密歇根新闻广播 美国的树木整体向西迁移究竟是为哪般（在线收听）

Most of us expect to hear that trees are moving north in search of colder temperatures because of global climate change. But trees don’t only need colder temperatures; they also need to have enough water.

A new study published in Science Advances suggests that trees are moving west in search of more moisture.

Associate Professor School for Environment and Sustainability Ines Ibanez joined us on Stateside to share her perspective on the many other global change factors that are causing this migration.

Forests provide humans with many services, include providing clean water and keeping soil in place. According to Ibanez, this migration west is a good thing because it shows that trees can adapt and continue to provide these services for humans.

“We have to understand that trees are not only responding to climate change, they are also responding to many other global change factors,” Ibanez said. “In this case it is probably also a response to changes in the landscape.”

One example Ibanez notes is that humans have been clearing out the land for agriculture and development. In the last century, much of that land that was cleared for agriculture has been abandoned and now is being naturally reforested.

“What we can see here is probably a combination of re-growth and also of responses to that increase in humidity,” Ibanez said. “The landscape being reforested has an impact in these plots, and I think that is part of what we see in this response.”