Electric resistivity of soils and upper permafrost layer of the Gydan Peninsula

Soils of the Gydan Peninsula have been investigated during the complex expedition “Yamal Arctica 2013” during the “Professor Molchanov” vessel route in August and September 2013 with special aim to characterize soil morphology in relation with parameters of electric resistivity with use of vertical electric sounding methodology. Data obtained show that soils investigated are quite different in terms of solum morphology, soil stratigraphy and active layer thickness. Main soil types of the Gydan Peninsula (Siberia, Russian Federation) are Cryosols with features of raw organic matter accumulation and gleyification features. These soils dominate on the watersheds and in lowlands due to poor drainage of parent materials and presence of continual permafrost in landscape. In some cases, two Gleyic layers formed in one soil profile – one in the upper or middle part due to seasonal fine earth over moisting, and second one – on the contact of the solum with permafrost. Histic soils with Cryic features are more typical for lowlands (relief depressions). Soils of the Beliy Island are presented by slightly podsolised soils in upper part, this is due to lithological contrast of sediments (sandy textured solum changes by loamy textured one). The Electric resistivity (ER) was measured directly in the soil profiles with using the vertical electrical sounding (VERS) method, which provides data on the changes in the electrical resistivity throughout the profile from the soil surface without digging pits or drilling. This method allows to divide the soil pit vertically into layers with different properties. A VERS modification with shorter electrode spans was used to study the upper up to 5-m thick layer in detail. The distance between the A and B electrodes was from 5 to 500 cm. Soils have been sounded be thoroughly from the 5 cm to 3-5 m in depth. It was shown that use of VERS methodology in soil survey is quite useful for identification of the permafrost depth without digging of soil pit. This method allows identify soil heterogeneity, because the ER values are strongly affected by soil properties and intensively changes on the border of different geochemical regimes, i.e. on the border of active layer and permafrost. VERS data obtained show that the upper border of the permafrost layer coincides with that border, which were identified in field on the base of soil profile morphology. The VERS method also can be used for identifycation of Gleyic, Histic and Podzolic layers. VERS methodology is useful for preliminary soil survey in the regions with permafrost affected soil cover. It is also can be applieThis research was supported by the joint Russian-German project CARBOPERM, Russian presidents’ grant for Young Doctors of Science No. MD-3615.2015.4, Russian Foundation for Basic Research, pr. No.16-34-60010 and the government of the Yamal region

Podzol development on different aged coastal bars of Lake Ladoga

This paper presents the result of the studies of soil formation on different aged coastal bars in the transgression zone of Lake Ladoga in the Nizhnesvirsky Nature Reserve (Leningrad region, North-West of the Russian Federation). The investigation presents the data on soil chronoseries, located on four Ladoga coastal bars of different ages from 70±25 to 1590±25 years BP. We estimated the trends of accumulation and transformation of organic matter, elemental composition of humic acids (HAs), development of plant communities and the influence of soil formation factors on the formation rate of soil horizons. We assessed the degree of soil organic matter stabilization using modern instrumental methods (spectroscopy of nuclear magnetic resonance CP/MAS 13C-NMR). An integral indicator of the hydrophobicity of HAs, which represents the total fraction of unoxidized carbon atoms, is proposed. The Ladoga Holocene transgression is one of the most informative and applicable models for pedogenesis; successional processes occurring in young and mature areas can be traced here. We identified local processes of soil formation such as podzolization, gleyfication, peat formation and humus accumulation. Physical, physical-chemical and biological soil properties with a detailed description of the morphology of soil of different aged coastal bars are presented

Molecular and elemental composition of humic acids isolated from selected soils of the Russian Arctic

Humic substances, isolated from selected soils of the Russian Arctic, were ,+investigated in terms of molecular composition and stabilization rate. The degree of polar soil organic matter stabilization was assessed with the use of modern instrumental spectroscopy methods. The analysis of humic acid (HAs) preparations showed that aliphatic fragments prevail in the organic matter isolated in polar soils. The predominance of aliphatic fragments was revealed in HAs from soils located in the coastal zone, which could be caused by regular refreshment of organic matter during sin-lithogenic process and processes of hydrogenation in HAs. Breaking of the C-C bonds and formation of chains with a high hydrogen content, which leads to the formation of aliphatic fragments in HAs, were noted. Data on the calculated atomic ratios of the elements in HAs are given and graphs show the main regularities in the formation of HAs and their properties. The integrated indicators of the molecular composition of humic acids of soils of the Russian Arctic are presented. The paper contains 4 Tables, 4 Figures and 44 References

Soil formation in technogenic landscapes: trends, results, and representation in the current classifications (Review)

For hundreds of years, humans have been a soil formation factor. With the recent industrial development of vast territories, the formation of soils in technogenic and postanthropogenic conditions requires more attention. This study reviews the literature on the soils of human-transformed or human-made landscapes (technogenic landscapes),in which soil formation starts on a new technogenic substrate. Such soils may occur in different bioclimatic conditions. We focused on processes that govern soil morphology and the subsequent transformation of these soils. Often, the soils of technogenic landscapes are characterized by high bulk density values and by the presence of dense contact. Their properties are affected mainly by organic matter accumulation (humus, litter, and peat). The paper also covers approaches to the reclamation of technogenic landscapes, the main stages, and partly the reclamation options. It is noted that the efficiency of reclamation activities depends on the available resources and timely decision-making. We assessed the efficiency of soil reclamation methods and suggested technogenic landscape survey techniques. The major approaches to soil classification in technogenic landscapes in national and international soil classification systems are briefly discussed, and an approximate correlation of soil names used in different systems is suggested. All considered classifications provide the opportunity to assess the soil properties and specifics of soil formation in technogenic landscapes. However, in most studies, the soil diagnostics are limited to top-order taxa only

Физико-химические и электрические свойства криоземов в дельте реки Лены

Vertical electrical sounding method is an express and most accurate method for measuring and analysing the resistivity through the soil profile. As a result of climate change, permafrost is melting, which leads to a significant transformation of landscapes, both natural and anthropogenically transformed. In the vulnerable environments of the Arctic region (long recovery after anthropogenic impact), this method allows to determine the active layer thickness and the heterogeneity in the soil structure without disturbing of the soil cover. This method is based on the measurement of electrical resistivity in the soil, the data obtained were processed in the form of one dimensional model. In the course of field research, the heterogeneous islands of the Lena River Delta were investigated. Complex soil investigations using the method of vertical electrical sensing allows to fully assess the most important properties of cryogenic soils formed in the delta complex of the Lena River. As a result of the work, the modeled boundaries of the active layer were determined, which were confirmed during the laying of soil transects, as well as the main physical and chemical parameters of soils. During the vertical electrical sounding observation an inhomogeneity in the distribution of resistivity under a drained lake was found, which may correspond to the presence of a talik or a layer of salt unfrozen water in a permafrost. Due to the change in the soil horizons, there is a sharp change in the electrical resistivity indicator occur, which corresponds to the change from soil to frozen rock

Physical properties as a key factor in the soil functioning in Chernevaya Taiga (Western Siberia)

On the barrier-rain slopes of the low mountains of Western Siberia, there are tall-grass forests dominated by fir and aspen. Their regional name is Chernevaya taiga (from the word "chernyj" – black). Chernevaya taiga is a unique representative of the highly productive and fertile ecosystems of Western Siberia. The key features of the development of these ecosystems in the mountains of Southern Siberia are still poorly investigated. The soil physical properties play a crucial role in forming the functioning of the Chernevaya taiga ecosystem. The thermal regime, particle size distribution (profile differentiation and texture class) and hydrophysical constants of soils in Chernevaya taiga are studied. It is shown that the soil profiles of Chernevaya taiga are differentiated by the content of fine particles, which indicates the development of eluvial-illuvial hydrological and biogeochemical regimes. The favourable thermic regime is caused by a thick layer of snow existence during the winter period, when the soils of Chernevaya taiga are not frozen during the winter period. This is one of the key factors of high productivity of this ecosystem. Soils of Chernevaya taiga are characterized by increased values of key hydrological constants in comparison with sandy textured soils of oligotrophic environments

Elemental and molecular composition of humic acids isolated from soils of tallgrass temperate rainforests (Chernevaya taiga) by 1H-13C HECTCOR NMR spectroscopy

The soils of Chernevaya taiga (tallgrass fir-aspen hemiboreal rainforest) have high fertility in comparison with oligotrophic analogs formed in boreal taiga. We have studied humic acids isolated from the soils of Chernevaya and oligotrophic taiga in the Novosibirsk, Tomsk, Kemerovo and the Altai regions of Russia and for the first time the structural and molecular composition of humic acids was determined using13C CP/MAS and1H-13C HETCOR NMR spectroscopy. According to data obtained in this study, up to 48% of aromatic compounds accumulate in the soils of Chernevaya taiga, which is higher than in the oligotrophic taiga and comparable with this rate of steppe Chernozems. In the course of active processes of transformation of organic matter, a significant number of aromatic fragments accumulates in the middle horizons of soil profiles. Using13C CP/MAS spectroscopy, it was possible to identify the main structural fragments (aliphatic and aromatic) that formed in humic acids of the Chernevaya taiga. The HETCOR experiment made it possible to accurately determine the boundaries of chemical shifts of the main groups of structural fragments of humic acids. Our results demonstrate that the stabilization of organic compounds occurs in the soil of the Chernevaya taiga, which leads to the resistance of organic matter to biodegradation that is not typical for benchmark soils of boreal environments

Airborne fungi in arctic settlement Tiksi (Russian Arctic, coast of the Laptev Sea)

Biodiversity and number of airborne fungi isolated from indoor and outdoor air of different location in the areas of arctic settlement Tiksi (Russian Arctic) are described. Different locations (coastal areas, landscape, streets of Tiksi, abandoned empty houses, flats, public buildings) were observed. Aeromycota characterized by a significant biodiversity (50 species), but only several species were abundant. Airborne fungal spores concentration (CFU) in Tiksi locations was found low. The maximum spore concentrations were observed in air of the abandoned empty houses (inhabited in the past). Many species common for soil were observed at the samples taken at streets and abandoned buildings. Most of them are also known as inhabitants of building materials. Microfungi CFU at settlement territory was twice as high as natural territory. Phospholipase, albuminase and hemolytic activities of microfungi isolates as well as their relation to temperature were studied. Most of the tested isolates demonstrated high levels of all the tested activities. It was concluded that there is a risk of ‘‘mold’’ allergy diseases for the people especially with weakening of immunity at arctic settlement Tiksi. Main sources of the air contamination in arctic settlements and houses could be many anthropogenic substrates which were colonized by soil fungi

Black carbon as a factor in deglaciation in polar and mountain ecosystems: A review

Black carbon is considered a product of the incomplete combustion of fossil fuels and materials that originated from volcanic eruptions or were emitted during wildfires. It is a strong light-absorbing component that has many atmospheric and surface effects in terrestrial and glacial ecosystems. Normally, black carbon is presented as a solid particle, consisting mainly of pure carbon, which absorbs solar radiation at all wavelengths. Some black carbon particles are amended by a mineral compound, though black carbon substances are normally dark or greyish dark. Black carbon is the most active part of suspended particles in the atmosphere and on glacial surfaces, absorbing solar radiation, the main component of ash, which consists of carbon particles with impurities in the form of mineral particles and also contains carbon of biogenic origin. In this paper, we have analyzed the literature on black carbon and its effect on deglaciation processes in the Earth’s polar and mountainous regions. The physical, chemical, and microbiological composition of black carbon accumulations were studied using the examples of the Arctic, the Antarctic, and the Central Caucasus. Potential sources and conditions of the transportation of black carbon into the polar zone and their effect on ice and snow have also been discussed