MAMMOTH HOT SPRINGS, Wyo. — Five years after devastating wildfires burned about 1.2 million acres in the greater Yellowstone area, researchers are finding long-term beneficial effects, including a vigorous recovery of most plants and steady or growing populations of large mammals.
In fact, new research shows that large catastrophic fires are not that unusual in the region, which includes about 13.9 million acres in two national parks, seven national forests and assorted federal enclaves in Wyoming, Idaho and Montana.
"The forest is going to be re-established. In many cases, the seedling density is greater than the original stand density," said Monica Turner of the Oak Ridge National Laboratory, one of a group of scientists who recently gathered here to study the implications of the 1988 fire.
In many burned-over areas where mature lodgepole pines once stood, Turner said, the number of established seedlings is eight times as large as the original number of trees. Many lodgepole seeds require fire to open.
"Large fires do not seem to be overriding the usual biologic processes," she said.
One species that may not come back, however, is aspen, the quaking, silver-barked tree that is a symbol of the Rockies. The decline in aspen trees appears to have more to do with overgrazing by elk, however, than with fire. Aspen is a favorite food of elk.
Despite some reports in 1988 of large numbers of animal deaths, the fires appear to have had virtually no impact on the ungulate population--elk, bison and deer. In 1990, forage available to ungulates in burned areas was triple that in unburned areas.
Steve French, a grizzly-bear researcher in the park, said the "Bambi" concept of animals fleeing wildly before the flames is a myth, based on his observations of animal behavior during the fires.
"'We didn't see a lot of stress on animals. Bison right in front of the fire line only moved out of the way very casually," he said.
In a survey of large animal deaths, French said he found more than 390 documented deaths from fire, nearly all from smoke inhalation. Of those, 333 were elk, 32 mule deer, 12 moose, nine bison and six black bears. His survey found no antelope, mountain lion, grizzly bear or bighorn sheep carcasses.
"Elk and bison had less than 1% of the animals perish," he said.
Yellowstone Park ecologist Don Despain found evidence of 63 large fires from 1510 to 1988 within what is now the park. The largest fires covered about 25,000 acres.
In addition, carbon-14 dating by University of New Mexico scientist G.A. Meyer indicates that major fires swept through the area regularly throughout history, including large blazes sometime between 1050 and 1200 A.D.
On the whole, the scientists were optimistic about the impact of the fire in Yellowstone. In a keynote talk, University of Wisconsin-Stevens Point professor Mark Boyce said that, if he were superintendent of Yellowstone, "I would maintain fire every chance I had. I would do my best to eradicate this species"--and he showed a slide of Smokey Bear--"from the park."