In Oregon, a mysterious tree grove conjures a colder time

Botanists have a joke about time, distance and themselves.

Where most people walk about three miles in an hour, botanists will tell you they dawdle along at one mile every three hours. After all, it is only when you pause that the green blur of a forest resolves into individual species.

Joe Rausch, head botanist for the Malheur National Forest in Oregon, claims to be different, though. The barrel-chested 44-year-old looks more like a firefighter than someone fascinated by the genetics of miner’s lettuce plants. “I am impatient for a botanist,” he said.

This “impatience” is relative. It’s true that Rausch strode down the trail, deep in central Oregon’s Aldrich Mountains, well ahead of forest geneticist Andy Bower and former Forest Service Northwest region botanist Mark Skinner, who stopped every 20 feet to inspect a new wildflower, exclaiming, “You don’t want to walk by all this stuff, do ya?” But as we switch-backed down a hot, bright slope of yellowing grass, Rausch also lingered over his fair share of plants, especially trees emblematic of the mountain range’s parched climate — juniper, ponderosa pine, mountain mahogany dangling with horsehair lichen. It was a good thing, too: Our destination was the kind you can easily miss, where a few steps take you into a different world.

Rausch signaled for us to leave the trail where it crossed a shadowy notch in the mountainside, threaded by a stream. The desert forest fell away as we climbed, and we soon found ourselves in a cooler, wetter grove of feathery conifers. Their limbs joined overhead like linked hands, softening the unblinking sunshine to an ethereal glow. These are the last creatures a botanist would expect to find in this place: a wayward pocket of Alaska yellow cedars, hundreds of miles inland from their core range, which stretches along the rainy coasts and cold mountains of Southeast Alaska and British Columbia, and through the high Cascades in western Washington and Oregon.

Yellow cedar has long been one of the far Northwest coast’s most culturally and commercially important trees, with strong, decay-resistant wood prized for building and sculpture, and soft fibrous bark used in weaving. They’re thirsty, too. Ketchikan, Alaska, deep in yellow-cedar country, receives a squelchy 150 inches of precipitation annually. The Aldrich Mountains get just 21.

“Why are these here?” I asked Rausch.

He beamed and lobbed the question back at me. “Right?”

The grove has been only thinly studied, so no one is certain of the answer. But scientists believe that the trees belong to the forests that may have blanketed these now-sere highlands during the last ice age, which ended roughly 12,000 years ago. When glaciers retreat, they often leave behind giant, freestanding boulders called erratics that seem out of context with their surroundings. Here, in the Cedar Grove Botanical Area, the long-lost climate that made those glaciers left behind a sort of arboreal erratic, protected, perhaps, by the north-facing slope and the cold springs that feed the stream we hiked up.

Pollen records from the region confirm that other tree species suited to colder, wetter conditions were once more widespread here. As the climate changed, they gave way to those with warmer, drier proclivities. In the 1974 paper that formally described the yellow-cedar grove, Robert Frenkel speculated it was a last remnant of a landscape chewed away over centuries by heat and wildfire. Just one other far-inland fragment is known, in eastern B.C.

The yellow cedars’ hold on this patch of Oregon soil may be increasingly tenuous, though. Under current climate change forecasts, the forest that surrounds them will grow yet warmer and drier, and, thanks also to fuel buildup, more prone to burning. Yellow cedars are poorly prepared for wildfire. The thin bark that works so well in the warp and weft of blankets and hats does a poor job insulating the trees from extreme heat, and their shallow roots are easily scorched. In 2006, the Forest Service set an ill-advised backburn through Cedar Grove as part of an effort to fight the Shake Table Complex Fire. Tragically, the backburn was enough to kill 90 percent of the mature cedars in the 26-acre protected area — all save the 2-acre swatch where we stood.

Fire scientists recently discovered that hundreds of the older cedar trees here had lived through past ground fires before dying in the backburn, suggesting the species may be more resilient than previously thought. But it’s unclear whether this will provide any hedge against future blazes. If not, flames may erase them from this extreme margin of their range, while ice threatens them in their northern coastal strongholds. Warmer temperatures have reduced snowpack at low elevations enough to expose the trees’ shallow roots to the extreme cold of spring frosts. They are freezing to death in such high numbers that the U.S. Fish and Wildlife Service is considering whether to list them under the Endangered Species Act.

For now, central Oregon’s grove seems to have begun a slow rebound. Beneath fire-killed trees, Skinner and Bower were relieved to see thousands of yellow-cedar seedlings fighting towards the sun. They looked fragile and improbable, spindly green sprays catching the light. But they had grown taller since Rausch last saw them, several years ago. He broke away from us to examine a spring where it poured directly from beneath the exposed roots of a healthy, mature cedar as big around as a rain barrel. The water here is consistently several degrees cooler than in most other springs he’s checked on the Malheur over the years, using the pocket thermometer he carries for this purpose. Maybe it will stay that way, anchoring the cedar grove even as the world changes around it.

Rausch reached into the sparkling water, lifted it in quick handfuls to his mouth. I did the same. It was icy and clean and tasted like snowmelt. It tasted like some other season, some other place, some other time. I looked at my watch and realized four hours had passed. We’d covered less than a mile.

Sarah Gilman writes and draws from Portland, Oregon. Her work has appeared in The Atlantic, Hakai Magazine, BioGraphic, Adventure Journal Quarterly, and others. She was a staff and contributing editor at High Country News for 11 years. Follow @Sarah_Gilman

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