Microbiomes of natural and abandoned agricultural soils of the Central part of Yamal region

Soil cover of the northern most regions of Eurasia are considered as underestimated in terms of their possible role in expansions of current agriculture to the cryolithozone. In this context, abandoned agricultural soils of Yamal region were investigated in terms of morphology, chemistry and taxonomy microbiome compositions and compared in these terms with mature tundra and taiga soils of pristine environments. The level of soil fertility was low in all cases – former agricultural soils and pristine ones. The level of microorganism’s biodiversity was higher in soils of agricultural lands. This fact indicates that the agricultural soil treatment in polar terrestrial ecosystem results in increasing of soil microbial biodiversity due to diversification of ecological niches. Also the is an essential lack of nitrogen sources in all permafrost affected soils studied.

Fungal Metagenome of Chernevaya Taiga Soils: Taxonomic Composition, Differential Abundance and Factors Related to Plant Gigantism

The Chernevaya taiga of Western Siberia is a unique and complex ecosystem, distinguished by the unusually large sizes of herbaceous plants, the reasons for which are poorly understood. Here, we explored the fungal diversity of the Chernevaya taiga soils in the Tomsk regions of Western Siberia in comparison with other soil types. The soil biomes of Chernevaya taiga and the control regions were investigated using Illumina ITS rRNA sequencing, and taxonomic analysis revealed a predominance of fungal phyla in the different soils. These results demonstrate that the fungi of the Chernevaya taiga regions have a higher species diversity (Faith’s PD) vs. the control soils, and the diversity is due more to the sampling sites rather than to the seasons (Bray-Curtis distance). We studied most of the differentially abundant taxa among the soil types, and we annotated the taxa with their ecological guilds and trophic types. Some of the abundant fungal taxa in the summer- and fall-Chernevaya taiga samples belong to the phylum Glomeromycota—arbuscular mycorrhizal symbiotrophs, which are known to establish symbiotic relationships and enhance plant growth. Additionally, several OTUs were assigned to novel genera in the Glomeraceae and Claroideoglomeraceae families. Our findings add a potential explanation of the high productivity and plant gigantism in Chernevaya taiga and expand our knowledge of fungal biodiversity.

Biological activity of meadow-chernozem and sod-taiga permafrost soils of the Yeravninsky basin

The biological and biochemical parameters of two types of permafrost soils of the Yeravninsky basin (the carbon content of the microbial mass, different groups of microorganisms, protease, catalase and the intensity of cellulose decomposition) were studied, depending on the water-thermal properties and the type of soil formation. It is established that permafrost soils do not have an optimal combination of potential and real (actual) enzymatic activity. It is also noted that the acidic reaction of the soil solution and the low availability of nutrients in sod-taiga soils increases the development of fungal microflora. The most significant soil-ecological factor that determines the microbiological activity of meadow-chernozem and sod-taiga permafrost soils is humidity, as evidenced by a direct correlation. In turn, these microbiological indicators can be used for diagnostic assessment of the biological state of soils, and also, along with other soil properties, should be taken into account when developing methods to increase the productivity of existing hayfields and pastures on them.

SOIL MICROBIOLOGICAL AND SOIL ZOOLOGICAL METHODS IN ENVIRONMENTAL MONITORING OF ALAs MEADOW SOILS OF CENTRAL YAKUTIA

The article discusses the results of research of soil microbiomass and communities of soil inhabiting oribatid mites in permafrost alas meadow-chernozem soil. This study allowed assessing the features of the state and main characteristics of the metabolic activity of microbiomass and the number and species diversity of the community of oribatid mites. In general, permafrost meadow soils of Central Yakutia are characterized by lower values of microbiomass and specific metabolic activity of this biomass than meadow soils of the European part of Russia, but higher values of microbial biomass and respiratory activity than permafrost taiga soils of Central Yakutia. The total average number of carapace oribatid mites in the meadow alas soil was 8640 sp/m2. This indicates a relatively high degree of favorable environmental conditions for communities of soil inhabiting oribatid mites in the studied ecosystem. The conducted research allows concluding that soil-microbiological and soil-zoological methods can be successfully used in the environmental monitoring of permafrost meadow soils of Central Yakutia.

INFLUENCE OF FROST PENETRATION AND CRYOGENESIS ON SOIL PROPERTIES

Изучено влияние низких температур на изменение процессов ионного обмена в исследуемых почвах, изменение растворимости малорастворимых и труднорастворимых соединений. В качестве объекта были выбраны мерзлотно-таежные почвы, характерные для Якутии. Замораживание почвенных растворов сопровождается увеличением концентрации ионов в незамерзшей части, разрушением алюмосиликатов, изменением прочности связи воды с почвенно-поглощающим комплексом. Это проявляется в инфракрасных спектрах, дериватограммах, а эффект был зависим от продолжительности и кратности промораживания. Замерзание верхней части почвенного профиля при наличии многолетней мерзлоты приводит к развитию тиксотропии. Установлено, что интенсивность развития этих процессов отличается для почв разного гранулометрического и минералогического состава, гумусированности, для органических и минеральных горизонтов. Содержание катионов водорастворимых солей в замерзших и незамерзших почвенных растворах мерзлотно-таежных почв составляло соответственно К – 4,7±2,5 и 42,8±28,5 мг/л; Са – 0,2±0,1 и 3,2±1,4; Fе – 0,04±0,01 и 0,38±0,03 мг/л. Эти отличия были характерны для отдельных горизонтов почв. Замерзшая часть раствора менее минерализована, незамерзшая часть содержит большие концентрации элементов. Обсуждается роль многолетней мерзлоты в процессах почвообразования. Низкие температуры профиля и сниженная биологическая активность обуславливают специфику протекания реакций ионного обмена, изменение растворимости осадков, создание водоупора. Эти процессы способствуют аккумуляции веществ в надмерзлотном слое, возникновению новых градиентов и геохимических барьеров в почвенном профиле. Наблюдается локальное развитие почвообразования в слое, образующемся над вечной мерзлотой, при отсутствии промывного водного режима. Low temperatures lead to alterations of ion exchange processes in the soil, fallout solubility. As an object, permafrost-taiga soils characteristic of Yakutia were chosen. The soil solution freezing is provided with ion densification in unfrozen parts, alumosilicate damage, change of bond strengths between water and the soil adsorption complex, infrared spectra, thermograms. Freeze-up of the upper soil profile in the presence of permafrost causes tixotropy development. However, the rate of these processes development differs for the soils of different granulometric and mineralogical content, high humus content, for organic and mineral horizons. At this rate, the water-soluble cation content in frozen and unfrozen soil solutions of cryomorphic-taiga soils was К – 4,7±2,5 and 42,8±28,5 mg/l; Са – 0,2±0,1 and 3,2±1,4; Fе – 0,04±0,01 and 0,38±0,03 mg/l accordingly. These distinctions were typical for certain soil horizons. Frost penetration of the soils modified their thermograms and infrared spectra. The effect depended on the persistency and frequency of the frost penetration. The frozen part of the solution is less mineralized, the unfrozen part contains large concentrations of elements. The role of permafrost in soil formation is discussed. Low profile temperatures and reduced biological activity determine the specifics of the ion exchange reactions, changes in the solubility of precipitation, the creation of a water seal. These processes contribute to the accumulation of substances in the permafrost layer, the emergence of new gradients and geochemical barriers in the soil profile. There is a local development of soil formation in the layer formed over permafrost, in the absence of washing type of water regime.

SOIL-BIOLOGICAL METHODS IN ENVIRONMENTAL MONITORING OF PALE YELLOW SOILS OF THE CENTRAL YAKUTIA

The article deals with the results of the study of soil microbiomass and the community of soil inhabiting oribatid mites in the zonal permafrost pale yellow typical soil. It is concluded that the zonal taiga soils of Central Yakutia are characterized by lower values of microbial biomass and higher values of specific metabolic activity of this biomass than the soil of the taiga zone of the European part of Russia. The population of soil inhabiting oribatid mites in these soils is characterized by a large faunal originality, which is significantly different from similar landscapes of neighboring regions. The conducted research allows drawing a conclusion that soil biological methods, and methods of the analysis of a condition and features of functioning of soil microbiomass, number and species diversity of community of soil inhabiting oribatid mites, can be successfully used for ecological monitoring of taiga ecosystems of the Central Yakutia. It is necessary to conduct additional studies to obtain quantitative characteristics of the features of changes in the studied parameters in the taiga ecosystems that experienced different in strength and nature of anthropogenic impacts.