Too extreme? Why UC researchers propose idea of cutting down 80% of Sierra trees
The Sierra Nevada is beloved for its endless miles of dense pine forests.
Now imagine that for every swath of 10 trees, only the two biggest trees are left standing. The rest are cut down, the result of some extreme logging.
That is the point of a new study by a group of University of California researchers. Rather than manage the state’s forests to limit wildfires, they say the real issue is to make trees more capable of withstanding the host of challenges they face: drought, pests, climate change, and yes, wildfire.
To accomplish that, the researchers contend a whole lot of chopping needs to be done.
Cutting down 80 percent of the forest seems like a radical idea. But the scientists turn the proposition around and say that, in reality, the way things are now is what is out of whack.
“The lower-to-mid-elevation Sierra used to burn every 10 to 20 years,” said Malcolm North, one of the six scientists who co-authored the study, which appears in the research publication, Forest Ecology and Management.
More than 100 years ago, the Sierra had 30 trees per acre, he explained. That is based on data from a 1911 timber survey of what are today the Sequoia and Stanislaus national forests. That same acre today has more than 300 trees.
The result? Instead of thick, hardy trees occupying their own spot, spread out from each other over the landscape, there are hordes of shrubs and thinner, weaker trees crowded together and competing for ever less water.
Why has this resulted? Mostly because over the last century the U.S. Forest Service’s mission has been to put out fires as quickly as possible. That belief has its roots in the early 1900s economic drive to harvest timber. Research reveals that fire is an essential part of the Sierra ecology and should be allowed to clear the forest floor of plants that compete for water, nutrients and sunlight.
Native Californians understood the benefits of low-intensity fires toward nurturing the forest. Their methods are getting renewed attention by forest managers as a key way to combat destructive blazes.
Sierra growth
The Sierra is an excellent place to grow trees, said North, who is a Forest Service research ecologist. But along with that comes undergrowth that must be burned away periodically. “We have a really productive forest, but one that is very dependent on fire,” he noted.
The 2012-16 drought left 150 million dead trees in the Sierra, with the majority in the central and southern portions of the mountain range. That was the impetus for North, who is also a professor at UC Davis, and his colleagues to hone in on what it would take to improve forest resilience.
The density of today’s forests “is a condition that the forest did not evolve with,” North explained. “There was no real exposure or experience for those forests to deal with the constant stress from competition.”
North realizes the idea of reducing tree totals by 80 percent comes with challenges. For one thing, the logging required does not exist today, nor does the ability to process all that timber.
For another, some environmentalists will surely oppose such thinning because of the possible disruption to wildlife.
But North said the researchers do not propose wall-to-wall tree removal. Areas in the forest around natural water supplies, like a spring, would be left untouched so wildlife could take refuge there. “But this is what the science is pointing us toward. We need to seriously be treating forests to reduce fuel loads.” He adds that most environmental groups in California are now in agreement, having seen the damage done by wildfires in recent years.
Forest now gone
From 1995 to 2001, North was stationed in Fresno, and remembers trips to Shaver Lake and the mountains beyond.
The danger of doing nothing, he says, is what happened two years ago when the massive Creek Fire burned around Shaver Lake and north to Huntington Lake. Nearly 380,000 acres were scorched in what was then the largest single wildfire in California’s history.
The Creek Fire’s heat was a kind North had never witnessed in his 26-year career with the Forest Service. “Everything was vaporized.”
I asked if he thought the forest would fully recover. North said that above the elevation of 5,000 feet, chances are the trees will rebound, especially if seedlings are planted.
But below that point, North foresees the landscape covered by shrubs, not trees. No more forest below Shaver.
North is now based in Mammoth Lakes, on the other side of the Sierra from Fresno. But like the Valley, Mammoth’s last storms came in late December. Since then, the snow that the ski town rejoiced over has been melting.
The dry weather of January and now February is leaving the Valley parched, a continuation of drought that is likewise bad for the Sierra’s forests. North waits to see if the research he and his colleagues have done gains the attention of state and federal leaders, and makes a difference.
The Sierra’s overgrown forests need the right answer.
This story was originally published February 10, 2022 at 5:00 AM with the headline "Too extreme? Why UC researchers propose idea of cutting down 80% of Sierra trees."
