Sooner isn't necessarily better: Climate plays havoc with sap seasonBy MELANIE PLENDA
Special to the Sunday News March 10. 2017 7:10PM
It used to be that when St. Patrick's Day was just over the horizon and New Hampshire temperatures starting tickling the 40-degree mark, maple syrup producers knew they needed to get their buckets and boots and head out to their trees to begin the sap harvest.
In recent years, however, New Year's confetti is practically still littering the ground when local weather, at least in southern parts of the state, begins flirting with springtime temperatures and the sap starts its run through the sugar maples.
"There's no doubt that seasons are coming earlier and earlier every year and that's due to the warmer weather we're seeing each year," said Nick Kosko, co-owner of Meadow View Sugarhouse in Union and a board member with the New Hampshire Maple Producers Association. "Typically, the season starts when the day temperatures get into the 40s and the night temps are in the 20s. But now, it's starting earlier and the tail end of the season is not lasting into the middle of April anymore."
Many believe the abnormally high winter temperatures, which have hit New Hampshire over the past several years, are a consequence of climate change and as such will only worsen over time. And it has already started affecting maple syrup production in the Northeast.
The Northeastern Region, which includes Connecticut, Maine, Massachusetts, New Hampshire, New York, Pennsylvania and Vermont, produced 3.78 million gallons of syrup in 2016, according to the U.S. Department of Agriculture. Vermont alone produced 47.3 percent of the United States' maple syrup in 2016, a year in which both Vermont and Massachusetts posted record numbers.
And yet, even during a relatively good year, the effects of climate change were still apparent.
"The 2016 maple syrup season in the Northeastern Region was considered mostly favorable," according to the USDA survey. "Producers were encouraged to tap earlier this season by the warmer than normal temperatures. The earliest sap flow reported was January 1 in Pennsylvania, Vermont and West Virginia."
According the USDA, syrup production in New Hampshire has gone from 112,000 gallons in 2014 to 169,000 gallons in 2016, and the seasons have tended to start earlier and last longer. That's because our weather is getting warmer and wetter, said Cameron Wake, University of New Hampshire Research Professor of Climatology and Glaciology, who recently spoke at a Climate Impacts Maple Breakfast.
What that means for New Hampshire is warmer winters, a loss of snow pack, and fewer very cold nights. And that is affecting the state's production of syrup.
"There used to be a consistent sap run. You would get a predictable amount every day, (and) when it cooled off you know you'd have a shorter run," Kosko said. "But the runs are all over the place now. They come in really hard and fast because the trees warm up so fast and then they slow down. So if you don't have modern equipment like vacuum pumps, people really struggle if they don't make that kind of investment. And it's very expensive equipment."
When it comes to temperatures, the sweet spot for sap production is temperatures in the 20s at night, and 30s and 40s during the day, said Kosko.
"The tree needs a freeze/thaw cycle in order to pressurize the tree," he said. "Once the tree thaws, the pressure is then greater than the atmospheric pressure and that allows the sap to flow out of the drill hole in the tree.
"Without the freeze and thaw cycle, you never get that kind of movement."
Ray LaRoche, owner of LaRoche Farm in Durham, who also recently spoke to the Climate Impact group, said the change has lowered sap production. He told the Climate Impact group that back when he bought his farm in 2000, he was getting 75 gallons of sap.
"But with the environmental changes we've been seeing, it's down to 15 gallons," he said. "That's a dramatic loss for us. And I don't know what to do about it."
The warmer weather also changes the final product. Warmer weather can cause a tree to bloom prematurely, which in turn leads to sap that's cloudy, off-tasting and difficult to work with.
"Once the trees start budding the sap gets a woody flavor," Kosko said. "It sounds like it would be good, but it's really not. It's really bad. Plus it's hard to boil. It is like a jelly in your pan and it's congealed and you can't really boil it and it foams over and ugh, it makes a mess.
"And I think this is where all us sugar makers are starting to get real nervous."
Warmer temperatures further complicate the process, said Jeff Moore of Windswept Farms in Loudon and a member of the NH Maple Producers board, because it can mess with a tree's natural healing process.
"The other day we had a nice 50-degree day, which is kind of the new normal but still not normal," Moore told the Climate Impact group. "One of the challenges we've had to start weighing is when do we actually tap, because putting a tap into a tree is a wound, the trees naturally act to try to compartmentalize that wound and wall it off."
So the longer that tap has been exposed to the environment, the more likely that the tree is going to try to seal it off, Moore said.
LaRoche said he's also seen a drastic drop in the sugar content of his sap, which means producers must process larger amounts of sap in order to get the same amount of syrup.
Kosko thinks the issue syrup producers are most concerned with is the health of sugar maples.
"Is the conventional maple that grows in our backyard going to be there in the next 50 years?" he said.
Sugar maples are very picky trees. Kosko said they need fertile soil and the right temperatures, and they only grow in a relatively small region of the world: From Quebec down into Virginia and along the border as far west as Wisconsin.
"And that's about it," Kosko said. "They don't really survive anywhere else. And they should still be around in 50 years, but they will only be in certain pockets. Maybe they will only be in the White Mountains or in the northern half of the state. That will obviously decrease production."
To tackle the problem, Kosko said he and the producers association need to foster sustainability.
"You go around and you used to see four or five even six buckets on those giant maple trees," he said. "Maybe we should cut that back to two . It's not recommended to put in anymore than two taps. In order to help save the trees, we don't want them to sustain any more unnatural damage than they are already sustaining during climate change."