## 3 Results and Discussion
#### The Characteristics of the Soil Microbiome
Perhaps, despite the cold climate, suboptimal conditions are formed in these soils, where spore formation does not prove to be a competitive advantage [27; 51; 52; 53]. In contrast, in disturbed soils, conditions are worse (openness to the cold), and the abundance of Firmicutes is significantly larger. The alpha-diversity values between the disturbed and undisturbed soils do not reliably differ, but the beta-diversity values indicate greater and substantial variability in the composition of disturbed soils, including both communities generally similar to undisturbed ones, and two separate isolated clusters. Communities of soils in the vicinity of Ukhta, sampled in the region adjacent to Vorkuta, also demonstrate a similar pattern: with typical for soils taxonomic composition without a significant difference in the representation of phyla in disturbed and undisturbed soils, and equal values of alpha-diversity, communities differ in the representation of individual taxa (forming different clusters in the analysis of beta diversity). A high proportion of Chloroflexi and Cyanobacteria in disturbed soils characterizes the soils around Nadym, probably; autotrophy plays an important role in these soils. In anthropogenically disturbed soils, it is also worth noting the increased proportion of Firmicutes as compared to undisturbed soils. According to the alpha-diversity data, these soils have less species richness than the average for the compared soils, but the number of species in the disturbed/undisturbed soils does not reliably differ. According to the beta-biodiversity results, the samples of disturbed and undisturbed soils form an extended cluster, which indicates a low change in the taxon representation for the compared soils [54]. In the samples of carbonate from the southern taiga soils of the Leningrad region (sample code--E), in the taxonomic composition at the level of phylum in the disturbed soils compared to undisturbed ones, we can note the increase in Verrucomicrobiota and decrease in Chloroflexi, Gemmatimonadota, and Cyanobacteria. According to alpha- and beta-diversity, the samples of disturbed and undisturbed soils are close to each other, which can be explained by relatively comfortable climatic conditions and increased reclamation activity by plants. Podzolic southern taiga soils near Borovichi are characterized by a very clear variability in both alpha- and beta-diversity data. It is connected with acidic poor substrates analyzed on a par with the mining plots. This separation can be clearly seen from the beta-diversity data, where some disturbed soils form a cluster with undisturbed ones, and some form  
Figure 4: Parameters of beta-biodiversity (Bray–Curtis distances). their own, different from all the others. Because of the merging of single samples, the phyla representation data show moderate differences: we can note a slightly higher proportion of Actinobacteria, Nitrospirota, and Firmicutes characteristic of disturbed soils [25]. The obtained data do not answer questions about the features of the cycle of biogenic elements in the studied soils. This requires more detailed studies within each soil horizon in the time dimension. However, data on the taxonomic diversity of the microbial community substantially close knowledge gaps about the core and minor components of soil bacteriophage of the East European Plain [10]. In general, alpha-diversity indices are not very informative, since different disturbed soils can have different characteristics--they can be both very poor in species and, conversely, very rich in minor members of the microbial community. The general trend here is rather in the hypervariability of the index values of disturbed communities as compared to undisturbed ones, which well corresponds with data obtained earlier [55]. This variability is clearly visible in Borovichi and Yamal, and to a less extent it is expressed in Elizavetino and the vicinity of Nadym. In the case of soils in the vicinity of Ukhta, the index values practically do not differ.