Climate change may be driving tree growth in the eastern United States west instead of north as previously believed, a new study in the journal Science Advances reports.
Ecologists have long predicted that climate change will send animals and plants up towards the poles. While such movements have been well documented in different parts of the world, rainfall patterns may be driving certain tree species in the United States in a different direction.
This new discovery comes from researchers at Purdue University, who tracked the shifting distributions of 86 U.S. tree species using data collected by the U.S. Forest Service’s Forest Inventory and Analysis Program between 1980 and 1995 and between 2013 and 2015. This revealed that more trees are moving west than north.
Researchers found that, over the past 30 years, roughly 34 percent of the species looked at in the study shifted towards the north pole at an average rate of nearly seven miles per decade. In contrast, 47 percent of those species shifted westward at a rate of roughly 10 miles per decade. Almost no trees trended south or east.
“We show that more tree species have experienced a westward shift than a poleward shift (62 percent) in their abundance, a trend that is stronger for saplings than adult trees,” the team stated, according to Motherboard.
Most of the trees that moved west were flowering trees — also known as angiosperms — while northbound trees were typically conifers. The team believes increased rainfall in the center of the country could be the reason for this trend. However, it is hard to tell because many forests in the eastern states are either complex or inhabited by people. In addition, there are other external factors that can affect distribution, such as natural succession of species and human influence.
Even so, scientists believe this new information is valuable and could help drive future research. There is no doubt future forests will look vastly different than the ones of today, and the team hopes studying those changing patterns will help them protect woodlands in the coming years.
“We live in an era of very rapid ecological change,” said Leander Love-Anderegg, a researcher at the University of Washington, who was not involved in the research, according to Nature.com. “In order to avoid some of the more drastic and negative consequences of that change — like massive forest fires and massive beetle outbreaks — we all have an interest in trying to predict change before it occurs.”