The importance of magnesium in the element cycling of forest ecosystems has only been fully recognized since the widespread symptoms of forest magnesium deficiency were identified to be a major component in the damage phenomena. The intensive research during the last 15 years revealed not only details on the role of magnesium as a nutrient in forest ecosystems, but led also to a more comprehensive understanding of these ecosystems themselves and their functioning.

R. F. HUTTL AND W. SCHAAF Brandenburg Technical University Cottbus, Chair of Soil Protection and Recultivation, P.O. Box 10 13 44, 03013 Cottbus, Germany The health status of forest trees and stands is determined by numerous site factors such as chemical, physical, and biological soil factors, water supply, climate, weather conditions, management history as well as atmospheric deposition impacts. In this context, the nutrient supply is an important evaluation parameter. Forest trees well supplied with nutrients are more resistant to stresses that affect the forest ecosystem than other trees....