Climate change is leaving a mark on one of New Hampshire's springtime rituals: maple sugaring.
Scientists and farmers dug into the latest research over pancakes in Plymouth on Tuesday.
Mount Washington Observatory research director Eric Kelsey says maple trees face a lot of stresses: abnormal storms, droughts, excess road salt, acid rain and new pests.
"And that might explain the general 25 percent decrease in sap-sugar content we've seen over the last 40 to 50 years,” Kelsey says.
He says climate change is a "wild card" in how those stressors may increase or decrease in future. Those issues also affect maple trees' fall colors, which help attract leaf-peeping tourists each year.
Longtime Granite State maple farmer Brad Presby downed a glass of syrup at the annual breakfast, then said his sugar season comes earlier each year.
He also says new regulations are making it harder to run a small-scale maple business.
The newly appointed head of the Environmental Protection Agency in New England, Alexandra Dunn, also spoke on the panel. It was hosted by several nonprofits that have been outspoken critics of EPA administrator Scott Pruitt's agenda.
Dunn says she hopes more local and state control of climate policy will help sustain traditions like maple syrup season.
An earlier version of this story incorrectly stated that all stressors on maple trees were increasing due to climate change. In fact, Mount Washington's Eric Kelsey says it's not yet clear how climate change will affect those stressors.