A synthesis of survey results: The Extent of Forest Decline in Europe

Abstract

During the last ten years, the concern about forest decline attributable to air pollutants has increased dramatically. In the early days of industrialization, symptoms of damage were evident on trees in the vicinity of smokestacks. However, the problem gained wide publicity only in the early 1980s when the first quantitative estimates of damage were made in some European countries. The estimates, based sometimes on expert judgment and sometimes on statistically valid surveys, were made with varying degrees of precision, and the definition of damage were different among countries. Only recently have surveys of the extent of forest damage throughout Europe been more consistently based on statistically sound measurements, so that it is now possible to collect and synthesize substantial quantities of data on the extent of the phenomenon of forest decline in Europe. The objectives of this article are: to summarize current data on the extent of forest decline for as many European countries as possible, to draw conclusions about the significance of forest decline in the context of forest resources and annual fellings of the countries, and to draw conclusions about the improved quality and consistency of data on the extent of forest decline.