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Red cedar trees breathing cleaner growing faster

A species of old trees in the Appalachian Mountains is growing faster than expected in the wake of clean-air controls implemented decades ago, a new study shows. Source: Huffington Post

The research on eastern red cedar trees all between 120 and 500 years old also showed changes in the types of carbon and sulfur in their tree rings a few years after the Clean Air Act was enacted in 1970.

“The first thing that got us interested was how these old trees are doing, and what are some of the physiological mechanisms that allow the old trees to stay alive,” said Richard Thomas, a biology researcher at the University of West Virginia.

“When we saw all this change in growth and the change in isotopes in the early 1980s, the research went into a different direction … it was like a detective story, almost, trying to eliminate each little thing.”

The Clean Air Act requires the Environmental Protection Agency to set air quality standards for six “criteria pollutants”: carbon monoxide, lead, nitrogen dioxide, ozone, sulfur dioxide and particulate matter.

It also has provisions to address problems such as acid rain.

Before its implementation, the Appalachians were a “bull’s-eye” for acid pollution due to a large number of power plants along the Ohio Valley, Thomas said.

The effects were clear in core samples taken from the trees: sulfur isotopes (variations of an element with a different number of neutrons) pointed to pollution, and carbon isotopes showed that the trees’ stomata (the pores that are opened and closed to regulate the exchange of carbon dioxide and water) were closing.