What immediate effect resulted from the reintroduction of grey wolves in the Greater Yellowstone Ecosystem?

Answer

Elk avoided vulnerable riparian areas, allowing willows to recover.

The reintroduction of wolves re-established an "ecology of fear," causing elk to avoid vulnerable riparian areas to evade predation, which allowed willows to recover and, subsequently, supported beaver populations.

What immediate effect resulted from the reintroduction of grey wolves in the Greater Yellowstone Ecosystem?
speciesEcologyRolekeystone species