Biological Alterations in the Stem and Root of Fir and Spruce due to Pollution Influence

Abstract

Wood biological investigations were carried out on healthy and diseased trees of 70 firs (Abies alba Mill.) and 33 spruce (Picea abies Karst.) from six sites in Germany. The tree-ring analyses reveal that trees even from the same site begin to respond to pollution in different calendar years. Stress due to drought, as in 1976, advances growth reduction, but is not its major cause. At some sites the decrease of tree vitality can be traced back for more than 30 years. Serious alterations could be observed on a cellular level with regard to the occurrence of elements in the fine roots. In acidic soils of about pH 4 or less the fine roots are deficient in the macro nutrients calcium and magnesium. Aluminium, normally present in healthy trees, had not been accumulated in the cortex of diseased trees.