INSTYTUT DENDROLOGII

Abstract: The study analyses the transfer of F^-, Cl^-, NO₃^-, SO₄^2-, Na⁺, K⁺, Ca²⁺, Mg²⁺, Fe²⁺, Mn²⁺ and Zn²⁺ from bulkprecipitation to throughfall, soil surface flow, vertical flow and intercover flow of water (gravity lysimeters at 20 cm soil depth) in spruce stands of different age classes (1st, 2nd, 5th, 6th), and the amount of these ions flowing out from the Potok Dupniański catchment in the Silesian Beskid Mts. The results cover the year 2000. The concentration and amount of SO₄ ^2- in throughfall systematically increased and the pH value decreased with the age of the stands and with successive elements of the ecosystem. The NH₄⁺ ion was probably absorbed in the canopy, which caused a washout of K⁺, Mn²⁺, F^- and SO₄^2- in the vegetation season in older stands. In the winter season, Fe²⁺, Mn²⁺, Na⁺ and K⁺ were washed out from the youngest stands (1st age class), whereas F^-, NO₃ ^-, SO₄^2--, K⁺, Ca²⁺, Mg²⁺, Mn²⁺ and Fe²⁺ – from older canopies. Decomposition of the organic matter caused a rise in water acidity and an increase in the concentrations of all the analysed ions; their leaching, however, was low (under 1%). Water from intercover flow contributed to an increase in the amount of water and the concentration and amount of ions and to a further decrease in water reaction at a soil depth of 20 cm. All the anions and cations flowed away with water penetrating vertically and horizontally. Considerable amounts of ions, especially SO₄^2-, Na⁺, K⁺, Ca²⁺ and Mg²⁺, were carried beyond the reach of the main mass of the root system and then out of the catchment, which may adversely affect the development and health of spruce stands.

Additional key words: bulk precipitation, throughfall, surface flow, soil water, stream water