The results of experiments to study changes in the hydrological properties of soil substrates composing profiles of artificial soils (constructozems) 1–4 years after their creation are presented. Constructozems are represented by two variants, layered soil including Ap horizons, lowland peat and quarry sand of equal thickness, and a mixture of these substrates in an identical amount by weight, as for layered constructozems. Water retention curves obtained by the capillarimetric method on samples with undisturbed structure are compared. A decrease in the water-holding capacity of the peat layer and an increase in the mixture samples are found a year after constructozems had been placed. The laboratory and field experiments have shown a statistically significant difference in moisture filtration rates of the layered constructozem and the mixture. The sharp boundaries between soil horizons contrasting in their properties reduce moisture migration rates to zero values. The obtained breakthrough curves of potassium ions suggest that the continuous pathways of rapid movement of moisture and dissolved substances have formed after 4 years of functioning of artificial soils and are most pronounced in the structures with the homogeneous soil profile.

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.

Results of the 60-year research on soil physical properties at the large lysimeters of the Experimental Soil Station of Moscow State University are discussed. The main studied issues include the elements of soil water balance, soil evolution, soil temperature regime, and transport of various substances within the soil profile. The long-term changes in soil texture, soil mineralogy, and organic carbon content have been observed. The horizon sequence in the soil profile affects the intensity of drainage flux and its stabilization in the long-term aspect. The amount of the transit transfer of substances in different soil profiles depends on both profile structure and upper boundary conditions.

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.

Northern peatlands represent one of the largest carbon pools in the biosphere, but the carbon they store is increasingly vulnerable to perturbations from climate and land-use change. Meteorological observations taken directly at peatland areas in Siberia are unique and rare, while peatlands are characterized by a specific local climate. This paper presents a hydrological and meteorological dataset collected at the Mukhrino peatland, Khanty-Mansi Autonomous Okrug – Yugra, Russia, over the period of 8 May 2010 to 31 December 2019. Hydrometeorological data were collected from stations located at a small pine–shrub–Sphagnum ridge and Scheuchzeria–Sphagnum hollow at ridge–hollow complexes of ombrotrophic peatland. The monitored meteorological variables include air temperature, air humidity, atmospheric pressure, wind speed and direction, incoming and reflected photosynthetically active radiation, net radiation, soil heat flux, precipitation (rain), and snow depth. A gap-filling procedure based on the Gaussian process regression model with an exponential kernel was developed to obtain continuous time series. For the record from 2010 to 2019, the average mean annual air temperature at the site was −1.0 ∘C, with the mean monthly temperature of the warmest month (July) recorded as 17.4 ∘C and for the coldest month (January) −21.5 ∘C. The average net radiation was about 35.0 W m−2, and the soil heat flux was 2.4 and 1.2 W m−2 for the hollow and the ridge sites, respectively. The presented data are freely available through Zenodo (https://doi.org/10.5281/zenodo.4323024, Dyukarev et al., 2020), last access: 15 December 2020) and can be used in coordination with other hydrological and meteorological datasets to examine the spatiotemporal effects of meteorological conditions on local hydrological responses across cold regions.

Saturated and unsaturated hydraulic conductivity as a function of a thermodynamic potential (pressure) of soil water K(P) are investigated in the sandy samples with admixtures of strongly swelling polymer hydrogels (SSPHs) in a wide concentration range from 0.01 to 0.3 %SSPHs. The author’s original centrifugation method has been used along with a kinetic model of the water removal process, which enables to determine the function of water conductivity of gel compositions operating in an unsteady state. In saturation state and within the range of low absolute values of soil water pressure |P| = 0.3-20 kPa the SSPHs significantly (2-10 up to 50 times) reduced the hydraulic conductivity in proportion to the dose of a superabsorbent. A heterogeneous layered structure with a layer of pure gel or gel composition 0.1-0.3% SSHP reduces the saturated conductivity by 10-80 times.In the range | P | = 100-3020 kPa, the K(P) function, on the contrary, strongly increased up to 10–20 times under the action of SSPHs. The calculation of K(P) using the Mualem theory disagrees with our experimental estimation, especially in a range of low water content, where such a calculation strongly (up to 100-1000 times) underestimates the values of K(P).

The results of field studies of methane emission to the atmosphere from different landscape elements of West Siberian oligotrophic bog (Mukhrino test plot, Khanty–Mansi autonomous okrug) in the cold season are discussed. The statistical parameters of the process are estimated, and the high variability of methane fluxes and their deviation from the normal distribution are shown. From October to May, the mean arithmetic and median values of methane fluxes were equal to 0.06 ± 0.01 and 0.02 mg С/(m 2 h), respectively, with the sampling ranging from–0.3 to 0.5 mg С/(m 2 h). In 22% of cases, the negative fluxes (gas consumption) were observed with the average intensity of–0.03 ± 0.01 mg С/(m 2 h) and the median of–0.01 mg С/(m 2 h). At the same time, a considerable underestimation of emission values cannot be excluded, because of the methodological problems of the routine calculation of fluxes by the linear approximation of trends in the gas concentration dynamics in the chamber. The alternative calculation models are provided, and the possible reasons for the experimentally observed phenomenon of methane sink recorded in the chambers on the snow cover surface, including photochemical processes, are discussed.

Pore-size distribution in a soddy-podzolic silt loamy soil developing from mantle loesslike loam (Eutric Albic Retisol (Loamic, Cutanic)) was calculated from the water retention curve according to Jurin’s equation and directly determined in microtomographic experiments. Rounded macropores with the diameter of their sections from 75 to 1000 μm predominate in horizontal sections if the studied soil samples. A larger part of the soil pores (>30–35%) belongs to micro- and nanopores, and they cannot be quantitatively determined by the tomographic method, because their sizes are smaller than the detection limit of the applied X-ray microtomography (8.75 μm per pixel). This leads to a significantly larger pore volume determined from the water retention curve in comparison with the “tomographic” pore volume. A comparative analysis of pore-size distribution curves obtained by these methods shows that the major regularities of the pore-size distribution in the range from 30 to 5000 μm are similar in both cases. Fine macropores and, partly, mesopores predominate. Common characteristics of the pore-size distribution curves obtained by these methods, including the coincidence of the peaks, attest to the validity of classical approaches, according to which the hydrology of soil pore space can be perceived as a physical model of cylindrical capillaries of different sizes with capillary-sorbed water.

We study the emission of methane fluxes from the snow surface in oligotrophic West Siberian swamp and profile distribution patterns of this gas in the snow thicker. Physically reasonable mathematical model of the process of distribution of methane in the snow cover, combining source on the surface of the peat soil and mechanism of diffusion transport of escaping gas from the soil into the atmosphere are developed. Stationary model variants are used to calculate emission of methane emissions from data on the profile of gas distribution (gradient method of snow survey). Calculated data often exceed the measured by chamber method flows 2-3 times or more, varying in the range of 0,01-0,2 mgС/m2/h. The proposed method of snow survey can successfully evaluate gas flows from marsh into the atmosphere during the cold season, smoothing their inherent large variation.

Fluxes and profile distribution of methane in the snow cover and different landscape elements of an oligotrophic West-Siberian bog (Mukhrino Research Station, Khanty-Mansiisk autonomous district) have been studied during a cold season. Simple models have been proposed for the description of methane distribution in the inert snow layer, which combine the transport of the gas and a source of constant intensity on the soil surface. The formation rates of stationary methane profiles in the snow cover have been estimated (characteristic time of 24 h). Theoretical equations have been derived for the calculation of small emission fluxes from bogs to the atmosphere on the basis of the stationary profile distribution parameters, the snow porosity, and the effective methane diffusion coefficient in the snow layer. The calculated values of methane emission significantly (by 2–3 to several tens of times) have exceeded the values measured under field conditions by the closed chamber method (0.008–0.25 mg C/(m 2 h)), which indicates the possibility of underestimating the contribution of the cold period to the annual emission cycle of bog methane.

The emission methane fluxes from the snow cover surface in an oligotrophic West Siberian bog and the profile distribution patterns of this gas in the snow stratum are studied. Physically reasonable mathematical models of the process of methane distribution in the snow cover combining the source on the surface of the peaty soil and the mechanism of diffusion transport of escaping gas from the soil into the atmosphere are developed. Stationary model variants are used to calculate the emission methane fluxes by the data on the profile gas distribution (gradient method of snow survey). The calculated data often exceed the fluxes measured by chamber method 2-3 times or more, varying in the range of 0.01-0.2 mgС sq m h. The proposed method of snow survey enables to successfully evaluate methane fluxes from a bog into the atmosphere during cold season smoothing their inherent great variation.

The major gases contributing to the greenhouse effect are carbon dioxide and methane (60 and 15–18%, respectively). The former Soviet Union area accounts for 11% of the global methane flux on the average. However, virtually no records of methane flux were kept in Russia in the late 1980s-early 1990s. Inventories of methane emission in Russia were reported in the middle 1990s, but those data were confined to measurements performed by the early 1990s. This paper presents generalized data on methane and carbon dioxide emission from the surfaces of marsh ecosystems in West Siberia in the 1990s, when the majority of measurements were carried out.