Distinctive features of heavy metals’ accumulation in coniferous trees in Buryatia, Russia

Abstract

Coniferous plants are very sensitive to atmospheric pollutants and frequently are used as environment pollution bioindicators. The purpose of this study was to define features of heavy metals (HM) accumulation by conifer needles from forest-forming tree species growing in Buryatia: Pinus sylvestris, Pinus pumila, Pinus sibirica, Picea obovata, Abies sibirica. The samples elements content was determined by ICP AES method after acid decomposition in microwave system MARS 6. HM accumulation rows showed similar trends for different tree species. The maximum content was determined for manganese in all needles samples, except Pinus sylvestris, growing around Ulan-Ude. It is shown that there is a difference in HM accumulation between conifer species due to their biological features. The variation coefficient of heavy metals in conifer needles were calculated, Zn, Ni, Hg exposed highest level of variation. Industrial pollution caused the significant changes in the needles elemental composition – it is observed the growth of Fe, Zn and lowering of Mn content in Pinus sylvestris needles growing around Ulan-Ude. The accumulation of HM by conifer needles growing in Buryatia was higher than the average terrestrial vegetation element contents that might be related with the forest fires.