Articles

The simulation model of seasonal dynamics of ¹³⁷Cs in the components of the snytevoy oak forest ecosystem EcoradOak_CS_FW was further developed, which now includes first- and second-order consumers. The radiocesium redistribution in a full-scale food web of   a forest ecosystem of the type “soil—vegetation cover—herbivores—predators” is modeled. The algorithm used in the model allows us to take into account the influence of soil, meteorological, phenological and physiological factors on the behavior of radionuclide in the food web and predict radiological situations under various conditions of radioactive fallout. Data   on the contamination of animals with radiocesium obtained using the model are used to calculate the dynamics of the internal dose. The results of modeling can be used in the rationing of forest products of deciduous forests. The model is also applicable to the study of potassium redistribution in the trophic chain of a deciduous forest ecosystem.

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.

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.

The characteristic of symbiotic relationships is presented on the example of vesicular-arbuscular mycorrhiza in the case of Trifolium pratenseL. at different succession stages of meadow phytocenoses. It is shown that the functional potential of symbiosis changes in the course of succession and is fully revealed under conditions of an undisturbed climax community. The fundamental possibility of biological diagnostics of the state of phytocenosis using discriminant analysis according to the indices of an individual legume plant, taking into account the symbiotic potential, has been demonstrated.

Under the conditions of a model vegetation experiment (30 days), the responses of microbial communities of agro-soddy-podzolic soil of two sites (Chashnikovo, Moscow region) with different organic carbon content (Corg 3,86 and 1,30%) to polymetallic pollution with heavy metals (HM: Cu 660, Zn 1100, Pb 650 mg/kg) and treatment with biochar (5%) and lignohumate (0,25%) Methods of classical inoculation on Czapek agar and analysis of soil lipid profiles by gas chromatography—mass spectrometry, an assessment of the differences in abundance colony forming units (CFU), the biomass of fungi and bacteria, the diversity of cultivated fungi in humus-rich and humus-poor soil. HMs did not have a significant effect on the number of CFU and the number of cultural-morphological types of colonies, but they reduced the biomass of fungi and bacteria in both soils, while this decrease was much more pronounced in a weakly humus soil. In addition, the differences between the soils manifested themselves in a different increase in the proportion of resistant melanized forms of fungi under the influence of HM in a highly humified soil — by 25,9%, and in a weakly humified soil — by 45,7%. The sensitivity and universal significance of structural indicators as indicators of the stability of microbial complexes under chemical contamination of soils of different humus content are discussed; among the studied, the most sensitive and reliable indicators include the assessment of the proportion of melanized fungi.

The characteristic of typical and humus petrozems of the most high-altitude belt zone of the Khibiny, formed under three predominant types of plant groups corresponding to different stages of primary succession, is presented. For these soils, there is no differentiation of the profile by the content of most elements, with the exception of phosphorus, which is concentrated in the surface organogenic horizons. According to many chemical and phy sicalchemical properties, the soils of the char belt are close to Entic Folic Podzols formed in the underlying mountain-tundra belt under shrubby vegetation. The biological activity of petrozems below or is comparable with this parameter in the soil of shrub tundra. It was found that as the structure of vegetation becomes more complex, the activity of microorganisms increases and the organic matter of the soil stabilizes. Overall, the microbial community of petrozems well adapted to extreme conditions.

Indicators of cadastral value of soils in agroclimatic subzones of agrolandscapes of the Irkutsk region are determined. The sensitivity of cadastral value calculation approaches to various soil and geographical conditions is shown. Low values of the cadastral value of agricultural land are due to low values of agroclimatic potential.

The article is devoted to the assessment of the influence of biotic, abiotic and anthropogenic factors on the dynamics of production processes of various ecosystems located in one natural and climatic subzone — the southern taiga of the Eastern European Plain.

The study was carried out on the example of four key sites in the Vladimir region, located in different landscape provinces in similar climatic conditions, but with certain differences associated with the characteristics of the soil and vegetation cover, anthropogenic load, and land use structure. Calculation of productivity indicators in carbon units is based on MODIS GPP/NPP data. The amount of organic carbon in the soil is determined according to the UN Food Organization (FAO) based on the Trends.Earth module of the GIS QGIS package.

Common to the four ecosystems is the course of changes in the indicators of vegetation productivity over the years against the background of its different absolute values. Favorable conditions for the accumulation of carbon in the soil are formed in areas with high productivity and a large number of overgrown lands. The results of analysis of variance ANOVA demonstrate that the factors of time and spatial position of key sites do not affect the content of soil organic carbon and gross biological productivity. Land use structure is a significant factor. It is shown that the insufficient productivity of some ecosystems is compensated by an increase in the productivity of neighboring ones, therefore, the preservation of intra-landscape diversity is a necessary condition for maintaining the stability of their functioning.

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.