Articles

The study of the mineralogical composition of sand (0,25-0,05 mm) and coarse silt (0,05-0,01 mm) fractions revealed a significant lithological heterogeneity of soil forming material on the territory of the Zvenigorod biostation. The predominance of ore minerals in the heavy fractions (up to 42% of the grains) and, to a lesser extent, hornblende and biotite, explains the ironing (significant presence of iron oxides, hydroxides) of the profiles and the brown color of sandy loam soils. This feature, along with the insignificant presence of the clay fraction, admit us to classify texturally undifferentiated soils as ferric-metamorphic soils, and more differentiated - as eluvial soils.

The composition of water extracts of the soil, litter and land litter was studied for the conditions of the nesting places of the gray heron and the control plots in the zone of distribution of gray forest soils of the broad-leaved ecosystems of the Tula area. It has been established that the entry of bird excreta leads to an almost universal degradation of land cover, the formation of specific litters, with a significant influx of large tree litter, which is associated with the nest building process. It is shown that the upper horizons of gray forest soil, litter and litter in nesting conditions are characterized by an increased content of such elements as calcium, potassium and magnesium, and among trace elements - copper, zinc and strontium. Among the anions in the soils and litters of bird nesting sites, an increase in the content of nitrates, phosphates and chlorine was found.

The properties of representative soil profiles of podzols included in the database of the Unified State Register of Soil Resources of Russia are considered. As a result of processing and analysis of the data array (53 measured profiles), the ranges of values of a number of parameters were adjusted. It was found that in most cases the properties of podzols had a wider range of values compared with the estimated profiles given in the literature (thickness of illuvial horizon, humus content in eluvial horizon), at the same time, the range of values of the humus content for the illuvial horizon was narrower. The specificity of the podzols of individual regions obtained by combining of soil provinces of the Map of soil-ecological zoning is revealed. Regularities can be traced in the geography of the profile thickness of these soils, the content of humus and its profile distribution. In Siberian regions humus prevails in the eluvial soil horizon, in the European territory of the country and in Primorye - in the illuvial horizon.

In hydromorphic soils are important not only sustainable Fe-minerals, defined traditionally in dried soil, but also unstable Fe-minerals, changing the colors of the clay after extracting the sample fr om the soil, as well as — weakening gley signs in the dry season. New indicators are offered for the additional characteristic of Fe-minerals. The first is that it characterizes the interaction of active Fe-minerals with colloids, it is index I: I = CEC/Fe (free), wh ere CEC is the cation exchange capacity. The second indicator is the change in the gley color after drying, assessed by the change in the redness Да*. In Fe-enriched, reduced gley Gr with a low index value (/0,1) and a strong increase Aa* ~ 9 after drying, the green rust is transformed into a brown lepidocrocite. During the humidity decrease, the transition of the reduction gley to the oxidized gley is accompanied by a change in the composition of the green rust: the transformation of fougerite into a trebeurdendite: Fe-ephemera with a higher degree of Fe oxidation and the growth of Да* ~ 3. When oxidized gley Go with the index I = 2—8 is dried, the slow Да* growth is caused by the inhibition of Fe-hydroxide crystallization by colloids. In the “de-ironed” gley Gdf with a high value the index 1= 6—27, the lack of red growth (a* « 0) on drying, is probably due to the Fe clay minerals inertia.

The paper presents a comparative analysis of the structural and functional characteristics of the microbial communities of the gray forest soil of fallow and intensively cultivated areas. Long-term anthropogenic impact with massive annual mineral fertilization when growing a monoculture of potatoes has led to the degradation of the soil microbial system. A catastrophic decrease in the functional potential of the microbial system (environmental services) is shown using eco-exergy as a thermodynamic indicator of the “health” of the soil.

The texture of bottom sediments of the Simmy River and its tributaries in the area of the “Bolon'sky” reserve (Khabarovskiy region, Far East) was studied with methods of laser diffractometry, sedimentation and electron microscopic analysis. It was found out that the texture of Simmy sediments in downstream is characterized by the accumulation of fine sand, which corresponds to alluvial-lake genesis of the studied area. In the wellhead part of river sediments are formed mainly by suspended sediments with a predominance of the clay fraction. This is due to the impact of the floodplain Bolon Lake, which level fluctuations correspond to changes in the level of water in the Amur River. It is shown that coagulation and deposition of suspended particles with low content of organic matter (< 1%) leads to the formation of volumetric aggregated, dense and viscous sediments. The high content of organic matter in sediments (> 6%, the Kirpy River, the tributary of the Simmy River) leads to the “nodal” differentiation of spatial structures and to the formation of porous microaggregates.

The taxonomy of peat soils is not currently given more attention, especially with regard to taxonomic units in the species rank. The procedure of diagnostics of 51 soil profiles in the various oligotrophic mire types in the Numto nature Park (north taiga subzone of West Siberia) allows to make some proposals to improve the existing soil classification. These ones are: 1) to limit the peat horizon thickness in the peat-gleyzem type to 30 cm; 2) to divide the peat-gleyzem type by the trophic status into oligotropic and eutrophic subtypes; 3) to expand the list of taxa, determined by the botanical composition of peat, by means of the division of soil species into subspecies on the basis of classifications of peat and peat deposits; 4) to use current vegetation as one of the main diagnostic (indicative) criteria in determining the soil type in mires; 5) in order to determine the variety of peat soil it is suggested to use the degree of decomposition of the peat layer underlying the peat soil. The article draws attention to the difficulties in determining the classification position of soils of frozen large mounds in palsa bogs and proposes alternative solutions to this problem.

We discuss the dynamics of the snow cover and its composition for the period 2013-2018 is shown that the annual dynamics of the snow cover is characterized by the alternation of high and low values. Thus, the highest values were typical for the winter of 2012/2013, followed by a decrease in 2013/2014. The leading role in the distribution of snow cover belongs to the position of the elementary landscape within the geochemical landscape. In all years of research, the water equivalent of snow cover is characterized by bicarbonate-calcium composition. The content of micro components in General is in the same order with the results given for the South taiga landscapes. Some excess of individual components in the composition of snow water in comparison with Meshchersk and Baikal landscapes, taken as a background, due to the proximity of the studied geochemical landscape and the main road M-10 (Moscow-St. Petersburg). It is assumed that the relatively high content of calcium in the snow water of the superaqueous landscape is associated with its possible arrival from the surface of meadowmarsh carbonate soils, boiling from the surface. Sulfate ion has been found to play a leading role in the diagnosis of atmogeochemical pollution, which is partially established for the studied landscapes.

The resistance to mineralization of water soluble organic matter (WSOM) extracted from a litter of Podzol is increased upon the interaction with the mineral horizons. Both the fraction of WSOM susceptible to mineralization and the average rate of decomposition decrease after the passage through E-horizon, by 2-3 times respectively, in comparison with the values obtained for the initial WSOM. Sorption in the BF horizon gives extra stability to the incoming organic matter. The relative content of mineralized carbon is reduced to 2% (by 8 times). In natural soils sorbed organic matter can be even more resistant to the mineralization, due to lower temperatures and less biological activity, so it can be considered as the basis for the formation of a humus storage. Taking into account the calculated rate of mineralization, the accumulation of the organic carbon in the BF horizon due to WSOM sorption, may range up to 13,5/100 g per year, but this value depends on the concentration of organic substances in soil solutions, hydrological regime and other factors.

The influence of anthropogenic activity on the quality of urban alluvial soils, the conditions of growth and the state of tree plantations is estimated. The level of negative consequences for natural components correlates with the degree of human exposure. In the profile of soils moisture decreases, humus content varies in different directions, pH of waters and electrical conductivity increase. Densification of soils and inhibition of biological activity are noted in the surface horizons. The coefficient of the ecological state of soils decreases by 6-24% compared to the optimum conditions. The correlation analysis showed the presence of a significant weak matching between vegetation state and soil quality (Spearman's coefficient is -0,53).