Cruises To The Caribbean - Did Reintroducing Wolves to Yellowstone Bring Back the Aspens?

By Linda Orlando

There was seemingly no explanation for these drastic changes. The plants and flora that had previously lined the riverbanks and safeguarded the soil had completely vanished. And soil was sloughing off to be flushed down river, the banks were eroding, he was shocked to discover that the stream had grown too wide. One of the park's largest and most beautiful rivers, hydrologist Bob Beschta was studying the Lamar River, in 1996. Biologists and hydrologists studying the landscape in Yellowstone National Park over the last decade have discovered some interesting changes that have affected the way researchers think about the fragility-and recoverability-of our ecosystem.

The Yellowstone aspen trees had evidently stopped regenerating sometime in the 1930s, surprisingly. They were startled to discover that most of the aspen trees in Yellowstone were at least 70 years old-almost none were younger, when they did this. By drilling cores to count growth rings, so they decided they had to look within the trees themselves. So the biologists concluded that lack of enough fires couldn't be the reason for the vanishing aspens, but a huge fire in 1988 had ultimately produced very few large trees. Since they are a species of tree that thrives after a burn, the researchers then wondered if the reduction in the number of forest fires in the park was hurting the aspens. While the numbers of aspens inside Yellowstone were dwindling, yet aspens in areas surrounding the park were flourishing. Aspens in the entire area would be declining, but decided that if that were the case, they wondered initially if changes in the global climate were affecting the trees. A team of biologists were probing into another unexplained mystery at Yellowstone-the steady disappearance of aspen trees in the park, around the same time.

The elk were free to graze brazenly and unencumbered on aspens and willows, the wolves-in Yellowstone, researchers have determined that because of the elimination of most of the large predators-namely. But the effect of the wolves on the ecosystem in the park would ultimately become far more important to the area than to the removal of the wolf from the endangered species list. Of course the landowners surrounding the park-farmers and ranchers-were infuriated by the sudden attacks on their animals since they had not had to deal with large predators before the wolves came back. Biologist Doug Smith and his colleagues imported 31 gray wolves from Canada and began introducing them to Yellowstone, in 1995. Which ultimately resulted in a highly publicized and widely controversial program being developed and planned to bring the wolf off the endangered species list, the gray wolf was later listed as an endangered species in the 1970s. 000 wolves were killed for bounty in Montana and Wyoming alone, more than 100, between 1883 and 1917, in fact. All the resident wolves in Yellowstone had been killed, by the 1930s. The biologists realized one significant change that had occurred in Yellowstone around that time, after some investigation.

One wolf kill serves hundreds of park inhabitants, so in essence. Down to small mammals and even insects, the feeding continues further. And grizzly bears that feed on the remains, bald eagles, coyotes, magpies, the carcass becomes a dinner invitation to a host of other animals including ravens, after the wolves have had their fill. Because a wolf kill isn't just a meal, and the impact of wolves on the ecosystem actually begins with the effects of their kills. And thereby severely affecting the vital plant and animal diversity of the park, evidently the ecosystem in Yellowstone needs to have a resident large predator in order to keep the elk from obliterating the aspen. It seems the disappearance of the aspen trees and the vanishing of streamside vegetation-which provided beaver and songbird habitats-can be linked to the absence of the wolves, although other factors may have contributed to changes in the park.

The majestic wilderness and vitality of Yellowstone National Park is making a comeback of its own. But the long-term effects have paid off, the reintroduction of wolves to Yellowstone may have been controversial. And beavers and songbirds have new homes and habitats in which to flourish, trees and shrubs are starting to grow back along the streams and rivers. The aspens and willows are allowed to grow unchecked, by keeping elk on the run. Researchers have discovered that wolves may literally be reshaping the landscape, but with the reintroduction of wolves to Yellowstone. And evidently they were also an integral contributor to ecosystems before bounty hunters decimated their numbers, wolves were once a vital part of the landscape of North America.