Mild Winters In Our Near Future Will Threaten The Trees That Define Vermont Forests

Feb 12, 2018

It's been a cold winter so far, so it might be harder to conjure up images of milder winters marked by more rain than snow, but a new report released by the USDA Forest Service says those kinds of winters are very much in our future due to climate change.

And a number of very important species of trees vital to the region's health are going to be threatened as a result.

VPR's Mitch Wertlieb spoke with Tony D'Amato, a forest researcher at the University of Vermont Rubenstein School, and one of the lead authors of the study.

Read the full report.

"When we look at projected changes in climate, and not just climate but changes and the occurrence of invasive insects and diseases in our forests, there's many species that we think of as characteristic of our forest today that are going to be impacted in the future," D'Amato explained.

"One example might be balsam fir, a species that we tend to think of as very characteristic of our mountaintops," D'Amato says. "As temperatures increase, as we start losing snowpack, which is vital to protecting and insulating the roots of many of those high-elevation trees during the winter, we're really concerned about how that might physiologically impact those species." 

Which would of course over time lead to us "seeing a decline in those species given they're are unable to deal with that stress," says D'Amato.

The study was conducted as part of a larger effort across the eastern U.S. known as a climate change response framework. It's being led by the U.S. Forest Service and the Northern Institute of Applied Climate Science.

Sugar Maples Might Be OK

There's one tree in particular that is of concern for many: the sugar maple.

D'Amato says there are certain conditions going forward that will be tough for the tree:

  • south facing slopes
  • areas with thinner soil and minimal moisture

Where as spaces with "cold, deep-soiled forest settings" will be perfectly suited for the sugar maple.

"Sugar maple is one that is moderately impacted by changing climate," D'Amato explained. "We certainly will see some stress on that species."

Invasive Species Will Thrive
 

"Many of the bark beetles that impact forest trees, they basically are living underneath the bark and rely on that as as a source of insulation," D'Amato says. "And so when we have really cold winter temperatures that actually can kill the larva of these bark beetles."

Other Trees Species May Shift North

"Yellow poplar, black cherry, and oak, if they're currently in the landscape," D'Amato says, "they're really going to be experiencing climatic conditions in the future that are more conducive to their growth as well as their reproduction."

"The best way to view a lot of these projections is we might have suitable growing conditions for yellow poplar in Southern Vermont in 100 years," says D'Amato. "The issue is that yellow poplar currently is hundreds of miles away from that location and so really these are almost like a shift in the zone map."

Global Weirding

D'Amato says rather than "global warming," we might consider these changes "global weirding."

"I think one of the biggest challenges, and this has been talked about quite a bit and in both the scientific literature and the popular press, is that we label this global warming and they are really the more appropriate term should have been global weirding," D'Amato explains.

"It's not that we're going to consistently have warm temperatures ... It's really that we're going to have the strange weather patterns — that for many of our trees and certainly those who sugar ... The trees respond to those cues and so when you start having more of that weird weird weather pattern, this bouncing up and down and can create some serious challenges from a from a health perspective for those species."