Biological Activity of Supraglacial Systems under Conditions of Intensive Ablation of the IGAN Glacier, Polar Urals

For the first time, a comprehensive assessment of the biological activity of the supraglacial systems of the IGAN Glacier—the largest glacier of the Polar Urals—was carried out. The stocks and structure of microbial biomass were estimated using luminescent microscopy and substrate-induced respiration methods; basal respiration, the intensity of methanogenesis and nitrogen fixation, the number of copies of ribosomal genes of microorganisms (bacteria, archaea, and fungi), and the numbers (CFU/g soil) of cultivated micromycetes, saprotrophic bacteria, and actinomycetes were also studied. The highest biological activity was found in the supraglacial zone, and the lowest—along its periphery and in the near periglacial zone. In all zones of the glacier, Geomyces pannorum, G. vinaceus, and Teberdinia hygrophila dominated among micromycetes, and representatives of the Arthrobacter and Bacillus genera dominated among bacteria. The microbiome structure of supraglacial bodies depended on their location on the glacier and differed significantly at the periphery and in the center of the supraglacial zone, as well as in comparison with soils and sediments in the adjacent periglacial landscape. The material released from the glacier body with a high content of organic matter affects the biological activity of supraglacial microbial communities.