What problems arose after reintroducing the wolves, and how did the park service attempt to deal with them?

A problem that arose is that a wolf was killed outside of Yellowstone that was a father to a new litter of pups. Without the father, the lives of the mother and pups were at risk, so the park’s service intervened and took the pups and cared for them before they were reintroduced.

We can plant more trees and plants.