Time trends of SO42- concentration and deposition of S-SO42- in precipitation, throughfall and soil solutions in a beech forest stand in the Štiavnické vrchy Mts.

Abstract

The work summarises the data assembled and compared during a 22-year research on deposition and concentrations of sulphate sulphur in soil solutions in a submountain beech forest in the Štiavnické vrchy Mts. We also investigated the sulphur amounts in throughfall and in precipitation water in open area. The average sulphur concentration in atmospheric precipitation on the open plot was 14.92 mg.l-1, in the forest stand 17.13 mg.l-1. The sulphur deposition in soil increased with increasing depth: from the average of 18.9 kg.ha-1.y-1 in the surface humus to 26.7 kg.ha-1.y-1 in a depth of 0.25 m. The average concentration in the surface humus was 19.06 mg.l-1 , at a depth of 0.25 m it was 29.32 mg.l-1. The total amount deposed in the soil over the whole study period was 587.1 kg.ha-1S-SO42-. The annual dynamics exhibited the highest SO42- concentration values in the winter and spring, the lowest values were recorded in the summer and autumn. Regression analysis revealed that the sulphur content in soil solutions was very significantly influenced by sulphur content in atmospheric deposition. There has also been confirmed a major impact of rainfall total on sulphur content in precipitation water as well as in soil solutions. In general, it has been confirmed a decreasing trend for sulphur in atmospheric deposition