Maple trees pose a rare threat

Due to this winter’s unusual February warm weather followed by the severe cold snap in March, experts say that Maple trees pose a particular, once in a generation risk. “In the right conditions – or should I say, wrong conditions – maple trees can experience what is known as sap pressure build-up,” Said Saint Michael’s College groundskeeper William MacDougal. “Older trees have been known to have branches actually explode from the pressure.”

While extremely rare, the phenomena is not entirely unknown. Professor Mark Lubkowitz of the Saint Michael’s biology department explained, “Maple trees have a large amount of liquid in the form of sap inside them.  During the winter months that liquid is stored below ground in their roots. As the weather warms, freeze thaw cycles begin which causes the liquid sap to move up the tree at night when it is cold, but during the warmer days the liquid-sap returns to the roots. The movement or “run” is what allows us to tap trees for sap to make syrup.” Lubkowitz added, “Sap-pressure build up can happen in older trees causing weaker branches to burst, and in rare cases the trunk of the tree can burst too.”

Groundskeeper MacDougal recalled a colleague maimed by an exploding maple in 1968. “We were sugaring as we usually did, when Mike started a new tap in an old maple. Well, doggone if after an inch or two there was a huge bang! It was like popping a balloon with a pin,” said MacDougal. “The face of that maple exploded putting sap and splinters all over Mike. Poor guy. He recovered ok, but never would put maple syrup on his pancakes anymore.”

The College Office of Communications was not able to confirm the phenomena in its research. Asked about sources for his knowledge of it, Professor Lubkowitz said, “groundskeeper Willie told me.”

More information about groundskeeper MacDougal can be found here.