Air pollution damage to U.S. forests.

Abstract

A survey was made of the perceptions and estimates by forestry and air pollution experts, using a Delphi procedure with three sequentially mailed questionnaires. Five pollutants: ozone, sulfuric acid, nitric acid, sulfur dioxide and nitrogen oxides; and seven forest ecosystems in the us were included. Of the five pollutants at ambient levels, ozone is perceived as the greatest threat to forest growth. In contrast acid deposition is thought to cause growth reductions only in Appalachian high-elevation spruce-fir forests.