William Ripple is a professor of ecology at Oregon State University. In a paper published in BioScience this month, Ripple and 19 other authors suggest using portions of federal lands in 11 western states to establish new habitat for the beaver and gray wolf.

They argue wolves and beavers improve biological diversity. Wolves by preying on grazing animals, which will allow more plants to grow. And beavers by creating ponds and wetlands.

“The reason we want to do this is because wolves and beaver are considered keystone species. And that means that even in low abundance, they have very stro...