Georgy Valerievich Matyshak
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Methodological approaches to the field investigation of root and microbial respiration contribution to soil CO2 efflux in permafrost zoneMoscow University Bulletin. Series 17. Soil science. N 1. p.46-51read more1216
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Изучены действие и последействие строительства трассы магистрального трубопровода на свойства гумуса и особенности его распределения по гранулометрическим фракциям дерново-подзолистой почвы. Охарактеризованы признаки техногенной деградации гумуса и степень их выраженности по сравнению с контрольной почвой в разные периоды наблюдений во взаимосвязи со спецификой экологической ситуации.
Keywords: autotrophic and heterotrophic respiration; CO2 efflux; microbiological activity; peatlands; permafrost; root respiration; Western Siberia
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Influence of plant cover on hydrothermal conditions in soils of Large lysimeters of the MSU soil station: results of a 60-year experimentMoscow University Bulletin. Series 17. Soil science. 2021. N 3. p.45-51read more1412
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Keywords: ecosystem; vegetation cover; hydrothermal regime of soils; biological activity of soils; temperature; soilmoisture; parameters of soil functioning; lysimeters
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Biological activity of organogenic soil samples under different moisture levelsMoscow University Bulletin. Series 17. Soil science. 2025. Vol. 80. N 2. p.84-95read more902
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The response of biological activity and the content of labile forms of biogenic elements in peats of different genesis to variation in their moisture content was studied under laboratory conditions. Samples of peat soils of the northern and southern taiga (Tyumen and Moscow regions) were used in this work. A series of manipulation experiments were conducted in which the dynamics of such indicators as basal respiration (BR), microbial biomass carbon, labile carbon and nitrogen content were estimated for different peat types at different moisture levels. The effect of the experiment duration and type on the dynamics of peat properties was also assessed. It was found that all the studied peat samples are characterized by a wide range of moisture content, at which the maximum of biological activity is observed. In general, it is in the range from 20–30% to 80–90% of water–holding capacity (WHC). In this range, no significant relationship is observed between moisture content and BR. In most experiments, a reliable decrease in biological activity was observed only in the "extreme" humidity ranges - less than 20% and more than 90% WHC. It is shown that the nature of the response to moistening is individual, determined by the properties of the sample and depends little on the type of sample preparation. In experiments and model calculations, it is proposed to use the obtained sensitivity coefficient to moisture — W20, which is 1.0‒1.2 in the range of 40‒80% WHC for peat samples of different genesis. Long-term variants of incubation experiments showed a more pronounced response to overmoistening and a reliable decrease in biological activity at high humidity values (more than 80% WHC). This may indicate their better applicability for solving problems of modeling the behavior of ecosystems in the event of a change in the hydrological situation.
Keywords: microbial respiration; mineralization rate; water–holding capacity (WHC); peat; carbon dioxide
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Methodological peculiarities of basal respiration measurement of organogenic samples of peat soilsMoscow University Bulletin. Series 17. Soil science. 2025. N 3. p.177-187read more912
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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.Keywords: peat; mineralisation rate; Histosol; soil respiration; biological activity of soils; carbon balance
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Diurnal dynamics of CO2 emission from soils of typical biogeocenoses in the north of Western SiberiaMoscow University Bulletin. Series 17. Soil science. 2026. N 2. p.211-220read more126
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Despite the widespread adoption of modern, high-precision methods for assessing ecosystem carbon budgets, most primary data for calculating monthly, seasonal, and annual gas fluxes are obtained through daily soil or ecosystem respiration measurements. The question remains whether such one-time, albeit regular, measurements can reliably reflect the average daily flux. The objectives of this study included assessing patterns in the diurnal dynamics of soil CO2 emissions for two northern taiga ecosystems (green moss pine forests and frozen hummocky peatlands) and three spotted-medallion tundra ecosystems (mineral spot, overgrown area, and dwarf birch area) in northern Western Siberia. In August2016 and 2017, CO2 emissions from the soil surface were measured every four hours for two days using a chamber method, as well as soil temperature and volumetric moisture at a depth of 10 cm. Significant diurnal dynamics were observed for all studied ecosystems, despite different absolute values of CO2 emissions. Minimum fluxes were observed in the pre-dawn hours, around 2:00 AM, for all sites. Maximum fluxes were recorded at various times but generally occurred between 2:00 PM and 6:00 PM. For most sites, the diurnal variation in emission values correlated with soil temperature, but a pronounced hysteresis was observed in this relationship. This phenomenon is explained by both biological factors—root respiration dynamics depend more on photosynthesis than on soil temperature—and physical factors—impeded gas diffusion in dense mineral horizons. The most favorable hours for measuring CO2 emissions, in terms of subsequent calculations of diurnal fluxes for most of the studied ecosystemsduring peak vegetation, are morning (before 10:00 AM) and evening (from 6:00 PM to 10:00 PM).Keywords: soil respiration; greenhouse gases; wetland ecosystems; forest ecosystems; spotted-medallion tundra
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