This article originally appeared on PRI’s Living on Earth.

Historically, trees have frequently shifted their range, Fei says, mostly due to the effects of glaciation or the retreat of glaciers. He points to studies that have tracked the movement of trees in New England — movement that was also driven by changing temperatures and precipitation. The difference, he says, is that those studies examined the movement of trees over thousands of years. Fei’s study looked at only a 30-year period, from 1985 to 2015.

The changes Fei has tracked would have happened over several thousand years, had nature taken its normal course and not been affected by changes in the climate due to human activity.

[This algorithm can identify every tree.]

Still unknown is to what degree the rapid movement of trees will change the ecological balance within large forest systems.

“In the current study, we are looking at individual trees. A forest is a composition of multiple species, which, in ecological terms, we call a ‘community,'” Fei explains. “So, we don’t know whether the community is currently vulnerable to breakdown because of the different directions of this shift by individual species.”

“We are interested in looking at how these communities are responding as a group. Are there certain community groups that are more vulnerable than others? This is what we are really interested in looking at next,” Fei says.