.

“We fear that some thresholds will be crossed. So that some of the species, some of the things that live here, can no longer be maintained,” Kerbavaz said.

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