What Is an ‘Old-Growth’ Forest?

Yves here. Some old-growth forests are also taking a beating from climate change. The Bowdoin Pines lost a lot of trees and limbs a couple of years back in an unusually fierce storm even by New England nor’easter standards. It took out tons of trees on the coast, and even in this protected stand inland.

By Will McCarthy, a freelance audio/print reporter and master’s candidate at the UC-Berkeley Graduate School of Journalism.. Originally published at Yale Climate Connections

Most visitors to California’s Humboldt County forests go there to camp and fish, leaving behind the problems of every-day life. Olive didn’t do that. Instead, she found herself fighting for a cause with worldwide consequences.

“I was arrested in the woods,” said Olive, a name she uses for privacy concerns. “A few times.”

The 24-year-old was arrested while trying to protect what activists call the last undisturbed stand of old-growth Douglas fir trees in California. The Rainbow Ridge trees are part of a temperate rainforest that stores more carbon per square acre than the Amazon. Experts say old-growth forests are one of Earth’s best bulwarks against warming temperatures. While both activists and Humboldt Redwood Company, the organization logging the land, agree that old-growth forest should be preserved – they don’t agree on a definition of old-growth forest.

There’s no universally accepted definition.

The way Olive tells it, she fell into the subject of old-growth forests by accident. She was visiting Arcata, California, and mistakenly went to a meeting aimed at organizing protesters to go out to Rainbow Ridge. Since then, their cause has become central to her life.

“As a kid I read about Julia Butterfly Hill and was like ‘Mom, I want to be a tree sitter. My mom was like you can’t – you’re seven. So, I lost track for, like, 15 years.”

What’s So Good About ‘Old Growth’ Anyway?

Old growth forests are like a giant bank account of carbon – they store an enormous amount of carbon in their trunks, and allow even more to be stored in forest soil. Although scientists long had thought old trees can no longer absorb carbon, recent studies suggest they continue to capture large amounts into old age.

Carbon in the atmosphere is one of the main causes of climate change, so preventing carbon emissions is more important than ever. Despite that, old growth forests continue to disappear globally – victims of land clearing for industrial agriculture and logging.

One reason: the lack of a single accepted definition of what constitutes old growth.

In the 1970s, researchers started using the term “old growth” to describe complex, biodiverse forests at least 150 years old. Environmentalists prefer using the term to describe forests with large, old trees undisturbed by human impact. Under the environmentalist’s characterization, much more forest would qualify as old growth. The tension between these two definitions remains unresolved.

Tom Spies, an emeritus scientist with the U.S. Forest Service research division and professor at Oregon State University’s College of Forestry, says old growth is defined by varying subjective values.

“If you approach the issue with a particular agenda,” Spies said, “you can take a really narrow definition that would exclude a lot of forest from being defined as old growth. Or you can have a very broad definition which would capture a lot of forest conditions.”

That variability makes it harder for forests to earn protection, and also contributes to a lack of recent research on the amount of old-growth forests left in the U.S. A 1992 U.S. Forest Service study pegged the amount of old growth remaining in California at 2.5 million acres, down from 9.5 million acres in the 1940s.

In Humboldt County, where Olive and other activists are determined to protect trees they define as old growth, data show that overall forest cover – including old and new growth – decreased by 7 percent between 2001 and 2018.

UC-Berkeley cooperative extension specialist and forest health expert Jodi Axelson said this decrease is especially significant as climate change has accelerated.

“There’s such a period of uncertainty around climate change,” she said. “We don’t know how forests are going to adapt.”

In March, the United Nations announced a goal to restore approximately 865 million acres of forest globally by 2030. One study made the case that tree planting can provide one-third of the climate mitigation needed to meet objectives set in the 2015 Paris Climate Agreement.

But experts like Axelson say scientists cannot anticipate how these new forests will fare with warming temperatures. They do know that old growth trees are more resilient than younger forests to drought and wildfires, conditions that are growing more severe in California.

‘They Make Up Their Own Definitions’

Humboldt Redwood Company owns over 200,000 acres in Humboldt County and is certified sustainable through the Forest Stewardship Council (FSC). That certification requires the company to prove that it abides by the council’s principles, which include boosting the long-term social and environmental benefits of forests, avoiding negative environmental impacts, and maintaining high conservation value areas. FSC standards also require that any area that has never been harvested be left intact.

“What we do is set the standards,” said Brad Kahn, a spokesperson for the Forest Stewardship Council. But he said that the standards are “a judgment call; if you ask Greenpeace, it’s going to be a different answer than a timber company.”

In two separate phone interviews, Humboldt Redwood Company director of forest policy John Anderson said the company does not log any old-growth trees. And that view conforms with that of Robert Hrubes, an inspector who audited the company on behalf of the Forest Stewardship Council in 2018.

“It’s not old-growth. Most of this area was meadows 120 years ago. Whatever old-growth trees are there, the company is not cutting,” Hrubes said of the trees on Rainbow Ridge.

In a 2018 response to a complaint activists registered with the FSC, Hrubes’ company, SCS Global Services, acknowledged that its representatives did not visit many of the stands activists had highlighted as being worthy of preservation based on FSC standards. The SCS response stated that auditors asked Humboldt Redwood Company to update its assessment of high conservation value forest in the area. The company’s response also said activists were conflating forest that has never been logged with old-growth forest.

Although SCS Global Services auditors wrote in the response that they identified one of the large trees in one contested stand as over 300 years old, they did not designate the stand as old growth.

“That’s why the term old-growth is limiting,” said Olive. “They make up their own definitions.”

“We’re auditing against the FSC standard,” Hrubes said.

A Long Struggle … ‘Losses Are Permanent, Victories Temporary’

Activists have been trying to protect Rainbow Ridge since 2014, when Humboldt Redwood Company filed a timber harvest plan on the land with CalFire. Over the years, forest defenders have set up blockades, organized protests, and risked arrest on numerous occasions in an effort to stop logging. One activist, who goes by the name Rook, this past summer lived for 60 days 100 feet up in the canopy of a Douglas-Fir tree on Rainbow Ridge. One of Olive’s arrests occurred while trying to resupply Rook in the tree.

Another strategy, which the group deployed on June 17th, was to vertically lash a 30-foot extension ladder to neighboring trees and the gate of the logging road. Olive herself sat atop the ladder, just above a flag that said “leave Rook alone” and “Protect Rainbow Ridge.” At least three protesters were arrested that day by the Humboldt County Sheriff’s Office.

A week earlier, on June 10th, four activists over the age of 70 were arrested trying to prevent logging trucks from entering Rainbow Ridge.

“Elders defend elders,” the group reportedly said.

The goal of all these strategies was to impede the harvest as much as possible, but activists acknowledge that a large portion was still logged. Anderson said all of the trees that were marked for harvest were still harvested, regardless of the protests.

One of the company’s three timber harvest plans on Rainbow Ridge expired on September 12. Another is active until 2021, and a third was approved in May. Logging could restart any day.

Unless, that is, activists, scientists, logging companies, and environmentalists are able to find a shared definition for what constitutes old growth. Until then, the struggle will continue.

“When you’re doing forest defense all your losses are permanent and all your victories are temporary,” Olive said.

Print Friendly, PDF & Email


  1. doug

    ‘Losses Are Permanent, Victories Temporary’
    Exactly, one must continue to fight even after ‘winning’; they always circle back and try again..

  2. Wukchumni

    There’s a bit of ‘old growth’ forest on the other side of the front porch of the back of beyond here, and what lucky happenstance that Sequoias weren’t all that useful of a tree from a making money standpoint.

    95% of coastal Sequoia Sempervirens have been cut down, while over 95% of Giant Sequoias are still standing.

    1. Susan the Other

      How do they truck a 100 ft. Douglas Fir, let alone a 500 ft. Giant Sequoia to the sawmill? Seems like if there’s one thing California could really use it’s trees. Clean the air; sequester carbon; enhance the soil; maintain a more humid climate. Why on earth don’t they practice better forestry? The lumber industry does not have unlimited privilege and access to the forests – so this is just a question of policy and enforcement, like every other damned thing in this country. And with the planet breaking under the weight of recyclable plastics and paper products there’s no excuse whatsoever for failing to use those as resources for new building materials and give the trees a break. Turn the lumber companies into foresters. Growers. Just think of the idiocy of “inventing” the reverse – turning recyclables into marvelous living factories to save the environment… We are so stupid. Or are we just lazy?

      1. Wukchumni

        In Mineral King along the road @ Atwell Mill is a Sequoia cemetery of perhaps 100 trees, 10-12 foot wide stumps that will probably decompose around 3019. It took a team of 2 men around 5-6 days to bring a Brobdingnagian down, and you can still see where they cut ledges 4-6 feet above the ground into the tree and inserted a board in to stand on, so as to be able to get ‘r done.

        That was merely step 1, and cars & trucks hadn’t been invented yet, so you’d have to cut it into bite sized chunks, and then put those on a horse drawn carriage that had for brakes either a stout stick levered against a wheel that slowed things down, or chains in the rear hooked up to logs that helped stop forward progress in the 20 mile drive where you drop 5,000 feet in altitude.

        And then largely the only use for them was turning them into fence posts or grape stakes.

    2. John Wright

      From the Northern California location where I write this, some Marin county towns south bear names related to previous lumbering operations that removed 95% of the Coastal Sequoia.

      “Corte Madera” = “cut wood”

      “Mill Valley” for the lumber mills that were there.

      When one views the remaining 5% up in Humboldt County and areas of Marin and Sonoma counties, one can imagine that the initial quantity of trees was probably so large that timber people thought they would never run out.

      But they came within 5% of doing exactly that.

      US finance, via a hostile takeover, was also involved in “extracting value” from these trees in Humboldt County.


      “Pacific Lumber has been at the center of multiple controversies since a hostile takeover by Maxxam, Inc. (of Texas), that was completed in 1986. The company maintains that it is still a sustainable operation, but its policies and practices bear little resemblance to those before 1986.”

  3. PlutoniumKun

    Its surprising how little we understand about the age of forests. A lot of what were considered quite recently to be old growth tropical rainforest in Central and South America are now thought to be of much more recent origin – many of the forests in the Americas date from the destruction of native American populations by disease in the very early days of European colonisation. Some have argued that very densely foliaged forests in Europe are not ‘natural’ they have arisen as a result of people wiping out the larger grazer animals – the ‘pristine’ forests may well have been much more open, more like landscaped parkland than the deep dark primordial forest of the imagination. It may even been that it was regular clearance in the tropics that contributed to the species richness by creating and recreating isolated ‘islands’ of forest.

    1. Wukchumni

      The first Europeans to glimpse Californian forests often described them as park-like with a fair amount of space in between trees, for the Native Americans had a long time to perfect prescribed burns, and any natural wildfires caused by lightning simply ran their course, keeping an even keel.

    2. Joe Well

      If the growth of these forests following the collapse of indigenous human populations sucked enough carbon out of the atmosphere to cause the Little Ice Age…that is a powerful argument for planting trees fast and leaving existing trees standing.

  4. anon in so cal

    Several years ago we visited Jedediah Smith Redwoods State Park, just outside of Arcata. It is one of the most pristine old growth redwood forests. Did not know about any old growth Douglas Fir trees in the Arcata area.

    1. furies

      The Sinkyone has old growth doug fir. Take your 4 wheel drive…more around Scotia/Carlotta…

      I think it’s interesting that this question seems somewhat similar to ‘we’ve got to put a price on it to *save* it’ stuff my youngest son learned at SOU.

      And Jedediah Smith Redwoods is actually a lot closer to Crescent City…

  5. lyman alpha blob

    You know what took down more Bowdoin pines than an unusually strong nor’easter? A few decades of college administrations who valued unnecessary new buildings to make the big donors feel good at the expense of all the trees.

    I was protesting removing these big pines when I was a student there 30 years ago. Lots of students approached the administration to complain. We wrote letters to the editor at the local paper. A friend and I spray painted a protest in huge letters on the side of one of the campus buildings at night in the hopes lots of people would see it the next day. They had it removed pretty much before the sun came up.

    30 years later the student body hasn’t really increased all that much but the number of buildings certainly has. My guess would be at least some of these are to house the ever expanding administration who spend their time raising money for more new buildings judging by the incessant fund raising emails barraging my inbox, despite this school having more money than it knows what to do with.

    But it would send entirely the wrong message if the massive endowment were used to pay for students’ tuition, so up go the buildings and down go the trees that have been the symbol of the school for centuries.

  6. McWatt

    I have my own definition of Old Growth, it is rather arbitrary, but based on my Midwest tree experience
    and based on a family tree farm. I define an old growth tree as those growing prior to 1910.

    1. Joe Well

      During the New Deal an enormous number of trees were planted and protected forests created, so maybe that would be a more logical cutoff point. Anything from before 1933 (or 1910, if you want to include a forest that would have been in full existence by 1933) is obviously rare.

  7. Tim

    I’m from Oregon. It’s always been easy to define an old growth forest. Any already designated forest that has never been logged off by non-Native Americans.

    Only a nation of lawyers could make it more complicated than that. And by that definition I find it shockingly hard to believe there is only one stand of Doug Fir left in California that has never been logged. It’s a 1000 square mile area of forest between Redding and Eureka.

  8. Oregoncharles

    We encountered an example of the headline in NE Oregon. In western Oregon, old growth is pretty obvious: Douglas Firs and Cedars get really enormous. Old growth=really big trees. Not as big as Sequoias, but unmistakable.

    But when we were visiting Wallowa Lake in eastern Oregon, we went on a hike to a grove of old growth, which turned out to be a long way down – and then a long way back up, on a very hot day. Tucked in the bottom of the valley, along a dried up stream, were old growth pines – maybe a foot across at their best. I don’t doubt they were old; there were no stumps, and things grow slower out there. Interesting, really.

    OTOH, it didn’t make the miserable trek back up the hill – my wife needed a bit of help; the youngers did some towing – seem any more worthwhile. Not our favorite hike. The lake is beautiful, and stocked with coho salmon, which were running up the creek to spawn. They’re bright red in spawning season, and not very big when they grow up in the lake, so a very odd spectacle as these bright red, trout-sized fish work their way up stream.

  9. Knifecatcher

    Throughout the Rockies, and likely in much of the rest of the countries, there are acres upon acres of standing dead. Drive through Rocky Mountain National Park and it feels like you’re in a black and white movie – whole mountains are covered in dead grey trees.

    These trees have been killed by the various types of bark beetles, which are surviving the warmer winters in much larger numbers. And it’s not just smaller / younger trees, as I’ve personally seen dead Engelmann Spruce well over 100 feet tall, with bases close to 5 feet in diameter, in the Wolf Creek Pass area of southern Colorado.

    A sane forest management policy would focus on harvesting those endless acres of dead trees rather than cutting down live, thriving old growth forests.

    1. Keith Howard

      I live in Denver, and I’ve hiked rather extensively in the Rockies. The conspicuous death of pine and spruce forests in NM, CO and WY is also notable for its speed. When I first hiked on the Continental Divide NST (national scenic trail) in ’88, walking from Monarch Pass south to Cumbres Pass, the forests all appeared to be thriving. Only thirty years later, as Knifecatcher notes, whole mountainsides, indeed whole ranges are covered with stands of dead trees.

      There is some harvesting of the beetle/fungus-killed trees, but the standing dead trees will topple over soon enough. There will be succession of some kind, but I wonder what will be the effect on watersheds of having so much of the high-altitude forest die.

      1. Stephen A. Verchinski

        Part of the disaster can be imho attributed to additive stress. We had coal electricity production where the utilities used to shut their scrubbers down in the winter

  10. MT_Bill

    The problem with trying to harvest the dead trees is that it is extremely dangerous. The roots are one of the first parts to rot, leaving a very hazardous “widow-maker” waiting to come down with the slightest disturbance. These types of trees kill firefighters each year. Currently the forest service is switching to using det cord (basically explosive rope) instead of chainsaws to remove standing dead trees because it’s safer to blow 30 of the trees up at once than cut them down one at a time. Really eerie to hunt through the standing dead timber, it’s no country for old men.

Comments are closed.