Root habitus and wind stability of trees

The present literature survey deals with the influence of soil acidification and environmental pollution on root systems and tree stability. The stability of trees under windy conditions is determined by their root anchorage. These relationships are explained using Norway Spruce (Picea abies [L.] Karst.) and European Beech (Fagus sylvatica L.) as exemplary species due to their broad distribution and frequent uprooting in Central Europe. Although tree root architecture is genetically determined, it can be modified by soil properties and other natural environmental conditions. The wind stability of a tree decreases with increasing height and/or age. In addition, stand structure, especially the social position of an individual tree, is important. Diseases caused by soil compaction, harvesting or other human-induced injuries are far more important causes of damage to the stability of roots and root systems than damage caused by soil acidification or environmental pollution. Due to a lack of data for comparison, a general assumption in regards to the current reduction of root plates and the greater wind-throw risk as compared to earlier times is not possible. This is explained by the fact that current environmental conditions of course had no effect on the early formation of the skeleton root system responsible for wind stability.