Arsenic concentrations in successive needle age classes of Norway spruce ( Picea abies [L.] Karst.)

Arsenic has been determined in needles of Norway spruce by neutron activation analysis. Trees from 8 sites grown under different soil and environmental situations have been sampled. Trees and needle age classes have been treated individually. Endogenous As concentrations in needles <100 ng/g have been detected. Concentrations increased linearly with the needle age class. This biodynamic behaviour is attributed tentatively to a predominant foliar uptake. Concentrations at the various sites differed by a factor of 7. No connection could be found between As concentrations in needles and total As in the soil or pH of the soil. However, the strong correlation between the endogenous and the exogenous concentrations, and differences of As concentrations in needles between different sites are thought to be due mainly to different inputs of As from the atmosphere.