Blame the deer! The eating habits of white-tail deer may be changing our forests. A University of Wisconsin-Madison research group says forests with a lot of deer have lots of ferns and grasses, while trees are thinned out and stand in a seemingly groomed park. That’s because voracious deer eat young native trees and create stubby shrubs. 

Maryland deer

(Photo courtesy Maryland Department of Natural Resources)

Donald Waller, professor of botany at the University of Wisconsin-Madison, says deer account for at least 40-percent of the change in forests over the past 60 years.

Professor Don Waller

Professor Don Waller (Photo courtesy University of Wisconsin-Madison News)

Take the Canada yew for example. The shrubby evergreen was once common across northern woods. Deer found them tasty and now they’re gone, according to botonists.

A research group led by Waller surveyed 62 sites across northern Wisconsin and Michigan. They kept track of sections of forests that were fenced to keep deer out and the forest surrounding the enclosures.

“We have exclosures in the same region where we have documented long-term changes in the plant community over the past 50 years. These are giving us the same message,” says Waller.

He points out that there’s no way of telling what deer chewed away before the researchers began their studies. “By that point, deer may have already eliminated some species that have not recolonized since. So this type of study would miss these losses,” Waller points out.

Deer impact study enclosure

A dense growth of white pines and some eastern hemlock lives inside this exclosure that protects it from deer. (Photo by Don Waller)

Read the full story about the deer study at University of Wisconsin-Madison News.