Stalwart species: tenacious and rugged, the fire-dependent whitebark pine endures where most other trees fail.
This sturdy, five-needled pine prospers in monumental landscapes like the Grand Tetons, Yellowstone, and Glacier National Park. No stranger to extremes, whitebarks inhabit high-altitude environments near timberline, where other tree species find it difficult to establish a roothold.
Under natural circumstances, whitebark is the premiere pine high up in the subalpine and alpine regions of our northern forests, where spruce and fir tend to dominate until only alpine tundra can survive the wind and cold. Whitebark pine tends to be tenacious even at these lofty, frigid extremes--but only as long as an exacting ecological regimen remains in place.
The tree's overall value to both humans and wildlife might seem minuscule, considering its habitat. But the species' presence on never-summer slopes tends to modify the microclimate, influencing fragile high-altitude life processes just enough to stabilize a number of critical natural functions at a variety of elevations.
Foresters point out that whitebarks serve as "nurse" trees, protecting subalpine fir seedlings as they struggle to survive at the high elevation limits of their range. And, because the multi-trunked, shrubby species grows well on windy mountain ridges and produces broad crowns in the process, the trees act as high-altitude snow fences, regulating spring runoff and reducing erosion.
Trout fishermen applaud the pine's effect on mountain stream hydrology, just as bear lovers grasp the importance of having and keeping healthy whitebark communities. The tree's large, nutritious oil-rich nuts provide an important food source for numerous species including a powerful symbol of American wilderness, the grizzly bear. Ironically. this massive species must rely on a relatively tiny one for the perpetuation of that food. Whitebark pine relies on the jay-sized Clark's nutcracker to help it release those prized nuts.
Clark's nutcrackers perform an invaluable symbiotic service for the whitebark pine community. They retrieve the pine nuts from the purple cones, store up to 150 in a pouch below their tongues and then cache each seed by drilling holes in disturbed meadows, sowing their precious cargo much like a farmer presses a kernel of corn into the ground.
The birds depend upon memory to retrieve the nutritious food source as needed and tend to favor recently burned forestland for their larders. Not all the seeds are recovered, allowing a new generation of whitebark pine seedlings to spring to life in the raw, wet, high mountain environment it relishes.
Nutcrackers are not the only birds to prize the trees. Flickers and bluebirds seek them out for nesting cavities and red squirrels eagerly cache the high-energy pine cones.
In average years, grizzlies as well as black bears consume the tree's fatty cones from August through late autumn. When bumper crops abound, even bruins just emerging from hibernation will immediately seek out whitebark cone caches that survived the winter unscathed. Some researchers insist hungry grizzlies can locate these caches under 6 feet of snow.
Whitebark pines are what silviculturists term a keystone species of upper subalpine ecosystems. As such, says Melissa Jenkins, forester for the Caribou-Targhee National Forest, whitebarks determine numerous other species' ability to persist within a biological community that doesn't allow much latitude. In other words, the whitebark's ecological impact comes down to this: When keystone species are lost, biodiversity suffers.
Whitebark pines take a long time to regenerate naturally, and years of well-intentioned fire suppression have hindered the process. Without our help, Jenkins says, the fate of this cloud-clinging species depends on the nutcracker's ability to gather and plant the seeds, usually on recently burned sites, in clusters of anywhere from three to 15 kernels per excavation.
"Nutcrackers can cache up to 100,000 seeds per season during good cone years, and they'll fly as far as seven miles or more to do so," Jenkins points out. "Yet they only need about 25,000 nuts per year to feed themselves and their offspring, so a large number of seeds remain to germinate and reestablish seedlings."
Forest fire usually invokes an image of blackened trees, but whitebark seedlings can tolerate harsh, post-fire conditions. This trait, along with the nutcracker's willingness to fly far with the seeds, helps the pines regenerate deep into the charred heart of seemingly inaccessible burn sites.
Due in part to the intricacy of the tree's reproductive process, all is not well currently with whitebark pine populations. The trees are declining in areas they once dominated. "About 98 percent of all whitebark communities occur on federal land," Jenkins says. "Throughout these areas trees are failing to recruit naturally while, at the same time, many are dying due to mountain pine beetle infestation and imported white pine blister rust."
Fire suppression during the past century has diminished suitable seed distribution sites for Clark's nutcrackers, he adds, and, except at the highest elevations, has allowed competing conifers to invade areas that historically were controlled by periodic burns.
"With fewer mature trees present to provide seed for Clark's nutcrackers to cache, we're left with fewer seeds in the ground to germinate," Jenkins says. AMERICAN FORESTS has joined the U.S. Forest Service in planting whitebark pine seedlings to help ensure nuts to feed future wildlife populations. Federal foresters hope to develop a seed orchard of trees that resist white pine blister rust, a process that could take up to 15 years. In the meantime, foresters use seeds from wild trees that appear to be blister rust-free.
The area's eco-history makes it tough going for the trees, but a future without whitebark would be bleak indeed.
"We have forest areas under our jurisdiction that haven't regenerated since the big fires of 1988," Jenkins says. 'It's the steep, dry sites that are suffering, and these are actually good places to plant whitebark pine. Harsh, high-elevation burn areas provide excellent seedbeds for this species.
"Whitebark is a slow-growing tree that doesn't compete well with other conifers, especially more shade-tolerant trees like subalpine fir and Engelmann spruce," she adds. "Planting whitebark pines on these tougher areas--places where you'd find the tree growing naturally--helps reduce erosion and provides wildlife food, cover, and nesting sites."
AMERICAN FORESTS' whitebark restoration efforts, planted under the auspices of Wildfire ReLeaf, have focused on the Greater Yellowstone area in Wyoming, Montana, and Idaho. One planting site is a section of the Targhee National Forest that burned during the 1988 Yellowstone fires. The fire combined with the onslaught of blister rust has been an ecological double whammy for biodiversity; the natural recruitment has been predominately lodgepole pine.
That leaves biologists concerned for an area within the heart of the Plateau Grizzly Bear Management Unit. AMERICAN FORESTS and the intermountain region of the U.S. Forest Service have forged a partnership to aid in the restoration of sustainable ecosystems," says U.S. Forest Service silviculturist Brian Ferguson.
Nowhere is that assistance more keenly felt than in the Greater Yellowstone area, where a healthy whitebark pine community is critical to grizzly bear recovery efforts. "Through the combined efforts of the Forest Service and our partners like AMERICAN FORESTS and their visionary Global ReLeaf program, we re taking the necessary steps to insure that America's forests remain as richly diverse as we found them," Ferguson says, "not only for future generations of man, but for grizzly bears and Clark's nutcrackers as well."
RELATED ARTICLE: RETURNING WHITEBARK 10 IDAHO
AMERICAN Foiutsi's' Wildfire ReLeaf program helps restore landscapes damaged by fire. These sites are in danger of losing valuable soil to erosion and native species to invasives. The possibility of beneficial community-based forest management exists-if the sites can be reforested and managed in a sustainable fashion.
A partnership with the U.S. Forest Service has allowed AMERICAN FORESTS to plant trees to heal these scorched lands through Wildfire ReLeaf.
For whitebark pines, "during recent years the organization has greatly enhanced our efforts by providing funds for seedlings needed to reestablish areas damaged by insects and by fires," says U.S. Forest Service silviculturist Brian Ferguson.
The species lives in very remote locations, yet it's being affected by humans either through introduced diseases--in this case white pine blister rust--or through the suppression of natural fires, points out Karen Fedor, vice president of Global ReLcaf at AMERICAN FORESTS. "And once this species goes, the surrounding high-elevation ecosystem will go along with it."
In 1999 and 2000, AMERICAN FORESTS planted 10,000 whitebark pine on a section of the Targhee National Forest that burned during the Yellowstone fires of 1988. That blaze destroyed 17,000 acres of mixed conifer woodland along the Henry's Fork River. Its effects combined with the onslaught of blister rust have meant an ecological double whammy for biodiversity, and the natural recruitment has been predominately lodgepole pine.
In addition to producing seeds as food for grizzlies and other wildlife in the Greater Yellowstone area, the trees will improve the general health of the ecosystem by promoting species diversity for both flora and fauna. The trees--which have virtually no timber value--also will stabilize soil and protect water quality.
In 1999 AMERICAN FORESTS planted an additional 5,000 trees nearby in the Island Park CaMera, an area adjacent to Yellowstone National Park in the Plateau Grizzly Bear Management Unit, The 1988 fires and the onslaught of blister rust have taken their toll on this area as well, by affecting the natural regeneration of the gnarled whitepine. Instead, the affected sites are coming back in lodgepole pine. The 5,000 trees planted are an effort to help sustain whitebark's ecological niche here.
"It's our responsibility to ensure that this species survives," Fedor says. "Through AMERICAN FORESTS Global ReLeaf program we have been in the forefront of trying to repair some of the lesser-known ecosystems damaged by humans: from whitebark and longleaf pine to Atlantic white cedar."
Gary Lantz and Michelle Robbins
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|Date:||Jun 22, 2002|
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