RUBIDIUM AND CESIUM IN SPRUCE NEEDLES - CONCENTRATIONS AND BIODYNAMICS

The endogenous concentrations of Rb and Cs have been determined in nee dles of 56 trees (Norway spruce, Picea abies) from eight different sit es. Analysis was done by instrumental neutron activation. Concentratio ns were found to have a very large range (3-28,000 ng Cs/g and 1-190 m u g Rb/g). The values on a given site have a tendency toward a log-nor mal distribution. There is a significant correlation between Rb and Cs , but the correlation is not Linear. The concentrations of both elemen ts are a function of the needle age. They decrease smoothly, approachi ng a constant value, when going from needle age class 1 to 5. It is sh own that one algebraic function describes this biodynamic behavior on all sites and at all concentration levels. The function and its parame ters are discussed.