Oleg Arnoldovich Anenkhonov

Climate warming is suspected of causing notable degradation of permafrost at the regional and global levels, resulting in carbon release and substantially high carbon storage, which in turn, accelerates climate warming. However, analysis of Siberia's carbon dioxide and methane fluxes reveals that permafrost dynamics are more stable than previously estimated. We systematically reviewed previous studies on the climate-permafrost-vegetation coupling system in southern Siberia and the Russian Far East, the Greater Khingan and Smaller Khingan Mountains in northeast China and northern Mongolia, which is the southernmost distribution of the Eurasian zonal permafrost and is characterized by the largest ecosystem-protected permafrost area in the world. Climate warming in recent decades has strongly affected the species composition of vegetation in this permafrost region. It has also contributed to the expansion or contraction of vegetation patches on a local scale. The increasing number of days of shallow frozen soil thawing per year leads to the deepening of the active layer, resulting in the degradation of permafrost. Permafrost degradation has both direct and indirect impacts on plant species composition and community structure. Permafrost melting changes local water conditions, which directly affects vegetation and indirectly affects the composition and growth of plant species through the impact of soil moisture change on soil nutrients. The interception and redistribution of snow by vegetation complicate the distribution of solar radiation and surface water received by the ground, which also indirectly affects the permafrost environment. However, there is still a large knowledge gap about the interactions among climate, permafrost, and vegetation, particularly at the regional level, which requires additional study.

In the current state the class Calamagrostietea langsdorffii contains 1 order, 3 alliances, 21 associations, 39 subassociations, 34 variants, and 2 unranked communities. Most of the units have been established at the early stages of the development of vegetation syntaxonomy in the USSR and Russia. By this reason a lot of nomenclatural shortcomings occur in the class. It is emphasized that the syntaxonomic structure of the class is imperfect, the cenotic diversity is revealed only partly, and problems of relationships between Calamagrostietea langsdorffii and the adjacent classes of meadow and marsh vegetation still have not been resolved.

Fatty acids, as part of cell membranes, determine their fluidity and dielectric constant. In addition, they play an important role in human and animal nutrition. This work examines the composition and fatty acid content of dried higher aquatic plants from Lake Kotokel (Republic of Buryatia, Russia) and their potential as a raw material for the production of feed and biologically active food supplements. A modified Bligh-Dyer method was used to extract lipid fraction. Fatty acids in the form of their methyl esters were analysed by gas chromatography–mass spectrometry. Palmitic C16:0 acid was the main saturated fatty acid found in Myriophyllum sibiricum, Elodea canadensis, Persicaria amphibia and Potamogeton perfoliatus in Lake Kotokel. The main unsaturated acid found in plants, regardless of their type, was the α-linolenic C18:3-ω3 acid. In addition, a relatively high content of stearic C18:0, myristic C14:0 and pentadecanoic C15:0 acids was noted. Branched acids (i-C14:0, i-C15:0, i-C16:0, i-C17:0, i-C20:0, a/i-C15:0, a/i-C17:0 and 10Me-C16:0) and odd carbon numbered acids (C13:0, C15:0, C17:0, C19:0, C21:0 and C23:0) were identified. An analysis of the authors’ and literature data revealed that the studied species of higher aquatic plants in reservoirs in the Asian part of Russia are characterised by a high content of α-linolenic C18:3-ω3 (up to 56%) and a low content of oleic C18:1-ω9 (up to 1.81%) acids. The content of α-linolenic C18:3-ω3 acid in plants from reservoirs in the European part of Russia was lower (up to 42%), while that of oleic acid C18:1-ω9 was higher (up to 14%).

The name Pino sibiricae-Laricion sibiricae was introduced in 1988 by Dostálek et al. and then again in 2004 by Ermakov. Further, the latter name, despite of homonymy, has been accepted in several Russian literature sources on the basis of a misapplication of ICPN Art. 37. The validity and legitimacy of the name introduced by Dostálek et al. are discussed and clarified, whereas Ermakov’s illegitimate homonym must be rejected according to Art. 31. Taxonomic reference: Catalogue of Life Checklist, Version COL23.5 (https://doi.org/10.48580/dfs6) [accessed 16 November 2023]. Abbreviations: ICPN = International Code of Phytosociological Nomenclature (Theurillat et al. 2021).

Plants of arid regions have adapted to harsh environments during the long span of their evolution and have developed a set of features necessary for their survival in water-limited conditions. Artemisia frigida Willd. (Asteraceae) is a widely distributed species possessing significant cenotic value in steppe ecosystems due to its high frequency and abundance. This study examines different patterns of formation of essential oil composition in A. frigida plants under the influence of heterogeneous factors, including climate and its integral characteristics (HTC, C_extr, SPEI and others). The work is based on the results of our research conducted in Russia (Republic of Buryatia, Irkutsk region), Mongolia, and China, from 1998 to 2021. A total of 32 constant compounds have been identified in the essential oil of A. frigida throughout its habitat range in Eurasia, from Kazakhstan to Qinghai Province, China. Among them, camphor, 1,8-cineol and bornyl acetate are the dominant components, contained in 93–95% of the samples. Among the sesquiterpenoids, germacrene D is the dominant component in 67% of the samples. The largest variability within the composition of the essential oils of A. frigida is associated with significant differences in the climatic parameters when plants grow in high-altitude and extrazonal conditions.

Leaf area index (LAI) is a key indicator of vegetation structure and function, and its products have a wide range of applications in vegetation condition assessment and usually act as important input parameters for ecosystem modeling. Grassland plays an important role in regional climate change and the global carbon cycle and numerous studies have focused on the product-based analysis of grassland vegetation changes. However, the performance of various LAI products and their discrepancies across different grassland types in drylands remain unclear. Therefore, it is critical to assess these products prior to application. We evaluated the accuracy of four commonly used LAI products (GEOV2, GLASS, GLOBMAP, and MODIS) using LAI reference maps based on both bridging and cross-validation approaches. Under different grassland types, the GLASS LAI performed better in meadow steppe (R² = 0.26, RMSE = 0.41 m²/m²) and typical steppe (R² = 0.32, RMSE = 0.38 m²/m²); the GEOV2 LAI performed better in desert steppe (R² = 0.39, RMSE = 0.30 m²/m²). When we assessed their spatial and temporal discrepancies during the period from 2010 to 2019, the four LAI products overall showed a high spatial and temporal consistency across the region. Compared with GLASS LAI, the most consistent to least consistent correlations can be ordered by GEOV2 LAI (R² = 0.94), MODIS LAI (R² = 0.92), and GLOBMAP LAI (R² = 0.87). The largest differences in LAI throughout the year occurred in July for all grassland types. Limited by the location and number of sample plots, we mainly focused on spatial and temporal variations. The spatial heterogeneity of land surface is pervasive, especially in vast grassland areas with rich grassland types, and the results of this study can provide a basis for the application of the product in different grassland types. Furthermore, it is essential to develop highly accurate and reliable satellite-based LAI products focused on grassland from the regional to the global scale according to these popular approaches, which is the next step in our work plan.

Artemisia jacutica Drob. (Yakut wormwood) is a biennial plant endemic to Eastern Siberia. This species is distributed across the Republic of Sakha (Yakutia) and southern Central Siberia, colonizing salt meadows and grasslands, steppe areas, saline to sodic surface soil patches, abandoned agricultural lands, and ruderal habitats. The species is rather rare in Buryatia, due to the southeastern frontier of its area. The essential oil of the Yakut wormwood contains chamazulene as a principal compound component with an anti-inflammatory effect. The data generated within the survey and the published statistics indicate that the climatic conditions affect the formation of the essential oil component composition in plants, which is obviously appropriate to provide the best adaptation of the plants to their environmental growing conditions. Therefore, the effects of climatic conditions on the essential oil component composition in the Yakut wormwood plants result in the formation of two chemotypes known as Buryat and Yakut. It has been ascertained that the formation of these chemotypes occurs due to the differences between the rates of heat and moisture supply to the lands favorable for plant growth, expressed by the hydrothermal coefficient (HTC). The temperature–humidity extremeness parameters defining the coefficient based on annual data greatly affect the ratio of components in the essential oil. The climate-related factors (air temperature, precipitation, etc.) and their integrated potential can influence certain constituents and their proportions in the essential oil, affecting their variability.

Лютик завитой (Ranunculus circinatus Sibth.) – бореальный, евроазиатский вид. В данной работе впервые изучены содержание тяжелых металлов и состав жирных кислот R. circinatus дельты р. Селенги – основного притока оз. Байкал. Установлено, что растения л. завитого дельты р. Селенги накапливают в значительных количествах металлы, из которых в наибольшем количестве Fe и Mn, тогда как содержание Pb и Сd ниже предела обнаружения. Пальмитиновая С16:0, миристиновая С14:0 и стеариновая С18:0 кислоты являются основными насыщенными жирными кислотами. Содержание ненасыщенных кислот варьирует от 53.7 до 58.6 отн.% и представлено кислотами n3-, n6-, n7- и n9-семейств. Вне зависимости от места и года сбора образцов доминирующими ненасыщенными кислотами являются линоленовая 18:3n3, линолевая 18:2n6 и пальмитолеиновая 16:1n7. Наличие изо-, антеизо- и 2-гидроксикислот в образцах связано с разрастанием микробных сообществ на растениях, а таких кислот как 17:1n7 и 20:3n6 – с обитанием животных в зарослях л. завитого. Полученные нами сведения подтверждают, что растения дельты вносят вклад в функционирование такого мощного естественного биофильтра как дельта р. Селенги.

The paper presents new locations of 11 rare plant species listed in the Red Data Books of the Republic of Buryatia, Zabaikalsky Krai, Irkutsk Region, and the Russian Federation. Thus, for both Adonis sibirica and Cypripedium guttatum 1 new locality in the Zabaikalsky Krai is revealed; for 3 species, namely Allium altaicum, Calypso bulbosa, and Physochlaina physaloides 1 locality in the Irkutsk Region is noted; for Krascheninnikovia ceratoides, Oxytropis peschkovae, and Saussurea krasnoborovii 1 new locality for every one of these species in the Republic of Buryatia is recorded; for Asplenium ruprechtii 1 new locality in the Republic of Buryatia and 1 new locality in the Irkutsk Region are reported; for Oxytropis sylvatica 1 new locality in the Irkutsk region and 3 new localities in the Zabaikalsky Krai are found. Additionally, for Stipa glareosa which is a regionally rare species and also recognized as relict species in Baikal Siberia, 2 new localities are indicated in the Republic of Buryatia.

Bupleurum L. has been widely used in various medical systems as an agent with a wide range of activities. The qualitative composition and content of lipid fraction components of the aerial parts of B. longifolium and B. chinense were elucidated in this work. The available data on the fatty acids (FAs) in Bupleurum plants were compiled and compared with species differentiation in the genus. As a result, the content of FAs in the studied Bupleurum plant species only partially corresponded to the species differentiation and, in some cases, contradicted it. The prognostic value of Bupleurum’s species differentiation for the identification of the potential composition of FAs was insignificant, and it was limited only by particular groups of species. This suggests that a complete phytochemical study of Bupleurum species needs to be conducted to determine the composition of FAs and to identify which species have a similar composition.