THE CONCENTRATIONS OF K, RB AND CS IN SPRUCE NEEDLES (PICEA-ABIES KARST) AND IN THE ASSOCIATED SOILS

The elemental concentrations of K, Rb and Cs were determined in needle s from individual spruce trees as a function of the needle age class. The concentrations are highest in current year's needles and decrease smoothly in older needles, approaching a constant value. Rb and Cs sho w similar behaviour, whereas that of K differs in so far as its relati ve decrease with time is less pronounced. Intra-and intersite variatio n of the needle concentrations are largest for Cs and smallest for K. Individual trees show a highly significant correlation between the log (Cs) and log (Rb) values. Total soil concentrations were determined a t 9 sites with different parent material. Intra- and intersite variati ons of K are comparable for soils and for needles, whereas those for R b and Cs are much smaller for soils than for needles. All three elemen ts are correlated in soil samples. There is not close connection betwe en soil and needle concentrations at the various sites. However, the r esults suggest that needle concentrations of Rb and Cs, but not of K, ar strongly dependent on the sorption properties of the associated soi ls