latest news Opinion: We were wrong about redwoods and wildfires

As my coworkers and I recently walked through the Nelder Grove of Giant Sequoias south of Yosemite National Park, we could hardly believe our eyes. In 2017 the Railway Fire swept through most of Nelder Grove, burning lightly in most areas but very intensely in the part we walked about six years after the fire. The naturally regenerating giant sequoia forest was so vigorous and lush that in many places we had to part the stems of young sequoias to walk between them. There were hundreds of them on almost every acre – many of them already 8 or 9 feet tall.

It was a remarkable sight because at this particular location the railroad fire burned, killing trees, including about three dozen mature redwoods. This high intensity fire zone is isolated; it is nearly half a mile from the closest remaining living and mature redwood trees to the grove. How was the extraordinary rejuvenation of the giant sequoias possible there?

The U.S. Forest Service, which manages the Nelder Grove and many other redwood groves, has repeatedly told the public, the media, and Congress that giant sequoias are suitable for light to moderate surface fires. The agency insisted that emergency actions in redwood groves are needed to save trees from high-intensity fires and ensure that only low-intensity fires occur. Those emergency actions could take the form of bulldozers, chainsaws and logging, without the benefit of the usual environmental safeguards, if pending legislation – the misleading Save Our Sequoias Act, introduced by House Speaker Kevin McCarthy (R-Bakersfield) – moves to Congress. Meanwhile, the Forest Service is already moving forward with logging plans in the Nelder Grove, based on this “emergency” posture.

But evidence on the ground in the Nelder Grove and other burned areas contradicts the narrative that low-intensity fire is the only good fire. Is it possible we have it all wrong when it comes to giant sequoias and wildfires?

It turns out that some of the US Forest Service’s own scientific studies already explored this question years ago, indicating that mixed-intensity fire, not logging, is the answer for giant sequoias. However, for an agency still focused on selling public trees to private logging companies and keeping the revenue for its budget, this may be an impractical response.

In 1994, for example, the Forest Service released a study concluding that the agency’s successful suppression of wildfires for more than a century was actually killing redwood groves and threatening their survival. Old “monarch” redwoods were slowly dying off, and new redwood seedlings and saplings were almost completely absent, resulting in “massive redwood reproductive failure”. The study found that, in order to maintain stable or growing populations, giant sequoias specifically depend on high-intensity fires in patches, noting that “giant sequoia is what is known as a ‘pioneer species,’ requiring destructive disturbances of the canopy to complete its life cycle. »

These pockets of intense wildfires melt the resins in redwood cones, allowing them to release seeds in the tens of thousands, while creating more sunlight for seedlings and consuming the thick layer of twigs and trees. needles on the forest floor, turning it into nutrient. -a rich ash bed that helps young redwoods grow and thrive. Twelve years ago, another Forest Service study found a clear lack of redwood reproduction in low-intensity fire zones and high reproductive density in high-intensity fire zones. Managing a homogeneous low intensity fire and trying to prevent and exclude a higher intensity fire is like managing the extinction of giant sequoias.

When the Washburn Fire scorched part of the famous Mariposa redwood grove in Yosemite last year, it burned at low intensity where the park had previously conducted prescribed burns. Park officials have claimed success, based on the assumption that reduced fire intensity is emphatically a good thing for the giant sequoias. But science has been telling us a more complex story for decades.

Of course, redwoods cannot tolerate just high intensity fire either. We want a mix of low, moderate and high, and that’s what we got in the Sierra. Despite reports of total decimation by high-intensity fires, my research, based on recent satellite imagery and ground surveys, indicates that the large wildfires of 2020-2021 killed about 8% of redwood trees, not up to at 20%, as some have claimed.

An 8% loss sounds bad on its own, but it may be consistent with what might have happened naturally before excluding the 20th century fires. And like in the Nelder Grove, where some patches of mature giant sequoia are set ablaze by high-intensity fires, there will likely be hundreds of saplings for every one killed.

If we really care about giant sequoia forests, the way forward should not involve mandated emergency powers that circumvent environmental laws and public participation, powers that could trigger potentially destructive logging. The Save Our Sequoias Act is misguided, which is why more than 80 environmental organizations strongly oppose it.

No, to have healthy and vibrant giant sequoia forests in the future, we need humility and respect for a species that has developed an interdependent relationship with mixed-intensity wildfires over 90 million of years. Above all, we will need to begin to appreciate and accept the dynamic forces of wilderness, such as wildfires, which may seem alarming to us, but which also shape and sustain forests of giant sequoias and many other fire-adapted ecosystems. on the planet.

We must learn to see the beauty in the burn.

Chad Hanson is an environmentalist and director of John Muir Project. He is the author of “Smokescreen: Debunking Wildfire Myths to Save Our Forests and Climate.”