Pollution controls help red spruce rebound from acid rain
Thirty years ago, acid rain caused mostly by pollution from coal and other fossil fuel burning plants in the Midwest was killing red spruce trees on mountaintops across the Northeast.
Now scientists say the trees are rebounding due to stricter air pollution regulations and a changing climate.
Researchers studied data from 658 red spruce trees in 52 plots in Vermont, New Hampshire, New York, Massachusetts and Maine and found that 75 percent of the trees and 90 percent of the plots showed increasing growth since 2001. They credited cleaner air and a warming climate that has given the trees a longer growing season.