Julija Beričnik-Vrbovšek
ERICo Velenje, Institute for Ecological Research, 3320 Velenje, Slovenia

Friedrich Pichlmayer,b Karl Blochberger
Österreichisches Forschungszentrum Seibersdorf, A-2444 Seibersdorf, Austria

Zvonka Jeran
J. Stefan Institute, 1000 Ljubljana, Slovenia

Jože Marsel
Faculty of Chemistry & Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia


Reported herein is the isotopic composition of sulphur in Norway spruce needles, lichens and soils from two well-defined climatic regions in Slovenia: The Šalek Valley and the Zasavje region. The samples are from distinct locations in these regions, where the impact of SO2  on vegetation is well documented. In both regions, the main source of SO2 pollution is from thermal power stations. The isotopic measurements of Norway spruce needles were complemented with d34S-analyses of coals (lignite and brown coal) and SO2 in stack-gases from two thermal power plants, to correlate SO2 pollution with a specific emission source. Reference samples of SO2 from an unpolluted region (The Triglav National Park) were collected for comparison.  To elucidate the turn over of SO2 from source to spruce needles via air and/or soil, characteristic soils and lichens (Hypogymnia physodes) were sampled. The sulphur in the samples was converted by combustion  in a  small oxygen bomb (Parr Instrument) to sulphate, precipitated as BaSO4 and the d34S values measured using an isotope ratio mass spectrometer coupled on-line to an elemental analyser. The d34S values demonstrate only a close relationship between environmental SO2 and lichens. Correlation between a particular emission source and the apparent impact on vegetation from the d34S values is not straightforward.