Open access publications in the SLU publication database

Abstract

The influence of air pollutants from an iron sintering plant in the northern part of Sweden on Scots pine trees and lichens has been studied. The emission has been around 175 ton HF and 2000 ton SO₂ yearly. The total fluorine and sulphur contents of Scots pine needles from different sample plots around the factory have been analysed. Three years old needles, which had the highest concentrations of fluorine, were used in the analyses. An increased fluorine content was evident within an area of 5 km radius from the emission source. The corresponding sulphur analyses did not show an equal clear relationship to the distance from the factory. The accelerated needle drop of Scots pine trees has been quantitatively recorded. A shorter lifespan of needles coincided with the proximity to the emission source. Together with the observations of the occurrence of the lichens Hypogymnia physodes (L.) W. Wats., Alectoria spp. and Nephroma arcticum (L.) Torss. their photosynthetic and nitrogen fixation activity was measured under laboratory conditions. The photosynthesis, measured by 14C-technique, was inhibited in samples of Hypogymnia physodes taken within the influence area mentioned above. Also the nitrogen fixation activity in excised cephalodia of Nephroma arcticum sampled near the emission source was significantly inhibited. The results presented are discussed in relation to the techniques used and the ecological consequences of the emission and imission in the area.