Observations of the atmospheric sources and sinks of carbon dioxide (CO₂) and methane (CH₄) in the pan-Arctic domain are extremely scarce, limiting our knowledge of carbon turnover in this climatically sensitive environment and the fate of the enormous carbon reservoirs conserved in the permafrost. Especially critical are the gaps in the high latitudes of Siberia, covered by the vast permafrost underlain tundra, where only several atmospheric monitoring sites are operational. This paper presents the first two years (September 2018–January 2021) of accurate continuous observations of atmospheric CO₂ and CH₄ dry mole fractions at the recently deployed tower-based measurement station “DIAMIS” (73.5068° N, 80.5198° E) located on the southwestern coast of the Taimyr Peninsula, Siberia, at the Gulf of the Yenisei River that opens to the Kara Sea (Arctic Ocean). In this paper, we summarized the scientific rationale of the site, examined the seasonal footprint of the station with an analysis of terrestrial vegetation and maritime sector contributing to the captured atmospheric signal, and illustrated temporal patterns of CO₂ and CH₄ for the daytime mixed atmospheric layer over the continent–sea interface. Along with the temporal variations reflecting a signal caused pan-Arctic and not very much influenced by the local processes, we analyzed the spatiotemporal distribution of the synoptic anomalies representing the atmospheric signatures of regional sources and sinks of CO₂ and CH₄ for the studied high-arctic Siberian domain of ~625 thousand km², with nearly equal capturing the land surface (54%) and the ocean (46%) throughout the year. Both for CO₂ and CH₄, we have observed a sea–continent declining trend, presuming a larger depletion of trace gases in the maritime air masses compared to the continental domain. So far, over the Kara Sea, we have not detected any prominent signals of CH₄ that might have indicated processes of subsea permafrost degradation and occurrence of cold seeps–still mainly observed in the eastern Arctic Seas—The Laptev Sea and the East-Siberian Sea.

Increased warming in the Arctic is of great concern. This is particularly due to permafrost degradation, which is expected to accelerate microbial breakdown of soil organic carbon, with its further release into the atmosphere as carbon dioxide (CO₂). The fine-scale variability of CO₂ fluxes across highly mosaic Arctic tundra landscapes can provide us with insights into the diverse responses of individual plant communities to environmental change. In the paper, we contribute to filling existing gaps by investigating the variability of CO₂ flux rates within different landscape units for dominant vegetation communities and plant species across typical tundra of the southern part of the Taimyr Peninsula, Siberia. In general, the variability of soil CO₂ flux illustrates a four-fold increase from non-vascular vegetation, mainly lichens and mosses (1.05 ± 0.36 µmol m⁻² s⁻¹), towards vascular plants (3.59 ± 0.51 µmol m⁻² s⁻¹). Barren ground (“frost boils”) shows the lowest value of 0.79 ± 0.21 µmol m⁻² s⁻¹, while considering the Arctic “browning” phenomenon, a further substantial increase of CO₂ flux can be expected with shrub expansion. Given the high correlation with top soil temperature, well-drained and relatively dry habitats such as barren ground and non-vascular vegetation are expected to be the most sensitive to the observed and projected temperature growth in the Arctic. For mixed vegetation and vascular species that favor wetter conditions, soil moisture appears to play a greater role. Based on the modeled seasonal pattern of soil CO₂ flux and precipitation records, and applying the rainfall simulations in situ we outlined the role of precipitation across enhanced CO₂ emissions (i.e., the “Birch” effect). We found that a pulse-like growth of soil CO₂ fluxes, observed within the first few minutes after rainfall on vegetated plots, reaches 0.99 ± 0.48 µmol m⁻² s⁻¹ per each 1 mm of precipitation, while barren ground shows 55–70% inhibition of CO₂ emission during the first several hours. An average additive effect of precipitation on soil CO₂ flux may achieve 7–12% over the entire growing season, while the projected increased precipitation regime in the Arctic may strengthen the total CO₂ release from the soil surface to the atmosphere during the growing season.

«Turczaninowia» Научные журналы Алтайского государственного университета Алтайский государственный университет Научные журналы АлтГУ

Trollius L. – plant genus of Ranunculaceae Juss. family that has decorative and practical applications. Onthe territory of Siberia, the greatest diversity of representatives is noted. During the study, a population genetic analysis for7 populations of T. asiaticus, 2 populations of T. vitalii and 1 population of T. sibiricus was carried out. Revealed 114 loci,the total polymorphism of which is 98.25 %. The number of amplified fragments is related to the primer and range from27 (17899A) to 32 (ISSR-17 and HB14). GST is 0,5186, therefore, the studied populations have a high degree of differentiation according to the classification of Wright’s classification and are divided into separate species. On the dendrogram of population similarity, 2 clusters are distinguished, one of which is formed by populations belonging to the speciesT. sibiricus. The second cluster includes populations of T. asiaticus and T. vitalii. A separate group that, probably, belongsto T. austrosibiricus Erst et Luferov is formed by the Baikal and Idzhim populations. When constructing a tree for individual representatives, a clear division of populations into separate groups is observed. Phylogenetic analysis of the nucleotidesequences of the ITS regions, chloroplast genes matK and rbcL revealed the absence of significant differences between thespecies T. asiaticus, T. vitalii, T. kolonok, T. europaeus L., T. altaicus, and T. sibiricus. SNPs were noted in the matK sequences in T. europaeus, T. altaicus, and T. kolonok.

This work is aimed at searching for marker features and assessing the significance of these morphological characteristics of the flower and basal leaf blade in the process of species identification of some Siberian species of the genus Trollius is assessed. To solve this problem, both classical approaches to the analysis of morphology and modern geometric morphometrics approach were used, which had not previously been widely encountered in the Russian scientific papers. It has been determined that the parameters of the leaf blade actually play a rather important role in classifying a plant to a particular species. Pairwise Tukey tests were conducted for each individual feature and for the totality of all features. For some relative features, including those listed in the literature as taxonomically important, the significance of differences between species has been assessed. Based on the results obtained, the problem of morphological similarity of T. asiaticus and T. kytmanovii has been identified. Statistically significant features have been identified that allow us to resolve the issue of the independence of the T. vitalii and T. kolonok species – the length of the styles and the width of the nectary petals at the base. The interspecific variation of leaf blade shapes has been determined within the framework of geometric morphometry.