Elements in tree rings of Norway spruce (Picea abies (L.) Karst.) as indicators for SO2 polluted sites at the East-Erzgebirge (Germany)

Up to 14 elements were determined by NAA in tree rings of Norway spruce tre es from two sites which differed in their degree of human disturbance mainl y caused by phytotoxic SO2 pollutions. The aim of this study was to identif y elements that might be useful to indicate environmental stresses. Signifi cant site differences were found with Mn by finding high Mn concentrations and Mn accumulation rates as well as Mn/Ca ratios at the heavily polluted s ites. This might indicate a long term soil pH change due to acid deposition . These results correspond well with data from the literature which also in dicate Mn in xylem being a key index element for the health status of the t ree.