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Geography in the News: Maple Syrup Time

By Neal Lineback and Mandy Lineback Gritzner, Geography in the NewsTM and SUGAR TIME IN NEW ENGLAND Sugar maple are tapped in New England and 2013 may be a better year for the maple syrup industry after several declining years. Maple syrup, that sweet sticky syrup that makes mere pancakes incredibly delicious, is threatened...

By Neal Lineback and Mandy Lineback Gritzner, Geography in the NewsTM and


Sugar maple are tapped in New England and 2013 may be a better year for the maple syrup industry after several declining years.

Maple syrup, that sweet sticky syrup that makes mere pancakes incredibly delicious, is threatened by warming trends in the Northeastern United States. Sugar maple farmers in New England declared the 2012 season too warm for optimal sap flow and have seen diminished production again this year. Especially dependent on the climate, the sugar maple tree needs freezing winter nights followed by warmer days to produce the sap used to make maple syrup.

The sugar maple is one of several sap-producing maples that occur in the mixed forests of the northeastern United States and southeastern Canada. Farmers cultivate the sugar maple, affectionately called “sugar-bush” by syrup producers, for its sap across the upper U.S. Midwest, Pennsylvania, New York and particularly New England.


The sugar maple is a hardy broad-leaf, deciduous tree, whose fall foliage turns the rural countryside into a kaleidoscope of yellows, oranges and reds. After the leaves fall, sugar maples go into a dormant period that lasts through the winter.

During subfreezing winter nights, maple trees concentrate their natural sugar, as sap chills in the trunks. Ideally, when sapping season begins in March, a sharp difference in nightly freezing and daily warming creates pressure inside the trees’ trunks, which begins the sap flow. Sugar collectors tap the trees’ trunks by drilling holes into them, allowing the sap to flow freely during the brief three- or four-week sapping season. If the weather is erratic, with days that are too warm or nights that are bitterly cold without protective snowfall, the run of sap will be reduced.

In the past, farmers tapped trees on their farms by inserting metal tubes and hanging buckets to catch the sap. Today, most commercial orchard taps are interconnected by a series of plastic tubes leading to a sugarhouse, eliminating the cold and difficult task of carrying buckets of sap through the snow. Maple syrup producers boil the sap in the sugarhouse to make maple syrup. It generally takes about 40 gallons (151 L) of sap to make one gallon of syrup.

The geographic trends in maple syrup production may hint as to how global warming is affecting the industry. In the 1950s, the United States produced 80 percent of the world’s maple syrup, with Canada producing the other 20 percent. Since the 1970s, however, Canada has more than tripled its maple syrup production, making it the current world leader. Canada now provides 80 percent of the world’s maple syrup, with Quebec alone producing more than two-thirds of the global supply.

Much of Canada’s syrup dominance has been perpetuated by generous farm subsidies from the Canadian government and the strong development of markets both in Canada and throughout the world. However, researchers now believe climate change is also playing a role. While rising temperatures and more erratic weather patterns have already affected New England’s maple syrup industry, they may eventually force maple syrup production to migrate farther north into Canada.

According to the Christian Science Monitor (April 6, 2005), a group of researchers at the University of New Hampshire forecasts that if climate change predictions are accurate, oak and hickory trees—not maples—will dominate New England forests by the end of the century. If temperatures rise 6 to 10 degrees F (2 to 4 degrees C) over the next century as predicted, sugar maples will be unable to compete with oaks and hickories.

A more immediate short-term affect, however, is the temperature-driven trend toward shorter sugaring seasons in New England, according to Dr. Timothy Perkins, director of the Proctor Maple Research Center at the University of Vermont. Perkins’ research shows that Canada is not experiencing the recent milder winter phenomena that have been exclusive to New England.

The period during which “sugaring” occurs has shortened substantially over the last four decades. As of 2007, the syrup-collecting period in New England and New York begins 8.2 days earlier and ends 11.4 days earlier than it did 40 years ago.

This year’s maple syrup production in the United States equaled 1.91 million gallons (7.2 million L), down 32 percent from 2011. This figure represents the lowest production since 2007. Vermont continues to lead the U.S. producers with 750,000 gallons (2.8 million L) in 2012, down 34 percent from its production in 2011.

Strangely, the first sap runs in New England began in January and February last year in 2012, catching producers unprepared. March brought a heat wave in the 70s and 80s F (16-21 C), which forced early budding of maple trees and quickly ended the maple syrup season. This year has been colder, prompting the first sap runs to be later and hopefully more productive.

If the warming trend and erratic weather persists during future sapping seasons, however, producers should expect a continued decline in traditional U.S. maple syrup production. We may still have maple syrup for our breakfast pancakes, but no longer will the label read, “Made in the U.S.A.”

And that is Geography in the News.

Co-authors are Neal Lineback, Appalachian State University Professor Emeritus of Geography, and Geographer Mandy Lineback Gritzner. University News Director Jane Nicholson serves as technical editor.

Sources: GITN #655, Global Warming Slows Maple Syrup’s Flow, Dec. 20, 2002; GITN #1168, Maple Syrup Affected by Climate Change, Oct. 19, 2012;;;; and

This article is an abbreviated and updated version of GITN #1168 published by in Oct. 2012. Nearly 900 of the 1200, full-length weekly Geography in the News articles (with Spanish translations) are available in the K-12 online education resource, including maps and other supporting materials and critical thinking questions.


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Meet the Author

Neal Lineback
Neal Lineback has written weekly Geography in the News (GITN) articles for more than 25 years (1,200 published articles) while he was Chair of Geography and Planning at Appalachian State University and since. In 2007, he brought his daughter Mandy Gritzner in as a co-author. She is also a geographer with a graduate degree from Montana State University. GITN has won national recognition and numerous awards from the Association of American Geographers, the National Council for Geographic Education and Travelocity, among others..