Shifting climate thins tree cover in East

Some species could go extinct, study says

@usatodayweather USA TODAY

It’s getting so hot that even the trees are heading north.

Man-made climate change — including warmer temperatures and deviations in rainfall patterns — appears to be one of the reasons tree populations in the eastern USA are shifting north and, more surprisingly, west, according to new research.

The shift could lead to the extinction of certain trees in select forests, the study said.

Overall, the changing climate has pushed trees an average of 20 miles north and 25 miles west over the past 30 years. Though the northern shift was expected because of warming temperatures, researchers said the more surprising westward movement could be the result of a change in rainfall patterns.

When researchers analyzed the impact of climate change, they found precipitation had a stronger impact on forests in the short term than temperatures, said lead author Songlin Fei of Purdue University.

The eastern USA has gotten warmer over the past few decades, and the Southeast has trended drier.

Fei said deciduous trees such as oak and maple primarily move west, and evergreens move north. Trees don’t actually move, of course, but where they sprout can change. Saplings can expand into a region while older growth dies in another, The Atlantic reported.

One of the more striking examples is the scarlet oak, which in nearly three decades has moved more than 127 miles northwest from the Appalachians, Fei told the Associated Press. Its population is reduced in the Southeast and more pronounced in the Midwest.

Brent Sohngen of Ohio State University, who was not involved in the study, told the AP the findings show “there is no doubt some signature of climate change.”

The research, which studied 86 species of trees and was based on data gathered by the U.S. Forest Service, was published in the journal Science Advances.