The public's attitude toward air pollution in the United States evolved substantially during the 1960s. One of the results of the nation's emerging environmental ethic was the creation of the U. S. Environmental Protection Agency (EPA) in December of 1970. Prior to this time, research was focused on the impacts of air pollution on human health and welfare and was largely conducted by several federal research agencies, which included the Department of Health, Education, and Welfare; the National Oceanic and Atmospheric Administration; and the U. S. Department of Agricul ture. After the creation of the EPA, much of this work was consolidated in one regulatory agency, which resulted in periodic evaluations of the various effects of atmospheric pollution on human health, materials, agriculture, and forest ecosystems. At the same time that environmental interest was growing in the United States, concern increased in the European scientific community and public over the ecological impacts of acidic deposition. As the magnitude of the damage to European lakes and streams and the widespread decline in Norway spruce and silver fir was reported, concern that similar problems were occurring in the United States increased substantially. This concern was heightened by press reports of high elevation spruce-fir forest declines in the Adirondack and Appalachian Mountains and the decline and death of sugar maples in the northeastern United States and Canada.

This book summarizes a five-year research program on the impact of air pollution on southern commercial forests. Topics covered include: the condition of southern commercial forests, abiotic and biotic stress factors on southern pine forests, growth and physiological effects of regional air pollutants on southern pines, and impacts of atmospheric deposition and ozone on southern commercial pines. The book will be of interest to scientists working on the effects of air pollution on trees, as well as environmentalists, policymakers, and resource managers.

The idea for this book arose in 1993, after the Free State of Bavaria through its Bayrisches Staatsministerium rur Landesentwicklung und Umweltfragen (Bavarian Ministry of Regional Development and the Environment) decided to discontinue both the Bavarian project management (PBWU) for forest decline research and the multidisciplinary field research on the Wank Mountain in the Alps near Garmisch. Forest decline through the action of ozone and other photooxidants was a main topic of the supported re search in the Alps and will be a topic of new investigations in the Bavarian Forest. Many interesting results were obtained, but the researchers involved have not had sufficient time to allow reliable conclusions to be drawn. It was therefore decided to ask inter national experts for contributions in order to summarize the best available evidence of a possible link between ozone and forest decline - a topic which has been studied in the USA since the late 1950s and in Europe since the early 1980s. The original idea of Waldsterben as an irreversible large-scale dieback of forests in Germany was soon recognized to be wrong (Forschungsbeirat 1989). However, the new criteria used for the official German and European damage inventories (loss or yel lowing of needles or leaves, tree morphology) indicate that per sistently high percentages of damaged spruce and pine remain, and there is an increasing percentage of damaged beech and oak, with a high proportion of biotic disease (Forschungsbeirat 1989; UN-ECE 1995).

The chapters in this book present a snapshot of the state of knowledge of air pollution effects at the beginning of the 21st century. From their different disciplines, a distinguished collection of authors document their understanding of how leaves, trees, and forests respond to air pollutants and climate change. Scenarios of global change and air pollution are described. The authors describe responses of forests to climate variability, tropospheric ozone, rising atmospheric CO2, the combination of CO2 and ozone, and deposition of acidic compounds and heavy metals. The responses to ozone receive particular attention because of increasing concern about its damaging effects and increasing concentrations in rural areas. Scaling issues are addressed - from leaves to trees, from juvenile trees to mature trees, from short-term responses to long-term responses, and from small-scale experiments and observations to large-scale forest ecosystems. This book is one major product of a conference sponsored by the International Union of Forestry Research Organizations, the USDA Forest Service Global Change Northern Stations Program, the Arthur Ross Foundation, NCASI, the Canadian Forest Service, and Michigan Technological University. The conference, held in May 2000 in Houghton, Michigan, USA, was appropriately titled "Air Pollution, Global Change, and Forests in the New Millennium". The Editors, David Karnosky, Kevin Percy, Art Chappelka, Caroline Simpson, and Janet Pikkarainen organized the conference and edited this book.

The effects of air pollution on biota may be subtle and elusive because of their interactions with natural stresses. Studies based on a network of sites in the Carpathian Mountains form the core of the content presented during this workshop. To this core are added key components on ecological sustainability, overviews on forest health in Europe and the world and several in-depth case studies.

The new approach to ecosystem health is proactive. As a result, the scope of environmental studies is growing and the methods are evolving. Integrated Assessment of Ecosystem Health aggressively broadens the range of ecotoxicology to include its related fields. The book begins with John Cairns, Jr.'s predictions and recommendations for the futur