Vol 10, No 1 (2019)

Cover Page
Theoretical works
Anaerobic methane oxidation by nitrate: kinetic isotope effect
Vavilin V.A.
Abstract

The ratio of stable carbon isotopes (13C/12C) in different environments serves as a significant limitation in estimating the global balance of methane [Hornibrook et al., 2000]. In this case, the value of 13C/12C largely depends on the kinetic isotope effect associated with the metabolism of microorganisms that produce and consume CH4. The article suggests a dynamic model of the processes of methane formation and its anaerobic oxidation with nitrate by methanotrophic denitrifying microorganisms (DAOM), which allowed estimating the fractionation factor of stable carbon isotopes. In the experiment with peat from the minerotrophic bog [Smemo, Yavitt, 2007], the dynamics of the amount of methane and was measured. The dynamic model showed that the introduction of nitrate leads to a slow decrease in the partial pressure of methane. Since methane in the DAOM process is a substrate, methane is enriched with heavier carbon 13C in the system under study. This leads to an increase in the value . The carbon isotope fractionation factor during methane oxidation with nitrate was equal to 1.018 and comparable with the fraction of carbon isotope fractionation in the process of acetoclastic methanogenesis (1.01). Model calculations have shown that during incubation the apparent fractionation factor of carbon isotopes with the simultaneous formation of methane and DAOM slowly decreases. The ratio of 13C/12C isotopes in dissolved and gaseous methane practically does not differ. The model showed that an increase in the initial concentration of nitrate increases the rate of DAOM, which leads to a decrease in the concentration of dissolved methane. In this case, the value of 13C/12C increases. In field studies, Shi et al. (2017) showed that the presence of DAOM in peat bogs in which fertilizers penetrate can be controlled by the amount of nitrate used and the depth of penetration into the anoxic layer. Two MATLAB files describing DAOM are attached to the article.

Environmental Dynamics and Global Climate Change. 2019;10(1):3-15
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Transformation of the relief of territories of development of gas mining deposits of the Taza peninsula
Bolshanik P.V., Mukhamedyanov T.I.
Abstract

The article discusses the natural conditions of the territory of the Taz peninsula in order to highlight the main natural factors in the transformation of the relief. Special attention is paid to the characteristics of permafrost and cryogenic processes and phenomena observed in this area. The characteristic of geological rocks that make up this territory is given. The influence of the hydrometeorological conditions of the Taz Peninsula is estimated. The main factors of the natural environment that determine the formation of a layer of seasonal melting are: the lithological composition and properties of soils, vegetation cover, topography, surface drainage. The main factor determining the heterogeneity of the soil temperature regime is the spatial unevenness of the snow cover thickness in this area depending on the microrelief of the region and vegetation. The influence of the anthropogenic factor on the transformation of the relief is substantiated. Three categories of violations were identified: areal (occurs during the development of fields and the construction of industrial transport facilities and other types of infrastructure); linear (when laying transport communications); and linear area (in the construction of industrial and residential facilities and a network of transport communications). The most common geomorphological processes on the territory of the Taz peninsula, activating the anthropogenic factor, are soil freezing and thermokarst caused by cryogenic processes, landslide processes and erosion, and more rarely deflation. The development of mineral deposits on the territory of the Taz Peninsula is accompanied by the construction of infrastructure for exploration and production, transportation facilities (pipelines, roads, power lines), and industrial and residential facilities. All these types of anthropogenic impact create pressure on the environment and its transformation, especially in conditions of weak stability of geosystems. Geological cryological zoning of the territory for the development of gas pipeline routes has been proposed. Priority activities in developed areas should include: recultivation of disturbed areas - restoration of damaged soil and vegetation cover, natural and geological environment, engineering and geocryological zoning, designed to develop plans for the development of the territory.

Environmental Dynamics and Global Climate Change. 2019;10(1):16-27
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Experimental works
On some physical and chemical properties of soils of sandy outcrops of the West Siberian northern regions
Kapitonova O.A., Aksarina K.Y.
Abstract

The ancient aeolian forms of relief, which are mainly covered with pineries and coniferous forests, are widely spread in the territory of Western Siberia. Anthropogenic transformation of these landscapes leads to the formation of technogenic deserts and sandy outcrops on soils of light mechanical structure generally because of the development of oil and gas extraction industry. Such transformed ecosystems are often met in the north of the West Siberian Plain within a subzone of northern taiga of the taiga natural zone and the zone of the forest-tundra. In 2016–2017, we explored three sites of sandy outcrops in the territory of Purovsky District of Yamalo-Nenets Autonomous Okrug (Tyumen region): in 27 km to the south from Muravlenko, in 32 km to the southwest from Gubkinsky and in 23 km to the East-southeast of New Urengoy. The first two sites are located within the northern taiga; the third site is at the southern border of the forest-tundra, in the area of its gradual transition to the northern taiga.

Results of the conducted researches show the considerable changes in a number of physical and chemical properties of podsolic sandy soils of technogenic deserts in comparison with soils of undisturbed ecosystems. We have revealed statistically significant decrease in the acidity of the surface soil layer to 5–6 units рН due to the destruction of the top soil horizons and exposure of the illuvial and eluvial horizons having smaller acidity. Our researches show the reduction of maintenance of fine fractions – clay and dusty particles – in the transformed soils and, respectively, increase in content of sand up to 95–100%. Also we have revealed statistically significant reduction of soil moisture content in soils of sandy outcrops. 

Thus, the soils of technogenic deserts are characterized by ease, flowability, they are usually not fixed by vegetation and easily are affected by wind. The ecotopes, which are formed on sandy outcrops, differ in extreme conditions. They can be mastered only by a small number of specialized species-erosiophiles, shifting to disturbed felted habitats with similar natural ecotopes with the friable sandy and sabulous sandy soils, often mobile soil typical of marine and lake shallows, river alluvium, taluses, slopes of ravines. On the periphery of sandy outcrops the shafts of falling up to 4,5–5,5 m high are formed. They constitute the real danger to natural undisturbed north taiga and forest-tundra ecosystems, burying them under sandy masses.

Environmental Dynamics and Global Climate Change. 2019;10(1):28-37
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Association Carici juncellae-Salicetum rosmarinifoliae (Alnetea glutinosae) on the south taiga section of the Ob River floodplain
Taran G.S., Dyachenko A.P.
Abstract

The Carici juncellae–Salicetum rosmarinifoliae Korolyuk et Taran in Taran 1993 association (Salicion cinereae, Salicetalia auritae, Alnetea glutinosae) includes the communities of the shrub (Salix rosmarinifolia, S. cinerea)-birch (Betula pubescens) tussock (Carex juncella, C. cespitosa) mires spread on the big West Siberian river floodplains within the taiga zone. On the Ob River, the association is represented by the C.j.–S.r. spiraeetosum salicifoliae Taran 1993 subassociation. Its range covers the Ob floodplain 830-kilometer distance crossing the subtaiga, south taiga and middle taiga subzones of Western Siberia. In the south taiga subzone (surroundings of the former village Kaibasovo, Krivosheinskiy district of Tomsk Region, 57º14'44"N, 84º11'05"E), the C.j.–S.r. spiraeetosum salicifoliae subassociation is studied for the first time. Near the Kaibasovo, the subassociation is represented by two facies: shrubby (Spiraea salicifolia, Salix rosmarinifolia, Salix cinerea) and birch (betulosum pubescentis). The communities of these facies found some floristic differences, which made it possible to attribute them to different variants: var. Cicuta virosa and var. Kadenia dubia. Carex juncella, C. cespitosa and Comarum palustre dominate in the field layer of the tussock mires. In the C.j.–S.r. spiraeetosum salicifoliae subassociation communities near the Kaibasovo, the average total projective cover (TPC) of the tree layer is 7%, shrubs – 34%, grasses – 48%, tussocks – 20%, ground mosses – 14%. Average tussock height is 59 cm. Average species saturation of the communities is 27 species of vascular plants and 18 species of mosses per 100 m2, the volume of the local coenoflora is 39 species of vascular plants and 28 species of mosses. Six moss species (Brachytheciastrum velutinum, Bryoerythrophyllum recurvirostrum, Bryum moravicum, Fissidens bryoides, Plagiomnium cuspidatum, Pylaisia selwynii) were found in the Ob communities of the C.j.–S.r. spiraeetosum salicifoliae for the first time. Due to this, the total volume of the moss flora of the subassociation Ob stands increased to 74 species. The analysis of the variability of the main coenotic and floristic parameters of the C.j.–S.r. spiraeetosum salicifoliae subassociation in the geographical space of the Ob floodplain (from the subtaiga subzone to the middle taiga one) is carried out. The main regularities of these shifts are revealed. The volume of the subassociation local vascular coenoflora (52-53 species) and average species saturation of the communities by vascular plants (20-21 species per 100 m2) are stable on the most of the Ob floodplain sections. At the same time, changes are observed downstream of the Ob River, which can be interpreted as an intracoenotic response of the subassociation communities to smooth changes in the ecological regime of the floodplain when moving in geographical space from south to north. Thus, from the south to the north, many average parameters increase in the subassociation communities, namely: the height of trees, TPCs of tree layer, tussocks and ground mosses, the species saturation with mosses (from 4 to 18 species per 100 m2). The species richness of local moss floras also increases from 11 to 54 species. On the contrary, the average TPCs of shrub and field layers from south to north decrease. A number of deviations from general trends were found in the Kaibasovo birch-shrub tussock mires, namely: high species saturation with vascular plants (27 species per 100 m2), low reach of vascular coenoflora (39 species). The first can be explained by the proximity of the studied mires to the Ob riverbed, the second – by the crowding of the relevés in a relatively small area of the floodplain.

Environmental Dynamics and Global Climate Change. 2019;10(1):38-46
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Discussions
Reply to A.V. Smagin: V. What is wrong with an “abiotic paper” and do we always need to take into account the abiotic gas absorption by soil?
Glagolev M.V., Sabrekov A.F.
Abstract

A paper of prof. A.V. Smagin [2007] is analyzed (both from outer scientometric and inner meaningful points of view). In this paper he considers the abiotic absorption of gases by organogenic soils. In this regard, claims of the author of the article to the work of V. M. Stepanenko and his colleagues on the modeling of methane emissions from lakes on the territory of permafrost are also discussed. An idea that (in contrast to the views of A.V. Smagin) a necessity to account for abiotic uptake depends on properties of modeled object is formulated. In particular, if blocks of climate models are developed (like the Stepanenko model), which should work on timescales of 103÷104 hours and more, it makes no sense to take into account the abiotic uptake that occurs within significantly shorter time intervals and concerns an extremely small amount of methane (compared to its total amount, which is released within the indicated 103-104 hours). In addition potential uncertainties of deep soil chamber technique that could be generated by abiotic absorption and biogenic oxidation of methane are discussed.

Environmental Dynamics and Global Climate Change. 2019;10(1):47-61
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