Saturday, October 5, 2013

An update on acid rain in Vermont

Several decades have passed since acid rain became a common catch phrase in most American households. Scientists and environmental groups blamed Midwest power producers, claiming that sulfur from coal power plants was entering the atmosphere, polluting the air and falling in the form of acid rain over places like New England, polluting lakes and killing trees.

More than 30 years later the battle has subsided but scientists say acid rain hasn't gone away."I think it's still a big problem," said Gary Hawley, a researcher at the University of Vermont.Now several decades later, most lakes and ponds have recovered from the effects of acid rain, but that same success isn't evident in the soil, where the effects of acid rain are long lasting.

"We are actually seeing a continued problem with forests in particular," said Paul Schaberg of the U.S. Forest Service. "The soil is not rebounding; the calcium is not coming back in those places."

Hawley and Schaberg are two of the leading acid rain experts in Vermont. After years of research they now know calcium is vital to a tree's physiology and that acid rain stresses trees by depleting calcium in the soil. Much of their research is conducted in New Hampshire where millions of dollars have been spent treating an entire watershed with calcium, restoring the forest to pre-acid rain levels.

"It's been remarkable," Schaberg said. "Every species we look at responds to the native stresses that are out there better than when the calcium is back."Today many New England forests still suffer from the acid rain of the 1980s and 90s. It takes a long time for calcium to build back up in the soil. But there are signs things are getting better."We've shown less acidity in the rain coming in more recently," Hawley said. "However it's not a huge change."Hawley credits clean air legislation in the 90s that forced coal plants and others to reduce emissions. But he cautions the acid rain problem is far from solved.

Thirty years later, acid rain is still taking its toll on the ecosystem. A problem Hawley says is now compounded by climate change and rising levels of car pollution."The same pollution in the air adding to climate change is the kind of pollution that's acidifying the atmosphere as well," he said.And that's why both of these men say events like

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