DETERMINATION OF TRACE-ELEMENTS IN TREE-RINGS OF PINUS BY NEUTRON-ACTIVATION ANALYSIS

The elemental composition of pine trees as a function of age was achie ved by the tree-ring method By using instrumental neutron activation a nalysis, trace elements were determined in individual rings of Pinus e lliottii var. elliottii of 32, 14 and 9 years, from an implanted fores t of Pinus sp., Buri, Sao Paulo, far away from industrial pollution. D ifferent components of the system such as needles, pith, bark soil and liner were also analyzed for 18 elements (As, Br, Ce, Co, Cs, Eu, Fe, Hf, K, La,Mn, Na, Rb, Sc, Sm, Yb, Zn, and Zr). Al, B, Ba, Ca, Fe, K, Mg, and P concentrations were determined by atomic absorption and/or e mission spectrometry (AAS; ICP-AES). Some elements have showed similar radial distribution Of the concentration for the three ages. Abrupt c oncentration changes in the pith and ring-bark boundary corresponding to the first and last growth rings were observed.