WET DEPOSITION IN THE BIOSPHERE-RESERVE-POLANA

This work reviews results on evaluation of acidity of precipitation, w et deposition and its changes after passing through a spruce stand on a permanent research plot in the Biosphere Reserve Pol'ana. Samples of precipitation water for hydrological years 1990-91, 1991-92 and 1992- 93 are evaluated as well. After passing through the canopy of spruce s tands the precipitation is enriched in the first place by sulphate sul phur, hydrogen ions, nitrogen, calcium, potassium and fluorides. The o verall inputs in the open space(OS) and in the stand (S) in sulphur ra nged from 16.2 to 24.9 (OS) and from 23 to 65.4 kg.SO42--S.hd(-1) (S), in hydrogen ions from 0.1 to 0.2 (OS) and 0.3 to 0.6 kg H+.ha(-1).a(- 1) (S), in calcium from 3 to 24.5 (OS) and 9.1 to 29.2 kg Ca2+.ha(-1). a(-1) (S), in potassium from 6.1 to 10.6 (OS) and from 27.3 to 32.3 kg K+.ha(-1).a(-1), in nitrogen from 3.8 to 7.1 (OS) and 6.2 to 9.9 kg N O3--N.ha(-1).a(-1) (S) and in fluorides from 1 to 3.2 (OS) and from 1. 4 to 2.6 kg F-.ha(-1).a(-1) (S).