Technical Bulletin No. 0561: Biological Indicators of Air Pollution Stress in Conifers: Progress Report
There are many sources of stress on trees. Insects, pathogens, drought, and other climatic or biological stresses can cloud our attempts to understand the impact of regional air pollution on forest health... This project is using ponderosa pine seedlings exposed to known air pollution conditions (ozone, sulfur dioxide, acid fog) to assess the effectiveness of several potential biological indicators of air pollution. This report is the first in a series on this project, and covers the development of such biological indicators and their initial assessment.