Ecological-Trophic Structure and Taxonomic Characteristics of the Communities of Soil Microorganisms in the Northern Part of the Novaya Zemlya Archipelago

Using the method of inoculation of elective nutrient media, the abundance and taxonomic diversity of ecological and trophic groups of microorganisms in soils of the northern part of the Novaya Zemlya Archipelago were evaluated. The content of aerobic and anaerobic nitrogen fixers, as well as denitrifiers, was low (tens and hundreds of CFU/g soil). The number of saprotrophic bacteria varied from 3.3 × 104 to 1.2 × 106 CFU/g soil; actinomycetes, from 1.3 × 103 to 4.0 × 105 CFU/g soil; and micromycetes, from 2.5 × 102 to 1.5 × 104 CFU/g soil. The abundances of all studied groups of microorganisms (except for aerobic nitrogen fixers) in the studied soils sharply decreased down the profile, and this correlated positively with the contents of organic carbon and total nitrogen. The community of soil microorganisms was dominated by gram-positive bacteria of the genera Arthrobacter and Bacillus; actinomycetes of the genera Streptomyces and Micromonospora; and micromycetes of the genera Goffeauzyma, Phoma, Pseudogymnoascus, and Thelebolus. In general, the abundance and taxonomic diversity of cultured microorganisms in the soils of the northern part of Novaya Zemlya were lower than in the soils of the more northern territories of the Franz Josef Land Archipelago. This phenomenon is associated with the drying and cooling effect of the largest glacier in Russia on the Novaya Zemlya Archipelago.