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Atmospheric waves on a planetary scale play the main role in the formation of the atmosphere regime, and a polar vortex forms in the stratosphere in winter. A striking example of the interannual variability of the stratospheric polar vortex caused by stationary planetary waves is sudden stratospheric warming (SSW). The internal dynamics of major sudden stratospheric warming accompanied by displacement and splitting of the stratospheric polar vortex (SPV) was studied based on the MERRA-2 reanalysis data from the point of view of explicitly calculating nonlinear interactions of planetary waves with each other and with the mean flow to identify similar trends in the formation of SSW of various types. In particular, it is shown that the formation of a SSW with SPV splitting is not always accompanied by dominant variations in the wave activity of stationary planetary wave with zonal wavenumber 2 (SPW2), but is determined by the maximum interactions of SPW2 with the mean flow. It was obtained that the wave-wave interactions during the generation of secondary stationary planetary wave with zonal wavenumber 1 (SPW1) are maximal 1-2 weeks before, and during the generation of secondary SPW2, 5-10 days before a SSW with SPV displacement. The results aimed at identifying predictors of SSW formation are important due to the fact that SSW significantly affects the entire middle atmosphere, ionosphere, as well as weather conditions in the troposphere and the formation of extreme weather events.

The results of DNA barcoding of Tubifex tubifex from various freshwater bodies within the Vychegda River basin (Komi Republic, Russia) are discussed. A molecular genetic analysis of 32 specimens collected from 14 locations, based on nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (cox1) gene fragment, revealed six distinct lineages (A, B, C, D, E, J) exhibiting inter-lineage divergence exceeding 17-24 %. A significant correlation was identified between the genetic diversity of the species and habitat characteristics, including hydrological and hydrochemical parameters of water and sediments. The observed ecological differentiation supports the presence of heterogeneous adaptive traits within T. tubifex and highlights the importance of considering population genetic structure in ecological assessments of freshwater ecosystems.

The present study addresses seasonal dynamics of the abundance, size-age composition, and production of the larvae of the caddisfly Apatania crymophyla McLachlan, 1880, which form high-density aggregations on water moss in the thermally and hydrologically altered section of the Yenisei River downstream of the Krasnoyarsk Hydroelectric Plant dam (HEP). The abundance of the larvae inhabiting water moss was highest in October 2022 and 2023 and in August 2021. The maximal abundance of the larvae on moss varied between 1242 and 4037 ind.·kg^-1 of fresh moss, and the fresh biomass of the larvae varied from 1.78 to 3.15 g·kg^-1 of fresh moss. The level of water in the river affected the quantitative parameters and the number of generations of A. crymophila. In the 2022, when the water level was abnormally low, the number of new generations in the population was smaller and the production of the larval biomass over the season was lower (by a factor of 1.8) than in 2023, when the water level was close to the long-term annual average. Hence, the conditions in the thermally altered section of the Yenisei River downstream of the Krasnoyarsk HEP are favorable for the development of A. crymophila; one of these conditions is the abundance of aquatic moss in this section, which provides the invertebrates with resources favoring the maintenance of the high-density population. The results obtained show that the invertebrates inhabiting aquatic moss should be taken into account in the estimate of organic matter production in the Yenisei River.

The peculiarities of reproduction and population structure of the northern red-backed vole in the northern taiga of Western Siberia are considered. Rodent trapping was carried out in the snowless period using the method of ditch with pitfalls (guide fences made of polyethylene film) and trap-lines. A total of 2704 northern red-backed vole were recorded in the southern strip of northern taiga over a 9-year period and in the northern strip of northern taiga over a 4-year period. The reproductive participation of females was determined by the presence of embryos and placental scars, the participation of males by the presence of spermatozoa in the epididymis and the size of the testis. The age of voles was determined by M² root development, and mass, body length, and thymus development were used. Adult overwintered voles have a reproductive period of up to five months, and up to three months for young voles. Overwintered males remain sexually active throughout the entire snowless period. Overwintered females of the southern strip bring three litters, and young females two litters. Most overwintered females in the northern strip bring two litters, and in rare cases a third litter is possible, while young females bring two litters. In the southern strip in April-May, and in the northern strip in June, the northern red-backed vole population is represented exclusively by overwintered animals. In August and September are universally dominated by young. Males predominate among adults and young animals, only in late summer and autumn the numerical advantage is shifted towards females among overwintered animals.

The plague microbe (Yersinia pestis) is unique in the family of pathogens of intestinal infections of the family Yersiniaceae (Enterobacteriaceae) and the genus Yersinia. This is the only species of the family and genus that, in natural conditions, is transmitted in rodent populations not by an alimentary route, as typical intestinal pathogens, but by a transmissible way through flea bites, which indicates some unique circumstances of its speciation. Such a special circumstance was the wound infection in populations of the Mongolian marmot (Marmota sibirica) with the causative agent of pseudotuberculosis of the 1st serotype (Y. pseudotuberculosis O:1b) or, in other words, Far Eastern scarlet-like fever (FESLF). The abiotic trigger for speciation was the maximum Sartan cooling, which covered vast areas of Central Asia at the turn of the Pleistocene and Holocene, 22-15 thousand years ago. Deep freezing of the ground in the settlements of the Mongolian marmot led to a change in the behavior of the larvae of the marmot flea Oropsylla silantiewi - a transition to hematophagy on marmots during hibernation, which caused a massive penetration of the FESLF pathogen into the blood of marmots through wounds on the mucous membrane in the oral cavity, created by flea larvae. Aberrant resistant wound infection of marmots with FESLF caused change in gene flow and speciation of Y. pestis. According to the optimistic version of the environmental scenario, the speciation process took place autonomously in three geographical populations of marmots; almost simultaneously, three initial microbial subspecies 2.ANT3, 3.ANT2 and 4.ANT1 appeared, which later became the basis of the entire world intraspecific diversity of this pathogen.

The results of parasitologic and metagenomic study of two nests of the long-tailed gopher obtained in the Tuva mountain plague focus (Mongun-Taiga kozhun of the Tyva Republic) are presented. The fauna of blood-sucking arthropods of both nests was formed by fleas Citellophilus tesquorum Wagn., Frontopsylla elatoides Wagn., Rhadinopsylla li transbaikalica Ioff et Tifl., Oropsylla alaskensis Baker, Neopsylla mana Wagn. and ticks Haemogamasus mandschuricus Vitzthum and Hg. hodosi Goncharova et Buyakova. F. hetera Wagn., F. frontalis baikal Ioff were sporadically present in nest No. 1. According to the size, depth of occurrence, length of passage to the nest chamber, species composition and physiological state of ectoparasites, nests were defined as wintering nest No. 1 and reserve nest No. 2. According to the results of metagenomic analysis, nest community No. 1 contained 64.2 % of Proteobacteria phyla (Allorhizobium - 22.8 %, Aureimonas - 9.71 % and Methylobacterium - 7.68 %), 35 % of Actinobacteria (including Brachybacterium - 3.8 %, Amycolatopsis - 3.33 %, Brevibacterium - 1.76 %), 0.8 % of Firmicutes (Staphylococcus). In the sample from nest No. 2, 87.1 % of sequenced sequences belonged to Actinobacteria phyla (Brachybacterium - 51.0 %, Brevibacterium - 19.6 % and Nocardioides - 7.4 %), 12.8 % to Firmicutes (Staphylococcus), 0.08 % to Proteobacteria (Methylobacterium). Possible reasons for the differences in the composition of nest bacterial communities are discussed.

Extreme weather events change the diurnal and seasonal variations in CO₂ fluxes between the forest and the above surface atmosphere. The analysis of interannual variability of net CO₂ exchange (NEE), total ecosystem respiration (TER), gross ecosystem photosynthesis (GEP) and evapotranspiration (ET) in a cowberry-lichen pine forest of the middle taiga subzone was performed under different weather conditions during the 2021-2023 growing season. According to measurements by eddy covariance system, in the pine forest over three years of observations, the total NEE in May-August varied from -653 to -980 g CO₂/m², GEP varied from 1711 to 2360 g CO₂/m², TER - from 913 to 1380 g CO₂/m². The total evapotranspiration corresponded to 137-262 mm, and the GEP/ET ratio varied within 1.8-3.9 mgC/g H₂O. As a result of multi-level statistical analysis, a correlation GEP with gross radiation, temperature and humidity in the growing season was revealed. A relationship between GEP and air temperature and humidity characteristics of the growing season was revealed. GEP and NEE decreased at abnormally high temperatures and a long absence of precipitation in the first half of the 2021 growing season. Maximal effect of air temperature on ecosystem CO₂ exchange was observed in 2023 at increased supply of soil moisture. It was concluded that the water reserve in the soil mitigates the negative effect of atmospheric moisture deficit in the summer on photosynthesis and evapotranspiration and thereby ensures a stable seasonal net sink of CO₂ in the ecosystem of the cowberry-lichen pine forest of the middle taiga subzone.

Understanding the relationship between the conditions prevailing in anthropogenic altered soils and the diversity of the soil microbiome can provide important information for assessing the state and solving the problem of maintaining the stability of natural and man-made ecosystems. Using high-throughput Illumina sequencing, the diversity and composition of bacteria, archaea, and fungi in the soils of five different phytocenoses within the Meshcherskaya Lowland (Southern Moscow region), as one of the most industrially saturated regions in the country, were analyzed. The results showed a reduction in taxonomic richness and a decrease in phylogenetic diversity and alignment of microbial communities during the transition from the soil of a conventionally background site to soils of secondary phytocenoses and soils associated with man-made objects - an overgrown phosphogypsum dump and an industrial wastewater discharge site. Representatives of 28 bacterial and 1 archaeal phylum were identified in the prokaryotic component of the microbiomes of the studied soils. The dominant position was occupied by the phylum Actinomycetota (relative abundance 21-30 %) and Pseudomonadota (16-19 %). The taxonomic composition of the fungal component of the communities was dominated by Ascomycota (53-74 %), represented by the classes Dothideomycetes, Sordariomycetes, Eurotiomycetes, and Leotiomycetes. Representatives of Basidiomycota in the soils of different phytocenoses accounted for from 16 to 29 % of all identified fungal taxa. The most numerous among the basidiomycetes were the classes Tremellomycetes, Agaricomycetes, and Microbotryomycetes. Using the FAPROTAX software package for predicting the ecological functions of bacterial and archaeal taxa obtained by sequencing 16S rRNA amplicons, as well as the automatic FUNGuild algorithm for sorting by ecologically significant categories of the fungal taxa identified during ITS amplicon sequencing, the ecological profiles of the studied microbial communities were characterized. The data obtained can be used in the environmental monitoring system of impact zones of industrial enterprises.

Biosorption is a promising method for preventing REE migration in natural environments and for their purification, and microscopic fungi are considered effective biosorbents. The article is devoted to studying the biosorption capacity of soil microscopic fungi in relation to REE in aqueous solutions. The dyna`mics of adsorption was studied using the example of lanthanum by the biomass of micromycetes Penicillium canescens and Talaromyces funiculosus depending on the contact time and its concentration in the solution. It was found that adsorption equilibrium in the fungal biomass - aqueous lanthanum solution system occurs within 24 hours, the T. funiculosus biomass demonstrated a higher sorption capacity. Lanthanum adsorption is more intense at medium acidic pH values of solutions; the maximum lanthanum sorption for 24 hours was noted at pH 3.1 by P. canescens biomass. It was revealed that REE with larger ionic radii are extracted more effectively, they more actively occupy free sorption centers with the formation of complexes. With prolonged interaction of REE with fungal biomass, nanoparticles are formed, the composition of which is close to monazite. According to IR spectroscopy data, the REE sorption centers are amide, carboxyl, amine and phosphate groups of the fungal cell wall. The presence of many ionogenic groups determines the high sorption capacity of the fungal cell wall. Intermolecular modeling of the interaction of lanthanum with amino acid residues of fungal cell wall proteins revealed that proteins form strong complexes by complex formation of REE with amino acid residues, where the active centers are glutamic and aspartic amino acids.

Based on the results of microbial indication for 2023 and 2024, it was established that Avacha Gulf and the southwestern coast of Kamchatka are subject to significant oil pollution. The number of hydrocarbon-oxidizing microorganisms at most of the studied stations was 10³ CFU/ml (g) and higher. The results of molecular genetic analysis identifying marker bacterial genes for the oxidation of alkanes (ALK-1, ALK-2, ALK-3) and PAHs (nah, phn, bphA1, xylE, GN-PAH, GP-PAH) in the environment indicated the dominance of bacteria capable to oxidize short- and medium-chain alkanes in the surface waters of Avacha Gulf in 2023, and bacteria that are potential destructors of medium- and long-chain alkanes in the waters of the southwestern coast of Kamchatka. Also, the waters of both areas were characterized by a significant presence of gram-negative bacteria that oxidize various types of PAHs. In 2024, the proportion of stations with bacteria that degrade phenanthrene and short-chain alkanes sharply decreased in Avacha Gulf, but the proportion of stations with microorganisms that oxidize long-chain alkanes increased. An increase in the proportion of water samples with bacterial biphenyl oxidation genes and PAH oxidation genes of gram-negative microbiota was noted for the southwestern coast of Kamchatka. In bottom sediment samples collected in 2023 from both study areas, the genes responsible for PAH oxidation by gram-positive microbiota and for the degradation of long-chain alkanes were most often detected. Analysis of bottom sediment samples collected in 2024 indicated a decrease in the proportion of stations with microorganisms capable of oxidizing various petroleum hydrocarbons in both study areas.