Demise of a charismatic champion: a search for the backcountry whitebark pine titleholder reveals a stunning tree but a casualty of age and global warming.
Scurrying down the trail's rocky switchbacks, I approached the pine, my excitement growing with every step. Although weary from schlepping my pack six uphill miles through Idaho's Sawtooth Mountains, I glided easily to the base of the champ, mesmerized by its overwhelming presence.
The tree was not only big, it was charismatic. As I circled the ancient giant, every careful step revealed a new world of sculpted bark striations that led my eye upward along a bulging polished trunk. Its upper arms reached outward in graceful arcs. The roots gripped the earth indomitably, like an eagle's clutching talons. I uttered unintentionally, nearly dumbstruck, "whoooa." The tree was eminent, strong, and dignified, but there was one flaw. It was dead.
I suppose I had anticipated this possibility. Monitoring the old champion's health was a part of my assignment from AMERICAN FORESTS, but it was still a harsh slap of reality to find that the great tree had passed.
I guess someone has to do the dirty work. After all, much has happened since the Imogene Lake Pinus albicaulis was first nominated for AMERICAN FORESTS' National Register of Big Trees more than a quarter century ago. Since then, disco has given way to hip hop, telephones have gone from dial wheels to cordless to cellular, and the weather has gotten warmer and warmer still.
Not that climate change was the lone culprit in the demise of this national champion. The tree was old, perhaps in the 1,000-year range considering that some whitebarks have been dated at over 1,200 years. Nothing lives forever, I thought, not even a stoic grandfather tree like this one. Old age coupled with a dry hot summer was apparently just enough to push the great tree over the edge. It hadn't been dead long. Rust brown needles still clung to its outstretched branches.
As I sat and looked at the slopes of the alpine bowl above me, my quiet acceptance of the tree's death was rattled into an alarming concern. Other whitebarks within view, both young and old, carried the same rusty badge of death as the fallen champ. The Imogene Lake whitebark, I realized, wasn't just a big tree that had finally reached the end of its life span. It was a huge, glaringly grotesque sign of the apocalypse.
Whitebark pines are dying. On the east side of Glacier National Park and in north Idaho's Selkirk Mountains, whitebarks are 90 percent dead. In southern Oregon's Umpqua National Forest, more than half the whitebark pines are dead or dying. Small isolated populations of Pinus albicaulis in Montana's Centennial Mountains are bordering on extinction.
And it's not just the whitebarks that are dying. Just two dozen miles from the Imogene tree, on the north side of the Sawtooths, swaths of lodgepole pines are crispy brown, ready to incinerate with the next lightning strike. On Alaska's Kenai Peninsula, 4 million acres of white spruce are dead. British Columbia has more than 17 million acres of dying trees. In the American Southwest, pinyon pine, Arizona cypress, aspen, corkbark fir, Englemann spruce, and ponderosa pine are all experiencing massive die-offs. The evidence is clear: Forests in western North America as we know them are becoming a thing of the past.
Each affected tree species has its own specific set of causes for its mortality, and it usually involves a small bark-boring insect. Arizona's pinyon pines are suffering from drought and an infestation of Ips confusus, the pinyon bark beetle. Alaska's white spruce have succumbed to Dendroctonus rufipennis, the spruce beetle. For whitebark pine (along with lodgepole, ponderosa, and several other pines), the villain is Dendroctonus ponderosae, the mountain pine beetle.
This industrious insect makes its home in whitebark pine's phloem, or inner bark, where it feeds on the tree and lays eggs. A pioneer female initiates the infestation before sending out a pheromone signal to other beetles in the area, and the onslaught begins. A healthy pine can sometimes fight the invasion with sap, but pine beetles carry a blue stain fungus that inhibits the tree's resin production, effectively disarming the pine's defenses. With beetles cutting off the supply of nutrients traveling from the roots upward to the rest of the tree, compromised whitebarks succumb in two to three weeks.
Pine beetles, spruce beetles, and other forest pests are of course nothing new. They have been a part of the ecosystem for millennia, providing a check on excessively profligate trees, culling the weak, and helping to maintain genetic integrity. The check on beetles, in turn, has primarily been climatic parameters.
Pine beetles respond to temperature. A warm spring combined with a mild fall can allow beetles to produce a second generation in a year, when normally they would only reproduce and mature once per season. Conversely, a late spring cold snap can kill beetles that are emerging from their winter larvae stage, and an early freeze in the fall can keep beetle eggs from hatching. In summer, cool weather can inhibit mature beetles from flying between trees. In winter, extreme low temperatures will kill beetle larvae that are over wintering in the bark.
In recent decades these temperature thresholds on the pine beetle have rarely been reached. Even a cursory examination of weather records for the Intermountain West illustrates a dearth of low temperatures in recent years. In Stanley, Idaho, near the Imogene tree (and one of the coldest locations in the continental U.S.), temperatures of -40 Fahrenheit have occurred in 11 of the past 44 winter seasons. Ten of those 11 occurrences came prior to 1990, and it has never reached -40 since that year.
On Alaska's Kenai Peninsula, where the white spruce vanished, the story is eerily similar. Extreme low temperatures (-30 degrees for this location) have been reached 38 times in the past half-century. Only five of those 38 extreme low temperatures were post-1990. Researchers in the Sawtooths measuring phloem temperatures, where Dendroctonus eggs over-winter, found that annual minimum phloem temperatures had "increased significantly" between 1980 and 2006.
Higher temperatures equals more beetles equals less whitebark pines. In a nutshell, this is the dilemma, but it covers only the tip of the melting iceberg. Whitebark decline is just one domino in a building wave of change, and a singularly significant domino at that.
Pinus albicaulis is a keystone species of sub-alpine forests. Through its seeds, it provides an energy-rich food source coveted by creatures large and small. The prized seeds are picked and stashed by red squirrels in some habitats, but more commonly, whitebark seeds are the domain of Clark's nutcracker. This iconic high country bird is almost entirely interdependent with whitebark pine, because it is the primary seed disperser for the tree.
Clark's nutcrackers have a specially developed pouch for transporting whitebark seeds. They sometimes travel over 20 kilometers with a pouch-ful before placing their harvest in a cache. Wind does not spread the dense seeds of whitebark pine. Only the nutcracker and an occasional squirrel can do that job.
Once stashed, the seeds are a favorite find of another mountain icon, the grizzly bear. Grizzlies can get over half their digested energy from whitebark pine seeds, making it a critical part of the bruin's diet. Some studies have shown that during bad whitebark pine seed crops, bear encounters with humans increase as grizzlies are forced to wander out of their preferred range in search of food.
Besides their seed production, whitebark pines are also considered nurse trees. They thrive in relatively harsh treeline environments, where cold drying winds and intense high altitude sun are standard conditions. Whitebarks create shelter in this difficult environment, making habitat for a host of plant species including paintbrush, lupine, arnica, goldenrod, mountain sagewort, wild strawberry, heather, and various sedges.
Without the micro-habitats created by whitebarks, many of these species will have to retract their range. As Elizabeth Campbell and Allan Carroll of the British Columbia ministry of forests report: "Potentially massive losses of whitebark pine will jeopardize the species and have cascading ecosystem impacts."
With my mind racing with these dire thoughts, I wandered away from the Imogene tree listlessly. It was, regretfully, time to find a new champion. My mental wanderings allowed my feet to lead the way, and in minutes I was hopping across a field of loose fallen boulders.
A hundred-pound chunk of white granite moved as I stepped on it, sending me scurrying for more stable footing. I thought of Aron Ralston, the experienced backcountry traveler (like me) who was scrambling solo (like me) when a loose rock shifted, pinning his arm beneath it. Four days later he snapped his necrosed arm off near the elbow and staggered back to his car. I didn't want to be the next Aron Ralston.
No sooner had I conjured that gruesome image when I found myself on the side of a steep debris pile, still with big loose blocks underfoot. Retreating up the tenuous boulders was not an option, so I kept moving, paid attention to my feet, and did my best to dance down the house of cards. My heart rate began to slow when I reached the safety of a bedrock outcrop 80 feet below. I was now snapped out of my dead tree reverie.
I scrambled to a notch among slabs of smooth granite that overlooked a nameless basin. A string of teacup lakes ran along the valley bottom, connected by a trickling spring-fed creek that meandered through bogs and fell in a series of slides between the water-filled bowls. I scanned with my binoculars, looking for the next great tree. At the very back of the basin, where talus met forest, there was a pine. It had the characteristic broad sweeping crown of a whitebark, and it was big. An hour of off-trail hiking later, I arrived at the tree.
It grew at the edge of a perfect alpine lake, looked relatively young and robust, and it was big. I measured it: 57 feet tall, 42 feet of spread, 16 feet of circumference. It wasn't as dramatic as the old champ, and I would later find that it was slightly smaller than another tree I measured on the trail out of the mountains. However, this lakeside tree is the one that my optimistic side will remember. Sitting deep in the wilderness, thriving and strong, it stands a good chance of gaining the title someday. Most of the challengers, after all, are dropping with the permanence of a red-hot setting sun.
Freelance writer/photographer Tyler Williams also wrote about the national champ subalpine fir.
Story and photos by Tyler Williams
RELATED ARTICLE: WHITEBARK'S NEXT GENERATION
After searching remote high mountain basins near the Imogene Lake tree, I discovered and nominated a new champion for the now-empty whitebark pine throne. Ironically, it is located right next to the trail.
"Triple Trunk" is the largest of a trio of huge whitebark pines located along the trail between Edith and Imogene Lakes in the Sawtooth National Recreation Area of Idaho. As is common in whitebark pines, the Triple Trunk tree forks into separate trunks several feet above the ground. It is the massive confluence of these three trunks that creates a girth of 268 centimeters and pushes the tree to champion status.
Next to Triple Trunk is another impressive whitebark that is actually taller than the record holder. This tree, located on the last switchback of trail above Edith Lake, lacks the girth of Triple Trunk, and therefore scores fewer points than the new champ. Just downhill from these companion trees, another huge whitebark completes the trio of giants.
Although this grove of whitebarks is remarkable and record-setting, none of these ancients are in the same league as the now-dead Imogene Lake Tree. That amazing specimen scored 412 points compared to the new champion's 340, but even those vastly differing numbers don't tell the whole story. The Imogene Lake Tree had a singular trunk that did not fork for more than 20 feet. Its spreading arms were numerous, and it had great sculpted burls worn by eons of wind and snow.
Still standing, the Imogene Lake Tree dominates the surrounding landscape definitively, and possesses a presence displayed by only the most elite big trees. Like the Douglas-firs that were the world's tallest trees before falling to the ax, the Imogene Lake whitebark pine is a giant tree emblematic of times past.--Tyler Williams
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|Date:||Mar 22, 2008|
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