bluuebunny/crossref_metadata_2025 huggingface dataset:
Biodiversity Survey of Hydrogen Sulfide Thermal Springs in Dagestan Using 16S Metabarcoding
Authors: Tutubalina N.A. ,   National Research Centre “Kurchatov Institute”, Ac. Kurchatov sq., 1, Moscow, 123098, Russia,   Moscow State University, Leninskiye Gory, 1, Moscow, 119234, Russia, Kozlova A.D. ,   National Research Centre “Kurchatov Institute”, Ac. Kurchatov sq., 1, Moscow, 123098, Russia, Krylova A.S. ,   National Research Centre “Kurchatov Institute”, Ac. Kurchatov sq., 1, Moscow, 123098, Russia, Prokopenko A.V. ,   National Research Centre “Kurchatov Institute”, Ac. Kurchatov sq., 1, Moscow, 123098, Russia, Alieva Z.A. ,   Institute of Ecology and Sustainable Development of Dagestan State University, Dakhadaeva st., 21, Makhachkala, 367000, Russia, Teymurov A.A. ,   Institute of Ecology and Sustainable Development of Dagestan State University, Dakhadaeva st., 21, Makhachkala, 367000, Russia, Gadzhiev A.A. ,   Institute of Ecology and Sustainable Development of Dagestan State University, Dakhadaeva st., 21, Makhachkala, 367000, Russia, Namsaraev Z.B. ,   National Research Centre “Kurchatov Institute”, Ac. Kurchatov sq., 1, Moscow, 123098, Russia, Toshchakov S.V. ,   National Research Centre “Kurchatov Institute”, Ac. Kurchatov sq., 1, Moscow, 123098, Russia
Published: September 2024

The Greater Caucasus region is rich in thermal hydrogen sulfide springs, but their microbiological composition is poorly studied. In this study, using high-throughput profiling of the V4 region of the 16S rRNA gene, we analyzed the microbial communities of such springs in the Republic of Dagestan, assessed their biodiversity, and investigated correlations between abiotic factors and microbial community composition. Results show that the alpha diversity of microbial communities is negatively correlated with temperature and pH, with community composition being significantly influenced by the presence of hydrocarbons, redox potential, and dissolved organic matter content. The springs near the village of Kayakent were distinguished by unique physicochemical parameters, and their microbial communities were characterized by high taxonomic novelty, dominated by uncultivated representatives of the families Arcobacteraceae and Hydrogenophilaceae.
Water and sediment microbial communities in shallow coastal ecosystems of Lake Baikal during summer 2021-2022
Authors: Zaitseva S.V. ,   Institute of General and Experimental Biology SD RAS, Sakhyanovoy Str., 6, Ulan-Ude, 670047, Russia, Dagurova O.P. ,   Institute of General and Experimental Biology SD RAS, Sakhyanovoy Str., 6, Ulan-Ude, 670047, Russia
Published: September 2024

The taxonomical structure of the microbial community of shallow coastal areas is closely related to environmental conditions, and also changes rapidly in response to changes determined by water level fluctuations. The taxonomic structure of microbial communities in the shallow coastal areas of the Lake Baikal was studied during the period of high water level in summer months 2021-2022. At the phylum level, Proteobacteria, Actinobacteriota, Bacteroidota, Firmicutes, Cyanobacteria, Verrucomicrobiota and Deinococcota were dominant, accounting for 98.55 to 99.46% of the total microbial diversity in water microbial community. A significant similarity was revealed in the taxonomic composition of microbial communities in the shallow coastal areas of the Lake Baikal during certain summer months of 2021-2022. Similar water microbial communities formed in June 2021/22; in July 2022 in the Enkhaluk and Sukhaya sample sites, as well as at the Goryachinsk and Sukhaya sample sites in August 2022. Sediment microbial communities were dominated by Gammaproteobacteria, Bacteroidota, Alphaproteobacteria, Actinobacteriota and Verrucomicrobiota.
Production of the violet pigment violacein by psychrophilic strains of bacteria: extraction and identification
Authors: Zakharova Yu.R. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Martsinechko A.S. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Marchenkov A.M. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Petrova D.P. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Fedorova G.A. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia
Published: September 2024

Psychrophilic pigment-forming strains, isolated from Lake Baikal and the Pokhabikha River, were studied. Based on culture-based, morphological, and biochemical properties, as well as the results of 16S rRNA gene sequence analysis, the studied bacteria were assigned to the genera Janthinobacterium and Iodobacter. The strains are able to form biofilms and produce violet pigment. When the pigments were extracted with methanol and identified by MALDI/TOF mass spectrometry, the pigments violacein and deoxyviolacein were identified.
Microbial communities in the fluid migration zone in the sediments of the Krasny Yar methane seep (South Baikal)
Authors: Zemskaya T.I. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Lomakina A.V. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Pogodaeva T.V. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Bukin S.V. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Kolesnikov P.M. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Shubenkova O.V. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Khabuev A.V. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Khlystov O.M. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia
Published: September 2024

The diversity and structure of microbial communities were investigated using 16S rRNA gene barcoding in the sediments of the Krasny Yar methane seep, in the zone of near-surface occurrence of gas hydrates and the presence of oxidized and restored channels. The diversity of both bacteria and archaea along the core depth was similar to the diversity found in sediments from other areas: methylotrophic methanogens and microorganisms involved in different stages of the organic matter fermentation were detected in the sediment strata of all depths investigated. Migration flows of oxygen-rich and aerobic bacteria-rich near-bottom water influenced greatly the diversity of microbial communities in oxidized channels. Fluids migrating from the deep zone to the bottom surface provided transport from anoxygenic sediments of anaerobic archaea involved in the AOM process. The data obtained are consistent with geochemical and geothermal indicators defining the zone of active migration of near-bottom waters.
Retrospective analysis of the deposition of artificial radionuclides in sediments of the Yenisei River
Authors: Bolsunovsky A.Ya. ,   Institute of Biophysics FRC KSC Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50-50, Krasnoyarsk, 660036, Russia, Vakhrushev V.I. ,   Institute of Biophysics FRC KSC Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50-50, Krasnoyarsk, 660036, Russia, Dementyev D.V. ,   Institute of Biophysics FRC KSC Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50-50, Krasnoyarsk, 660036, Russia
Published: September 2024

Large-scale research of the Yenisei River sediments that has been conducted in the area affected by the MCC of Rosatom over a long distance, up to 1580 km downstream of Krasnoyarsk, has revealed the presence of various artificial radionuclides, thus making it possible to calculate sedimentation rates by using different radioisotope techniques. Retrospective analysis shows that in the past 60 years, considerable activities of the artificial radionuclides 137Cs and 152Eu entered the sediments of the river from the MCC-affected area during the anomalous floods in 1966 and 1988 and 60Co – during the 2006 flood. To explain the radionuclide peaks in the layers dated to other periods, additional sediment research is needed.
Biogeochemical features of the formation of Holocene sediments in Lake Dukhovoe (Eastern Baikalia)
Authors: Leonova G.A. ,   V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, av. Akademika Koptyuga 3, Novosibirsk, 630090, Russia, Maltsev А.Е. ,   V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, av. Akademika Koptyuga 3, Novosibirsk, 630090, Russia, Kondratieva L.М. ,   Institute for Water and Environmental Problems, Far Eastern Branch of the Russian Academy of Sciences, st. Dikopoltseva 56, Khabarovsk, 680000, Russia, Krivonogov S.К. ,   V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, av. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
Published: September 2024

A 6-meter core of Holocene sediments from Lake Dukhovoe was studied. As shown by the radiocarbon dating of lacustrine sediments, Lake Dukhovoe was formed in the Early Holocene (10 cal ka BP). The upper 180 cm of sediment is represented by sapropel, and the boundary of lake sediments is at 293 cm. This is an early stage of lake evolution, devoid of biogenic sedimentation. The microbiological studies of the sediment were carried out, which showed a high total number of heterotrophic bacteria in the upper (0–15 cm) and deeper (110–180 cm) sapropel intervals. Mineral bottom sediments (180–293 cm) are characterized by the presence of groups of phosphorus-reducing and ferromanganese bacteria. The contents of Na, Mg, Al, Si, Al, Ca, Fe, Mn, Zr and Cr in sapropel are within the average concentrations for the earth’s crust, and U and Mo exceed them.
Terrestrial environmental conditions during the Last Interstadial based on analysis of aquatic invertebrate communities from coastal exposures at the Dmitry Laptev Strait
Authors: Frolova L.A. ,   Kazan Federal University, Kremlyovskaya Str., 4/5, Kazan, 420008, Russia,   Institute of archaeology and ethnography of the Russian Academy of Sciences, Acad. Lavrentiev Avenue 17, Novosibirsk, 630090, Russia, Nigmatullin N.M. ,   Kazan Federal University, Kremlyovskaya Str., 4/5, Kazan, 420008, Russia, Nazarova L.B. ,   Kazan Federal University, Kremlyovskaya Str., 4/5, Kazan, 420008, Russia, Wetterich S. ,   Permafrost Research, Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Potsdam, Germany,   Institute of Geography, Technische Universität Dresden, Germany, Schirrmeister L. ,   Permafrost Research, Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Potsdam, Germany
Published: September 2024

For the first time, data on the composition of cladoceran communities in lake bottom sediments from Bol’shoy Lyakhovsky Island and Oyogos Yar on the coast of the Dmitry Laptev Strait during the last major interglacial period (MIS 5e, 124-119 thousand years ago) have been obtained. 13 Cladocera taxa were identified in the composition of the taphocenoses. The composition of the Cladocera taphocenoses of Oyogos Yar indicates the presence of a well-developed littoral zone in the paleolakes, as most of the cladoceran remains belong to littoral-phytophilic taxa closely associated with macrophytes. In the Cladocera communities of Oyogos Yar, both cold-water representatives and more southern thermophilic taxa, such as Leydigia leydigi, were found. The findings of Cladocera remains from the MIS 5e period on the coast of the Laptev Sea, significantly north of their current ranges, allow for the reconstruction of warmer climatic conditions than those of today. The data obtained on Cladocera are well consistent with the results of chironomid analysis.
Holocene environmental conditions in the Eastern Sayan foothills according to a comprehensive paleoecological study of the Sosnovka mire
Authors: Grenaderova A.V. ,   Federal State Autonomous Educational Institution of Higher Education «Siberian Federal University», Svobodny str, 79, Krasnoyarsk, 660041, Russia, Mikhailova A.B. ,   Federal State Autonomous Educational Institution of Higher Education «Siberian Federal University», Svobodny str, 79, Krasnoyarsk, 660041, Russia, Sharafutdinov R.A. ,   Federal State Autonomous Educational Institution of Higher Education «Siberian Federal University», Svobodny str, 79, Krasnoyarsk, 660041, Russia, Stoyko T.G. ,   Federal State Budgetary Educational Institution of Higher Education «Penza State University», Krasnaya st., 40, Penza, 440026, Russia
Published: September 2024

This research is devoted to the study of the combined vegetation dynamics, hydroclimatic conditions and fires in the foothills of the Eastern Sayan northwestern macroslope in the Holocene. The paleoecological reconstruction results obtained on the basis of AMS-dating, pollen, macrofossils, charcoal and malacofaunal analysis of peat deposits of the Sosnovka mire (right bank of the Yenisei River), covering the last ≈11,000 calendar years are presented. It was established that the process of waterlogging began at ≈9700-8500 cal yr BP at the optimum heat and moisture, when the waterless valley were covered with a mixed siberian pine-spruce-fir forest, with the maximum participation of spruce and fir. According to the study of Sosnovka mire sediments the reaction of local and regional communities to the Holocene Thermal Maximum (7500-6000 years ago) was clearly manifested. The participation of spruce and fir in the trees layer stand decreased sharply. The increase in fire activity was noted, which contributed to the lightening of forests and greater development of the shrub layer. During this interval, the process of swamping actively began in the floodplains of rivers with a drainage area in the western part of the Eastern Sayan. Based on the results of charcoal analysis six stages of increased fire activity were identified: I – about 10,000-8,800 cal yr BP, II – 7500-7200, III – 5600-5000, IV – 3700-3000, V – 2100-1800, VI – 800 cal yr BP - until now.
Organochlorine compounds in the bottom sediments of the meromictic Mogilnoe Lake (Kildin Island, Russia)
Authors: Kolpakova E.S. ,   N. Laverov Federal Center for Integrated Arctic Research, Ural Branch of the Russian Academy of Sciences, Nikolsky Av., 20, Arkhangelsk, 163020, Russia, Velyamidova A.V. ,   N. Laverov Federal Center for Integrated Arctic Research, Ural Branch of the Russian Academy of Sciences, Nikolsky Av., 20, Arkhangelsk, 163020, Russia, Koroleva Т.А. ,   N. Laverov Federal Center for Integrated Arctic Research, Ural Branch of the Russian Academy of Sciences, Nikolsky Av., 20, Arkhangelsk, 163020, Russia
Published: September 2024

The paper presents the results of a study of the behavior of organochlorine compounds (chlorinated benzenes and phenols) in the bottom sediments of Mogilnoe Lake (Kildin Island, Barents Sea). Mogilnoe Lake is a meromictic water reservoir located in the high latitudes of the Russian Arctic. A unique feature of the lake is its underground connection with the sea, which makes it similar to tropical anchialine lakes. Lake sediment samples were taken at three deep-water stations during complex expedition work in June 2019 by employees of the N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences (Arkhangelsk). Organochlorine compounds were extracted from air-dried samples of bottom sediments using accelerated flow-through solvent extraction with a hot mixture of organic solvents. Determination of the concentrations of chlorinated benzenes was carried out according to RD 52.24.417-2011 (RF), and the concentrations of chlorinated phenols and their derivatives – in accordance with the ISO 14154:2005. Quantification and identification of individual organochlorine compounds were carried out by capillary gas chromatography with electron capture detection. The presence of organochlorine compounds in sediments of the meromictic Mogilnoe Lake has been established. Concentrations of persistent organochlorine pollutants were assessed as high. Most likely, the component composition of organochlorine compounds and their detected levels (primarily pollutants) in the bottom sediments of the lake are due to the influence of various local anthropogenic sources, as well as atmospheric long-range transport from low/moderate latitudes and nearby regions.
Changes in the Baltic Sea levels during the Late Pleistocene the Late Pleistocene-Holocene transition
Authors: Kublitskiy Yu.A. ,   Herzen State Pedagogical University of Russia, 48 Nab. Moyki, St. Petersburg, 191186, Russia, Subetto D.A. ,   Herzen State Pedagogical University of Russia, 48 Nab. Moyki, St. Petersburg, 191186, Russia, Shatalova A.E. ,   Herzen State Pedagogical University of Russia, 48 Nab. Moyki, St. Petersburg, 191186, Russia, Demidionov M.Y. ,   Herzen State Pedagogical University of Russia, 48 Nab. Moyki, St. Petersburg, 191186, Russia
Published: September 2024

The article discusses the Pre-Baltic Sea history during the Late Pleistocene and Holocene periods. Despite a long history of research on this topic, there are still gaps in our knowledge that prevent us from creating an accurate and comprehensive paleo geographic reconstruction of the region during this time period. A table that provides information on the dates of bottom sediment samples from lakes, peat bogs, and archaeological sites that mark the earliest stages of Baltic Sea evolution, is included. The article identifies problems with the limited research on the Baltic Glacial Lake and Ioldium Sea sediments, as well as the maximum extent of the Ancylian transgression. A brief chronology of changes in water levels during the earliest stages of the Baltic is presented.
Environmental changes at the Pleistocene-Holocene boundary in glacial lakes of the North-East of Russia: results and prospects of multidisciplinary studies
Authors: Minyuk P.S. ,   North-East Interdisciplinary Scientific Research Institute n.a. N.A. Shilo FEB RAS, 16 Portovaya str., Magadan, Russia, Pozhidaeva D.K. ,   North-East Interdisciplinary Scientific Research Institute n.a. N.A. Shilo FEB RAS, 16 Portovaya str., Magadan, Russia, Morozova M.A. ,   North-East Interdisciplinary Scientific Research Institute n.a. N.A. Shilo FEB RAS, 16 Portovaya str., Magadan, Russia, Burnatny S.S. ,   North-East Interdisciplinary Scientific Research Institute n.a. N.A. Shilo FEB RAS, 16 Portovaya str., Magadan, Russia
Published: September 2024

Glacial lakes of the Magadan region - Grazevoe (61°08’21” N, 152°19’57” E), Tschuchye (61° 08.780’ N, 152° 19.860’ E), Nalimnoe (61°07’41” N, 152°20’8” E), Chernoe (61° 06.690’ N., 152° 15.570’ E), Sosednee (62°03’29” N, 149°31’22” E), Sapog (63°29’9” N, 147°50’41” E), Vodorazdel’noe (63°44’8” N, 148°13’4” E), Ui (63°49’31” N, 147°53’21” E), Forel (63°50’01.61” N, 147°51’03.75” E) have been studied. Most lakes were formed at the end of the Late Pleistocene or at the beginning of the Early Holocene. The sedimentation features of the Late Pleistocene and Holocene differed significantly. The Late Pleistocene stage is characterized by the dominance of terrigenous sediment, while the Holocene is dominated by biogenic sedimentation. The key biotic and abiotic paleoenvironmental proxies from glacier records are shown.
Palaeoecological reconstruction of the Late Glacial and Early Holocene based on pollen data from lake Novozhilovo (Perm region, Russia)
Authors: Lapteva E.G. ,   Perm State Humanitarian Pedagogical University, Sibirskaya str., 24, Perm, 614990, Russia,   Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences, 8 Marta str., 202, Yekaterinburg, 620144, Russia, Rudaya N.A. ,   Institute of Archaeology and Ethnography, Siberian Branch of the Russian Academy of Sciences, Lavrentyev prospect, 17, Novosibirsk, 630090, Russia, Zaretskaya N.E. ,   Institute of Geography, Russian Academy of Sciences, Staromonetniy Pereulok, 29, Moscow 119017, Russia,   Geological Institute of Russian Academy of Sciences, Pyzhevskiy Pereulok, 7, Moscow 119017, Russia, Kopytov S.V. ,   Perm State Humanitarian Pedagogical University, Sibirskaya str., 24, Perm, 614990, Russia,   Perm State University, Bukireva str., 15, Perm 614990, Russia, Sannikov P.Yu. ,   Perm State University, Bukireva str., 15, Perm 614990, Russia
Published: September 2024

This paper provides the first paleolimnological studies performed in the upper Kama basin (Perm region). These yielded a detailed pollen record characterizing the changes in the natural conditions of the transition from the periglacial environment of the Late Glacial period to the interglacial conditions of the Holocene between 14.15 and 10.0 cal ka BP. It was found that open birch woodland with larch existed in the Allerød period (14.15–12.7 сal ka BP) and was replaced by larch forest-steppe during the Younger Dryas (12.7–11.5 cal ka BP). The spread of spruce began in the early Holocene between 11.5 and 10.7 cal ka BP, whereas open larch and spruce woodlands became dominant between 10.7 and 10.0 cal ka BP. Quantitative palaeoclimatic reconstruction reveals that the average temperature of the warmest month (July) and the annual precipitation were considerably lower than modern values. The average July temperature increased from 10 to 16ºС between 14.15 and 12.7 cal ka BP. Then, small fluctuations within 1ºС occurred between 12.7 and 10.0 cal ka BP. The average annual precipitation was 200-300 mm below modern values between 14.15 and 10.7 cal ka BP and reached them only after 10.7 cal ka BP.
The content and distribution of natural (232Th, 238U, 40K) radionuclides in the model small lakes bottom sediments of different sedimentogenesis types (south of Western Siberia)
Authors: Ovdina E.A. ,   V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences, Akad Koptyug Ave. 3, Novosibirsk, 630090, Russia, Strakhovenko V.D. ,   V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences, Akad Koptyug Ave. 3, Novosibirsk, 630090, Russia, Malov G.I. ,   V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences, Akad Koptyug Ave. 3, Novosibirsk, 630090, Russia, Malov V.I. ,   V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences, Akad Koptyug Ave. 3, Novosibirsk, 630090, Russia
Published: September 2024

The assessment of the content and distribution of natural radionuclides (232Th, 238U, 40K) in stratified bottom sediments cores of the similar composition (silicon class) in model small lakes, taking into account the type of sedimentogenesis (humid, arid, and nival), in consistently changing landscape conditions of the south of Western Siberia, was carried out. In the bottom sediments of the model small lakes (silicon class) of the humid and arid sedimentogenesis type, the average content and distribution of Th, U and K are similar throughout the studied time interval (about 200 years). For bottom sediments in model lakes of the nival sedimentogenesis type, fluctuations in the average composition along the core, as well as generally higher Th and U contents, are observed.
Quantitative methods for reconstruction of the Holocene paleoclimatic characteristics and vegetation changes based on palynological data from lake and peat sediments
Authors: Novenko E.Yu. ,   Institute of Geography of the Russian Academy of Sciences, Staromonetny lane, 29, Moscow, 119017, Russia, Andreev R.А. ,   Institute of Geography of the Russian Academy of Sciences, Staromonetny lane, 29, Moscow, 119017, Russia,   Lomonosov Moscow State University, Faculty of Geography, Leninskie Gory, 1, Moscow, 119991, Russia
Published: September 2024

The paper presents the results of a methodological study of the quantitative reconstruction of paleoclimatic characteristics (mean January and July temperatures, mean annual temperature and precipitation) and forest cover within a 20 km radius of the study site using palynological data from lake and peat sediments. The following quantitative methods have been tested: the best modern analog technique, transfer functions as weighted averaging, weighted averaging partial least square, and the Random Forest method, a meta estimator that fits a number of decision tree classifiers on various sub-samples of the dataset. A database of subfossil pollen assemblages for northern central Siberia (north of 60°C) was used as a training data set for model construction, containing 174 pollen assemblages, climatic characteristics for the sampling area, and calculations of forest cover based on remote sensing data. Leave-one-out cross validation was appy for testing of the methods. The results showed that all models had the highest coefficients of determination (R2), the smallest errors and the lowest uncertainty for the reconstruction of the mean July temperature. The developed methods were applied to two key sites in Central Siberia, located in the vicinity of Igarka and the settlement of Tura (Krasnoyarsk Region). The results obtained showed similar trends in the changes in palaeoclimatic characteristics reconstructed by different methods, but a rather large variation in temperature and precipitation values at some time intervals.
Paleoecological reconstruction of water level changes in a cascade of lakes on Lunkulansaari Island (Lake Ladoga) based on the analysis of Cladocera remains in lake sediments
Authors: Pastukhova Yu.A. ,   Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119991, Russia, Tsyganov A.N. ,   Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119991, Russia, Sapelko T.V. ,   Institute of Limnology of the Russian Academy of Sciences – St. Petersburg Federal Research Center of the Russian Academy of Sciences, Sevastyanova, 9, St.Petersburg, 196105, Russia, Mazei N.G. ,   Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119991, Russia, Zharov A.A. ,   A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninskiy ave. 33, Moscow 119071, Russia, Mazei Yu.A. ,   Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119991, Russia
Published: September 2024

In this study we investigate the dynamics of Cladocera subfossil assemblages (taphocoenoses) during the formation of the cascade of three lakes located on the island of Lunkulansaari in the northeastern part of Lake Ladoga in the late Holocene. Since the last regression of Lake Ladoga and the formation of the lake cascade, Cladocera subfossil assemblages began to accumulate in bottom sediments. Their species structure was alternately dominated by species typical for aquatic vegetation in the littoral zone or species that prefer to live in open water. The data obtained allowed to reconstruct changes in lakes’ water levels and clarify the stages of their development, previously revealed on the basis of pollen spectra of aquatic vegetation.
Sediments and morphology of deep lakes of Central Tunguska Plateau (Krasnoyarsk krai, Evenkia): on the problem of the Tunguska Event at 1908
Authors: Rogozin D.Y. ,   Institute of Biophysics, Siberian Division of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia,   Siberian Federal University (SibFU), 79 Svobodny Ave, Krasnoyarsk region, Krasnoyarsk, 660041, Russia, Darin A.V. ,   Sobolev Institute of Geology and Mineralogy Siberian Division of Russian Academy of Sciences, Prospekt Koptyuga 3, Novosibirsk, 630090, Novosibirsk, Russia, Kalugin A.I. ,   Sobolev Institute of Geology and Mineralogy Siberian Division of Russian Academy of Sciences, Prospekt Koptyuga 3, Novosibirsk, 630090, Novosibirsk, Russia, Krylov P.S. ,   Kazan (Volga) Federal University, Kremlevskaya18/1, Kazan, 420008, Republic of Tatarstan, Russia, Meydus A.V. ,   Astafiev Krasnoyarsk State Pedagogical University, Ady Lebedevoi 89, 660049, Krasnoyarsk, Russia
Published: September 2024

The shape of the bottom and the thickness of sediments of small lakes Zapovednoye and Peyungda, located 50-60 km from the supposed epicenter of the “Tunguska Event” of 1908, were studied using echo-sounding and seisimo-acoustic profiling, and their age was estimated using 137Cs, 210Pb, 14C. It was revealed that both lakes have funnel shape with a depth of 60 and 34 m, respectively, and are similar in shape and size to Lake Cheko, which, according to some researchers, is an impact crater formed by a celestial body as a result of the “Tunguska Event 1908”. The examples of lakes Zapovednoye and Peyungda show that the shape of Lake Cheko is not unique to this area. The age of the bottom sediments of lakes Zapovednoye and Peyungda exceeds several thousand years. In the sediments of lakes Zapovednoe and Peyungda, a layer with a high content of terrigenous elements was identified, presumably formed due to the input of disturbed soil layer as a result of the massive fall of trees after the “Tunguska 1908”. Thus, the presence of two deep funnel-shaped lakes near the epicenter of the “Tunguska 1908” much older than 1908, casts doubt on the uniqueness of Lake Cheko, and therefore its impact origin. In addition, according to our estimate, the age of Lake Cheko is no less than 300 years, which contradicts the hypothesis of its origin as a result of the “Tunguska 1908”.
New data on Late Glaсial diatoms of the SE Baltic region based on the results of studying the Kulikovo section
Authors: Rudinskaya A.I. ,   Institute of Geography RAS, Staromonetniy Lane 29b4, Moscow, 119017, Russia, Druzhinina O.A. ,   Herzen State Pedagogical University of Russia, River Moyka Emb., 48, Saint-Petersburg, 191186, Russia, Filippova K.G. ,   Institute of Geography RAS, Staromonetniy Lane 29b4, Moscow, 119017, Russia, Lazukova L.I. ,   Institute of Geography RAS, Staromonetniy Lane 29b4, Moscow, 119017, Russia
Published: September 2024

The sediments of shallow basins formed along the coast of the Baltic glacial lake around 14,500-14,000 cal BP provide a valuable source of information for reconstructing environmental changes in the Bølling-Allerød. Radiocarbon dating and complex lithological and diatom analyzes were performed for the deposits of one of these paleo-reservoirs, exposed in the Kulikovo section (northern part of the Sambian Peninsula). Diatoms of the sediments formed 14,100 – 13,400 cal BP are mostly presented by benthic and epithytic oligohalobic species. We compared the obtained data with existing ideas about the Late Glacial diatom flora for this region to identify general and local patterns of diatom communities formed at that time.
Late Glacial vegetation changes in the Kostroma Volga region based on pollen study of Lake Chukhlomskoye bottom sediments
Authors: Samus A.V. ,   Institute of Geography, Russian Academy of Sciences, Staromonetny L., 29/4, Moscow, 119017, Russia, Konstantinov E.A. ,   Institute of Geography, Russian Academy of Sciences, Staromonetny L., 29/4, Moscow, 119017, Russia, Filippova K.G. ,   Institute of Geography, Russian Academy of Sciences, Staromonetny L., 29/4, Moscow, 119017, Russia
Published: September 2024

The article presents the results of a palynological study of Lake Chukhlomskoye bottom sediments. Pollen analysis in combination with the results from 14C and 137Cs dating made it possible to reconstruct the main stages of changes in plant communities in the Kostroma Volga region at the end of the Pleniglacial and during the Late Glacial: 19.5–16.9 cal. ka BP – periglacial steppe, 16.9–14.7 cal. ka BP – birch periglacial forest-steppe, 14.7–12.7 cal. ka BP – spruce and birch-spruce forests and open woods with periglacial-steppe and meadow communities, 12.7–11.7 cal. ka BP – birch periglacial forest-steppe with rare participation of spruce.
Environmental evolution of the south shore of Kandalaksha Bay, as indicated by the study of bottom sediments from small lakes
Authors: Shelekhova T.S. ,   Institute of Geology, Karelian Research Centre, Russian Academy of Sciences, Pushkinskaya St., 11, Petrozavodsk, 185910, Karelia, Russia, Lavrova N.B. ,   Institute of Geology, Karelian Research Centre, Russian Academy of Sciences, Pushkinskaya St., 11, Petrozavodsk, 185910, Karelia, Russia
Published: September 2024

Environmental changes on the south shore of Kandalaksha Bay in Holocene time were reconstructed by analyzing the data obtained by palynological and 14C methods. Diatom complexes of marine, freshwater and transition facies are described. The possible application of pollen indicators for a better understanding of the genesis of sediments is discussed.
Reconstruction of changes in sedimentation conditions of lakes of the Barents Sea coast during their isolation from the sea in the Holocene (Mustatunturi Ridge, Kola region)
Authors: Shikhirina K.A. ,   Herzen State Pedagogical University of Russia, 48 Moika Embankment, St. Petersburg, 191186, Russia, Tolstobrov D.S. ,   Geological Institute of the Kola Science Centre of the Russian Academy of Sciences; 14 Fersmana Str., Apatity, 184209, Russia
Published: September 2024

In this short communication presented a reconstruction of the isolation process of 4 lakes located on the coast of the Barents Sea (Musta-Tunturi ridge). The reconstruction was carried out on the basis of a lithological description of lakes’ bottom sediments, interpreted as transition zone sediments from marine to lake sedimentation conditions. The lithological description was compiled based on the results of grain-size and LOI (losses on ignition) analyses of 4 lakes’ bottom sediments and its radiocarbon dating. An assumption about the role of tectonic and climatic factors in the isolation of lake basins was made.
Provenances of Upper Quaternary sediments in the Northern Caspian Sea
Authors: Tkach N.T. ,   Department of Oil-Gas Sedimentology and Marine Geology, Faculty of Geology, Lomonosov Moscow State University, Leninskie Gory 1a, Moscow, 119991, Russia, Sorokin V.M. ,   Department of Oil-Gas Sedimentology and Marine Geology, Faculty of Geology, Lomonosov Moscow State University, Leninskie Gory 1a, Moscow, 119991, Russia, Luksha V.L. ,   Department of Oil-Gas Sedimentology and Marine Geology, Faculty of Geology, Lomonosov Moscow State University, Leninskie Gory 1a, Moscow, 119991, Russia, Tkach A.A. ,   Laboratory of Pleistocene Paleogeography, Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory 1a, Moscow, 119991, Russia
Published: September 2024

This paper presents a generalization of the clay minerals composition in the sediments of the KOR-3 core located in the central part of the Northern Caspian Sea (19 samples). The history of changes in the different river basins contribution to the sedimentary supply in the central part of the Northern Caspian Sea could be traced by changes in clay mineral ratios in the Upper Quaternary sediments. Changes in the ratio reflect differences in material sources during the first and second stages of the Khvalynian transgression of the Caspian Sea — one of the most controversial stages in the history of the Caspian Sea. Consequently, our conclusion is that there were different causes of sea-level uprise at different stages of the transgression. The subsequent events (deep Mangyshlak regression and New Caspian transgression) are not associated with abrupt changes in the inflow of rivers into the Northern Caspian Sea, according to the composition of clay minerals.
New data on changes in the White Sea level on the Karelian coast the Holocene
Authors: Tolstobrov D.S. ,   Geological Institute of the Kola Science Centre of the Russian Academy of Sciences; 14, Fersmana Str., 184209 Apatity, Russia, Tolstobrova A.N. ,   Geological Institute of the Kola Science Centre of the Russian Academy of Sciences; 14, Fersmana Str., 184209 Apatity, Russia, Korsakova O.P. ,   Geological Institute of the Kola Science Centre of the Russian Academy of Sciences; 14, Fersmana Str., 184209 Apatity, Russia, Vashkov A.A. ,   Geological Institute of the Kola Science Centre of the Russian Academy of Sciences; 14, Fersmana Str., 184209 Apatity, Russia
Published: September 2024

The article presents new data on the study of bottom sediments of a lake isolated from the sea basin in the area of the village of Chupa (North Karelia). A lake basin at an altitude of 34.0 meters was studied. Based on comprehensive study of the lake bottom sediments was established that the sea coastline was located at this altitude approximately 5800 years ago. The results of comparison of new data with data from earlier studies may indicate differentiated movements of blocks of the earth’s surface, or a local activation of seismic processes in the Middle Holocene in this area.
Holocene stable oxygen isotope record from the North Caspian Rybachya core
Authors: Tkach A.A. ,   Laboratory of Pleistocene Paleogeography, Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory 1a, Moscow, 119991, Russia, Zenina M.A. ,   Laboratory of paleooceanology, Geological department, P.P. Shirshov Institute of Oceanology, Russian Academy of Science, Nakhimovsky prospect 36, Moscow, 117997, Russia,   A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Palchevsky 17, Vladivostok, 690041, Russia, Yanina T.A. ,   Laboratory of Pleistocene Paleogeography, Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory 1a, Moscow, 119991, Russia, Tkach N.T. ,   Department of Oil-Gas Sedimentology and Marine Geology, Faculty of Geology, Lomonosov Moscow State University, Leninskie Gory 1a, Moscow, 119991, Russia
Published: September 2024

The first results of 22 δ18Oost measurements on ostracod shells from the Rybachya core in the North Caspian Sea are presented. The stable oxygen isotope record here confirms previous studies of Upper Quaternary and Holocene sediments of the Rybachya core area, where it was suggested that a paleovalley was formed during the Mangyshlak regressive stage and then gradually filled during the Holocene transgressive stage. We recorded three local isotopic stages, each characterized by δ18Oost values. The hydrological variability and sea level changes associated with the transgressive-regressive rhythm of the Caspian Basin and the climatic changes in the Northern Hemisphere led to the δ18Oost changes obtained in this work. Relatively depleted δ18Oost values from sediments filling the paleovalley allowed to interpret the isotope record in terms of freshwater influx. The average δ18O enrichment of ostracod shells is taken as evidence for the isolation of the paleovalley during the Caspian Sea level retreat. However, the higher δ18Oost values obtained for the last (modern) stage of Caspian history are under the strong control of host water salinity, which is higher than during the paleovalley filling episode.
Prospects for studying the paleo archive of lake sediment from the Sarskoe Bog
Authors: Zakharov A.L. ,   Institute of Geography RAS, Staromonetny Lane 29/4, Moscow, 119017, Russia, Garankina E.V. ,   Moscow State University, Leninskie Gory 1, Moscow, 119991, Russia, Konstantinov E.A. ,   Institute of Geography RAS, Staromonetny Lane 29/4, Moscow, 119017, Russia, Rudinskaya A.I. ,   Institute of Geography RAS, Staromonetny Lane 29/4, Moscow, 119017, Russia, Shorkunov I.G. ,   Institute of Geography RAS, Staromonetny Lane 29/4, Moscow, 119017, Russia, Yurchenko A.P. ,   Institute of Geography RAS, Staromonetny Lane 29/4, Moscow, 119017, Russia, Shukhvostov R.S. ,   Institute of Geography RAS, Staromonetny Lane 29/4, Moscow, 119017, Russia,   Moscow State University, Leninskie Gory 1, Moscow, 119991, Russia
Published: September 2024

In the center of the East European Plain, lake sediments provide the most detailed and high-resolution paleoarchives of the Late Pleistocene and Holocene periods. However, not all lake sediments can be used to reliably reconstruct regional paleoclimate and landscape changes. Factors such as the shape of the lake basin, the type of rocks beneath it, the number and flow of tributaries, and the vegetation present all play a role in determining the rate and composition of sedimentation in lake deposits, creating a unique record of the local environmental conditions. The Sarskoe Bog Basin has promising potential for providing a high-resolution record of the Late Pleistocene period. The core sample collected from the central part of the swamp met all expectations, but during the geophysical study of the geological structure and search for the maximum depth of lake sediments, it was found that the reference well was not in the most appropriate location. The first geophysical surveys conducted in the bog have improved our understanding of the paleorelief of the basin and will allow us to choose a location for the main well that is suitable for our research objectives.
Pollen analysis in reconstruction of paleo vegetation on the southwestern part of the Yamal Peninsula
Authors: Nigamatzyanova G.R. ,   Kazan Federal University (KFU), Kremlevskaya Str., 18, Kazan, 420008, Russia,   Institute of Archaeology and Ethnography SB RAS (IAET SB RAS), Acad. Lavrentiev Avenue, 17, Novosibirsk, 630090, Russia, Nigmatullin N.M. ,   Kazan Federal University (KFU), Kremlevskaya Str., 18, Kazan, 420008, Russia, Frolova L.A. ,   Kazan Federal University (KFU), Kremlevskaya Str., 18, Kazan, 420008, Russia,   Institute of Archaeology and Ethnography SB RAS (IAET SB RAS), Acad. Lavrentiev Avenue, 17, Novosibirsk, 630090, Russia
Published: September 2024

The aim of this study is to explore the pollen palynomorphs from the bottom sediments of an unnamed tundra lake whilst attempt to reconstruct the past vegetation and paleoecological conditions for the southwestern part of the Yamal Peninsula. 34 pollen (11 boreal, 18 arboreal) and 5 spore palynomorphs were identified. Pollen spectra characterized by a predominance of arboreal pollen (Betula sect. Nanae, Betula sect. Albae, Alnus). It was found in the range of ~6000-5100 cal. yr BP during the Holocene optimum birch forest and shrubby vegetation with bogs has been developed in the lake’s catchment area. The tundra biome was dominant, however, around ~5800 cal. yr BP, the indicator of the taiga biome increases to maximal values. Since the beginning of the Subatlantic period (~2200 cal. yr BP), local vegetation began to evolve into the modern southern tundra with shrubs (dwarf birch, alder, willow), and sedge-sphagnum bogs in lowlands.
Correlation of small isolated reservoirs in the Zaonezhsky Peninsula area with the Onega Ice Lake level changes
Authors: Orlov A.V. ,   The Herzen State Pedagogical University of Russia, Moika River Embankment, 48, St. Petersburg, 191186, Russia,   Northern Water Problems Institute, Karelian Research Center of the Russian Academy of Sciences, Alexander Nevsky pr., 50, Petrozavodsk, 185030, Russia, Potakhin M.S. ,   The Herzen State Pedagogical University of Russia, Moika River Embankment, 48, St. Petersburg, 191186, Russia,   Northern Water Problems Institute, Karelian Research Center of the Russian Academy of Sciences, Alexander Nevsky pr., 50, Petrozavodsk, 185030, Russia, Subetto D.A. ,   The Herzen State Pedagogical University of Russia, Moika River Embankment, 48, St. Petersburg, 191186, Russia
Published: September 2024

The article discusses data on the lithological composition of bottom sediments from two small lakes – Lake Lavkozero and Lake Gangozero, located on the Zaonezhsky Peninsula, within the area of the Onega Ice Lake. In the recovered sediment sequences from studied lakes, two sediment units from top to down have been recognized: Holocene gyttja from small isolated lakes and Late Pleistocene sediments from the Onega Ice Lake, which are represented by varved clays and silts. Based on lithological data, a “pink horizon” of varved clays was identified. It is similar to one which found in the sediment section of the Unitskaya Bay in Lake Onega. The absolute hypsometric position of this “pink horizon” was determined based on the elevation levels of the lakes under study.
GIS-based reconstructions of Lakes Onego and Ladoga development in the Late Pleistocene
Authors: Potakhin M.S. ,   Northern Water Problems Institute, Karelian Research Center of the RAS, Petrozavodsk, 185030, Russia,   Herzen State Pedagogical University of Russia, St. Petersburg, 191186, Russia, Zobkov M.B. ,   Northern Water Problems Institute, Karelian Research Center of the RAS, Petrozavodsk, 185030, Russia, Kublitsky Yu.A. ,   Herzen State Pedagogical University of Russia, St. Petersburg, 191186, Russia, Anisimov N.V. ,   Herzen State Pedagogical University of Russia, St. Petersburg, 191186, Russia,   Vologda State University, Vologda, 160000, Russia, Subetto D.A. ,   Herzen State Pedagogical University of Russia, St. Petersburg, 191186, Russia
Published: September 2024

The article provides a review of GIS-based reconstructions of the development of Lakes Onego and Ladoga in the Late Pleistocene. It is shown that recently GIS methods have been used for reconstructions. At the moment, there are three GIS-based paleoreconstructions of the study area (Gorlach et al., 2017; Zobkov et al., 2019; Anisimov, Minina, 2020). All reconstruction used DEMs and digital bathymetry models of lakes. However, areas, volumes, maximum, and average depths for various stages of lake development are calculated only for Lake Onego (Zobkov et al., 2019; Paleolimnology…, 2022).
Effect of heavy metals on the production of siderophores by an endolithic strain of Bacillus velezensis S18
Authors: Elistratova A.A. ,   Kazan (Volga Region) Federal University, Institute of Fundamental Medicine and Biology, Kazan, Russian Federation, Shirshikova T.V. ,   Kazan (Volga Region) Federal University, Institute of Fundamental Medicine and Biology, Kazan, Russian Federation, Ivoilova T.M. ,   Kazan (Volga Region) Federal University, Institute of Fundamental Medicine and Biology, Kazan, Russian Federation, Sharipova M.R. ,   Kazan (Volga Region) Federal University, Institute of Fundamental Medicine and Biology, Kazan, Russian Federation, Khilyas I.V. ,   Kazan (Volga Region) Federal University, Institute of Fundamental Medicine and Biology, Kazan, Russian Federation
Published: September 2024

The high anthropogenic load of heavy metals on water resources has a negative impact on all living organisms, causing environmental, medical and economic problems. One of the most ubiquitous microorganisms in aquatic ecosystems is the genus Bacillus. The study of the mechanisms by which Bacillus bacteria adapt to heavy metal exposure contributes significantly to the understanding of physiological and biotechnological processes. This study focuses on the effect of heavy metals on the production of siderophores by the endolithic strain Bacillus velezensis S18. The B. velezensis S18 strain was found to demonstrate resistance towards high concentrations of heavy metals, as well as the ability to secrete siderophores. Thus, B. velezensis S18 has significant potential for the detoxification and recovery of metals from contaminated surface and groundwater.