Researchers at a loss to explain why sugar maple trees are in decline

Researchers are at a loss to explain why the trees that produce maple syrup are in decline, Glenn Coin reports for Syracuse Media Group. The study by the SUNY College of Environmental Science and Forestry published in the online journal Ecosphere shows that sugar maples "are growing more slowly since 1970 than they were before, even though growing conditions have gotten better." (Post-Standard photo by Michelle Gabel: Sugar maples in the Adirondacks are growing more slowly than they used to.)

Researchers studied 76 northern hardwood stands in northern Pennsylvania, New York, Vermont and New Hampshire, concluding "that acid deposition induced changes in soil nutrient status that crossed a threshold necessary to sustain sugar maple growth during the 1970s on some sites."

Since the 1990s, "new regulations have dramatically reduced acid rain and its effects," Goin writes. Professor Coin Beier, who oversaw the study, told Goin, "Given these changes, we would expect these trees to be thriving, but they are not." Graduate student Daniel Bishop, who led the study, told Goin, "Given their relatively young age and favorable competitive status in these forests, these sugar maples should be experiencing the best growth rates of their lives. It was a complete surprise to see their growth slow down like this." (Read more)