Sugar maples rely on consistent snow cover to thrive, and climate change is threatening that.
Maple syrup is a food that you might have to describe to your great-grandchildren because they won't be able to try it themselves. As climate change reduces the amount of snow in the northeastern forests of North America, where sugar maples grow, it will negatively affect the trees' ability to grow and produce sap, making maple syrup a treat from the past.
This alarming discovery was revealed in a study last week, published in Global Change Biology. The researchers explain how lack of adequate snowpack causes sugar maples to grow 40 percent slower than usual, and when the snowpack returns, they are unable to recover. One biochemist has described the study as a "big deal" and NPR writes, "This spells trouble for the trees — and for humans — as the trees not only give us syrup, but also eat up a chunk of carbon pollution."Forests play an important role, sucking carbon dioxide out of the air and storing it. They offset an estimated 5 to 30 percent of U.S. carbon emissions. But right now the forecast is dire for northeastern forests. Climate change is expected to shrink the amount of snow cover by up to 95 percent, which species like sugar maples rely on. (The snowpack insulates the trees and regulates "soil frost severity" – in other words, keeps the roots from getting damaged by too much cold.) In a worst-case scenario, that snow could go from covering 33,000 square miles each winter to a mere 2,000 by the end of the century.
"That's dwindling from an area bigger than Maine to one that's half the size of Connecticut. Even under a lower emissions scenario, the snowpack-covered area could still decline by 49 percent, to 16,500 square miles, says lead study author Andrew Reinmann, a forest ecologist at the City University of New York. 'So if you like skiing, go now.'" (via NPR)
The way in which the study was conducted is interesting. For five years (2008-2012), researchers shovelled away patches of snow that fell during the first four weeks of winter in the 8,000-acre Hubbard Brook Experimental Forest in New Hampshire. This was meant to approximate the diminished snowfall that's expected in New England by end of century. After four weeks of shovelling, the snow was left to accumulate for the rest of the season. NPR reports on the findings:
"After five winters of shoveling, and then a year off to see if the trees would bounce back, the researchers took core samples of the sugar maples and examined their growth rings. The sugar maples' growth slowed by about 40 percent after the first two years of the experiment. They did not recover in the year off. Reinmann says it's unclear if the trees will return to their normal growth pattern after a few more years with normal snow, or if the damage is permanent."
So far sugar maples – and the maple syrup industry – have managed to withstand climate change without difficulty, but there will come a time when conditions are too hostile for them to thrive. And that will be a sad day for so many more reasons than the fact that maple syrup-drenched blueberry pancakes will no longer be a breakfast staple.