• Photo: flickr/ kylemac

The crisp March air is fragrant with woodsmoke and sap. Snow crunches underfoot as we haul metal pails of the translucent liquid to a squat wooden building, where my uncle tends the fire. His job is to ensure that the sap doesn’t boil down too far, but he always makes time to dribble fresh maple syrup onto the snow, where it turns into a gooey, sugary mess. With this taffy sticking to my teeth (and keeping me quiet), my uncle tells stories about growing up on an Ontario farm during the Great Depression and sings along to a scratchy Louis Armstrong eight-track.

Map of the shifting region of sugar maple growth.

These are my childhood memories of spring, of sharing in an intrinsically Canadian tradition that dates back centuries, when maple syrup season was seen by First Nations as a time of rebirth for the Earth. Canada produces about 85 percent of the world’s maple syrup, a product valued at more than $354 million in 2009, with the vast majority coming from Quebec. The United States is both Canada’s largest export market and the world’s only other major producer. But these statistics and this rite of springtime are at risk as a changing climate impacts the health of sugar maples and our ability to efficiently harvest their sap.

There’s no immediate cause for concern. In Quebec, 2009 was a banner year, an anomaly with nearly double 2008’s maple syrup production. But 2010’s production will likely dip below the 2008 level ($212 million was the national total that year), and taking a long-range view, Kevin Pelletier is worried. For 80 years, his family has been making syrup in the Saint-Pamphile area east of Québec, near the Maine border. They’ve been producing syrup commercially for 18 years as Ferme Vifranc Inc. and keep a logbook in the sugar shack to determine when to start tapping. But such predictions have become problematic. “Spring is coming sooner than expected,” says Pelletier. “We normally start at the end of March, but this year, we started March 7.”

The story is the same in Ontario. Wayne Horne, whose family has been making maple syrup near Orillia, Ont., for more than 100 years, says “we’ve seen radical season changes. Either winter weather in spring or summer weather in spring.” Indeed, 2010 was wonky. Some producers began tapping as early as January. Yet in several recent years, the sap has barely run. Moreover, Ferme Vifranc’s records show a decline in sap production over the past five years, from about 1.4 kilograms per hole to about 1 kilogram. And that’s despite the array of high-tech help, such as vacuum pumps and reverse-osmosis techniques, now commonly used to increase production. All of this begs the question: Why? To produce sap, sugar maples need nights below freezing, followed by warm days, but this once consistent springweather pattern is becoming erratic. Changing snowfall patterns also have an impact. Under a reduced snowpack, the ground freezes deeper and takes longer to thaw, which delays the flow of sap. Snow cover also moderates the rate at which the ground thaws, which can create a longer “sugaring period.”

Acid rain, which changes soil composition, is also a factor. In acidic soil, sugar maples produce fewer seedlings that survive and mature, and more adult trees die as well. Smog, drought and severe heat are additional stresses that can reduce the amount of sugar a tree produces. And without the cold winters of my uncle’s childhood, the pests and diseases that harm maples are more likely to proliferate.

The only thing that producers can do is be reactive to these changes. “We can’t control how maple sap is produced by the trees,” says Horne. In other words, people can better time their tapping, use high-tech techniques, tap more trees and seed the soil with pellets to reduce acidity, but without conditions close to the ideal temperature swing from -5°C nights to 5°C days, those efforts could be moot. In the United States, maple syrup producers face bigger challenges. As temperatures gradually increase, the climatic range that maples need in order to grow is shifting north. But maples prefer deep, fertile, well-drained sandy loam, which isn’t found farther north. “In the long term, maples could become extirpated from parts of the United States,” says Tim Perkins, director of the University of Vermont’s Proctor Maple Research Center. “It’s possible that the industry will disappear in the United States and that only a few hobbyists will remain.”

Considering that much of Vermont lies north of prime sugar maple territory in Ontario, that’s a cause for concern on this side of the border too.