SEASONAL DYNAMICS OF INPUT OF SULFATES IN THE CENTRAL-EUROPEAN BEECH AND SPRUCE ECOSYSTEMS

European beech together with Norway spruce form the skeleton of the Ca rpathian forestsstability. Their health condition is endangered by a h igh input of sulphur. The lowest content of sulphates reached in throu ghfall of beech and spruce ecosystems 5-7 mg.1(-1) and in an open spac e 6-9 mg.1(-1). Upper content varies between 50-70 mg.1(-1), in spruce ecosystems up to 200 mg.1(-1), in a clear-cut area 35-60 mg.1(-1), in isolated cases even more. In water streams of forested catchments we recorded data within the mast frequent range between 15 to 50 mg.1(-1) . A common sign of sulphate dynamics in rainfall is their higher conce ntration in stands opposite to open areas. A synchronization of sulpha te content in throughfall and in rainfall in an open space testifies a n expressive exogenous influence of sulphate dynamics. The fact, that the highest quantity of sulphur input penetrates in the forest soil du ring three spring months (40-75 % of annual deposition) has relevant e cological consequences, which unfavourably influence the health condit ion of forest ecosystems. Maximum ascertained annual values of input r eached 240 kg SO42-, i.e. 80 kg S.ha(-1). At a critical load of soils with an annual maximum amount of 7 kg S.ha(-1), it cannot stay without an influence on the total productivity and stability of ecosystems.