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Yellowstone ecosystem needs beavers

NSF Award:

LTREB: Understanding controls on state-tranisition on Yellowstone's northern range  (Colorado State University)

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After eliminating wolves from Yellowstone National Park in the early 20th century, the park landscape experienced major changes. Young trees, especially willows, all but disappeared under intense browsing by an unchecked elk population. This, in turn, changed the habitats and distributions of other species that depend on young trees and shrubs. 

The wolves, a keystone species, were a critical element supporting the links between many other species in the regional ecology. In the late 20th century, rangers began a program to return wolves to the park to help restore the ecosystem to its prior state. In the years since reintroduction, elk behavior changed, allowing small trees and shrubs to return.  However, fertile wetlands that once nurtured young trees were missing.

To learn why, a research team synthesized a decade of data that tracked ecosystem changes in Yellowstone resulting from the reintroduction of wolves. The team discovered that beavers play a critical role in creating and maintaining park wetlands. The team's studies also explored how landscape changes when wolves were absent actually drove beavers out of the area. 

The reintroduction of wolves has drawn tourists and spurred an ecological boon in Yellowstone.  However, ecosystem recovery is still incomplete. The study suggests that with specific management practices, the park can be made more habitable for beaver and allow them to eventually contribute to further restoration of this culturally valuable ecosystem.

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  • a beaver
Beavers are an important part of the Yellowstone ecosystem.

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