Climate change triggers triage in Northwest forests

Siuslaw National Forest managers must decide whether to save meadows or let trees encroach.

 

Frank Davis strides to the edge of a clearing near the top of Marys Peak, the highest point in Oregon's Coast Range. "You want to see the coolest thing in this meadow?" asks Davis, a veteran natural resource planner for the Siuslaw National Forest, which manages the peak. "It's a Harry Potter snag," he says, gesturing to a tall, mossy tree that looks like it could be the lair of some enchanted creature, "one of the most beautiful things a person could ever want to see." Its shaggy limbs reach down toward him, groping through the mist that shrouds the peak's 4,097-foot summit.

On a clear day, Marys Peak commands views from the shimmering Pacific Ocean to the sheen of a dozen snow-capped volcanoes far to the east. The peak, which the Forest Service designated a scenic botanical special interest area in 1989, is home to a distinctive plant community, including a rare noble fir forest and rolling meadows, which showcase a menagerie of native grasses and wildflowers. Glacier lilies poke through the snow in spring, followed by fiery columbine, purple alliums and dainty pink phlox.

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Lilies growing on Marys Peak.
Julia Rosen

Davis is here because, over the last century or so, the Harry Potter tree and its fellow noble firs have invaded the meadows on the summit of Marys Peak. In places, the trees have crowded out the wildflowers and blocked the mountain's panoramic views, which draw approximately 10,000 annual visitors. Many worry that the meadows could vanish completely.

In response, the Siuslaw National Forest has decided to fight for the meadows. In the fall of 2015, crews undertook a campaign to remove roughly 3,000 trees from 25 acres of former meadow. Crews have also sawed the stumps down to the ground, and plan to reseed reclaimed land with native grasses. On this cool November day, the work continues; the roar of chainsaws splits the fog and the air is sweet with the aroma of fresh sawdust.

The trees aren't the real enemy, however. They're collateral damage. In fact, these proud stands of noble fir are just as unique as the meadows themselves. Scientists think both ecosystems date back more than 10,000 years to the last glacial period, when they covered large swaths of western Oregon. As the planet thawed, they retreated to high-elevation parts of the Cascade Mountains and isolated pockets in the Coast Range, like Marys Peak.

Since then, the firs and meadows have shared this piece of real estate. But here and elsewhere across the West, climate change and other human activities have started to tip the scales in favor of forests. Now, an encroaching tide of trees threatens to erase an iconic component of the Western landscape, swallowing entire ecosystems in the process. When that happens, land managers like Davis face a difficult choice: Should they sit by and let the meadows disappear, or should they intervene in nature's response to a changing world?

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Young trees crop up along the edge of meadows on Mary's Peak.
Harold Zald/Oregon State University

To understand why a meadow exists, you have to understand why trees don't. "The big picture is that meadows are places where there's one or many limiting factors that make it hard for trees to establish," says Harold Zald, a forest ecologist at Oregon State University in Corvallis. In subalpine zones, long winters and deep snow often keep the growing season too short for tree seedlings to thrive. At lower elevations, below the snowline, frequent fires can singe saplings before they grow strong enough to survive. Wet, cold soils — and thin, rocky ones — can also make it hard for trees to gain a foothold.

But even though meadows have small footprints, they have outsized significance. "They are real biodiversity hotspots," says Kaitlin Lubetkin, the interim director of the Sierra Nevada Research Stations in Yosemite, Sequoia and Kings Canyon national parks. Many meadow plants grow only in open clearings, and many more insects and animals depend on them, or the easy cover of the forest edge. Meadow soils also play an important role in the hydrologic cycle. "They sort of act like a sponge," soaking up rain and helping prevent flooding, then slowly releasing water later, Lubetkin says. And of course, humans love meadows for the views.

These days, though, rising temperatures, shrinking snowpack and fire suppression have weakened the forces that once held trees at bay. On Marys Peak, people have also meddled with the meadows. Early settlers used them as sheep pastures in the late 1800s and early 1900s, perhaps helping keep them open. More recently, various projects, including the construction of a short-lived ski lift and several communications towers on the summit, have disturbed the soil and encouraged trees to take root.

But even if the exact causes of forest encroachment remain uncertain, the trajectory is clear. Using historical photos, Zald calculated a 35 percent loss in meadow area between 1948 and 1994. That figure served as a wake-up call for Frank Davis, who brought it to the attention of a Forest Service ecologist named Cindy McCain in 2007. The pair considered their options, and saw an opportunity to act when it came time to reassess the management plan for the lands around Marys Peak.

Harold Zald/Oregon State University

"If we stepped aside and let what is a perfectly natural process go — as it would be appropriate to do in many circumstances — then the meadows would be extremely reduced," says McCain, who has since retired. "But if we wanted the meadows, it was now or never." So the Siuslaw developed a plan to restore the meadows to their 1948 extent — a somewhat arbitrary benchmark, but one that would succeed in re-establishing connectivity between the half-dozen lobes now separated by trees.

They presented the idea to local residents of Benton County, who overwhelmingly supported it, in part because they had witnessed the changes themselves. "The meadows that I used to be able to walk through just aren't there anymore," says Phil Hays, a Corvallis resident who has visited the peak regularly since 1974 and meticulously documented its native plants. The Siuslaw plan got final approval from the district ranger in 2010, and the Forest Service negotiated a deal with Miller Timber Services — a subcontractor for the paper giant Georgia Pacific — to remove the offending trees. The sale also included the right to thin other plots of more valuable Douglas-firs.

Felling a forest to free a meadow may strike some as a drastic response, but the Forest Service saw that the future of a beloved ecosystem might be at stake. At some point, Jerry Ingersoll, supervisor of the Siuslaw, says he realized inaction was also an active choice: "Doing nothing has its own consequences."

The same philosophy has guided land-management practices in other places where trees have invaded meadows. Every year, the Bureau of Land Management conducts prescribed burns across the Intermountain West to restore the meadows that, among other things, provide important habitat for big game. In Montana, for instance, the BLM burned 200 acres near the ghost town of Garnet in 2012. "The diversity is just incredible of what came back," says John Thompson, chief fire officer for the Western Montana District. Historically, wildfires would have done the job, aided in places by human-sparked blazes, which Native Americans used to manage hunting grounds.

Yosemite National Park also has a long history of managing the trees on its lands. As far back as the 1930s, the Civilian Conservation Corps — which put the unemployed to work improving public lands during the Great Depression — removed young lodgepole pines from Tuolumne Meadows to preserve its eponymous expanses. A modern continuation of that effort is the Scenic Vista Management Program, which aims to protect Yosemite's famous "viewsheds" and the natural processes behind them, according to park spokesman Scott Gediman. So far, the park has tackled 30 out of more than 100 potential sites, removing dozens to hundreds of trees at each one.

Such efforts may be warranted in certain high-priority spots, says Lubetkin, who has thoroughly studied Yosemite's meadows. But when it comes to the Sierra's countless other meadows, land managers may be fighting a losing battle. Lubetkin's research suggests that although fire suppression and other human activities may have hastened meadow declines in the park, climate change now plays a dominant role. And while a few meadows may survive on their own, most will likely need some kind of help. Removing trees from these would be great, Lubetkin says, "if we had infinite manpower." As it is, "it's sort of a futile effort."

The best way to save climate-sensitive meadows is to rein in greenhouse gas emissions, says Janneke Hille Ris Lambers, a meadow expert at the University of Washington in Seattle. "The trees are just responding to climate change," Lambers says. "It's a little weird to prevent them from doing it."

Others worry about the unknown — and perhaps dangerous — consequences of cutting down trees. "We don't know how many things we change once we start removing them," says Regina Rochefort, a science advisor at Washington's North Cascades National Park, which has also experienced forest encroachment. Taking out trees won't stop shrubs from moving in, and many fear that the disturbance could create openings for invasive species. With the world changing around them, Rochefort says, "you're not going to preserve the flower fields the way you think you are."

Ingersoll and his colleagues at the Siuslaw are well aware of the risks of intervention, and they have tried to protect the natural processes at work on Marys Peak as much as possible. All logging equipment is cleaned and inspected for hitchhiking seeds before workers drive the long winding road to the summit. And crews have laid down freshly cut slash, so heavy machinery can cross the meadows without tearing up the soil.

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Looking out from the summit of Mary's Peak.
Harold Zald/Oregon State University

Ingersoll also acknowledges that the task won't be finished when the last truck of logs lumbers down the road. Success will depend on long-term monitoring, and on diligently removing noble firs and invasive plants before they spread, a daunting task. For that, Ingersoll says, the Forest Service will rely on help from citizen groups, like local chapters of the Native Plants Society of Oregon and the Sierra Club, and a volunteer task force called the Marys Peak Alliance, whose members include Cindy McCain and Phil Hays.

In the end, Ingersoll feels confident about the decision to intervene. "One of the precautionary principles that you try to follow is 'try to keep all the pieces,' " he says, a nod to Aldo Leopold's Land Ethic. If the Siuslaw hadn't acted, an important piece — the meadows — might have been lost forever. Instead, the Forest Service took the more conservative path, Ingersoll says, which was to "preserve options" and not "commit things that are irrevocable."

"We're turning the clock back a little bit," Ingersoll says. But if, years or decades from now, land managers come to regret the decision, all they have to do is stop maintaining the meadows. Then, the trees will resume their slow, steady march, and "we'll be right back where we started."

Julia Rosen is a freelance reporter based in Portland, Oregon.