|Austrian Bio-Indicator Grid - Sulphur|
PrefaceSulphur belongs to the plant nutrients and is an important constituent of proteins. In plants sulphur is stored either in organic compounds (proteins) or in the inorganic form of sulphate. It is taken up either through the soil (as sulphate) or the atmosphere (as sulphur dioxide). Sulphur dioxide is e.g. formed by combustion of sulphur-containing fuels (oil, coal,…) or in the processes of paper manufacture and ore dressing. It is a strong poison and inhibits the assimilation process in plants. As a reaction for detoxification, the plant oxidizes the sulphur dioxide to sulphate, and an accumulation of inorganic sulphur compounds (mostly calcium sulphate) occurs in the cytosol of the assimilation organs.
This accumulation of sulphur compounds during the vegetation period, caused by SO2 pollutions, is determinable via plant analysis. In the Austrian forest law “Zweite Verordnung gegen Forstschädliche Luftverunreinigungen, BGBl. Nr. 199/1984” there are effect-related threshold values for the maximum natural sulphur content specified for the tree species spruce and beech. Apart from these statutory threshold values, for a number of tree species there are maximum natural sulphur contents mentioned in the technical literature, allowing assessment.
Results of the Austrian Bio-Indicator GridDuring the sample period, sulphur impacts were determined in the eastern part of Carinthia, in the south-east of Styria, in Burgenland, in the Waldviertel, around Linz as well as in the Inn valley and the Danube area. In the end of the eighties the regions with the highest sulphur contamination were in the area around Lenzing (textile fibre production) and in Arnoldstein (lead/zinc works). Measures were taken to reduce emissions, including factory closings, so that by the beginning of the nineties considerable improvements were detectable, particularly manifesting in a significant decrease in the maximum sulphur levels.
The altitudes with the highest sulphur impacts are up to 800m above sea level, near by local pollution sources. At higher altitudes, there is an incremental decrease in the number of plots with an exceedance of the threshold values for sulphur (Altitude Dependence).
Trend in the sulphur content from 1983 to 2006 (Download Flashanimation as Zip-File)
Exceedances of the threshold value were observed in 1983 with the Austrian Bio-Indicator Grid close to the border to Czech Republic for the first time. Significant improvements were detected here after 1998.
However, in south-eastern Styria and southern Burgenland considerable deteriorations occurred from 1995-1999. As from 2000 improvements were detectable, because of the emission-reducing measures that were taken at the brown coal-fired power plant Sostanj/Slovenia.
Whereas in the beginning of the eighties (Sulphur results 1985) exceedances of the threshold value were detectable at around 25% of the measuring plots, in 2004 only at 4,3% of the plots exceedances were found (Sulphur results 2004).