<p>The soils mycobiota of Apatity was first characterized. Significant differences in quantitative and qualitative parameters of urban soils fungal complexes of the Subarctic zone in comparison with zonal soils were revealed. It was shown that the biomass of fungi in the soil of the residential area of Umbric Leptic Entic Podzol (Arenic, Neocambic) is 0.18 – 0.20 mg/g, in the background forest soil Folic Leptic Albic Podzol (Arenic) – 0.31 mg/g. The smallest values (0.04 – 0.08 mg / g) are typical for areas with no vegetation and a densely compacted surface (playground - Leptic Entic Podzol (Arenic, Neocambic, Technic), unpaved pedestrian walkway – Umbric Leptic Entic Podzol (Arenic, Neocambic).</p><p>In the soils of recreational and forest areas, fungi were mainly in the form of mycelium (66-70% of the total biomass), while in the soils of residential and agricultural areas in the form of spores. Spores are mainly represented by small forms up to 3 microns. The amount of large spores is insignificant, but they were mainly detected in the soil of the residential area.</p><p>The number of copies of ITS rRNA genes of fungi in soils of different functional zones varies from 4.0×10<sup>9</sup> to 1.14×10<sup>10 </sup>copies/g of soil, with the highest values in the natural Podzol of the forest zone and Podzol of the unpaved pedestrian walkway.</p><p>The number of micromycetes CFU in the upper soil horizon ranges from 1×10<sup>3</sup> to 9×10<sup>4</sup> CFU/g of soil, reaching maximum values in the soil of the Umbric Leptic Entic Podzol recreation zone (Arenic, Neocambic, Technic). The features of cultivated forms of micromycetes distribution on the soil profile in different functional zones were revealed: in the Podzol of the residential area, the maximum accumulation of fungi was noted in the lower horizons, while in the soil of the recreational, agricultural and forest areas, their maximum number was noted in the top horizon. However, the first two differed from the background one in the absence of a second maximum accumulation of micromycetes in the illuvial Bs horizon.</p><p>In general, urban soils were characterized by a low species diversity of micromycetes complexes and a specific structure significantly different from the background soils. The genus Penicillium is characterized by maximum species diversity. Trichocladium griseum and Penicillium dierckxii dominate in the communities of microscopic fungi in the soil of the residential zone, P. melinii in the soil of the recreational areas and in the playground, in the soil of agricultural area Plaggic Entic Podzol (Arenic) - micromycetes of the genus Fusarium, and in the background forest soil - P. decumbens.</p>

<p>The anthropogenic impact on soil microbiota in polar climate remains overlooked and the comparison between microbiota in urban and natural soils in polar regions are highly interesting. Fungi are the key components of soil microbiota, responsible for improtant functions and ecsystem services and highly senstive to direct (e.g., pollution) and indirect (e.g., urban heat island) anthropogenic effects. Urban soils of Murmanks (68.967 N, 33.083 E) – the biggest polar city in the world – were studied in comparison to Podzols of the natural forest-tundra area. Soil fungi in urban and natural soils were analyzed by luminescence microscopy and PCR real time.</p><p>The fungal biomass in the upper horizon of Technosol varied from 0.50 to 0.75 mg/g of soil, which was 1.5-2 times less than in Podzol. Different profile distribution of fungal biomass was shown for urban and natural soils. In natural Podzol, the highest fungal biomass was observed in the upper organic O horizon, then decreased in the topsoil mineral elluvial E horizon, and then slightly increased in the subsoil mineral illuvial Bs horizon. In urban soils, the second maximum of number of fungi in the soil profile was not found. The biomass of fungi decreased exponentially in the soil profile.</p><p>The number of ITS ribosomal gene copies of fungi in the topsoil organic horizon of natural Podzol reached 10<sup>10</sup>gene copies/g of soil. In urban soils, there was a decrease in their number by 6 or more times. The number of fungal gene copies decreased sharply down the soil profile in both urban and natural soils. So, if the number of fungi in topsoil horizons was about 10<sup>8</sup>-10<sup>10</sup> gene copies /g of soil, in subsoil horizons it was 10<sup>6</sup>-10<sup>7</sup> gene copies/g of soil. First of all, this may be due to the mycorrhizal mycobiota, which has the largest extent of mycelium in the topsoil horizons of soil. In forest soil, the number of gene copies in horizon E was 37 times less than in the topsoil horizon; in urban soil, the content of gene copies in the subsoil BC horizon is 10 times less than in the topsoil horizon.</p><p>The proportion of fungal mycelium varied from 28 to 80%. A minimum of mycelium was found in the subsoil horizons, while the topsoil horizons were abundant with fungal hyphae, the length of which in them reached more than 160 m/g of soil. The maximum amount of mycelium (581.72 m/g of soil) was observed in natural Podzol. The number of single-celled fungal propagules (spores and yeasts) was 10<sup>4</sup>-10<sup>5</sup> cells/g of soil. Most of the propagules are represented by small-sized forms (2-3 microns), the proportion of which increased from the topsoil horizons (68-93%) to the deep ones (up to 100%). This trend was observed for both urban and background soils. Large propagules with a diameter of 5-7 microns were found exclusively in the topsoil horizons, and their number is no more than 10<sup>3</sup> cells/g of soil.</p><p><strong>Acknowledgements </strong>This research was supported by<strong> </strong>state task AAAA-A18-118021490070-5 and Russian Foundation for Basic Research project № 19-29-05187.</p>