Trace element accumulation in tree rings of pinus halepensis during the last 140 years

Abstract

The trace element analysis of Aleppo pine (Pinus halepensis Mill) as a function of tree age, was achieved by the tree-ring sampling method, in a polluted region of Attica, Greece. The elements quantitatively determined for the last 140 years by atomic spectrophotometry analysis were: Cu, Fe, Zn, Mn and Pb. With the exception of Pb, all other elements tend to increase for the time period of this study. A very interesting fluctuation was noted between the years 1920 to 1960-1970, a time coinciding with the major industrial activity of the area. The decreasing concentration of all elements for the last few decades may be attributed to the increasing environmental awareness as well as respective regulations posed by the government and the E.U. The radial distribution of concentrations in annual tree rings provides adequate information that, in most of the cases, can be related to the history of the tree and the biological processes interacting on its growth. Soil, litter, air deposits and water are important nutrient sources contributing to changes in elemental concentration in the annual rings.