ANNUAL RINGS OF SCOTS PINE (PINUS SYLVESTRIS L.) IS THE INDICATOR OF GEOCHEMICAL CONDITIONS AND CHRONOLOGICAL CHANGES IN CHEMICAL ELEMENTAL COMPOSITION OF THE ENVIRONMENT

The relevance of the research consists in the need to search for invention of accurate and informative indicator for ecological monitoring. The aim of the research is to study the features of chemical elements accumulation in annual rings of pine (Pinus sylvestris L.) of different areas of growth; evaluate the information content and accuracy of the annual rings of trees as an indicator of the environment state. Object: annual rings of Scots pine (Pinus sylvestris L.). Methods: selection of ordinary pine cores; natural drying, separation of samples into time intervals, grinding of cores; quantitative instrumental neutron-activation method of analysis (28 chemical elements) for all samples; processing and analysis of empirical data by statistical methods. Results. Chemical elemental composition of annual rings of Scots pine (Pinus sylvestris L.) was determined. The samples were selected in three regions of Russia: Tomsk region, Kemerovo region and the Republic of Buryatia. Comparison of chemical elemental composition of annual tree rings of different regions helped to see geochemical features of each territory separately. Specific elements for the Tomsk region tree were: Rb (0,5 mg/kg), Cs (0,01 mg/kg), Ba (3 mg/kg), Ce (0,02 mg/kg) and other. For wood of Kemerovo region: Fe (34 mg/kg), Cr (1 mg/kg), Sb (0,002 mg/kg), As (0,01 mg/kg), La (0,01 mg/kg), U (0,004 mg/kg) and other. For wood from the Republic of Buryatia: Br (1 mg/kg), Sr (7 mg/kg), Ag (0,04 mg/kg), Au (0,001 mg/kg), Th (0,001 mg/kg) and other. Thus, the dendrogeochemical method of research can be used to assess the geochemical situation of the territory by the level of accumulation of chemical elements in the annual rings of the tree. The dynamics of chemical elements entering the annual rings allow us to study the history of transformation of chemical elemental composition of the environment. Thus, iron and chromium trends for Pinus sylvestris of Kemerovo region reflect the development of ferrous metallurgy, and trends As, Ag, Cs, Sb, U, Sm, Th and Br - the development of the coal industry in the region. Trends in alkali metals Rb, Cs, radioactive U and rare earth elements Nd, Sm, Eu showed the intensity of the impact in different time intervals of the nuclear fuel cycle and other alleged sources on the environment of the Tomsk region. Dendrochemical monitoring can be used for studying local and global environmental changes and allows reconstructing the history of past contamination.