1 Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
2 Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), CH-8903 Birmensdorf, Switzerland
The endogenous concentrations of Sc, La, Ce, Sm, Eu, Tb, Yb, and Lu were determined by neutron activation analysis in up to five successive needle age classes of Norway spruce (Picea abies). Trees from nine sites over different bedrocks were sampled individually. Concentration values found are generally much lower than those reported in the literature. This is attributed to the careful removal of any aerosols or soil particles from the needle surface prior to analysis. The concentration of each element increases linearly with the needle age class, i.e., the accumulation can be characterized by just one parameter, the yearly increment. This pattern is followed at small as well as at large concentrations. The accumulation behavior of the investigated elements is identical to that of Si. The relative concentrations of the rare earth elements (REE) in the needles are similar to those in the earth crust. There are significant correlations between the individual REE and between Sc and La.
Keywords: scandium, rare earth elements, accumulation, needles, Norway spruce, Picea abies, soil