New York Times today: “At Yosemite, a Preservation Plan That Calls for Chain Saws: With treasured forests perennially threatened by fierce wildfires, many experts say it’s time to cut and burn protectively. A lawsuit is standing in the way.” It’s subscription only, unfortunately. Excerpts:
A judge this month temporarily halted the park’s biomass removal efforts, as the tree cutting was euphemistically known, in response to a lawsuit filed by an environmental group based in Berkeley, Calif., that argues that the park did not properly review the impacts. The thinning project covers less than 1 percent of Yosemite’s forests.
Whether or not the lawsuit proves successful, it is resonating well outside of the park’s boundaries by raising larger questions about how to manage forests in the age of climate change.
Increasingly, leading forestry experts are propounding a view dissonant to a public accustomed to the idea of preserving the country’s wild lands: Sometimes you have to cut trees to save trees. And burn forests to save forests, they say.
The polarization during the Trump administration between climate scientists and a president who downplayed rising temperatures and stressed the need for greater forest management, or “raking” as former President Donald J. Trump once called it, has passed for now. It has given way to what many experts say is a consensus among scientists and political leaders on the need to thin and burn forests more proactively.
“Most of us are absolutely convinced that this is not only a good thing to do, but is absolutely necessary,” said John Battles, a professor of forest ecology at the University of California, Berkeley, and a science adviser to the California Wildfire & Forest Resilience Task Force.
About a century ago, the National Park Service, which manages Yosemite, effectively made a promise to the American people that it would keep valued places looking “more or less like they always did,” said Nate Stephenson, a scientist emeritus in forest ecology for the United States Geological Survey. The act of Congress that established the National Park Service in 1916 called on parks to remain “unimpaired for the enjoyment of future generations.”
But, Dr. Stephenson added, “in this era of rapid and intense environmental changes, that promise is falling apart.”
Central to the thinking of scientists looking for ways to protect forests is research showing that the “natural state” of America’s wild lands was for millenniums influenced by humankind.
Decades of research have shown that the wilderness appreciated by early European settlers, as well as 19th century naturalists like John Muir, was often a highly managed landscape. Core samples from beneath a pond in Yosemite, retrieved in the way that scientists might bore deep into a glacier, showed centuries of layers of pollen and ash. The findings suggested a long history of frequent fires in Yosemite and buttressed the oral histories of Native American tribes who have long seen fire as a tool.
“Not all trees are good and not all fire is bad,” said Britta Dyer, a forest regeneration specialist at American Forests, a nonprofit organization that promotes the use of forests to slow climate change.
In the iconic Yosemite Valley, with its glacier-carved granite walls, vertiginous waterfalls and flowering meadows, Garrett Dickman, a forest ecologist at the park, is leading an effort to restore the area to what it looked like more than a century ago, when it was sculpted by native burning practices.
Mr. Dickman uses some of the earliest photographs and paintings of the valley to guide him in deciding whether trees need to be felled.
Photos by Carleton Watkins in the 1860s were viewed by Abraham Lincoln and helped convince the president of the need to declare Yosemite a protected public trust, a prelude to it becoming a national park. Mr. Dickman uses the same photos today.
“I will quite literally take the photo and look at where I think the view is and mark the trees that I think need to be removed to restore the vista,” Mr. Dickman said.
Live trees that are thicker than 20 inches are never felled, Mr. Dickman said. He has calculated that if he cannot wrap his arms around a tree it usually is too large to qualify for cutting.
Dr. [Chad] Hanson, who is well known among conservationists and loggers for the frequency of his lawsuits, takes a more conservative view.
One of his main arguments is that a heavily thinned forest is more vulnerable to fire, not less, because the cooling shade of the canopy is reduced, as is the windbreak. Other experts say that while cutting down trees can in theory create drier, windier conditions, forests in the West are already very dry for much of the fire season. They also say that even if wind speeds do increase, it is rarely enough to overcome the benefits of having reduced the amount of vegetation that can burn.
Dr. Hanson agrees that within 100 feet of homes, selectively thinning seedlings and saplings, and even removing lower limbs on mature trees, is essential to create “defensible space.” But he argues that instead of lopping down large trees, forest managers should allow more wild land fires to progress naturally.
“Natural processes are meant to be the primary approach,” Dr. Hanson said. “Not chain saws and bulldozers and clear cuts.”
A number of environmental groups, however, counter that they support careful forest thinning, including Save the Redwoods League, a group that advocates for preserving redwood and giant sequoia forests, and the Nature Conservancy, an environmental nonprofit.
Daniel Swain, a climate scientist at the University of California, Los Angeles, and the Nature Conservancy, said it was “exhausting” having to confront Dr. Hanson’s flurry of arguments and litigation. He added, “It is a waste of time.” Other experts have published critiques of Dr. Hanson’s methodology.