Air pollutant-induced stress to forest ecosystems

In recent years the term "acid rain" has captured the attention of the American public as a possible cause of forest damage and decline. As research progresses, it appears that the adverse impacts of "acid rain" on forest ecosystems are more complex and not as well understood as they generally are for aquatic ecosystems. Different types of air pollution -- including but not limited to precursors of acid deposition -- alone or in combination with stress factors, may pose a wide range of threats to forest ecosystems. This report examines the extent of forest damage and decline in the United States, the dynamics of the forest ecosystem and the major hypotheses put forth by the scientific community to explain the role of air pollutants in forest declines. The report concluded that the forest decline debate must take into account a wider range of pollutants than are usually included in legislative proposals which emphasize sulphur dioxide emissions.,Adela Backiel, Analyst in Natural Resources Policy and Alison L. Holt, Reference Assistant in Natural Resources Policy, Environment and Natural Resources Policy Division,CRS 86-560 ENR,"February 10, 1986.",SuDoc# 14. 18/3