The features of vegetation and terrestrial detritus within the boundaries of the Chashnikovo UOPEC in the upper reaches of the Klyazma River have been studied, theses ecosystems corresponding with coniferous-deciduous forests conditions. Based on the ecological scales of L.G. Ramensky and E. Landolt, as well as the ecological-cenotic classification of A.A. Nitsenko, a grouping of terrestrial ecosystems differing in trophic and humidification levels was obtained by the method of main components. Within the studied territory, based on the ecological and cenotic structure of living ground cover, three groups of phytocenoses were identified — moderately wet forest phytocenoses with a predominance of spruce, wet forests with a predominance of small–leaved species, as well as phytocenoses of dryland and floodplain meadows. For all sampling points, the classification and stocks of litter, as well as their spatial distribution within the phytocenosis, were assessed. The studied ecosystems vary significantly in litter stocks from high values in the tree trunk spaces of spruce forests – about 5 kgm-2 – to extremely low values – less than 0.5 kgm-2 — in upland and floodplain meadows, which determines the high heterogeneity of potential carbon accumulation within the territory. The typological affiliation of litter is interconnected with stocks only at the biogeocenotic level in relation to spruce forests, but this pattern does not work at a higher level when considering ecosystems at the landscape level.

The predominance of nemoral (larch, spruce, and linden forests), meadow (birch forest), and weed-ruderal (pine forest) species has been revealed in the herbaceous layer in weakly tramsformed ecosystems on the territories of urban specially protected natural areas. Such species compositions are not typical for natural zonal phytocenoses. Boreal species are found in small numbers in all phytocenoses, with their proportion reaching 35

Properties of forest litter in the European larch stands planted in the Izmailovo Park specially protected natural area in Moscow were studied in two sites of 100–120-year-old larch plantations on the typical sandy loamy soddy eluvozems on sandy deposits underlain by moraine (Luvic Cambisols). One of the sites is the control and the other was subjected to human impacts typical of park areas as a result of recreation. A classification of litter structure and transformation characteristics is proposed to assess a stepwise change in organic matter corresponding to different periods of litter functioning. In seasonal dynamics, a uniform decrease in litter stock over the year is observed in control stands versus the disturbed plot, where the most significant decrease in stock is recorded in November–June. In the annual cycle, a considerable decrease in the stock of active fraction is observable in the annual cycle, suggesting an intensive biological turnover in the studied larch stands. The dynamics of the stocks of litter fractions are different. The recreational load in larch stands determines a decrease in the accumulation of litter organic matter and influences the dynamics of this process. A significant twofold decrease in litter thickness and stock during recreation is recorded and is accompanied by a significant simplification of the litter structure and changes in its typology, which is especially pronounced in the conditions of near-trunk spaces. The characteristics of structural and functional litter organization in larch stands are the informative criteria for the specific features of organic matter biogeochemical cycles appropriate for other types of tree stands both natural and urban.

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.

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 easydecomposed 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

A comparative analysis of the composition of lysimetric waters for 2021–2022 was carried out for two groups of stationary soil lysimeters under urban conditions. The first group of lysimeters is formed by the “fallow–herbaceous phytocenosis–overgrown fallow–spruce forest–mixed and broad-leaved plantation” system developing on the same type of mantle loam. The second group of lysimeters represents soils with different types of tillage: conventional plowing, extradeep plowing according to Bushinsky, plowing according to Mosolov, and deep plowing according to Kachinsky. The same type of migration of components, in which the most migrating elements include carbon, mono- and divalent cations, and chloride ions with minimal migration of iron, manganese, and aluminum, is shown for both groups. The concentration of such important biophilic elements as magnesium, calcium, potassium, and carbon and, among anions, chloride and sulfate ions increases significantly in the group of lysimeters under various types of vegetation as the tree canopy develops and, increasing, accordingly, the intensity of the biological cycle increases in migrating waters. Cluster analysis identifies two different subgroups in terms of the composition of natural waters: the first one is formed by the “fallow–herbaceous phytocenosis–overgrown fallow” system, and the second contains tree plantations. A cluster that characterizes the composition of water in lysimeters with reclamation plowing according to Mosolov and deep plowing according to Kachinsky is distinguished in the group of lysimeters with different tillage. At the same time, individual aggregates form lysimeters with conventional plowing and ultradeep plowing according to Bushinsky. This is explained by the fact that the initially created soil-profile design, which is characterized by the placement of eluvial and illuvial soil horizons in various combinations and at different depths, is transformed in this group of lysimeters.

Living ground cover and forest litter under spruce stands in the city of Moscow were studied for the purposes of environmental monitoring. The application of the Ramensky, Ellenberg, and Landolt scales made it possible to establish that the ground cover undergoes ruderalization as a result of recreation. Regardless of the spruce forest type, the absence of understory results in a higher illumination and the number of species increases. The diversity of ecological niches is a result of moderate trampling that is more typical for intercrown spaces. The high L.G. Ramensky trophicity score is determined by elevated ground-cover littering. It is shown that living ground cover reflects the ecosystem diversity and the level of anthropogenic impact on the phytocoenosis. Litter under urban spruce stands is sensitive to changes in functioning conditions and can be used as an environmental monitoring object. The immediate availability of litter for analysis and the simplicity of parameter estimation techniques make it possible to obtain operational information on organic matter deposition in urban ecosystems affected by anthropogenic impacts of various intensity. In forest stands (both conditionally reference and disturbed ones), the litter structure is expectedly simplified in the trunk–crown–opening tesserae system, and the total organic matter reserves decrease, which can be considered an invariant process. The recreational impact reduces litter reserves by 1.5 times and redistributes it within tesserae; as a result, up to 85 Sampling points in stands must be selected taking into account the priority of near-trunk and intercrown spaces that are most sensitive to external changes. Due to their location, near-trunk elevations are affected by recreation at a minimum and better reflect changes in environmental conditions; while intercrown spaces are more indicative for recreation-impact estimations. In terms of methodological approaches, two groups of parameters reflecting the structural and functional litter organization have been proposed for environmental-monitoring purposes. Parameters reflecting the structural litter organization include the total litter reserves and reserves in the L subhorizon. The following parameters reflect functional litter parameters: detritus reserves and proportion, reserves and proportion of easily decomposable components, ratio between the L subhorizon thickness and the F subhorizon thickness, and ratio between detritus reserves in the L subhorizon and in the F subhorizon. Litter typology in the system of trunk–crown–opening tesserae characterizes its long-term spatial functioning.

The long-term component composition of natural waters in the snow waters–soil solutions–soil–ground waters–surface waters system has been studied within the landscapes of the upper reaches of the Klyazma River . 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 is first replaced at subsequent stages 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 anions such as 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, which are presented by nodules in soils of semihydromorphic landscapes, up to ortsands, and the formation of typical bog ores in the boggy conditions of near-terrace depressions on the border with the superaquatic landscape. 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 and explaining the mechanism of how soil formations arise.

This paper describes properties of soils and litter formed in pine forests of Moscow oblast in areas used by gray herons as nesting grounds. It is established that the total trophicity of ecosystems sharply increases in areas with a high density of heron nesting sites compared to control sites, which is manifested in the widespread occurrence of species with strict requirements as regards the soil nutritive regime. The elevated content of water-soluble phosphorus forms, nitrates, sulfates, potassium, magnesium, and calcium in soils of heronries confirms this. By contrast, the concentrations of main components in control soils are typical for the zone of coniferous–deciduous forests. Taking the low mobility of phosphorus and its probable fixation in the composition of immobile complexes, it has been suggested that elevated concentrations of this element in areas where sod–podzolic soils are widespread and the role of anthropogenesis is excluded, which may indicate past effects of ornithogenic ecosystems.

The types and total reserves of mortmass in the forest litter of the main types of biogeocenoses within the stationary bulk lysimeters of the Soil Experimental Station of Moscow State University have been studied. It is shown that the litters are mainly destructive in spruce forests, fermentative in mixed stands, and humified in broad-leaved forests. There is an exchange of plant debris between biogeocenoses: leaves are found in spruce biogeocenoses, overgrown fallows, and black fallow. The calculated litter-debris coefficient (LDC) according to N.I. Bazilevich enables us to characterize the biological cycle in spruce plantations as the slowed-down type: the LDC is 2.8, which is related to the domination of decomposition-resistant needle debris. In broad-leaved and mixed plantations, the turnover is intense: the LDC is 1.2. It is shown that the content of mineral admixtures should be taken into account when calculating the total organic matter reserve in litter; and their portion should be estimated during laboratory studies.

The operation of stationary soil lysimeters is largely determined by the areal and vertical limitations of the soil mass. The areal spatial limitations of large lysimeters operating at the Moscow State University Soil Station and the proximity of phytocoenoses developing in them to each other contribute to the additional transport of plant litterfall by wind, while the vertical limitations eliminate the role of groundwaters and their soil-forming effects. The absence of lateral subsurface flow that is typical for natural landscapes and the increased inflow of alkaline-earth elements with atmospheric precipitation and dust reduce the manifestation of the eluvial–illuvial process. Comparative analysis of lysimetric waters in 1967–1968 and in 2014–2015 shows a significant increase in concentrations of such cations as calcium, sodium, magnesium, and potassium and such anions as chloride and sulfate over this period. The local spatial geochemical contrast of lysimetric waters caused by the impact of deicing agents does not affect the relative migration capacity of elements. Based on their biogeochemical accumulation levels in the soil, macroelements form the following series Ca > K > Al > Mg > N; microelements: Zn > Sr > Cu > Ba. The above patterns persist in all types of lysimeters. The calcium concentration in soils increases in the series: broadleaf forest > mixed forest > spruce forest > black fallow. The increased accumulation of elements in soils of spruce forests correlates with the humus type (moder-like) formed under them; this humus type is determined by the combination of coniferous and deciduous litterfall.

The composition of water-soluble macro- and microelements and anions has been studied in soils formed within a monolithic soil–geochemical catena. It has been shown that the carbon and nitrogen contents regularly increase from eluvial to accumulative landscapes parallel to their hydromorphism. The distribution of water-soluble forms of macro- and microelements is related to bioaccumulative processes and features of eluvial–illuvial differentiation of soils. The margins of the watershed depression are characterized by the combination of eluvial–illuvial differentiation and intensive lateral removal of elements in spring, which determines the maximal leaching of the top soil horizons. The data of the cluster analysis confirm that there is a correlation of soil genesis and location in the system of geochemical catena with the composition of water extracts.

This paper discusses the composition of soil–water extracts prepared from soils developing within a heterolithic geochemical landscape of the Klyazma River basin at the upper reaches of the river. The main factors determining the content of water-soluble components are the soil genesis and position in the series of elementary landscapes. The content of water-soluble macro- and microelements in soil profiles not affected by anthropogenic impacts is determined by the eluvial–illuvial structure of these soils. In a superaqual landscape withdrawn from the floodplain regime and featuring a complex soil cover, the distribution of water-soluble components in the soil profile is determined by calcareousness of soil–ground waters and their occurrence depth. Another factor affecting the soil solution composition is peat deposits underlying the soils. It is shown that calcium is one of the key elements determining the specificity of the studied heterolithic landscape. The performed cluster analysis confirms the identified differences in the composition of water-soluble components in each of the studied soils.

Annual dynamics, composition, and pools of total organic matter and ash elements in litters of urban forests in Moscow were studied. The destructive litters are shown to prevail in all studied phytocenoses; the share of easily decomposing fraction is high (62–90%), which allows to estimate the cycle intensity as high and typical for similar natural stands. A term “litter implementation” was proposed for a set of abiotic and biotic processes of litter transformation. Three methods to estimate the litter organic matter involvement into cycling are described. The first method is based on using litters typology. The second method is derived of the juxtaposition of litter supply before and after the fall of leaves. The third method presumes the comparison of easily decomposed and hardly decomposed litter components along with the analysis of litter and detritus fractional composition. It is shown, that with the same type of organic matter decomposition processes, in conventionally standard stands of the botanical garden and park, the characteristics of their seasonal dynamics are determined to a greater extent by the type of edificatory tree than by the nature of anthropogenic impact. The maximum reserves of litter were found for the maple stands (800 g/m 2 ) in botanical garden, and the minimum one for the birch stands (250 g/m 2 ) in the park area, which corresponds to the pattern revealed for the total thickness of the litter. The litters of lime stands are characterized by the largest fraction of leaves and easily decomposed components (about 60%).

This paper studies the litter properties of Moscow State University urban stands using the examples of birch, linden, and maple forests with a different type of care, varying from periodic care, regular care, and lack of care. 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 influence litter 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 recycling of organic matter and ash elements in urban ecosystems.

The composition of soil, ground litter, and litterfall water extracts was studied for zones affected by gray heron nesting places and for background sites covered by broad-leaved forests in the gray forest soil zone of Tula oblast. It is established that birds’ activities result in an inflow of bird excreta, formation of specific forest ground litters, and increase in the share of large-size tree litter that accumulates in the course of nest building. It is shown that ground litter, litterfall, and upper horizons of the gray forest soil in nesting places feature higher concentrations of macroelements (calcium, potassium, and magnesium), microelements (copper, zinc, and strontium), and anions (NO$$_{3}^{ - }$$, PO$$_{4}^{{3 - }}$$, and Cl−).