Articles

The article examines the distribution features of one of the main radionuclides of the Chernobyl release — 137Cs — in the wood of the trunk of the Scots pine, depending on the age class. It is shown that in the long-term period after precipitation, the distribution of 137Cs in the stand of pine biogeocenoses in the territory of the Bryansk Polesie of the Russian Federation, which was most severely affected by the Chernobyl accident, at contamination  densities (2183 kBkm–2), exceeding the indicator established by the Law of the Russian Federation "On Social Protection of Citizens Exposed to radiation as a result of the Chernobyl disaster", and classifying the territories as radioactively contaminated (37 kBkm‒2), the minimum index (0,23 kBk kg‒1) and the average value of the specific activity of 137Cs in wood (2,24 23 kBkkg–1) does not exceed the standards for wood products for various purposes, with the exception of that for wood used for the construction of residential premises. The obtained novel data indicate that in the distribution of 137Cs, both by trunk height (from the top of the tree to the trunk) and by average indicators of wood contamination in general, there is a clear trend of a decrease in the specific activity of radionuclide depending on the age of the stand. In this regard, for the most adequate assessment of possible contamination of wood and compliance of the identified levels of specific activity of radionuclides with regulatory indicators, in particular in the context of construction use, sampling of this component should be carried out in relation to age groups in increments of 10 years.

Keywords: Bryanskoe Polesie, Chernobyl fallout, nuclear contamination, pine biogeocenoses, wood use, tree age class.

Methodological peculiarities of basal respiration (BR) measurement have been studied on the peat soil samples from two taiga subzones. It is found that the BR values at the initial incubation time (30 minutes) significantly exceed the ‘classical’ variant (24 hours) and gradually decrease with time. It is observed for all types of samples. The dependence of BR on the volume of the gas phase in the system was revealed - the values are higher the larger the volume of the incubation vial and the larger the ratio of the volume of the gas phase: mass (volume) of the sample. Initial values of CO2 concentration do not influence the dynamics of BR, because both at about zero and relatively high (4400 ppm) starting values of CO2 content the results of incubation were similar. It is critical to maintain the same incubation time interval, the same vial and sample volume while assessing the biological activity of soils using the BR method. The standard variant of BR determination during 24-hour incubation showed results that differed minimally depending on vial volumes and is probably preferable in this variant of experiments.

This article describes the experiment to study measures to combat Heracleum sosnowskyi Manden. The introduction provides a historical overview of the study of Heracleum sosnowskyi, the basis for its use in agriculture, the consequences of the large-scale spread of Heracleum sosnowskyi as an invasive species in the territory of modern Russia. Using the historical research method, the authors put forward a hypothesis about the causes of the invasive spread of Heracleum sosnowskyi in the territory of the Russian Federation. A brief analysis of the methods of combating Heracleum sosnowskyi Manden is presented, an ecological assessment of various approaches is given, which is a comparative research method. The article provides an analysis of weed infestation data, and soil and climatic indicators of the first growing season of the experiment are studied. The morphological method and the method of soil-regime observations were used in the process of sampling. As a result of the experiment, a large array of data was obtained, based on which, with statistical reliability, an agrochemical analysis of soils, weed infestation of plots was carried out, an economic assessment of control measures was made, which in total is a numerical-statistical research method. Keywords: Invasion of Sosnowsky's hogweed, control measures, mistakes in agriculture, harm of herbicides, methods of environmental control, soil indicators, climate data.

The article considers the elements of introduction of milk thistle in the zone of soddy-podzolic soils of the Moscow region. The article presents the results of studies on the efficiency of using the complex organo-mineral fertilizer Ideal and foliar feeding with Epin-Extra when growing milk thistle. Foliar feeding with Epin-Extra (24-epibrassinolide) resulted in the highest yield of milk thistle seeds (1.0 t/ha) due to improved yield structure indicators with their best biochemical indicators. It is shown that the studied Ideal and Epin-Extra preparations improved the yield structure: increased the number of heads per 1 plant, the number of seeds, the weight of seeds per head, and the weight of seeds per plant. They had a positive effect on the formation of the yield of milk thistle seeds. Foliar feeding with the preparation "Epin-Extra" (24-epibrassinolide) resulted in the highest yield of milk thistle seeds (1.18 t/ha) due to the improvement of the yield structure indicators with their best biochemical indicators. It was noted that double application of the organo-mineral preparation Ideal and the steroid phytohormone (Epin-extra) leads to stabilization of cell membranes and, as a result, to the optimal physiological state of the whole plant. Double application of the preparation Epin-extra (24-epibrassinolide) for foliar treatment can be considered the most optimal, since it, to a greater extent than the organo-mineral preparation Ideal, promotes stabilization of cell membranes, reduces the loss of electrolytes, potassium and sodium ions and, ultimately, increases the yield of seeds of this crop. When studying the dynamics of the taxonomic structure of bacterial complexes, it was found that 60% of epiphytic bacteria are represented by pigment forms. It has been established that in the phyllosphere and rhizosphere of milk thistle, significant changes in the ecological-trophic structure of the bacterial complex are observed. They are associated with the replacement of eccrisotrophic proteobacteria during the flowering period of plants by bacteria of the hydrolytic complex during the ripening of seeds. It has been revealed that proteobacteria were dominant on the flowers and seeds of milk thistle, their share is 50-70%. It has been established that the share of Rhodococcus is significantly higher on the leaves and roots of milk thistle.

It is shown that a significant amount of soil and environmental studies necessary for the economic assessment of damage/harm from pollution, degradation and clutter can be reduced through the use of express methods for assessing the ecological state of soils. Such methods include the determination of the volumetric magnetic susceptibility of soils (MV), which characterizes the degree of anthropogenic load on the territory — the so-called level of anthropogenic land pollution. For the territory of the Educational and Experimental Soil and Ecological Center of Lomonosov Moscow State University "Chashnikovo" (EE SEC "Chashnikovo"), the area with the highest soil moisture index and the magnitude of damage from "man-made" pollution is the "roadside strip" — the territory directly adjacent to the Leningradskoye Highway. In the "ditch" zone, the magnitudes of magnetic susceptibility and soil damage decrease compared to the "roadside strip", but still have significant values. In the "forest belt" zone, the values of soil moisture indicators decrease significantly compared to the "road strip" and "ditch", and the amount of damage from "man-made" pollution here is zero, just as for the "arable land/fallow land" zone. The obtained maximum amount of damage from technogenic pollution in the "roadside strip" — 17.37 rubles/m2 (at a cadastral value of 6.03 rubles/m2) — gives an approximate idea of the damage caused to lands by man-made load.

Some historical data on the study of the soil and vegetation cover of the Chashnikovsky extension of the Klyazma River are presented, as well as the results of the study of parent rocks, soils, snow cover composition and distribution of elements in the territory of the superaquatic landscape of the MSU TESEC, including the floodplain soils of the Klyazma River. The parent rocks for this territory are alluvial deposits (14.5% of the total area), peat underlain by deluvial deposits (13.2%), peat underlain by alluvial deposits (12.9%), and alluvial deposits underlain by peat (8.4%). Nine subtypes of alluvial soils have been identified, belonging to 5 types. Alluvial meadow-bog soils predominate (35.8% of the floodplain territory); alluvial meadow acidic soils (21.2%), alluvial bog silt-peat soils (18.9%), alluvial soddy acidic soils (15.5%), and alluvial bog silt-humus-gley soils (8.6%) are also distinguished. The distribution pattern and chemical composition of the snow cover of the EE SEC "Chashnikovo" superaquatic landscape were studied based on 9 selected sampling points. The average height of the snow cover in the floodplain area is 37.8 cm, the snow cover reserves are 118.8 kg m–2 with an average snow density of 0.32 g cm–3. The snow within the superaquatic landscape of the EE SEC "Chashnikovo" is characterized by a low content of components and belongs to the bicarbonate-calcium-sodium-magnesium class. The superaquatic landscape zone is characterized by low values of the content of the main components in the snow water, since it is located far from the M-10 "Moscow - St. Petersburg" highway and populated areas. In the terrace part of the floodplain, relatively high levels of calcium, magnesium and potassium are found in soil solutions. The soils of the central floodplain depressions are characterized by a significant increase in the content of sodium and iron, chloride ion, and among microelements - chromium, copper, zinc and strontium. For the soil of the elevated part of the central floodplain, which has already entered the automorphic stage of development, a decrease in the content of most cations and anions was found. The predominant elements in the composition of new formations in floodplain soils are iron and manganese. Among heavy metals, lead ranks first in terms of accumulation.

The features of the morphological organization of sod-podzolic soils are considered using the example of age-diverse deposits operating in various ecological and genetic conditions. Separate phases of transformation of the soil material of the former arable horizon are identified, associated with the stages of overgrowth of fallow lands. Attention is paid to the resistance of sod-podzolic soils, on the one hand, to agropedoturbation, and, on the other, to the action of zonal factors of soil formation in the postagrogenic period, depending on the degree of soil cultivation in the previous time. It is shown that by the age of 20‒30, the upper part of the profile shows traces of the effects of gilding and eluvial-gley processes, which are reflected in the specific features of the structure of the soil stratum — the appearance of interlayers and spots of podzolized material with characteristic horizontal layering, the appearance of humus nodules, ferruginous-manganese compounds and lightening of the entire material of the former arable horizon.

The article summarizes and presents the results of long-term studies on the effect of mineral, organic fertilizers and liming on crop productivity depending on the degree of cultivation of sod-podzolic soil. It is shown that fertilizers act as a powerful factor capable of increasing the yield of agricultural crops and improving their quality, that the yield of field crops is directly dependent on the degree of cultivation and fertility of the soil. It is shown that in sod-podzolic soil of varying degrees of cultivation, complete or partial replacement of urea with MFU in the composition of triple (NPK) mineral fertilizer does not solve the problem of increasing the efficiency of nitrogen fertilizers. When studying the productivity of grain crops (winter wheat, winter rye, spring wheat, oats, barley), it was found that regardless of the form of nitrogen fertilizers, the optimal dose of NPK for all the above crops did not exceed 100–150 kgha-1 of the active substance of each element. This dose made it possible to realize the potential of the studied varieties of grain crops by 60–80%. The efficiency of nitrogen doses over 100 kgha-1, both when using urea and its combinations with MFU, leads to deterioration of the enzymatic activity of soils. The level of cultivation of sod-podzolic soil remains decisive in the formation of agricultural crop yields and with intensive use of fertilizers.

A detailed morphological study of bog-podzolic superficial-gleyed soils (sod-humus and peaty subtypes) and living ground cover within the soil-geochemical catena in Moscow region Solnechnogorsk district was conducted. For the first time, more than 20 morphological indicators of soils within the organogenic, eluvial and eluvial-illuvial parts of the profile were determined and analyzed over a thirty-year period. At the same time, the characteristics of the associated living ground cover (biomass, proportion of hygrophytes, moisture and trophicity scores according to L.G. Ramensky) were studied. Based on monitored indicators analysis, it was shown that convincing and reliable identification of the degree of bogging of a biogeocenosis is possible without additional analytical studies of soils and plants. Mathematical analysis of field research results indicates statistically significant relationships between the degree of swamping and such indicators as the proportion of hygrophytes, moisture score, litter thickness, the ratio of subhorizon reserves F/L, the thickness of the eluvial horizon, the depth of gleying from the lower boundary of the organogenic layer, and the abundance and size of nodules. It is likely that in the landscape, the soil serves as an “archive” of hydromorphism conditions of varying degrees, while the living ground cover can serve as a sign of swamping only at significantly pronounced process stages. The greatest contribution to the hydromorphism of the studied bog-podzolic surface-gleyed soils is made by: the groundwater level, the upper boundary of the appearance of signs of gleying from the lower boundary of the organogenic horizon, the general abundance of spots in the eluvial horizon, the average size of nodules in the eluvial-illuvial horizon.

The carbon reserves in main components of Moscow region coniferous-broadleaf forest were studied: various fractions of the tree stand, dead wood, mortmass, litter, living ground cover and mineral profile of the soil. To assess the potential intensity of organic matter decomposition, a number of indicators of the functioning of the microbial biomass were determined. An assessment is given of the carbon reserves and their shares in the ecosystem components that differ in the rate of renewal and potential capacity for carbon sequestration, as well as the degree of their spatial variation. The total carbon pool of the studied forest ecosystem is 18.7+0.8 kg·m–2, with almost 90% of the total stock concentrated in the perennial parts of the tree stand, dead wood, mortmass and mineral profile of the soil. These most stable pools are characterized by the least spatial variation within the biogeocenosis. The carbon reserves of the assimilating part of the grass layer and tree leaves are only 0.02 and 0.08 kg·m–2, respectively. The carbon reserves of litter are quite low - 0.21 ± 0.04 kg·m–2, which does not exceed 2% of the total carbon reserves of the ecosystem. The data obtained indicate that even secondary subclimax forest ecosystems are a significant absorber of atmospheric carbon, mainly due to the mass of the tree stand and soil organic matter.