Most cases of decline have been reported from Europe, North America, Australia and the Pacific Region. However decline is by no means restricted to these regions. There are reports of trees and forests affected by decline throughout the world. While the symptoms of decline may be strikingly similar, they can be the result of many different abiotic and biotic factors, often interacting in a complex manner. Some decline are the result of processes which are an integral part of the dynamics of forest communities. Others may be related to human activites including land management practices, emissions from motor vehicles or industrial processes. In many instances the causal factors responsible for decline are not known. The frequency of occurrence, pattern and intensity of decline or dieback may adversely affect the sustainable flow of goods and services from forests and influence forest management. Declines may also serve as indicators of forest response to climate change, an issue which is currently in the forefront of scientific and public interest. It is important, therefore, that foresters, ecologists, biologists and scientists from related disciplines understand the mechanisms and factors involved in declines so that appropriate forest monitoring and management systems can be implemented. The purpose of this paper, which is based on surveys of the published literature, unpublished reports, correspondence, personal experience and review by a number of specialists, drawn from developed and developing countries worldwide, is to provide an overview of declines and diebacks in a global context. Similarities and differences between decline events are examined, as are the mechanisms which are believed to cause decline. This paper is intended to serve as a reference source which describes case histories of declines from most of the world's forest regions and is designed for use by foresters, forest scientists, policy analysts and decision makers.
48 (Schäden infolge unbekannter oder komplexer Ursachen (nach Holzarten geordnet)) 425.1 (Gase und Schwebestoffe (Rauchschäden)) 181.45 (Einflüsse durch Verunreinigungen der Umwelt) 174.7 (Coniferae [Siehe Anhang D]) 176.1 (Dicotyledoneae [Siehe Anhang D]) [100] (Universal im geopolitischen Sinne in bezug auf Ort. International. Die Gesamtheit aller Länder)
