Valeria Mikhailovna Telesnina

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.

The features of the dynamics of the morphology and chemical properties of forest litter during post-agrogenic reforestation of arable land in the southern taiga subzone are studied. The relationship between the dynamics of the structure of litter with the floristic composition and the ecological-coenotic structure of the soil cover is shown. The increase in stocks, as well as the diversity of the structure and the degree of spatial variation of the main morphological indicators of litter as the regeneration of the stand has been established. Acidification and a decrease in the ash content of litter, as well as a decrease in the fraction of easily decomposed fractions, are adequately reflected in the composition of the soil cover, in which the role of species adapted for increased acidity and low content of nutrients in the substrate increases. After spruce enters the first tier, the spatial distribution of the structure, reserves, power, and fractional composition of litter is determined by the position in the tesser. In general, the course of succession, as well as the dynamics of the morphology and chemical properties of litter, indicates a decrease in the rate of circulation in biogeocenosis. The ecological scales of Ellenberg, Landolt, Tsyganov and Ramensky as applied to ground cover can serve as an important tool in analyzing the dynamics of forest litter in forest ecosystems.

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.

The litter properties of Moscow State University urban stands with a different type of  care, from lack of care to regular care, were studied using birch stands, lime stands and maple stands as examples. Simplification of the vertical structure as a result of care increases the open space inside the stands, changing the degree of shading and wind regime. For park stands, the special role in litter formation belongs to lateral wind transfer and care regularity, these factors influencing on litters pool and fraction composition. The use of stand care is accompanied by the withdrawal of from 50 to 90% of the stocks of litter, which leads to decreasing recirculation of organic matter and ash elements in urban ecosystems.

In south taiga, as the former hayfields overgrow, the biomass of herbaceous layer decreases even before the formation of a closed tree stand. In the topsoil, increase of actual acidity   was observed, which was adequately reflected by the species of living ground cover;   a more distinct trend was revealed for light soils. The content and reserves of organic carbon in the soil of the hay meadow, where the mowing was preceded by perennial grazing, is rather high in comparison with the soils of hayfields without prior grazing. In general, after grass mowing stop, the content and reserves of organic carbon in topsoil decrease. Long)term cattle grazing slows down the postagrogenic dynamics of organic matter in meadow soils.

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.

The features of the ground cover in connection with the use of care in typical urban plantings in Moscow are determined. The character of plantings care determines the main features of ground cover more than the type of tree species. As a result of planting care, nemoral shade-tolerant species in the grass layer are actively replaced by meadow nitrophilic and ruderal species belonging to annuals and turf grasses, which contributes to an increase the biological cycle intensity.  In urban ecosystems, the indicative role of plants in relation to soil properties is reduced due to the lack of direct long-term relationships between these components.

For the purposes of ecological monitoring, the features of living ground cover and forest floor in spruce stands within Moscow urban territory were studied. Using ecological scales by Nitsenko, Ramensky, Ellenberg and Landolt, let to consider, that ruderalization of living overground cover is a result of recreation. Independently of spruce forest type, the absence of undergrowth results in increasing light penetrating and increasing species quantity. Variety of ecological spaces is a result of moderate trampling, which is mostly expressed in between-crown spaces. Hight trophy index by L.G. Ramensky is a result of increased weediness of overground cover. It is shown, that living overground cover characterizes the variety of tree layer and the level of anthropogenic impact on phytocenosis.

The forest floor in urban spruce stands is sensitive to changes in functioning conditions and can be used for ecological monitoring. Availability of forest floor studying and simplicity of parameter estimation allows getting information about organic matter accumulation in express-regime under various degrees of anthropogenic impact on urban ecosystems.

Within the system of trunk, crown and open space, the simplification of litter structure and decreasing organic matter total deposit are observed — this can be considered an invariant process.

Maximal uniformity of coverless spaces litter, composed by needles and branches, results from absence of living overground cover, in combination with low recreation in these spaces. This fact let to conclude, that coverless spaces are able to be used as most important objects for comparing spruce ecosystems with different overground cover. Two groups of indexes, characterizing structure-functional litter organization, are proposed. Indexes, characterizing structural litter organization, include the total deposit of litter and L horizon deposit. Indexes, characterizing functional litter features, include deposit and proportion of detritus as well as the same for easy-decomposed components, ratio of thickness (deposit) of L horizon and F horizon. The peculiarities of long-term spatial functioning are characterized by litter typology in the system trunk-crown-open space.

The aim of the work was to assess the contribution of the following components – biomass and mortmass of tree stands, undergrowth, living ground cover, and forest litter — to the total organic matter’s pool of plant community. The object of the study was a territory of coniferous-deciduous forest located in Solnechnogorsk City District of the Moscow region, in which five permanent sample trial plots of 50×50 m were allocated. The greatest contribution to the total organic matter mass of studied plant communities was made by forest stand perennial parts (up to 87%) and forest stand mortmass (up to 14%), and phytomass of deciduous trees in stand containing 32 to 98%, which was connected with incompleteness of forest restoration succession process. The contribution of forest litter was no more than 3%; litter deposit was low (0,18–1,21 kg×m^-2), which is not typical for spruce forests, as is the fact that all litter is of the destructive type. Living ground cover in terms of floristic composition and ecological-coenotic structure was typical for the subzone of coniferous-deciduous forests; its contribution to the overall productivity of forest biogeocenosis was insignificant. The spatial intrabiogeocenotic structure of litter reserves and living ground cover biomass distribution was disturbed compared to typical spruce forests due to the high proportion of deciduous species in the forest stand. Deciduous species inclusion in the tree tier, typical of the final stage of formation of a secondary coniferous forest during succession, caused a slight increase in the intensity of the biological cycle, which was indicated in this case by a decrease in the supply of litter and a simplification of their structure. Since the biomass and mortmass of tree stand make the greatest contribution to the sequestration of carbon by forest biogeocenoses, it is these components that require the most detailed assessment during monitoring observations, the purpose of which is to assess the carbon reserves of terrestrial ecosystems.

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.