UMass Amherst Professor Gives Advice on Extensive Tree and Shrub Bending

AMHERST, Mass. - A University of Massachusetts tree expert says the recent heavy snowfall has taken its toll on the region''s trees, causing many to break and others to remain bent over from the weight of snow and ice.

Those that were bent will most likely recover on their own, says Brayton Wilson, professor of forestry and wildlife management. Wilson has conducted extensive research on tree and shrub bending and says that almost all trees and shrubs have some mechanism for recovering from this kind of trauma.

"If you leave them alone," he says, "in all likelihood, they''ll come back on their own." He cautions people not to permanently tie trees that have been bent into an upright position. That makes the lower portion of the tree grow more slowly and become weaker as a result.

Particularly hard hit by this year''s storms, says Wilson, are small white pines and birches. "If they''re kept down long enough," he says, "they won''t come back up. But most can usually recover. Those that are bent over now, though, can''t do anything to recover until they start growing again, probably in mid-May."

Wilson says pines manufacture a certain kind of brownish wood called "compression wood" that forms inside the trunk along the underside of the bent portion. According to Wilson, when a tree is cut, one can actually tell how many times it has suffered from bending from the amount of compression wood that''s visible. "If the tree can grow enough of this wood, it can actually push the entire tree back into a vertical position," Wilson says. It all depends, however, on factors such as how much light the tree receives and how big it is.

Birch and other deciduous trees, says Wilson, react in a similar fashion to bending by growing a kind of wood known as "tension wood." Some shrubs also act in the same manner while others, he says, simply put out new shoots that grow vertically and help the plant stay upright.