Assessment of the reindeer pastures safety in the Avam tundra: content of heavy metals in the vegetative organs of plants
The changes in migration routes of the wild reindeer (Rangifer tarandus L.) have made it relevant to use pasture lands in the Avam tundra (south of the Taymyr Peninsula) for the development of domestic reindeer husbandry. The safety of forage plants is an essential condition for the reindeer husbandry. We aimed to study vegetative aboveground phytomass of the most common forage plants (lichens, cotton grass, sedge, shrubs). The ultimate composition and concentration of heavy metals were determined by pyrolysis using an atomic absorption analyzer RA-915+. We have assessed pasture safety by comparing the obtained data with the established maximum permissible level (MPL) of the chemical elements contained in feeds for the farm animals. The detected high variability of the element concentrations (υ = 21.8-96.6 %) can be attributed to the biological specifics of the species under study. We have found the maximum content of the elements of hazard class I (As, Hg, Pb) in lichen thallus (Cladonia genus). Regardless of the taxonomic status of the species, three chemical elements (Mn, Cu and Ni) account for 96.88-99.97 % of the gross content of their water-soluble forms. The concentration of nickel (except for baceous species) and chromium(except for shrubs) exceeded the maximum permissible level established for the farm animal feeds by 1.1- 1.9 and 1.1-2.1 times, respectively. Taking into account the features of the regional geochemical background, the actual content of heavy metals in forage plants is not dangerous. Therefore, we conclude that the territory of the Avam tundra is suitable for developing domestic reindeer husbandry.