Climate Change-Related Vulnerabilities in Hardwood Forests of Central US Detailed in New Study

Hardwood forests in regions of the US Midwest will see increased periods of precipitation and drought, as well as higher temperatures, according to a US Forest Service report assessing forest vulnerability and ability to adapt to climate change.

The study centered around Midwestern hardwood forests in what's known as the Central Hardwoods Region, which encompasses southern Indiana, southern Illinois, and the Missouri Ozarks.

"People often think of climate change as being distant, either geographically or temporally," said lead study author Leslie Brandt, a climate change specialist with the Forest Service's Northern Institute of Applied Climate Science (NIACS).

"Our intent was to create a climate change resource that will be relevant to people who work, study, recreate, manage and care about the ecosystems in the Central Hardwoods Region," Brandt said.

Rising greenhouse gas concentrations are expected to bring higher temperatures to the region, which will lead to a longer growing season, the Forest Service reports.

Wintertime temperatures will also rise, which will lead to changes in typical snow cover and soil frost.

When and how the region will experience precipitation will also change, the researchers report, noting that it's possible soil moisture may decrease later in the growing season.

As the climate changes, conditions will likely come to favor southern tree species like shortleaf pine, while northern species such as sugar maple, American beech and white ash may see adverse effects, the researchers report.

The vulnerability assessment also found that in the future, tree species may have a more difficult time spreading to new areas.

Ecosystems that are adapted to fire, such as open woodlands and savanna, may be more resilient in the future if climate change leads to more fires, the researchers said.

"Plants, animals, and people all depend on forests and may all face additional challenges as temperatures increase and precipitation patterns shift," said study co-author John Shuey, Director of Conservation Science for the Indiana Chapter of The Nature Conservancy. "But we don't have to wait until these changes wreak havoc on our forest habitats. We can start managing for the future today by nudging our forests towards species adapted to withstand future climates."

More than 100 years of data on the Central Hardwoods Region has revealed that the minimum temperature in the region has increased by about 2 degrees Fahrenheit, that the region receives as much as 17 percent more precipitation now than it did at the turn of the last century, and that a decrease in snow cover since the 1970s has led to an increase of soil frost.

"Confronting the challenge of climate change presents opportunities for managers and other decision-makers to plan ahead, foster resilient landscapes, and ensure that the benefits that forests provide are sustained into the future," said Michael T. Rains, Director of the Northern Research Station and the Forest Products Laboratory. "Forest Service science is delivering tools and data that will help managers in the Central Hardwoods and throughout the nation meet this challenge."