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Specific features of the morphology, properties, and temperature regimes of soils functioning in two different drained lake basins of the Bol'shezemel'skaya tundra are characterized. The basins differ significantly in the features of landscape evolution, the composition of bottom (soil-forming) sediments, and the patterns of the soil and plant covers. Soils in the naturally drained basin with mineral (sandy and clayey) bottom sediments are assigned to the orders of gley, and weakly developed soils that are also typical of watershed landscapes in the studied region. These are ecosystem-modified permafrost-affected soils that are partially protected from thawing. They have an acid reaction, low base saturation, and moderate carbon content in the mineral horizons. In the artificially drained basin with a silty peat layer of bottom sediments, peat permafrost-affected soils, including specific peat soils under tundra meadows, are developed. Permafrost peat soils of the former lake bottom are ecosystem-protected from thawing and are characterized by the high ash content and slightly acid reaction. The studied soil parameters are significantly differentiated with respect to lake basins, which is determined by the composition of parent materials, specific features of landscape development, and activity of modern cryogenic processes. [ABSTRACT FROM AUTHOR]

The specific features in the distribution of organic and mineral nitrogen compounds in marsh and tundra soils of the European Russian Arctic (coastal areas of the Barents and White Seas) were analyzed. Total nitrogen was determined by gas chromatography (CHNS-O elemental analyzer), and inorganic nitrogen, by photometry. The composition of hydrolyzable amino acids was analyzed by liquid chromatography on ion exchange resins. Mineral compounds accounted for an insignificant part of the total soil nitrogen; its major part (to 97% of the total content) was represented by organic substances (Nоrg). The Nоrg varied within a wide range in both marsh (0.3–15.8 g/kg) and tundra soils (5–20 g/kg in the peat horizons and 0.3–2 g/kg in the mineral horizons). The content of N- varied from 5 to 20 mg/kg in marsh soils and from 30 to 200 mg/kg in tundra soils. In marsh soils, the content of nitrate nitrogen was 0.2–4.6 mg/kg in the upper horizons. Marsh soils were characterized by the accumulation of Nоrg either on the surface or in the middle part of the profile in the presence of humus-accumulative horizons buried under recent marine sediments. The accumulation of Nоrg and N- was observed above the permafrost in the peat-gley soil and in the permafrost in the oligotrophic peat soil. The content of hydrolyzable amino acids in the soils of different geneses was 0.6–8 g/kg, which corresponded to 30–60% of the soil organic nitrogen and 2–12% of the soil organic carbon. Distribution patterns of the amino acid nitrogen and organic nitrogen in the soil profiles were similar. The qualitative composition of amino compounds was relatively uniform, and the ratios of most of them were close. The shares of arginine, histidine, phenylalanine, tyrosine, and isoleucine were less than 4% each; of lysine, valine, proline, serine, and threonine, 5 to 7%; and of alanine and leucine, 10–12%. The share of glycine increased downward the profile from 12 to 20%, and the shares of aspartic and glutamic acids decreased from 11 to 6%. In marsh soils, Nоrg, N- , and nitrogen of most amino acids correlated (r = 0.6–0.9) with the clay content and nonsilicate iron forms. The tightest correlations were observed between the dithionite-soluble iron and the nitrogen of threonine and histidine. [ABSTRACT FROM AUTHOR]

Water extracts from soils of the Barents Sea coast (the Khaipudyr Bay) were analyzed for the contents of organic carbon and total nitrogen by the method of high-temperature catalytic oxidation with non-dispersive IR registration; the contents of low-molecular-weight acids, carbohydrates, and alcohols were determined by gas chromatography and gas chromatography–mass-spectrometry. The mass fraction of inorganic carbon was measured potentiometrically, and the content of inorganic nitrogen (N– N– ) was determined by photometry. In marsh soils (Tidalic Fluvisols (Arenic or Loamic, Epiprotosalic)), = 0.1–0.8, = 0.01–0.05 g/kg, = + 0.01, and = 7–21. The content of individual components does not exceed 20 mg/kg, including carbohydrates (50–90%), acids (10–50%), and alcohols (<3%). In peat horizons of tundra soils (Cryic Histosols and Histic Cryosols), = 4–10, ~ 0.2 g/kg, and = 25–56. Litter and peat horizons accumulate both individual humus components and total dissolved organic carbon. The total weight of the identified substances is 200–300 mg/kg, 80–90% of them are carbohydrates, 10–20% are acids, and 0–9% are alcohols. The accumulation of and (N– takes place above the permafrost table. It is argued that the ratios of organic forms of carbon and nitrogen in soil water extracts and the content of low-molecular weight organic compounds in soils can be used as indicators of pedogenic processes in the Far North. [ABSTRACT FROM AUTHOR]

Concentrations of total carbon and nitrogen were measured by gas chromatography method, and the carbon content of inorganic compounds was determined by the volumetric method in soils of undisturbed coastal landscapes of the Barents Sea (Khaypudyrskaya Bay). Two groups of soils were specified. The first group included saline marsh soils formed under flooding by tidewater and surging seawater. The second group included soils of tundra ecosystems, which were subjected to precipitation of marine aerosols. In the first group, the content of Corg varied from 5 to 75 g/kg, the content of N total varied from 1 to 5 g/kg, and the Corg/Ntot ratio varied from 10 to 18. Humus-accumulative horizons buried under recent marine sediments were described in the middle part of the marsh soil profile. In the second group, the contents of Corg was 430–470 g/kg and Ntot 4–7 g/kg. The Corg/Ntot ratio in the surface peat horizons equaled to 64–95 g/kg and decreased by three–seven times in the deeper layers. The soils of the low-level marshes flooded each tide and especially their surface horizons contained more inorganic carbon than any other soils. Mass fraction of inorganic carbon varied from 4 to 20% of the total carbon content. Seawater and carbonate-containing rocks could be the source of the inorganic carbon. A correlation was found between the contents of Corg and Ntot in soils and in plant communities growing on these soils. Additional input of Corg and Ntot into marsh soils was due to the living activity of birds and to organic substances in seawater. [ABSTRACT FROM AUTHOR]