Technical Bulletin No. 0495: Forest Health and Air Quality in the Western United States

For at least one decade prior to this technical bulletin, there was concern about "acid rain" and associated air quality problems in the eastern United States. Reports about forest die-back in Germany and unexplained growth declines for some species in the United States focused these concerns on forest effects. Although much of the research on air quality and forest health continued to center on the Northeast and Southeast United States, other regions, including the West, came under increasing scrutiny.