TITLE: Intensified Ozone Monitoring and Assessment of Ozone Impacts on Conifers in

PROJECT OBJECTIVES: The overall objective of this project is to quantify ambient ozone concentrations and tree conditions that constitute a risk to forest health in southern California national forests. Specific objectives include: 1) Installation of and collection of data from passive ozone monitors at 25 sites in southern California. 2) Evaluation of 50 ponderosa and/or Jeffrey pine at each site for ozone injury, mortality, and damage by other agents such as insects or diseases. 3) Co-location of 4 of the 25 passive monitors with existing active continuous monitors. 4) Analysis of ozone data and tree health data to characterize ozone distribution at landscape or forest stand scales, identify ozone hot-spots, and correlate ozone measurements among active, passive, and biological systems to tree injury and mortality. JUSTIFICATION: a) Linkage to FHM survey and plot data. The FHM/FIA program monitors ozone on an extensive grid consisting of one ozone biosite per 250,000 to 1,000,000 acres of forested land. In southern California, there are only 8 FHM/FIA ozone biosites in or nea