SULPHUR POLLUTION: CA, MG AND AL IN SOIL AND SOIL WATER AND POSSBI.E EFFECTS ON FOREST TREES.

Abstract

Results from field plots (with Norway spruce, Scots pine or silver birch) and lysimeters exposed to artificial rain are de-scribed. "Rain" was acidified to pH levels from 6 to 2.5 or 2 by means of H2S04, and applied to field plots and 40 cm deep lysimeters in quantities of 50 mm month-1 in the frost-free period. Increased acidity of the "rain" increased the leaching of Ca, Mg and AI. When "rain" acidity increased from pH 3 to pH 2, Al concentration in the effluent increased from an average of 80 ~mol 1-1 to an average of 1290 ~mol 1-1. The Ca/Al mol ratio decreased from 7 to 0.5. Significant and corresponding changes in soil chemistry were observed. Neither the growth of trees nor the chemical properties of the foliage indicate that the trees suffered from AI-toxicity.