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Park elk damage to riverbank called irreversible YELLOWSTONE NATIONAL PARK, Wyo. (AP) - Grazing elk have removed protective vegetation from the banks of Yellowstone National Park's Lamar River, making it wider and shallower, a research conference was told this past weekend. And, the changes are probably irreversible. "The adult willow is a disappearing life form in the Lamar Valley," Oregon State University professor Robert Beschta told scientists studying natural regulation of park animals. Cottonwood trees "are on their way out," he added. "Restoration of riparian (streamside) shrubs is not possible, given the current levels of elk browsing." Berry-producing shrubs are scarce and other woody plants, including aspen and "last resort" foods like dogwood and alder, are hit hard, added Richard Kiegley, a biologist for the federal Biological Resources Division. The two men were talking to a committee of 12 scientists organized by the National Research Council to look at natural regulation, which calls for minimal interference by man and for natural forces like predators, disease and starvation to regulate the size of animal herds. Prior to 1967, the Park Service culled herds of bison and elk, shooting or slaughtering thousands of them and shipping live animals around the country because managers feared they would overgraze the range here. After a public outcry, the policy changed. Several speakers noted that in similar habitat just outside the park, aspen stands are flourishing and streambanks wear a protective armor of willow and other plants, which slow erosion and protect water quality. Even if all elk were removed from the park's northern range, an idea Kiegley called "very unrealistic," the changes may be irreversible. "I think we have changes on the northern range that can't be undone," he said. And natural regulation ends at the park border, noted Tom Lemke, a wildlife biologist for the Montana Department of Fish, Wildlife and Parks. "When animals cross that political boundary, they leave natural regulation behind and enter the world of wildlife management," Lemke said. "Human predation becomes a major player." This year, he said, hunters killed 28 percent of the elk that wintered outside the park on winter range in Montana. About half the park's northern herd of almost 12,000 animals came to Montana this year. More and more elk have been leaving the park in recent years, and they are moving farther north. FWP encourages hunters to kill lots of them because managers fear they will eat up the habitat of other species, especially sagebrush and aspen stands, Lemke said. "One could ask, is the northern herd of the Yellowstone elk population really naturally regulated?" he told the committee. He argued the damages they see inside the park "would be more pronounced" without hunting outside the Copyright 1999 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.park.
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