MANHATTAN, KAN. -- A collaborative project involving a Kansas State University ecologist has shown that the Clean Air Act has helped forest systems recover from decades of sulfur pollution and acid rain.
The research team -- which included Jesse Nippert, associate professor of biology -- spent four years studying centuries-old eastern red cedar trees, or Juniperus virginiana, in the Central Appalachian Mountains of West Virginia. The region is downwind of the Ohio River Valley coal power plants and experienced high amounts of acidic pollution -- caused by sulfur dioxide emissions -- in the 20th century.
By studying more than 100 years of eastern red cedar tree rings, the scientists found that the trees have improved in growth and physiology in the decades since the Clean Air Act was passed in 1970.
"There is a clear shift in the growth, reflecting the impact of key environmental legislation," Nippert said. "There are two levels of significance in this research. One is in terms of how we interpret data from tree rings and how we interpret the physiology of trees. The other level of significance is that environmental legislation can have a tremendous impact on an entire ecosystem."
The findings appear in the scientific journal Proceedings of the National Academy of Sciences of the United States of America, or PNAS, in the article "Evidence of recovery of Juniperus virginiana trees from sulfur pollution after the Clean Air Act."
The principal investigator on the project was Richard Thomas, professor of biology at West Virginia University. Other researchers include Scott Spal, master's graduate from West Virginia University, and Kenneth Smith, undergraduate student at West Virginia University.
For the study, the scientists collected and analyzed data from eastern red cedar trees ranging from 100 to 500 years old. The researchers wanted to better understand the trees' physiological response and the
|Contact: Jesse Nippert|
Kansas State University