Trees Suffer One-Two Punch Of Acid Rain And Climate Change
Sep
02
Forests in Vermont’s Green Mountains transition abruptly from a heat-loving mix of sugar maple, American beech, and yellow birch on the lower slopes to a cold-adapted mix of red spruce, balsam fir, and paper birch higher up.
A new study shows that the altitude of that transition zone rose as much as 400 feet between 1962 and 2005-right in sync with a hike of 2 Fahrenheit degrees in the area’s mean annual temperature.
Brian Beckage of the University of Vermont in Burlington and five colleagues documented those changes with aerial photographs, satellite imagery, and on-site measurements. That cold-loving vegetation should retreat up mountain slopes as the climate warms is hardly unexpected. But the researchers were surprised that such a marked shift occurred within just 40 years -less than the natural life span of many trees.