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The formation of soils on loamy deposits during the primary succession of vegetation after biological reclamation of a technogenically disturbed area (quarry) in the middle taiga subzone of the northeast of European Russia (Komi Republic) is considered. The planting of Picea obovata on the reclaimed area activates the formation of the tree layer and helps to accelerate pedogenetic processes. In drained conditions, by the beginning of the third decade of succession, litter horizons were formed, soil bulk density in the upper mineral horizons decreased, and a tendency towards redistribution and differentiation of the clay fraction and iron and aluminum compounds in the soil profile was noted. The latter may indicate the beginning of eluviation. The heterogeneity of the quarry surface (presence of highs and lows with a height difference of up to 2–6 m) contributes to the redistribution of moisture within the quarry and the appearance of areas with surface waterlogging. Under these conditions, the role of conservation of organic residues (peat formation) is enhanced, and gleyzation processes are activated. With an increase in the degree of surface waterlogging of soils, the soil acidity and the stocks of soil carbon and nitrogen increase, which is typical for an analogous series of background soils. The calculated rate of organic carbon accumulation in the soil layer of 0–20 cm in drained soils of the quarry is about 0.4 t/ha per year. In the waterlogged soils, it increases to 1.0–1.2 t/ha per year. The stocks of organic carbon in the upper 20 cm of the profile of young soils remain two–four times lower in comparison with the background native soils. [ABSTRACT FROM AUTHOR]

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]

Information on different compounds of elements, such as Na, K, Ca, Mg, Al, Fe, and Mn, contributes to our understanding of the genesis of poorly studied soils of northern coasts. The analysis has been carried out of the composition of various forms of compounds. To determine total element contents, a mixture of concentrated HF, HClO4, and HCl was used; acid-soluble forms were extracted with a mixture of concentrated HNO3 and H2O2; and acetate ammonium buffer solution was used to determine mobile forms. It is shown that the amount elements added to the tidal marsh zone is largely determined by the volume and composition of solids entering with seawater and with runoff from coastal catchments. For mineral soil horizons, a close correlation is found between the contents of clay fraction and exchangeable forms of K, Mg, and Al (R2 = 0.4–0.5), as well as between the contents of clay and highly mobile forms of these elements and Fe (R2 = 0.6–0.8). The distribution of elements along the profile of zonal soils on the highest positions of the relief is significantly influenced by the permafrost conditions and the aerial transfer of salts with seawater drops. [ABSTRACT FROM AUTHOR]

The research was conducted in the European northeast of Russia (Komi Republic), in the reclaimed quarries for mining construction sand in the middle taiga subzone, in the course of two decades after the forest reclamation (Pinus sylvestris) had been applied. The specific features of initial pedogenesis on substrates of different textures have been revealed. On sands and sandy loams, the dynamic soil sequence is composed by abralith (the 0-moment) → residual-calcareous humus psammozem (11th yr) → humus-raw-humus residual-calcareous podzolized humus gleyic psammozem (18th yr). On the loamy substrate, the following soil sequence is formed: abralith → humus residual-calcareous pelozem (3rd and 11th yr) → humus-raw-humus residual-calcareous eluviated gleyic pelozem (the 18th year). The formation of litter and humus-accumulative horizons are the leading soil forming processes. Their intensity is determined by the degree of plant community development. By the end of the second decade, the humus-accumulative horizon (0–20 cm thick) of sandy loamy soils accumulates up to 2.7 t/ha of organic carbon. Organic carbon pool in loamy soils reaches 6.3 t/ha. The stocks of soil nitrogen reach 0.1 and 0.4 t/ha, respectively. The rate of organic carbon accumulation in soil reaches 0.16 (sandy-loamy substrates) and 0.37 t/ha per year (loamy substrates). The organic matter of humus-accumulative horizons in the young soils of quarries is characterized by a higher content of water-soluble and labile components of humus and a low degree of condensation of humic acids as compared to the background soils. Initial pedogenesis on quarry substrata is characterized by an increase in the acidity of soil water extracts from pH 8.0 in abralith to pH 6.3–6.7 in the W horizon of the forming soils. The rate of acidification in loamy soils is lower than in sandy and sandy loamy soils. Carbonate leaching is confirmed by the absence of calcite and dolomite in the mineral composition of the upper W horizons of the forming soils, a decrease in the total content of calcium oxide from 4% in abralith to 2–3% in the W soil horizon and in the content of calcium carbonates (3 and <0.5%, respectively). In 18 years, weakly expressed features of eluviation, illuviation, and gleying appeared in the soil profiles. [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]

Abstract: Exchangeable acidity in samples from organic and mineral horizons of taiga and bog soils with strongly acid reaction (pHKCl < 3.3 and ≤ 4.4) was determined by the Sokolov method of potentiometric titration of KCl extract before and after the addition of a sodium fluoride solution. In the same extracts, the contents of Al, Fe, and Mn ions were determined by the atomic emission method. NaF was added in an amount sufficient for binding all metal ions into fluoride complex compounds. It was found that the content of metals determined by atomic emission is lower than that calculated from titration results in 1.5-2 times in organic horizons and by 20-25% in mineral horizons. Even a higher difference between the two methods was observed for exchangeable protons: from the titration data, their content in organic horizons was 10-12% of the content determined as the difference between total exchangeable acidity and total metal ions determined by atomic emission, and 3-15% in mineral horizons. The revealed differences were attributed to the underestimated results of determining exchangeable protons in the presence of NaF, which was confirmed by the potentiometric titration of model solutions of strong and weak acids prepared from a KCl solution. It was found that the addition of NaF during the titration with a strong acid results in reaching the point of equivalence after the addition of a smaller amount of base. Reasons for the shift of the point of equivalence during titration with a strong acid in the presence of NaF require special investigations. It is recommended to estimate the exchangeable acidity of strongly acid soils due to metal ions by atomic emission or other adequate methods. [ABSTRACT FROM AUTHOR]

Soils and vegetation of the coastal zone of the Khaipudyr Bay of the Barents Sea have been examined and compared with analogous objects in the Karelian coastal zone of the White Sea. The environmental conditions of these two areas are somewhat different: the climate of the Khaipudyr Bay coast is more severe, and the seawater salinity is higher (32-33‰ in the Khaipudyr Bay and 25-26‰ in the White Sea). The soil cover patterns of both regions are highly variable. Salt-affected marsh soils (Tidalic Fluvisols) are widespread. The complicated mesotopography includes high geomorphic positions that are not affected by tidal water. Under these conditions, zonal factors of pedogenesis predominate and lead to the development of Cryic Folic Histosols and Histic Reductaquic Cryosols. On low marshes, the concentrations of soluble Ca2+, K+ + Na+, Cl-, and SO2-4 ions in the soils of the Khaipudyr Bay coast are two to four times higher than those in the analogous soils of Karelian coast. Cluster analysis of a number of soil characteristics allows separation of three soils groups: soils of low marshes, soils of middle-high marshes, and soils of higher positions developing under the impact of zonal factors together with the aerial transfer and deposition of seawater drops. The corresponding plant communities are represented by coastal sedge cenoses, forb-grassy halophytic cenoses, and zonal cenoses of hypoarctic tundra. It is argued that the grouping of marsh soils in the new substantivegenetic classification system of Russian soils requires further elaboration. [ABSTRACT FROM AUTHOR]

The influence of edaphic and orographic factors on the formation of algal diversity in biological soil crusts was studied in mountain tundras of the Polar and Subpolar Urals. Bare spots developed in the soils on different parent materials and overgrown to different extents were investigated. Overall, 221 algal species from six divisions were identified. Among them, eighty-eight taxa were new for the region studied. The Stigonema minutum, S. ocellatum, Nostoc commune, Gloeocapsopsis magma, Scytonema hofmannii, Leptolyngbya foveolarum, Pseudococcomyxa simplex, Sporotetras polydermatica species and species of the Cylindrocystis, Elliptochloris, Fischerella, Leptosira, Leptolyngbya, Myrmecia, Mesotaenium, Phormidium, Schizothrix genera were permanent components of biological soil crusts. The basis of the algal cenoses in soil crusts was composed of cosmopolitan cyanoprokaryotes, multicellular green algae with thickened covers and abundant mucus. The share of nitrogen fixers was high. The physicochemical properties of primary soils forming under the crusts of spots are described. The more important factors affecting the species composition of algae in the crusts are the elevation gradient, temperature, soil moisture, and the contents of Ca, Mg, mobile phosphorus, and total nitrogen. [ABSTRACT FROM AUTHOR]