As scientists and leaf-peeping vacation planners wrestle with the question of how climate change is altering New England’s autumn foliage show, a tourist destination in Sugar Hill is proving valuable.
As reported in the Washington Post, Nancy Aldrich, owner of Polly’s Pancake Parlor, began writing down in 1975 when fall leaves changed colors because so many visitors asked when peak was going to be.
Cote, not to mention forest researchers, have that found estimating peak has become trickier in recent decades. Warmer temperatures have delayed the onset of fall, pushing the peak of fall leaf season back as much as a week in some areas over the past seven decades. Extreme weather events have also abruptly curtailed recent seasons or caused the color of the leaves to become duller.
“There has been and will be more variability year-to-year and more uncertainty,” said Andy Finton, a forest ecologist with The Nature Conservancy in Massachusetts, told the Post. “With climate change, it just adds more complexity to an already complex phenomenon.”
Cote told the Post her family’s documentations was mainly based on eyeballing when most leaves were red, orange and yellow instead of green. The observations were on display at the parlor for customers to read while they were waiting.
But environmental scientist Stephanie Spera was thrilled when she saw the observations, which are now posted on the restaurant’s website. She said this is the “longest record of fall foliage” that she has ever found.
Suitable satellite data only documented fall foliage back to 2000, which was not long enough to discern any trends. Instead, Spera and her student had to crowdsource information and photographs before the 2000s from the public, national park reports and newspaper clips.
Through the Second Century Stewardship Foundation, Spera is analyzing fall foliage changes at Acadia National Park in Maine.
“We actually were able to piece together, from the 1950s to now, peak foliage is occurring a full week later. It’s actually delaying a day a decade,” said Spera. Now, peak season doesn’t occur until around the second weekend of October.
The delay is partly linked to warmer temperatures, particularly at night, Spera told the Post. During the day, leaves use the sunlight to produce sugars. Cooler nights help trap the sugars in the leaf. The sugars lead to the production of pigments, such as anthocyanin that produce the brilliant red seen in maple leaves.
As summer temperatures last longer into the fall due to climate change, the warmer temperatures can degrade anthocyanin pigments as well as postpone the peak.
Spera analyzed Polly’s Pancake Parlor observations and found a similar delay in northern New Hampshire. Peak fall season is also extending to the mid-month holiday weekend in October, which Cote said is “great for business.”
Finton said the delayed onset is notable in New England due to the vibrant tree species and fall foliage tourism. Leaf peeping season generates billions of dollars for the local economy.
But he said these leaf peeping patterns could also be seen in deciduous trees around the world. The amount of delay differs depending on the region, with some studies showing a more pronounced trend in areas over others.
Rising temperatures could also relocating tree species. New England could see less of the brilliant Sugar and Red Maple trees, as southern species that flourish in the warmer weather could expand northward. Some of the southern species, like the oak or pine trees, have more muted hues.