Air pollution damage to US forests: a survey of perceptions and estimates by scientists

Used a modified Delphi procedure to survey the work of experts in forestry and air pollution to obtain estimates of the current and future forest stand growth change in major US forest ecosystems caused by air pollutants, and to determine the degree of variability associated with those estimates. Ozone was perceived as having caused some growth reduction in all major forest ecosystems, and represented the greatest threat to forest growth, while most respondents felt that sulphur dioxide and nitrogen oxides had not caused damage on a regional scale. The overall prognosis, however, was of increasingly severe damage over the long term. Of the 7 major forest ecosystems examined, the S California conifer and Appalachian high elevation spruce-fir systems are perceived as having experienced the greatest damage from air pollution. -P.J.Jarvis