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Plant, Animal Life Abounds : Mt. St. Helens Rebirth Surprises Scientists

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Times Staff Writer

A young wilderness is thriving here, where forests covering 100 square miles were blown flat and buried under a thick layer of lifeless gray ash when Mt. St. Helens erupted five years ago this week.

The primitive beginnings of life that we found when we accompanied the first ground searchers into this valley just 72 hours after that tremendous blast have multiplied and prospered.

When the volcano exploded, a furious storm of winds raced through the hills and valleys north of the mountain at up to 400 m.p.h. for 10 to 15 minutes. The heat, for miles around, reached 500 degrees Fahrenheit.

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Now, plants and animals have reclaimed what was a desolate, primal wasteland of debris and dust with a speed that is surprising to scientists. The rate and pattern of the recovery are causing some of them to reassess conventional theories about the regeneration of natural areas.

“For some of us, it will serve as a philosophical corrective,” said Jerry F. Franklin, chief plant ecologist for the U.S. Forest Service’s Pacific Northwest Experiment Station.

Five years ago, this reporter and a Times photographer walked into this bleak valley along with relatives of loggers who had disappeared in the eruption. That first search party discovered a wasteland that seemed to have been hurled back to the time of creation and given an opportunity to begin life anew. In exploring the area weeks before the initial scientific expeditions, we found both death and life in a monochrome of gray mist and gray ash.

Survivors’ Tracks

There were bodies of dead animals and, in the fresh ash, the scattered tracks of a few that had survived. A baby snake crawled at the river’s edge, and on hillsides ferns were already pushing through the fine dust.

But the loggers we were searching for have never been found.

The mountain exploded on May 18, 1980, with a lateral blast to the north. On our search three days later, we moved slowly, sometimes taking hours to go only a few miles, our travel inhibited by massive barriers of fallen trees that we had to climb over or crawl under. Now, the debris has been cleared and the logs, which were scattered like match sticks, have been salvaged. Logging roads, though rough, are open.

The blast killed 36 persons. Of the 21 who were never found, at least five are believed to be buried in this valley. The rest who are still missing are presumed to be in other areas.

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Now, the air of gloom and death has been replaced by the sights, sounds and scents of spring.

Ponds edged with bright green algae shimmer with activity. Insects scurry across and under the clear water as tadpoles dart in the shadows of giant cattails bowing in the breeze.

Frogs can be heard in nearby weed beds. Under a log, a furry black and brown caterpillar lounges. Armies of spiders dash as if perpetually late for appointments.

Birds are nesting in young trees.

Puzzle of Animal Tracks

At the edge of the Green River, which rushes through the narrow valley with a loud hiss, a jigsaw puzzle of animal tracks is stamped in the mud. Elk and deer, cougars and bobcats have all left impressions.

On the steep hillsides that climb toward Mt. St. Helens’ cratered peak, a new generation of weeds and mountain flowers, vines and alders, ferns and young cottonwoods is poking through the 6- to 12-inch-thick layer of ash that remains. All this is taking place amid the litter of decaying stumps and splintered trees that lies like bones on a forgotten battlefield.

A helicopter trip to the summit disclosed that there is even some life on the desolate, broad, moonscape-like Pumice Plain, which spills out from the gaping mouth of the mountain’s mammoth crater, about 11 miles south of this valley. Birds could be heard and insects seen during a stop near the mouth of the steaming, snow-covered volcano. There are still large areas north of the mountain’s peak, where mud flows and lava reached depths of up to 600 feet, in which scientists have yet to find any plant life. However, even there, windblown insects can be found.

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“The outstanding lesson for me is the incredible resilience of ecosystems, their ability to take a really major insult . . . (and) if left alone to their own devices, their ability to come back,” plant ecologist Franklin said.

However, Franklin said that, although the eruption of Mt. St. Helens is often compared to a nuclear blast in terms of energy released, the ability of the surrounding region to recover from the eruptions is very different from its ability to recover from a nuclear explosion and its continuing radiation.

“What we had (with the eruption) is a single catastrophic event, whereas, following an atomic disturbance, we would have a persistent, chronic disturbance that would dramatically reduce (the region’s) ability to come back,” he said.

Franklin will join hundreds of other scientists at Eastern Washington University next weekend for a symposium reviewing research resulting from the eruption.

“Even in what appears to be an incredibly catastrophic disturbance, there are survivors. If there is one striking lesson and one thing that surprised everyone, it’s that,” said James A. McMahon, biology professor at Utah State University and one of the scientists involved in more than 400 research projects being conducted on and around Mt. St. Helens.

Life Below Ground

“There were just a lot more organisms surviving there than we had ever anticipated,” McMahon added. He said that, in each year since the eruption, “plants that were below the surface of volcanically altered areas have been sprouting back . . . . Stuff that you would have thought would be dead and gone is still there.”

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One of the key research findings is that plant and animal life that was either below ground or covered by snow on the morning of the eruption survived better than species that were above ground. For example, McMahon reports that almost 90% of the reptile and amphibian species known to inhabit the blast area “survived somewhere.” The same, he said, is true of shrews, mice, moles, gophers and a wide range of plant life.

“Between the incredible number of survivors and the reinvasion of higher animals and birds, the devastated zone probably has all the species that it had,” Franklin said. “Probably nothing has been lost from the area.”

Biologists and foresters from the Weyerhaeuser Co., which owned much of the land in the blast zone, including land in the Green River Valley, have compiled a list of wildlife that they have encountered in the zone in the last five years. It includes black bears, beavers, bobcats, coyotes, deer, elk, rabbits, raccoons, river otters, porcupines, weasels and more than 100 species of birds.

Evelyn Marrill, a University of Washington researcher who is studying the elk population in the zone, has found that, since the eruption, more calves are being born than before the blast, which killed about 1,500 Roosevelt elk, 5,000 black-tailed deer and an estimated 200 black bears.

“There are no real surprises in terms of anything missing,” Weyerhaeuser wildlife biologist Jim Rochelle said. The surprise is the rate at which things have come back, he said.

Another unexpected finding is the manner in which the recovery has taken place. Before the eruption, many scientists believed that a blast zone would recover from the edges, with plants and animals reinhabiting the area and forming an ever-shrinking circle.

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But, within weeks after the first blast, little islands of life appeared throughout the zone. They became sites for small colonies of plants, animals and insects.

‘Rain’ of Insects, Seeds

Scientists have also found that a constant “rain” of small insects and seeds, riding wind currents into the area from great distances, has played a major role in the recovery.

In “elementary biology, one learns the process of succession . . . the process by which areas get colonized first by bacteria, then by lichens, then by plants, then by insects and then, finally, predators and scavengers. Well, at Mt. St. Helens, it’s all going backwards,” John S. Edwards, professor of zoology at the University of Washington, said.

“The rain of insects and spiders into the blast area gives food for a few insects so species can survive on what’s being blown in on the wind. We’ve got the top of the food chain getting in there first and only later do we find plants developing,” Edwards added.

Here in the Green River Valley and in other places throughout the blast zone, man has helped the biological recovery. Weyerhaeuser, for example, has planted 17 million seedlings on 40,000 acres since 1981. Virtually all the hills and the narrow flats at the river’s edge here have been replanted with Douglas fir trees. Some of those trees are already 10 feet tall.

But efforts by the Agriculture Department’s Soil Conservation Service to prevent erosion by aerial seeding of slopes has been relatively unsuccessful, scientists report. Although the grasses took hold in some places, including along some creeks feeding the Green River, in most areas they were washed away by heavy rains, along with the unstable ash that they were planted in to stabilize.

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Although scientists involved in research throughout the volcano area caution that it may take another five years for them to fully understand what is happening on and around the mountain, plant ecologist Franklin believes that there is already something to be learned.

“We better be very sensitive to the fact that ecology is not classical physics,” he said in an interview. “Our way of thinking should be a little more attuned to the incredible diversity and randomness of the real world . . . . To have that lesson where we could get at it and have our noses rubbed in it is neat.”

Researcher Wendy Leopold contributed to this story.

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