Overview

• A decade-long experiment in New Hampshire showed that warming soil during the growing season boosted red maple biomass by 63 percent, but adding winter freeze-thaw cycles cut gains to 31 percent.
• Loss of insulating snow exposes soils to repeated freezing and thawing, damaging tree roots and slowing growth during winter months.
• Extrapolations across northeastern temperate forests suggest unaccounted snowpack decline could reduce carbon storage by more than one million tonnes per year by 2100.
• Northeastern forests currently offset about 20 percent of regional greenhouse gas emissions, a service threatened by shrinking winter snowpacks.
• Scientists are calling for Earth system models to integrate year-round climate dynamics and account for variability among forest types to improve carbon sink forecasts.