Impact of simulated acidification and liming on forest soils and Norway spruce (Picea abies [L.] K a r s t.) seedling growth in a container experiment

In order to identify potential causes of Norway spruce stand dieback in the Beskydy Mts an experiment was established where the input of elemental sulphur in amounts of 100 and 300 kg ha^-1 year^-1 was simulated during 7 years (1987-1993) and for two soil substrates originating from Starc Hamry (healthy spruce forest) and Maly Smrk locality (dead forest). Both sulphur treatments were tested without and with application of ground dolomitic limestone in amounts of 2.5 and 5 t ha^-1, given only once. Effects on soil substrates, leachate chemistry, growth and the nutritional status of Norway spruce plants were monitored. Sulphur application in both substrates induced considerable acidification of soil matrix and soil solution and drastic changes of soil sulphur chemistry. The application impact could be compensated for by liming. The Norway spruce seedlings, however, were in all treatments adequately supplied with nutrients, and no significant growth differences showed up. Therefore it is concluded the rapid death of spruce stands at Maly Smrk to be caused not by soil acidification but by interaction of SO₂ and weather stress.