Forest Decline And Ozone

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 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).

Forest damage, forest decline, forest dieback - not related to biotic agents - is occurring in the Atlantic and Pacific regions. In Europe and Eastern North America this serious problem is considered to be, at least to some part, related to industrial air pollutants and their atmospheric conversion products, such as acid rain or ozone. Forest declines in the Pacific region have been attributed largely to natural causes involving forest dynamics, since air pollution and other negative anthropogenic influences are practically absent. Presented here are typical decline phenomena in the Pacific and Atlantic region, potential causes, effects and mitigation strategies, and the question whether there are any similarities on a functional or structural basis is addressed.

The book contains information on geology, climate and vegetation of the Sierra Nevada with a special emphasis on air pollution effects on the mixed conifer forests. A history of the extent of air pollution effects on mixed conifer forests, especially ponderosa and Jeffrey pines is provided. The physiological basis for ozone-type injury development in ponderosa pine, a discussion of ozone uptake by plants at different levels of biological organization and the effects of air pollution and other stresses on mountain forests are discussed. A considerable portion of the book is dedicated to development of statistical models and maps of ambient ozone distribution in the Sierra Nevada based on the 1999 monitoring data with passive samplers. The implications of the methodological results, formulation and application of regional air quality models for integrated assessment of urban and wildland pollution and the need for functionally integrated models of ozone deposition to the Sierra Nevada forests are also discussed. Management and monitoring needs for improved long-term understanding air pollution effects on forest ecosystems, discussion of options for proper management of the air pollution affected forests, and comparison of monitoring and modelling of ozone and forest health status in the Sierra Nevada with similar efforts in mountains of North American and European mountain ranges are the focus of the later chapters of the 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.

Overzicht van chemische eigenschappen van werkzame stoffen