How climate change is making maple syrup less sweet and undermining production in NY, NJ
On a cold February day in the hills of the Finger Lakes, thousands of leafless maple trees lay dormant, patiently awaiting the kiss of spring. Armed with a hammer and a drill, Aaron Wightman walked through deep snow in the Arnot Teaching and Research Forest.
Wightman pointed the drill into the bark of a sturdy tree and followed with a sharp forward thrust. Then he hammered a beak into the wooden hole. Within weeks, the tree would produce a fine, sweet sap that would become maple syrup.
Wightman’s family has been making maple syrup for generations. He has been tapping trees since childhood, but has seen warming winter-spring temperatures push back the tapping season by more than a month.
“We didn’t even tap until late February or early March when I was young,” said Dr. Wightman, co-director of the Maple program at Cornell University. “Now we’re typing in early January.”
Americans are the world’s largest consumers of maple syrup and New York State holds the title of second largest US supplier after Vermont. Now, in the midst of a global pandemic as more of us cook at home, demand for gold has skyrocketed.
But this increase in demand coincides with a changing climate that is bringing warmer winter temperatures to much of the northeast. And winter and early spring temperatures determine how well the valuable maple sap flows. The climate problem was so detrimental last year that it reduced the world supply of maple syrup.
Relentlessly, it could even threaten the production of maple syrup on this side of the northern border.
This is because the sugar maple—Acer saccharum—is extremely sensitive to temperature changes. It’s a bit like Goldilocks. Sap flow depends on temperatures being “just right”.
“When trees go through a period of freezing followed by a thaw, that sugar-laden sap gets pressurized inside the tree and we can drill a hole in the tree and the sap flows out,” said Wightman.
In the northeast, these freeze-thaw events occurred in early to mid-spring, he said.
“Now we see sap collection peaking more from early February to late March,” Wightman said. “We have fewer of these freeze-thaw cycles.”
Wightman and his small team operate an evacuated tube system that connects to approximately 8,000 maple trees. Once collected, the sap passes through a reverse osmosis machine which removes 80% of the water and sends the sweet concoction through an evaporator, which concentrates it into a thick, tea-colored syrup.
The system draws sap through rain and snow. But that was no match for spring 2021, when excessively hot temperatures brought the season to an abrupt end. The taps dried up and New York’s maple syrup harvest dropped 20%. Wightman thinks that number could be even higher.
“It’s been a horrible year, by any standard,” he said.
After last year’s maple sugaring season was cut short by mild weather, New York’s maple syrup producers are hoping for a break from the heat.
Native Americans used maple trees for food and healing centuries before the arrival of Europeans.
“Maple syrup is a real niche crop in North America,” said Dr. Navindra Seeram, a natural products chemist at the University of Rhode Island. “It’s one of the few cultures that wasn’t brought by the settlers, the Europeans, when they came to America and Canada.”
Hundreds of years later, climate change is having a direct effect on maple trees, and that includes warming summers.
“That’s because the trees we rely on to make maple syrup are mostly growing during the summer,” said Dr. Pamela Templer, professor of biology and forest ecologist at Boston University. “If the conditions are right in the summer – it’s neither too hot nor too dry – then the trees will have higher rates of photosynthesis.”
The more photosynthesis, the more sugar trees can produce. But the summer of 2020 was particularly hot and dry in the northeast, leading to poor growing conditions and less sugar in the sap the following spring.
Sugar maples prefer cool, moist climates, notes Templer. So much so that models predict that the range of sugar maples will shift north.
“As air temperatures warm, we are seeing a northward shift in sugar maple distribution,” she said. “Some people think that by the year 2100 maple syrup production could change about a month earlier, which means that eventually it will happen so much earlier that we won’t have the good conditions for making maple syrup, whatever it is.”
The lackluster 2021 season has resulted in a supply shortage that has been superimposed on a global increase in demand for maple syrup. According to Les Producteurs acéricoles du Québec, their worldwide sales increased by 23% last year. Demand is such that Quebec, the world’s leading supplier, has to draw on its strategic syrup reserve.
Yes, French Canadians have a strategic reserve of maple syrup, located in Laurierville, Quebec, about two hours northeast of Montreal. The reserve houses the beloved golden syrup in 600-pound barrels.
But the production shortfall siphoned off 65% of the reserve last year, the group said. “Production has gone down, and consumption has gone up,” said David Hall, president of the group’s Montérégie Est region. And on a sour note, the sap wasn’t very sweet, he said.
“The sugar content of the sap was lower, and I mean much lower,” Hall said. “We had a lot of sap. There was just no sugar in it.
Pure maple syrup – not to be confused with processed pancakes or table syrup – is about 67% sugar when finished. It also contains a multitude of nutrients.
“It is well known to contain potassium, manganese, magnesium, calcium, as well as vitamins like B12, thiamin, as well as phytonutrients – a wide variety of natural compounds known to be present in other healthy plant foods such as green tea, red wine, berries and flax,” Seeram said. But, he added, pure maple syrup contains more than 50 calories per tablespoon.
“It’s a product you should spritz on, not swallow,” Seeram said. “It should be used like any other sweetener, in moderation.”
Other species such as red and silver maples have ranges that extend further south. They can withstand warmer temperatures, but their sap is less sweet.
At Happy Day Farm in Manalapan, New Jersey, farmer Tim Stockel threw logs into the bottom of a wood-fired evaporator in late February. The machine uses approximately 80 gallons of sap, made primarily from red maple trees, to produce one gallon of maple syrup.
“Here in New Jersey we don’t have that many sugar maple trees, at least not here in Monmouth County in central New Jersey, where I am,” Stockel said. “So I have to work a lot harder to boil this sap water to get maple syrup.”
While his maple trees were productive last year, his other crops haven’t been as good.
“We were hit by two horrible storms,” he said. “My zinnia flowers and my blueberry plants were in a foot of water. So yes, the storms that come through, they are rougher and stronger.
When asked how he coped with the extreme weather conditions, Stockel said he was resigned to face whatever might come his way. “(I) just roll with the punches, you know,” Stockel said.
Extreme weather events — ice storms, floods and tree-destroying winds — are another aspect of climate change that maple producers must deal with.
Melting snowpack is another problem, as it exposes the ground to freezing temperatures that can damage sensitive root systems, said Eric Randall, former president of the New York State Maple Producers Association. “This snowpack acts like a giant refrigerator,” he said.
Randall is also concerned about threats posed by invasive species like the spotted lanternfly and the Asian longhorned beetle, which together have decimated thousands of maple trees in New York, Massachusetts and other states.
But he remains positive about the future of American-made maple syrup.
“It’s as pure a product as it gets,” Randall said, pointing to the growing demand for products like maple soda and beverages. “It’s not just a pancake filling anymore.”