Oxidant Air Pollution Impacts in the Montane Forests of Southern California

Section 1. Description of Soils, Climate, Natural Resources, and Their Modification by Anthropogenic Influences.- 1. Geography, Geology, Geomorphology, and Forest Soils.- 2. Climatology.- 3. Vegetation, Fire Regimes, and Forest Dynamics.- Section 2. Effects of Ozone and Other Air Pollutants on Vegetation and Soils in the San Bernardino Mountains.- 4. Ambient Air Quality at Barton Flats and Other California Forests.- 5. Visibility Impairment in the San Bernardino Mountains.- 6. Physiological Responses of Ponderosa Pine to Gradients of Environmental Stressors.- 7. Temporal Changes in Crown Condition Indices, Needle Litterfall, and Collateral Needle Injuries of Ponderosa and Jeffrey Pines.- 8. Air Pollution Effects on Growth of Ponderosa Pine, Jeffrey Pine, and Bigcone Douglas-Fir 179.- 9. Effects of Ozone on Understory Vegetation in the Mixed Conifer Forest.- 10. Epiphytic Lichens in the San Bernardino Mountains in Relation to Oxidant Gradients.- 11. Wet and Dry Pollutant Deposition to the Mixed Conifer Forest.- 12. Direct Effects of Nitric Acid on Forest Trees.- 13. Nitrogen Deposition and Cycling in Mediterranean Forests: The New Paradigm of Nitrogen Excess.- Section 3. Interactions of Physical, Chemical, and Biological Factors and their Influences on Forest Health and Forest Use.- 14. Insects and Pathogens in a Pollution-Stressed Forest.- 15. Impact of Oxidant Air Pollutants on Forest Succession in the Mixed Conifer Forests of the San Bernardino Mountains.- 16. Simulated Effects of N Deposition, Ozone Injury, and Climate Change on a Forest Stand in the San Bernardino Mountains.- 17. Human Aspects of Air Quality in the San Bernardino Mountains.- Section 4. Synthesis and Conclusions.- 18. Assessment of Ecological Risks and Implications for Policy and Management in the San Bernardino Mountains.- 19. Implications of Chronic Air Pollution in the San Bernardino Mountains for Forest Management and Future Research.

Because of their proximity to major urban areas, the San Bernardino Mountains have served as a natural laboratory for studying effects of oxidant and acidic air pollution on a mixed-conifer forest. This volume presents a body of research conducted over more than thirty years, including an intensive interdisciplinary five-year study begun in 1991. Chapters include studies of the relationships of biogeography and climate to the region's air pollution, the chemical and physiological mechanisms of ozone injury, as well as the impacts of nitrogen-containing pollutants and natural stresses on polluted forests.