Copyright © 2001 The Seattle Times Company
Local News : Monday, May 15, 2000
Mount St. Helens: Lessons in life from the zone of destruction
by Chris Solomon
Seattle Times Eastside bureau
Part two of a three-part series
MOUNT ST. HELENS - Two decades later, the tourists still arrive by motor home and rental car like devastation's pilgrims, driving hours to gawk at the burnt relics. Framed in a Winnebago's windows, the scene is all the awfulness they hope for.
Mount St. Helens squats in snow and soot, beyond a frothy apron of pumice and 10-story chunks of volcano she spewed on the bright morning of May 18, 1980. With her north flank scooped away, the peak tribes once called "beautiful maiden" wears the toothless gape of a child surveying her tantrum - a tantrum unequaled in Northwest recorded history.
These days, a tour among the ashes reveals a different story, of a landscape consumed with the business of righting itself. Once so lunar that Hollywood tried to rent it as a Star Trek sound stage, the place is exuberant with pocket gophers, spiders, moss and bouquets of blushing paintbrush.
Peter Frenzen, the scientist for the Mount St. Helens National Volcanic Monument, motions to a grove of alders 25 feet high and growing 3 feet a year. Give this place 20
more years, Frenzen said, amazed, and people may have trouble seeing the volcano's shattered cone from the lower trails.
"The pace," he said of the rebound, "has really picked up."
When this mountain scoured, scorched or buried 230 square miles of iconic Northwest landscape, scientists got a front-row seat to nature's recovery from massive disturbance. What they have seen has shattered some notions about the nexus of relationships that prop up nature, underscored others - and suggested ways humans can help ameliorate the myriad insults they inflict upon the land.
Recovery first required cataclysm.
It began at 8:32 a.m. with an earthquake that collapsed the swelled north flank of the mountain. In fewer than 10 minutes the landslide filled 23 square miles of the North Fork Toutle River to an average depth of 150 feet.
The land was not tortured just once. The slide was like uncorking a shaken champagne bottle. A blast of superheated gas and rock traveling from 220 to 670 mph raced past the landslide, knocking down trees for 15 miles. Beyond that, the volcanic wind roasted a narrow ring of trees but left them standing. The top 1,300 feet of the mountain were blown away.
Closest to the crater, gas and pumice as hot as 1,300 degrees flowed out of the gap. A delta of land reaching as far as five miles to the north was sterilized by this pyroclastic flow. Melting glaciers, boulders and soil formed a slurry that ran down several sides of the mountain. The hot, wet mudflow helped liquefy the original landslide, sending more slides and floods down the Toutle River. Fifty-seven people died that Sunday morning.
The blast knocked down enough timber to build 300,000 two-bedroom homes. More than 5,000 deer died, along with 1,500 elk, 15 mountain goats, 200 black bears. Fewer than half of the 32 species of small mammals known to live in the blast zone survived.
Spirit Lake, a popular recreation spot in the blast's path, was slammed with earth, lifted, reshaped, its trout killed as hot flow brought the lake to nearly 100 degrees.
From the high overlooks where visitors stare into Mount St. Helens' maw, the place can still seem a wasteland, punctuated by a few brave conifers.
It is misleading. Beneath Coldwater Ridge, Frenzen, the scientist for the Mount St. Helens monument, stands atop a massive hummock of old volcano that is now the valley floor and points out horsetail along a stream, Sitka alder whose trunks are scarred by bull elk rubbing velvet from antlers. An eagle kites overhead.
Though the pre-1980 valley lies some 200 feet below Frenzen's feet, there is little respectful or tentative about the riot of life growing on its grave.
Insects were the shock troops of nature's recovery. Sixty-five types of beetles soon paratrooped in to establish a beachhead on even the sterilized pumice plain, said John Edwards a UW professor of zoology who helped catalog the return. The wind blew an estimated 1,500 different species of insects into the blast zone in the months after the eruption, Edwards said.
Only a few, such as wolf spiders, thrived and bred, but the rain of doomed bugs wasn't without purpose: On an average summer day Mount Rainier's glaciers wriggle with about 10 tons of insects, Edwards said. At Mount St. Helens their carcasses were fertilizer for ash otherwise as inhospitable as powdered glass. Their nutrients helped give some plants a foothold.
Insects weren't the only hardy pioneers. Frenzen digs his fingers into a mat of prairie lupine, a ground-hugging plant with dainty white, four-petaled flowers considered the pioneer in these areas, and he takes up the typical tale of recovery in the blast zone:
After the turmoil, a few wind-thrown lupine seeds grew in the nutrient-poor ash because their roots contain a bacteria that pulls nitrogen out of the air. The plant's tight weave acts like a net to collect detritus such as dead insects and bits of dirt. The lupine is a jealous landowner that permits few neighbors while alive, but by the time a plant expires in three or four years enough humus has collected to make the spot hospitable for another pioneer, such as fireweed or pearly everlasting.
Elk drop grass seeds in their scat. Sitka and red alder, greedy trees whose roots have their own deal with bacteria, plant themselves in the stingy ash. Their leaves provide mulch for still other plants, which in turn lure still more animals and insects.
"As (famed Harvard entomologist) E.O. Wilson said, `It's the little things that run the world,' and that's sort of the case here," said John Bishop, an assistant professor of biology at Washington State University-Vancouver, who for a decade has studied creatures on the once-barren pumice plain near the crater mouth.
The alder thickets now emerging will dominate for about 60 years and cover much of the landscape, until they crumble under their own weight, Frenzen said. With their shady canopy gone, a coniferous forest will thrive. By the year 2100 a mature forest will again cover the land. In 200 years the area will look akin to old-growth forests found in the monument's undisturbed areas.
And so it goes, albeit with different players and timetables, in all of the places hit by the explosion.
Lakes and streams are alive, too. After finding no fish in ash-choked streams after the blast, scientists within four years counted higher numbers of the adaptable shorthead sculpin than expected, said Chuck Hawkins, a professor in fisheries and wildlife at Utah State University.
Brook trout in Meta Lake that survived the blast under ice-covered ponds helped feed downstream populations, some of which now have small but stable numbers. Yet fish counts in area lakes remain about twenty times lower than for an undisturbed lake, said Charlie Crisafulli, a Forest Service ecologist with the Pacific Northwest Research Station.
Scientists knew the area would rebound eventually, of course. Wracked by volcano, wildfire and flood, the Pacific Northwest is built on its own singed and soggy bones. Yet watching this reeling land recover yielded key insights.
In 1982, Congress designated 110,000 acres of the blast zone as Mount St. Helens National Volcanic Monument - a place where people were to step back and let nature find its way, with minimal intrusion.
Recovery has plodded along in some places, skipped ahead in others, gone on different tangents in still others. Pacific silver fir and mountain hemlock, for example, which were encased in snowdrifts or sheltered by lee slopes during the blast, now thrive on the naked landscape where they didn't have the opportunity before.
To scientists' surprise, birds from many different habitats have colonized the pumice plain. Rock wrens, western meadowlarks and horned larks usually found in the Great Basin of Nevada and Utah fly alongside species such as American pipits and gray-crowned rosy finches - birds more expected at 3,000 feet in the western Cascades. Species that prefer lowland pastures - red-winged blackbirds, savannah sparrows - have shown up, too, said Crisafulli, who has studied biological recovery on the mountain since 1980.
In time, these birds will be supplanted by the hermit thrushes and gray jays of a more mature Northwest forest.
The Vaux's swift, a bird thought to depend on old-growth stands, also has become "very abundant" in the standing dead forest, he said. Understanding the lure of this place for the birds - the standing snags, in the case of the Vaux's swift - has provided new insights into some birds' adaptability, and others' specific habitat needs, he said.
This complex revival underscored a hugely important ecological lesson for scientists: What remains after a disturbance plays a major role in revival.
The notion that downed trees and scorched snags could provide food, shelter and jump-start new growth was not a novel idea in 1980. Yet before Mount St. Helens, scientists tended to subscribe to the "if something's dead it doesn't count anymore" philosophy, said Jerry Franklin, a UW professor of forest ecosystems who was heavily involved in early research.
"What St. Helens did was it gave us a good slap in the face and said, `Hey, take another look, fella!' "
The recovery in areas of Yellowstone National Park, burned by fierce fire in 1988, further drove home the point.
Said Frenzen, "Large-scale disturbances don't leave a clean slate. You hear reports on forest fires that `23,000 acres were destroyed.' Well, how do you destroy an acre? Even then, there are patches spared.
"What was left behind is as important - is more important - because it drives regeneration. Plants and animals that survived or moved in, and the trunks and stems of blown-down trees, are all starting points of the next system."
A standing dead tree becomes a perch for a bird, whose droppings contain seeds, Crisafulli explained. The seeds fall in the snag's shadow, which then provides shade and shelter from wind. Water drips from the trunk into the soil. Sloughing bark provides nutrients. A plant grows. Insects commingle. A forest begins anew.
Recognizing the importance of such "biological legacies" influenced the Northwest Forest Plan, President Clinton's 1994 land-management plan for most federally owned lands within the range of the northern spotted owl.
The plan dictates that live trees, both scattered and in patches, must remain on 15 percent of an area after a major harvest. Large logs must be left on each acre, as must snags, said John Roland, forest planner for Gifford Pinchot National Forest. These living trees and dead trees act as "lifeboats" for species, according to Franklin.
Private industry has been slower to embrace the tactics, though similar strategies have been used in Canada and South America, and by Plum Creek Timber in the United States, he said.
20 years later
Twenty years later, many of the scientists who rushed to ground zero have gone home, the research money nearly dried up. But some continue to watch the land for its lessons, such as Connie Harrington with her 400-acre petri dish.
In the Clearwater Valley, flattened by the eruption, Harrington oversees a test forest that may help show foresters how to grow trees for timber while keeping habitat healthy for diverse wildlife.
The forest, just outside the monument's eastern boundary, was densely planted in the 1980s with mostly Douglas fir, and later divided into 16-acre test plots.
The Forest Service is now experimenting with thinning the forest in a variety of ways, to gauge the effect on tree growth and groundcover.
Two years after a mid-1990s thinning, scientists found more than double the percentage of plants, lichen and grasses on plots with irregular spacing - which mimics nature - than on the untouched plots, Harrington said. That means more food and habitat for wildlife.
"We want to know what the tradeoffs are," said Harrington, a Forest Service forest researcher. "Maybe the loss in tree volume (from more spacing) is not as much as you might think, because the remaining trees are going to grow quite well."
Nearer the crater, other scientists keep watch on the mountain for signs of activity. Although the volcano has been fairly quiet since 1992, scientists think it may again erupt in the next millennium. Volcanologists also worry about the buildup of more than 50 million cubic meters of snow, ice and rockfall within the crater's shaded south side, according to Ed Klimasauskas of the U.S. Geological Survey.
An eruption or major releasing of hot gases could melt the mass into a large lahar, or mudflow, that would roar down the Toutle once again. But the attention Mount St. Helens receives means scientists are unlikely to be caught off guard, according to Klimasauskas.
A few other researchers, including Bishop, the WSU-Vancouver biologist, continue to prowl the pumice plain, nose to ash, trying to tease out the relationships of nature. Why are caterpillars eating the pioneering lupine only on the fringes, and not in other places? And how will the next forest look different from the old forest?
Too much of what can help fill in that picture - the charts and the memories - is shut away in file cabinets and in the brains of scientists soon to retire, said Fred Swanson, a research geologist for the Pacific Northwest Research Station in Corvallis, Ore. This year the monument has sent out invitations to 100 scientists who have worked in the mountain's shadow since the blast, in hopes they will return in July to share information. A comprehensive collection of information is also in the works.
If any place can lure them back, it is Mount St. Helens.
"It's a beautiful and compelling place," Swanson said. "And those attributes of the place bring scientists back again and again to observe the course of change."
For more information
Seattle Times staff reporter Richard Seven contributed to this report.
Chris Solomon's phone message number is 206-515-5646.