Philip Ivanovich Zemskov

On the basis of a detailed study of the vegetative-detrital cover (VDC) of pine ecosystems of the Mari Zavolzhye, it is shown that, depending on its genesis, a specific hydrothermal regime of soils is formed in each type of forest. It has been established that the VDC has the highest moisture capacity in lichen pine-mossy pine forests in comparison with lichen pine forests. For the first time, based on the parameters of the VDC, a scale was proposed for estimating the rate of the biological cycle. It is established that the most important indicators are the power of the VDC, ash content and hydrolytic acidity.

Forest litter of some coniferous and deciduous plantations within the Botanical Garden of the Moscow State University is studied. It is established that in the conditions of the deciduous plantations, forest litters of destructive types develop, whereas in the coniferous plantations - fermentative and humified ones. The total reserves of forest litters range from 500-800 g/m² in deciduous plantations, up to 1000-5000 g/m² in coniferous ones. It is shown that small-leaved plantations are characterized by high rates of cycling, with a significant decrease in the coniferous ecosystems. It was shown for the first time that with an increase in the proportion of leaves in the litter, the overall decomposition rate of terrestrial litter increases substantially, which is confirmed by the theory of “hot points” proposed in the scientific literature.

A comparative description of the structural and functional organization of plant litter and forest floor in the course of natural postagrogenic reforestation in the chronory series of ecosystems for 12, 40 and 100 years is given. As the age of the stand increases, an increase in the total reserves and diversity of litter types, a decrease in the proportion of easily decomposable components, and a decrease in their pH and ash content are found. The change of ground cover is accompanied by the replacement of grass cover with grass-shrub, which indicates a decrease in the trophicity of ecosystems. The characteristics of the litter are adequately reflected by the composition of the ground cover. As the stand is restored, a regular decrease in the decomposition intensity of the ground detritus and the speed of the biological cycle occurs. Spatial differentiation of litter types serves as a trigger for the subsequent divergence of soil organic profiles.

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 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.

In soils developing within a monolithic soilgeochemical catena, the composition of water-soluble macro-, microelements and anions has been studied. It has been shown that, as hydromorphism increases from eluvial to accumulative landscapes, the carbon and nitrogen contents naturally increase. The nature of the distribution of water-soluble forms of macro$ and microelements is due to bioaccumulative processes and features of eluvial-illuvial differentiation of soils. In the marginal parts of the watershed depression, the combination of eluvial$illuvial differentiation of the soil and intensive lateral removal in the spring determines the maximum leaching of the upper soil horizons. The use of cluster analysis confirms in the system of geochemical catena the relationship of genetic affiliation and soil position with the composition of water extracts.

The composition of water extracts of soils developing within the het erolithic geochemical landscape of the Klyazma river basin in its upper reaches has been studied. The main factor that determines the content of water-soluble components is the genesis of soils and the position of the soil in a series of elementary landscapes. The specifics of the content of water soluble macro- and microelements in the soil profile outside the zone of anthropogenic influence and developing according to the eluvial- illuvial type is due to their natural organization, with the combination of podzolization in combination with texture organization. Under the con ditions of a supersquale landscape that has emerged from the flood regime, characterized by the complexity of the soil cover, the distribution of water soluble components in the soil profile is determined by the carbonate content and proximity to the surface of soil ground water. An additional factor determining the composition of soil water on the lowered elements of the relief is the underlying soil with peat bogs. It is shown that calcium is among the most important elements that determine the specificity of the studied heterolithic landscape. The composition of water-soluble components for each of the soils is specific, which is confirmed on the basis of the results of cluster analysis.

Within the landscapes of the upper reaches of the Klyazma River, the long-term component composition of natural waters in the system has been studied: snow waters — soil solutions — soil-ground waters — surface waters. It has been determined that the regular excess of the content of the main macro- and microelements in soil solutions in comparison with snow waters at subsequent stages is first replaced by an increase in the concentration of components in soil-ground water, followed by a decrease in the content in surface waters — streams and river waters. It is shown that the relatively high mobility of sodium, magnesium, potassium and calcium, and of the anions chloride and nitrate ions, is accompanied by a significant decrease in the mobility of elements of the family of iron, copper and zinc at the transition from groundwater to surface water. This explains the wide distribution of segregated forms, presented in the form of nodules in soils of semi-hydromorphic landscapes, up to ortsands, and in the boggy conditions of near-terrace depressions on the border with the super-aquatic landscape, the formation of typical bog ores. Thus, the composition of natural waters and its change serves not only as a good, but also a necessary tool for explaining the features of migration of elements in the soil — natural water system.

For landscape conditions in the upper reaches of the river Klyazma, Solnechnogorsk district, Moscow region, the height and reserves of snow cover were investigated, and the chemical composition of the snow was determined. The basis for considering the component composition of snow cover was the geochemical taxonomy of chemical elements based on the characteristics of water migration and abundance.

Data from 23 snow sampling points were interpolated in SAGA GIS using the inverse distance weighting (IDW) method. On this basis, zones differing in the chemical composition of snow are identified. One of the zones is confined to the M-10 Moscow-St. Petersburg highway, while the second borders on populated areas. The area close to the highway is characterized by increased levels of calcium, sodium, aluminum, and chloride ions in the snow cover. The second zone, bordering populated areas, is characterized by a high content of calcium, copper, and manganese in the snow. For the third zone, low concentrations of components in the snow were observed, which are characteristic of a superaquatic landscape due to the distance from sources of pollution.

The studied composition of snow waters belongs to the bicarbonate-sodium-calcium-chloride class. It has been shown that the height and reserves of snow cover are partially controlled by two factors: the type of elementary landscape and the type of ecosystem. Against this background, the spatial distribution of concentrations of elements and anions in snow is predominantly controlled by the anthropogenic factor.