Архив метки: microbial communities

SPATIAL AND TAXONOMIC STRUCTURE OF SOIL MICROBIAL COMMUNITIES IN THE DRY-STEPPE ZONE OF THE SELENGA MOUNTAINS (WESTERN TRANSBAIKALIA)

Arid Ecosystems

UDC 579.26; 631.41

E.P. Nikitina, Buyantueva L.B., Baturina O.A., Gyninova A.B., Lavrentyeva E.V. SPATIAL AND TAXONOMIC STRUCTURE OF SOIL MICROBIAL COMMUNITIES IN THE DRY-STEPPE ZONE OF THE SELENGA MOUNTAINS (WESTERN TRANSBAIKALIA) // Arid Ecosystems. 2023. Vol. 29. № 3 (96). P. 111-123. | PDF

Investigations of soil microbial communities in the dry-steppe zone of the Selenga Mountains have been carried out. The natural and climatic conditions of the region (a long cold period, the small amount of precipitation and uneven distribution during the growing season) cause the formation of mainly chestnut soils with a light granulometric composition, thin humus horizon, low humus and nitrogen content. The article presents data on seasonal dynamics and spatial structure of microbial communities of the studied soils. It was found that the number of different ecological and trophic groups of aerobic chemoorganotrophic bacteria varied from several thousand to several million CFU/g. The highest numbers were observed in the second half of summer. The studied soils had quite similar trends in the spatial distribution of the cultivated part of microbial communities. For hydrolytic bacteria, the highest numbers were noted in humus horizons, for oligotrophic bacteria – in the middle ones. Using high-sequencing we performed a full-profile analysis of the taxonomic structure and diversity of prokaryotic communities of light-humic and chestnut quasi-gley soils. It was found that Bacteria prevailed at the domain level, the number of Archaea was insignificant. The structure of bacterial communities at the phylum level was formed mainly by representatives of Actinobacteria, Acidobacteria, Proteobacteria, Bacteroidetes, Chloroflexi, Verrucomicrobia and Gemmatimonadetes with the dominance of actinobacteria and acidobacteria. Indices of diversity of prokaryotic communities of the genetic horizons of the studied soils were evaluated. It was found that the Shannon and Pielou indices correlated significantly with the content of humus and total nitrogen. During the analysis of beta diversity, it was revealed that microbial communities formed two disjoint clusters that combined humus and mineral horizons of soils when analyzed at the level of orders and lower taxonomic levels.

Keywords: chestnut soils, microbial communities, hydrolytics, oligotrophs, microbial biodiversity, 16S rRNA gene, Selenga Mountains.

Financing. The work was carried for the state task No. 121030100229-1 of the Institute of General and Experimental Biology SB RAS “Microbial Communities of Extreme Natural Ecosystems of the Baikal Region: Structural and Functional Organization and Biotechnological Potential”.

DOI: 10.24412/1993-3916-2023-3-111-123

EDN: GAGPVC

SPATIAL-TEMPORAL DYNAMICS OF THE STATE OF MICROBIAL COMMUNITIES IN THE STEPPE SOILS OF THE VOLGA-DON INTERFLUVE

Arid Ecosystems

Demkina T.S. SPATIAL-TEMPORAL DYNAMICS OF THE STATE OF MICROBIAL COMMUNITIES IN THE STEPPE SOILS OF THE VOLGA-DON INTERFLUVE // Arid ecosystems. 2020. V. 26. № 1 (82). P. 76-83 . | PDF

Soil microorganisms are the essential part of soil composition. Almost every soil process depends on the microorganisms’ activity, in one way or another. That is why characteristic of microbial communities is one of the most important diagnostic indices representing the conditions for soil formation. Paleosols maintain some features from the moment of their burial, which can be found in some of the parameters of their microbial community, such as the active biomass of microorganisms, ecologic and trophic structure of community, oligotrophy index etc. We studied microbial communities from the soils of different ages and different natural areas of Volga-Don interfluve, to determine the patterns of their spatial-temporal changes in connection with the current conditions of soil formation. We found out that the characteristics of communities of the modern soils in the dry-steppe and deserted-steppe areas in the south-east of the East European Plain mostly determine the specificity of the local conditions for soil formation. Thus, the soils of one sub-class, while being under different geomorphological and landscape conditions, can vary in their microbiological parameters. Or the characteristics of microbial communities of different soils can be very close, if the latter are related to the similar reliefs, soil-forming rocks and ground water level. Conditions of those communities during different historical periods are mostly determined by the patterns of evolution of specific soil areal (landscape) and bioclimatic changes during the century. Therefore, the local specificity is formed under the dynamics of the microbial communities’ conditions and their structural and functional organization.

Keywords: steppe, chestnut and light chestnut soils of different ages, microbial communities.

DOI: 10.24411/1993-3916-2020-10086