Dendrogeochemistry of Hg according to the study of Scots pine (Pinus sylvestris) in the Tomsk region

Abstract

Relevance. The need for an ecological and geochemical assessment of the mercury intake characteristics into pine wood in order to identify the factors determining the accumulation of the element by trees. Aim. Quantitative evaluation of mercury content in the annual rings of Scots pine (Pinus sylvestris L.) in the Tomsk region, as well as identification of geoecological and climatic factors affecting the accumulation of pollutant. Object. Annual rings of Scots pine (Pinus sylvestris L.) widely used in world science to obtain information about environmental pollution by chemical elements. Methods. Pine core sampling, samples drying at room temperature. Determination of the number, width of annual rings and growth of wood on the LINTAB device (TSAP-Win and LIGNOVISION software) at the Institute of Monitoring of Climatic and Ecological Systems SB RAS (Tomsk). Determination of concentrations on the mercury analyzer RA-915+, by atomic absorption (pyrolysis method) on the basis of the Engineering School of Natural Resources of Tomsk Polytechnic University. Calculation of ecological and geochemical indicators: concentration coefficient, temporal allowable concentration, noosphere clark, normalization according to B. Markert, enrichment factor. To assess the climatic response of mercury accumulation by trees, the average daily data for 1933–2021 from the Tomsk weather station were used. Results. The authors have obtained the data on the gross content and geochemical features of mercury accumulation by Scots pine wood in the territory of the Tomsk region. The results of calculations of the main geoecological indicators of the mercury load indicate an excess of element concentrations relative to the background, the average for terrestrial plants, as well as according to scandium rationing data. The paper highlights the period of increased mercury concentration in pine wood (1941–1974) as a result of the influence of the city industry. A similar pattern of pollutant accumulation for 1970–1986 was revealed in the study area, with an excess of 1.6–1.8 times relative to adjacent environments (soil, solid snow sediment, pine needles, mosses). Hg accumulation by wood is affected by the precipitation amount, both per year and during the growing season and during the period with positive temperatures, as well as the duration of precipitation during the year and the growing season.