Red cedar trees rebounded after Clean Air Act
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.
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 theirtree 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," Richard Thomas, a biology researcher at the University of West Virginia, told LiveScience.
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.
Results from the 1930s, the Great Depression era, were almost identical to the results from post-1980, Thomas said. The suppressed economy during the Great Depression led toreduced fossil fuel emissions. Tree rings from the 1930s showed improved tree growth and physiology.