Abstract: The study focuses on palsa and high-centered polygonal peatlands. Engineering surveys for construction in bumpy permafrost peatlands are complicated by the lack of clear criteria for distinguishing between different types of mounds, such as palsa and high-centered polygonal peatlands. These mounds differ in height, shape, and distribution of their main engineering components. These two kinds of bumpy permafrost peatlands respond to human impact in rather different ways throughout structure operation, necessitating distinct safeguards. In this sense, techniques for more precise mound identification needs to be developed early on in engineering and environmental surveying. Examining the distribution of the carbon to nitrogen ratio in the peat that covers the mounds could be one strategy. The remaining landforms known as high-centered polygonal peat blocks were created "passively" by thermokarst processes along the frost-breaking cracks, with vein ice separating them. Palsa peat massifs are mostly found in the sporadic permafrost zone, though they are also frequently observed in the discontinuous and even continuous permafrost development zones, such as the Norilsk region, the Putorana plateau, the Mirny region of Yakutia, Chukotka and Kamchatka, etc. The thickness of peat on both convex and flat surfaces It is typically high, ranging from 1 to 3 meters, but rising to 5 meters and occasionally 8 to 9 meters on convex mounds. Palsa and high-centered polygonal peatlands exhibit distinctive genesis, height, shape, and distribution of engineering and geological characteristics, particularly ice content. Improved methods for identifying mounds during early stages of engineering and environmental studies are needed. One approach could be to analyze the carbon and nitrogen ratios in the peat covering the mounds. Palsa peatlands have higher carbon content (50-55% on average) and lower nitrogen content (0.5-2.0%) compared to high-centered polygonal peatlands (35-40% carbon and 1.5-2.5% nitrogen). The C/N value in peatlands varies, with palsa ranging from 30-36 (reaching -240) and high-centered polygonal peatlands rarely exceeding 25-27 (often 10-20).

Abstract: Study considers horizontal and vertical sampling directions for pollen analysis of ice wedges, taking into account the special mechanism of wedge ice formation. Pollen spectra from the Late Holocene ice-wedges on high polygonal floodplain of the Lyakkatosyo River are studied. Shrub-lichen-moss-polygonal tundra dominates the site. We accounted for the number of elementary veins. The main research methods are pollen and geochemical analyses. We collected samples for pollen analysis along ice wedges' axis and horizontally at depth of 1.20 m, while we also took samples for chemical analysis along the same axis. The high concentration of pollen and spores in ice wedges made it possible to compare results of horizontal and vertical sampling with sufficient degree of accuracy. Pollen spectra characterizing ice wedge horizontally and vertically showed significant differences in the main components. The main difference between horizontal and vertical pollen spectra in AP is the spruce and birch pollen percentages. Along the ice wedge axis, spruce pollen (2.0–13.0%) and birch pollen (6.0–14.0%) are always visible. However, we only find spruce pollen (2.0–4.0%) up to 0.3 m from the vein axis and birch pollen (2.0–14.0%) up to 0.4m from the vein axis. We detected similar-composition pollen spectra in only one case. The sample that is closest to the center of the ice wedge, located at 0.1 m from axis and at depth of 1.2 m, exhibits approximately the same pollen spectra as the sample that is located at depth of 1.2 m from the central part of ice wedge. It is quite natural that certain pollen taxa do not have a general sequence of culminations. Chemical composition of ice wedge suggests that spruce pollen got into the ice due to flooding of the Lyakkatosyo River.

Abstract: The palsa and lithalsa are reliable indicators of the presence of permafrost, especially on the its southern border. The subject of the study is the consideration of the C/N ratio in the peat of the palsa and the litter and humus horizon of the lithalsa as a criterion for the separation of the palsa and lithalsa. The palsa near the Yeletskaya village in the Bolshezemelskaya tundra and the lithalsa in the Southern Transbaikalia near the Preobrazhenka village and in the valley of the Sentsa in the Eastern Sayan are considered. The history of the study of lithalsa and palsa in Russia at the beginning of the twentieth century is considered also. It was found that the nitrogen content in the surface layers of the lithalsa (0.45-1.73% in the valley of the Sentsa River and 0.47-2.01% near the Arachley Lake) is approximately in the same range as in the surface horizons of the palsa, regardless of the permafrost region. The results of the carbon and nitrogen content determining, as well as their ratios in the peat cover of the palsa are summarized. In contrast to lithalsa, the carbon content in the peat horizons of the palsa and flat-hummock peatlands is many times higher than the values obtained for both surface and buried organic horizons of the lithalsa. The value of C/N less than 13 has not been recorded for the peat cover of palsa, this indicator for lithalsa never exceeds 10-12.

Abstract: Palsas and peat plateaus have an important role in the bio- and geodiversity of Northern environments. The peat of the palsa is an archive of geochemical and biochemical conditions of high quality. The palsa peat bog of Eletsky was studied in the north-east of the Bolshezemelskaya tundra (67°16′ N, 63°39′ E). Palsa of 1.5 to 4 m height were studied in detail. The content of carbon and nitrogen in the peat has been determined, as well as the isotopic composition of carbon. The analysis of the carbon and nitrogen content in plants growing both on the surface of the heave mounds and in the depressions between the mounds was carried out. Variations in C/N values indicate changes in the peat moor humidification regime and the rate of peat decomposition. The results obtained indicate a high degree of watering of the Eletsky massif as a whole during the accumulation of peat and mainly anaerobic conditions of its decomposition. It was found that the change of plant associations also affected the value of C/N. Studies of the Eletsky palsa peat bog have shown that the isotopic composition of carbon is determined primarily by the botanical composition of plant remains. New ecological niches are formed in the process of palsa growth, some plant communities are replaced by others. There was not detected difference of the isotopic composition of thawed and frozen peat.

Abstract: The content of carbon and nitrogen, as well as the carbon-to-nitrogen ratio in the genetic horizons of the soil cover, yedoma deposits and in organic residues in syngenetic ice wedges (IW) of the upper IW complex of the Batagay megaslump were studied. The studied soils belong to the silty-loam Spodic Cryosol (Dystric,Humic) and post-pyrogenic Spodic Cryosol (Dystric,Humic). To study the carbon and nitrogen content, ice wedges of the first and second tiers of the upper IW complex
were tested. The highest values of the C/N ratio were obtained in the upper horizon of the silty-
loam Spodic Cryosol (Dystric, Humic) near the Batagay megaslump. The average value of
the carbon content in the ice wedges of the Batagay yedoma is of 0.13 mol, the maximum is 0.36
mol, the minimum carbon content is 0.06 mol, the average nitrogen content is of 0.04 mol, maximum 0.12 mol, minimum 0.02 mol. For the entire data array of ice wedges, the
value of C/N is of average 3.90, maximum 6.96, minimum 1.05.

Abstract: The object of this research is the reconstruction of the climatic conditions of the Late Pleistocene summer seasons based on the pollen spectra of syngenetic ice wedges and inclosing Yedoma deposits. For quantitative assessment of summer temperatures and phenological relationships, the author applies the total annual thaw index, since namely the sum of positive temperatures is the only indicator that determines the beginning of pollen emission in majority of plant species. The relationship between the composition of pollen spectra and the total annual thaw index is deterministic, although it cannot be formulated strictly mathematically. Yedoma is a unique object for research by many parameters, which allows acquiring paleogeographic information on two components, such as ice wedges and deposits, because the accumulation of pollen and spores occurs differently therein. The structure of vegetation cover during the accumulation of Yedoma deposits during the Late Pleistocene differed significantly from the Holocene and modern periods, which is recorded in the pollen spectra of syngenetic deposits and ice wedges. It is established that in certain periods, the diversity of species of Late Pleistocene vegetation was higher compared to modern vegetation of tundra and forest tundra due to the large number of ecological niches and peculiarity of temperature regime of the summer season.

Abstract: This article is dedicates to the assessment of the contribution of Professor Vasilchuk to the development of isotopic geocryology, as well as testing the reliability of paleogeocryological reconstructions based on the study of isotopic composition of polygonal ice wedges. His discovery of direct dependence of isotopic composition of the sprouts of modern ice wedges on the temperature characteristics of the winter season of 1989 marked the beginning of a promising research of the Holocene and Late Pleistocene syngenetic ice wedges as a reliable paleoclimatic archive. He was first to obtain the characteristics of the winter period for the late Pleistocene and Holocene, as well as create the maps for distributing paleotemperatures for the key periods of Late Pleistocene. The data on the isotopic composition of ice wedges acquired by other scholars later fit into the distribution of paleotemperature within the cryolithozone reconstructed by Professor Vasilchuk. For establishing the degree of reliability of paleotemperature reconstructions, the authors tested the ratio proposed by Y. K. Vasilchuk and regression equations from the works of Konyakhin, Mayer, and Oblogov. The acquired results demonstrate that the values of winter-average and January-average temperatures in reconstruction by Vasilchuk’s ratio always fall within the reliability interval in the entire modern temperature range. Testing the current temperature using regression equations often determine a considerable deviation (often within 3-4°C) from the actual values of winter-average and January-average temperatures.

Abstract: This article examines the sections of the high floodplain of the Seyakha River (Zelenaya) and sections of Holocene peat layers with ice wedges on the third terrace. Palynospectra from sediments and ice wedges of the high floodplain are characterized by a rhythmic fluctuations typical to floodplain facies. The presence of spruce pollen is related to resedimentation, since spruce pollen is detected in the samples with the composition of verifiably resedimented palynomorphs around 10% or higher. The change in composition of the pollen of Siberian pine, scots pine, and birch tree is associated with a change in wind drift, since fluctuations in the composition of the pollen of these taxonomic units do not correlate with fluctuations in resedimented palynomorphs. Therefore, the three periods of increased wind drift and possible increase in pollen productivity can be determined based on mid-period contrast changes in the structure of palynospectra. At the same time, the local peak of cereals is replaced three times by the maximum pollen of dwarf birch and alder. The absence of larch trunks can be substantiated by fires, the traces of which are observed in the section, as well as that larch at the northern limit of its habitat has crumbly wood tissue, which is being rapidly destroyed. Tree limb, needles, and cones usually remain, while the wood tissue is absent. It is assumed that ice wedges formed here 8.5-6 thousand years ago during a single cycle of the change in wind direction and speed , when prevalence of birch tree pollen with some alder pollen at a relatively low pollen concentration was replaced by the dominance of gramineae pollen, and then, dwarf birch pollen in the spring pollen rain. Palynospectra of these ice wedges indicates an increase in the sum of positive temperatures from 8.3 to 6 thousand years.

Abstract: The pollen characteristics of the Zelyony Mys yedoma record cyclical changes in vegetation cover, both on a local and regional scale. There are three local pollen zones such as: Varia +Artemisia, Varia + Selaginella sibirica, and Pinus + Betula sect. Nanae. Pollen spectra reflect open landscapes of mosaic hypo-arctic tundra. Some local pollen zones in the ice wedges correspond to the local pollen zones of yedoma: Varia + Selaginella sibirica dates from 41.9-33.8 CalBP, Pinus + Betula sect. Nanae (P+B) is approximately dated to 33.5-30 CalBP. Reconstruction of the annual thawing index showed several fluctuations: two short-term periods of significant deterioration of vegetation conditions (annual thawing index was about 200-300 deg. × days, about 46, 34-33 CalBP), and two periods of improvement of vegetation conditions 45-43 and 32 CalBP (annual thawing index was about 600-750 deg. x days). Regional pollen in burrows is the same in synchronous horizons of yedoma. Noticeable amount of larch pollen (10%) in the fossil burrows in the Zelyony Mys yedoma showed that favorable conditions are created in the burrows for the preservation of larch pollen. The seeds found in minks reflect animal dietary preferences and only partlially local vegetation around minks. Reconstruction of positive temperature sums indicates the palinospectra reflect three-fold fluctuations of vegetation conditions: two short periods of substantial deterioration of vegetation conditions (the sum of positive temperatures is about 200-300 degrees x days), about 46, 34-33 thousand years (and two periods of improvement of vegetation conditions 45-43 thousand years (sum of positive temperatures about 600 degrees x days) and 32 thousand years (sum of positive temperatures about 750 degrees x days).

Abstract: The subject of the study is the analysis of the ratio of carbon (C) and nitrogen(N) and δ13C values in polygonal landscapes on the coast of Onemen Bay, near the Anadyr city. The maximum values of carbon (59.09%) and nitrogen (2.18%) in peatlands were obtained at a depth of 1.1 m in a narrow peat vein. The values of δ13C in the peatlands on the coast of Onemen Bay vary from -24.1% to -28.6%, the N content varies from 0.37% to 3.24%, the C content varies from 3.1% to 59.09%, the C/N value varies from 8.3 to 34.4.The values of δ13C and C/N values in the 1.5-m peat correspond to C3 plants, the values of δ13C and C/N values for a 2.5–m peat suggest the presence of algae along with plants C3. Fluctuations in the nitrogen and organic carbon content in the section of a 1.5-meter peatland to a depth of 0.8 m are synchronous, which suggests an autochthonous mechanism of peat accumulation, below depth of 0.8-1.2 m, there is a lightening of the carbon isotope composition, which suggests the participation of reworked organic matter in the beginning of peat accumulation. Fluctuations in the nitrogen and organic carbon content in the section of a 2.5-meter peat bog are synchronous, which suggests an autochthonous mechanism of peat accumulation.

Abstract: The subject of this study is the ratio of carbon and nitrogen content in the soil of the lithalsa landscape in the Sentsa River valley. The focus is on the spatial distribution of C/N ratio in the genetic soil horizons: humus (A), illuvial (B), the parent rock(C), as well as in the buried peat horizon (T). The carbon and nitrogen content is analyzed in 70 samples using the element analyzer C, H, N, S –O EA 1110. Sample preparation included drying the soil through a sieve and grinding it with a rubber pestle in a porcelain mortar. It is found that cryogenic concentration of soil solutions, cryogenic heaving, thermokarst, zoogenic turbations, peat burial, and alluvial loam deposition are the main processes determining the peculiarity of soil formation within lithalsa landscapes. The maximum variation in the ratio of carbon and nitrogen content is observed in the illuvial horizon, while in the humus horizon and in the parent rock, as well as in the buried peat horizon, this indicator is of a smaller range.

Abstract: The subject of this study is the peatlands of the Seymchan-Buyunda depression, in particular the composition of gases contained in the permafrost peatlands and ice-wedge ice. Special attention is paid to conditions of the peat formation, features of the Seymchan-Buyunda depression climate and the Magadan region in general, the characteristics of the main types of vegetation, soil cover and landscape. The trend of changes in the average annual air temperature in the area of Seymchan town is considered. To estimate the time of formation of ice-wedge ice, the composition of spring pollen rain during the accumulation of the ice wedges was reconstructed. The composition of trapped gases in peatlands is established. Determination of gas composition was carried out using the chromato-mass-spectrometer Hitachi M-80. There are high methane content in frozen peat bog Chokachi and lake water on the surface of the peat bog; it was discovered that the lake on the surface of the peatland is both, a trap for gases released from the thawing peat and a depositing medium, in which the processes of reduction of hydrocarbons take place intensively; in the composition of gases trapped in the frozen peatland there is a high content of hydrogen, which is one of the mandatory conditions for the life of methane-forming bacteria.

Abstract: The object of this research is the organic-mineral deposits of the Late Pleistocene polygonal ice-wedge complex. They are studied in the outcrop of the second terrace, located on the left bank of the Mongatalyangyakha River, 3 km west of the estuary (71 ° 58'60 "N, 75 ° 16'0" E), on the Yavay Peninsula in the north of the Gydan Peninsula. The botanical composition of allochthonous peat in the upper part of the section is dominated by the remnants of Ledum palustre, and in the organic-mineral sediment the remains of Drepanoladus fluitans, Calliergonella cuspidata (or Calliergon cordifolium) are prevalent. A field outcrop study was performed; three wells were drilled. Palynological and hydrochemical diagrams were constructed and the radiocarbon age of the Late Pleistocene polygonal massif was determined. The main conclusions of the study are: 1. The age of the organic-mineral deposits varies from 30,200 to 21,900 years BP. 2. The rate of accumulation of organic-mineral deposits in the Karginsky time at the mouth of the Mongatalyangyakha River is about 0.25mm/year. 3. According to the palynological analysis, three local pollen zones are distinguished.

Abstract: The two outcrops of Holocene peat with ice wedges in the mouth of Salemlekabtambda River in the Mammoth Peninsula are the object of the study, such as Holocene peat in the bog meadow of Kara Sea and the peat inset in the 15 m terrace. Ice wedges occur in the meadow bog sediments, their height is about 1.5 m. The height of ice wedges in the terrace sediments is about 4.5 m. We studied pollen spectra both, in the ice wedges and their host sediments, as well as determined isotope composition of ice wedges. Series of 14C ages have been obtained. The obtained isotopic and pollen data demonstrate that in the North of the Gydan Peninsula the Holocene optimum was the time of increase of climate continentality. Summer was warmer by 1-3°C than today, and winter was by 2-3°C colder. The intensity of frost cracking and ice wedge formation increased both in organic and mineral alluvial and alluvial-marine sediments.

Abstract:  
The object of this research is the most southern massive ice in the Yamal Peninsula, located on the left bank of the Erkutayakha River (68°11ʹ18ʺ N, 68°51ʹ39ʺ E). A dislocated ice massif occurred in the 15-18 m exposure of the sandy layer. Its total length is about 100 m. The ice massif is composed of different types of ice. There are four types of ice: 1) pure matte white ice with a large number of gas xenogenic inclusions; 2) crystal clear ice, sometimes with soil inclusions; 3) gray ice with a steel tint, layered parallel to the slope of the upper surface of the massive ice; 4) gray block-ice, lies in the form of tiles. Each type of the ice was examined, and 10 samples of ice from different parts of the outcrops and of ice of different types have been selected for pollen study. The results of this study allowed more adequately evaluating the origin of the ice.
 

Abstract: The outcrop of 7-m terrace in the mouth of Gyda River (70°53ʹ41ʺ N. 78°30ʹ14ʺ E) is the object of the study. There are two generations of ice wedges and four stages of ice lens occurred in peaty sand. Syngenetic ice wedges are in paragenesis with massive ice. Considerable reworking of organic material is proved. Seven cycles of vegetation changes corresponded to local pollen zones. Their duration is about 0.5-2 ka. Sediments accumulated at alternation of subaerial and subaueous stages in 3-13 ka BP.Ice wdges accumulated at the end of the Late Pleistocene in 11-12 ka BP and in the Holocenein 3-4 ka BP. The total annual thawing index variated from 200 to 800 oC x day

Abstract: The research subject is the varieties of subrecent pollen spectra in the unbroken surface layer of bottom sediments of the Laptev Sea shelf, which had been lifted by multicorers in the expeditions ARK 27-3 and Transdrift XXI in 2012-2013 on the shelf and continental slope. The authors substantiate the possibility of reconstruction. The authors consider how the following aspects are reflected in marine pollen spectra: 1) the level of ice coverage of the sea basin, which can be seen in the presence and concentration of index types of marine cysts of dinoflagellates; 2) oscillations of the river flow, assessed by the changes of concentration of organic suspensions of terrigenous genesis in bottom sediments (spores, pollen, fresh-water green algae), transferred mainly from the yedoma sediments; 3) transformed Atlantic water migration, which can traced by index types of microfossils; 4) climate conditions, defining the level of productivity of the flora of the dominating biomes of the shore, pollen to the Laptev Sea shelf comes from. The main research method is the study of marine pollen, which includes the analysis of the species composition and the changes of concentration of terrigenous and water palynomorphs in bottom sediments collected in the southeastern part of the Laptev Sea in the paleovalley of the Lena river, which was drowned during the Postglacial transgression. The obtained varieties of quantitative and qualitative composition of pollen and non-pollen palynomorphs in the unbroken surface layer of bottom sediments and their comparison with the results of the study of pollen from yedoma complex of northeastern Siberia help evaluate the modern conditions of formation of marine pollen spectra. 

Abstract: Holocene ice wedge structures in the arctic tundra in the Tambey river valley and in the Belyi Island are the subject of the study. The author studies the pollen spectra in the ice wedges and surrounding sediments and their chemical composition. To substantiate paleograhic reconstructions, the author analyzes radiocarbon datings of the Holocene sediments from the studied areas and the surrounding territories. Pollen analysis is the main research method. Adjacent sediment samples have been studied according to the standard procedure, but without acetolysis mixture. Pollen has been extracted using the simplified method due to low pollen concentration. The main result of the study is the systemization of the data of palynological analysis of Holocene ice wedges located in the zone of sea-level changes' imact. The author shows that ice wedges in the Tambey River valley had been accumulated from precipitations and because of the inundation by marine water. Ice wedges in the first marine terrace of the Belyi Island are characterized by the abnormally high concentration of marine salt, but the salinization is caused by ice wedge formation on the sides of remnant shallow saline lakes, not by sea-level changes.

Abstract: Holocene wedge ices are widespread within laidas, peat bogs and flood plains of lakes and rivers of the Yamal Peninsula. The aim of the paper is to study palynological characteristic of exposures of wedge ices located at different geomorphological levels. The author estimates realibility of radiocarbon dating of polygonal wedge ices of the base of palynological characteristic and considers the possibility of estimating the idiogenousness of wedge ices on the basis of comparison of palinospectra of wedge ices and their deposits. The author detects several stages of vegetation evolution in this region. The main approach to ice wedge complex study is based on the fact that palynospectra of ices and deposits represent different seasons of pollen accumulation. While subfossil palynospectrum is accumulated during the whole vegetation season and consisits both of local and regional peculiarities of land cover, palinospectra of wedge ices are formed of spring pollen rains and reflect mainly regional characteristics. Reliability of the radiocarbon dating is estimated according to the constitution of Pre-Quaternary pollen in the sample, because it indicates the constitution of aicient penecontemporaneous organic material in the sample indirectly. Main stages of vegetation cover development in Holocene are distinguished on the base of these studies.

Abstract: The subject of the study is the subfossil pollen spectrum from polygonal tundra of different succession stages: the formation of a framework of vegetation and overgrowing patches of polygons. It is established that local components of the pollen spectrum are basic information on the stages of succession. Determination of the sequence of changes in the dominant pollen taxon in the process of typical succession enables the allocation of such sequences for pollen plots, allowing to more objectively assessing the changes in biocenoses. We also analyze the pollen spectrum features during the development of waterlogging and pyrogenic succession reflected in the palynologic signal. The main research method is the palynologic analysis of surface samples and interpret the results in relative stages of succession. The main conclusions of the study is allocation of the standard sequence of dominants on pollen plots, which correspond to the stages of succession. Pollen dominants sequences are detected migration of woody vegetation to the North by open ground, eutrophication of lakes, overgrowing of polygons in the Arctic tundra, as well as for pyrogenic succession