Specific features of the ecological functioning of urban soils in Moscow and Moscow oblast

Urban soils (constructozems) were studied in Moscow and several cities (Dubna, Pushchino, and Serebryanye Prudy) of Moscow oblast. The soil sampling from the upper 10-cm-thick layer was performed in the industrial, residential, and recreational functional zones of these cities. The biological (the carbon of the microbial biomass carbon, C_mic and the microbial (basal) respiration, BR) and chemical (pH_water and the contents of C_org, heavy metals, and NPK) indices were determined in the samples. The ratios of BR to C_mic (the microbial respiration quotient, qCO₂) and of C_mic to C_org were calculated. The C_mic varied from 120 to 738 μg C/g soil; the BR, from 0.39 to 1.94 μg CO₂-C/g soil per hour; the C_org, from 2.52 to 5.67%; the qCO₂, from 1.24 to 5.28 μg CO₂-C/mg C_mic/g soil per h; and the C_mic/C_org, from 0.40 to 1.55%. Reliable positive correlations were found between the C_mic and BR, the C_mic and C_mic/C_org, and the C_mic and C_org values (r = 0.75, 0.95, and 0.61, respectively), as well as between the BR and C_mic/C_org values (r = 0.68). The correlation between the C_mic/C_org and qCO₂ values was negative (r = −0.70). The values of C_mic, BR, C_org, and C_mic/C_org were found to correlate with the ammonium nitrogen content. No correlative relationships were revealed between the determined indices and the climatic characteristics. The principal component analysis described 86% of the variances for all the experimental data and clearly subdivided the locations of the studied soil objects. The ANOVA showed that the variances of C_mic, C_org, and BR are controlled by the site location factor by 66, 63, and 35%, respectively. The specificity of the functioning of the anthropogenic soils as compared with their natural analogues was clearly demonstrated. As shown in this study, measurable biological indices might be applied to characterize the ecological, environmental-regulating, and productive functions of soils, including urban soils.     

Properties of soils and soil-like bodies in the Vorkuta area

The specific features of the formation of soils and soil-like bodies on technogenic substrates in Vorkuta—a polar city specializing in coal mining—are characterized. According to the new Russian soil classification system, these soils are classified as urbanozems (urban soils) and constructozems (soil-like bodies constructed by humans); the latter are subdivided into recreazems (soil-like bodies of recreation zones) and replantozems (soil-like bodies of reclaimed urban areas with planted vegetation). They are characterized by the increased content of heavy metals and by some alkalization of the upper soil horizons in comparison with the natural background soils. The benz(a)pyrene content in most of the soil samples exceeds the maximum permissible concentration (MPC). The maximum levels of the soil contamination with benz(a)pyrene reach 80 MPCs. According to the total contamination index calculated relative to the background concentrations of the major contaminants, the upper horizons of the investigated soils and soil-like bodies are qualified as ecologically hazardous and extremely hazardous bodies.     

Artificial soil-like bodies of a river valley and their evolution in an urban environment (Based on the example of the Moscow River valley)

Technogenic soil-like bodies and raw soils on technogenic sediments in the valley of the Moscow River in the city territory were investigated. Soil destruction and the accumulation of techogenic sediments, as well as their remediation, result in the formation of soil-like bodies called replantozems. Spontaneous overgrowth and the formation of raw soils that gradually evolve into mature urban soils result in soils called urbanozems. It is shown that the best foundation for replantozems in river valleys is in situ alluvium with relatively favorable physical and physical-chemical properties.     

Microbial biomass and biological activity of soils and soil-like bodies in coastal oases of Antarctica

The method of luminescent microscopy has been applied to study the structure of the microbial biomass of soils and soil-like bodies in East (the Thala Hills and Larsemann Hills oases) and West (Cape Burks, Hobbs coast) Antarctica. According to Soil Taxonomy, the studied soils mainly belong to the subgroups of Aquic Haploturbels, Typic Haploturbels, Typic Haplorthels, and Lithic Haplorthels. The major contribution to their microbial biomass belongs to fungi. The highest fungal biomass (up to 790 μg C/g soil) has been found in the soils with surface organic horizons in the form of thin moss/lichen litters, in which the development of fungal mycelium is most active. A larger part of fungal biomass (70–98%) is represented by spores. For the soils without vegetation cover, the accumulation of bacterial and fungal biomass takes place in the horizons under surface desert pavements. In the upper parts of the soils without vegetation cover and in the organic soil horizons, the major part (>60%) of fungal mycelium contains protective melanin pigments. Among bacteria, the high portion (up to 50%) of small filtering forms is observed. A considerable increase (up to 290.2 ± 27 μg C/g soil) in the fungal biomass owing to the development of yeasts has been shown for gley soils (gleyzems) developing from sapropel sediments under subaquatic conditions and for the algal–bacterial mat on the bottom of the lake (920.7 ± 46 μg C/g soil). The production of carbon dioxide by the soils varies from 0.47 to 2.34 μg C–CO₂/(g day). The intensity of nitrogen fixation in the studied samples is generally low: from 0.08 to 55.85 ng С₂Н₄/(g day). The intensity of denitrification varies from 0.09 to 19.28 μg N–N₂O/(g day).     

Heavy-metal ecology of terrestrial plants,microorganisms and invertebrates

Ecological and physiological effects of heavy metals on terrestrial organisms are reviewed, considering evidence from both laboratory and field studies. Problems concerning how to define heavy-metal exposure and to assess the sensitivity of field biota to heavy metals are discussed. Mechanisms of heavy-metal tolerance are considered including avoidance, exclusion, immobilization and excretion, as well biochemical mechanisms including enzymatic change. The taxonomy of heavy-metal tolerance and problems concerning tolerance and ecological performance are discussed briefly. Efforts are made to compare the relative sensitivity of various groups, including bacteria, fungi, bryophytes, lichens, vascular plants and soil invertebrates. An emphasis is placed on organisms of temperate forest ecosystems, particularly coniferous forests.     

Inclusion of soils and soil-like bodies of urban territories into the Russian soil classification system

The results of the Internet discussion on the classification of urban soils aimed at evaluating their possible inclusion into the modern Russian soil classification system adopted by a wide range of specialists are presented. The first step was to address the urban diagnostic horizons as the basis for identifying soil types according to the rules of the Russian soil classification. New diagnostic horizons were proposed for urban soils: urbic (UR), filled compost-mineral (RAT), and filled peat (RT). The combination of these horizons with other diagnostic horizons and layers of technogenic materials correspond to different soil types. At the subtype level, the diagnostic properties (qualifiers) that may reflect both natural phenomena (gley, alkalinity) and technogenic impacts on the soils (urbistratified; phosphatic; or poorly expressed urban—ur, rat, rt) are used. Some corrections were proposed for the system of parent materials in urban environments. Urban soils formerly described in another nomenclature—urbanozems, urbiquasizems, and culturozems—are correlated with the taxa in all the trunks of the system. The proposals accepted can be used for the next updated version of the new Russian soil classification system.     

Gravity factor of the formation of the field and capillary water capacities in soils and artificial layered soil-like bodies

The water retention capacity of soils characterizes a quasiequilibrium between the forces retaining and removing the soil water. It has been studied under field and laboratory conditions. It is shown that the gravity factor, as well as the soil particle-size distribution and structure, has an important role in determining the soil water capacity after the outflow of gravitational water. Our study enlarges the traditional notion about the nature of the field water capacity and capillary water capacity. Physically substantiated methods for determining these constants from the soil water retention curves are suggested. The assessment of the amount of perched water in the layers with broken capillary systems, such as in the layered soils and in the artificial soil-like bodies created upon the construction of soil drainage systems, is of particular importance. Regularities of the water retention capacity in such layered soils of different textures with inclusions of gravelly and peat layers have been analyzed. It is shown that the creation of layered soils with gravelly and peat layers may be an efficient method to rise the soil water retention capacity and protect the soil from secondary salinization.     

Spatial variability in the carbon of microbial biomass and microbial respiration in soils of the south of Moscow oblast

Soil samples from the upper 10-cm-thick layer of the humus horizon (without forest litter) were taken in Podol’sk and Serpukhov districts (1130 and 1080 km², respectively) of Moscow oblast. At each sampling site, ecosystem (forest, plowland, or fallow), soil (soddy-podzolic, soddy-gley, bog-podzolic, meadow alluvial, gray forest, and anthropogenically transformed soils of lawns and industrial zones), predominant vegetation, and topography (floodplain and low, medium, and upper parts of watersheds) were determined. The carbon content of the microbial biomass (C_mic) was determined by the method of substrate-induced respiration; we also determined the rate of basal (microbial) respiration (BR) and the organic carbon content, pH, and particle-size distribution. Overall, 237 samples from Serpukhov district and 45 samples from Podol’sk district were analyzed. The BR/C_mic ratios (respiration quotient qCO₂) and C_mic/C_org ratios were calculated. The C_mic content in the soils ranged from 43 to 1394 μg C/kg; the BR varied from 0.06 to 25 μg CO₂-C/g per h, qCO₂, from 0.34 to 6.52 μg CO₂-C/mg C_mic per h; and the C_mic/C_org ratio, from 0.19 to 10.65%. It was found that the most significant factors affecting the variability of the C_mic and BR are the parameters of ecosystem (50% and 80%, respectively) and soil (30% and 9%, respectively). The most significant variability of these indices was found in forest soils; it was mainly controlled by the soil texture (33 and 23%) and the C_org content (19 and 24%). The C_mic parameter made it possible to differentiate the soils of the territory for the purposes of their evaluation, monitoring, and biological assessment more clearly than the BR value and the soil chemical characteristics.     

Evolution of the soil cover of soccer fields

A soccer field can be considered a soil-like technogenic formation (STF). According to the theory of soil cover patterns, the artificially constructed (anthropogenic) soil cover of a soccer field is an analogue of a relatively homogeneous elementary soil area. However, the spatial homogeneity of the upper part (50–80 cm) of the STF of soccer fields is unstable and is subjected to gradual transformation under the impact of pedogenetic processes, agrotechnical loads, and mechanical loads during the games. This transformation is favored by the initial heterogeneity of the deep (buried) parts of the STF profile. The technogenic factors and elementary pedogenetic processes specify the dynamic functioning regime of the STF. In 50–75 years, the upper part of the STF is transformed into soil-like bodies with properties close to those in zonal soils. Certain micro- and nanopatterns of the soil cover are developed within the field creating its spatial heterogeneity.     

Assessment of soil quality in different ecosystems (with soils of Podolsk and Serpukhov districts of Moscow oblast as examples)

The values of the soil-ecological index and microbiological parameters (the carbon of microbial biomass C_mic, its ratio to the total organic carbon C_mic/C_org, and basal respiration) were determined for the soddy-podzolic, soddy-gley, bog-podzolic, meadow alluvial, and gray forest soils under different land uses (forest, fallow, cropland, and urban areas) in the Podolsk and Serpukhov districts of Moscow oblast (237 and 45 sampling points, respectively). The soil sampling from the upper 10 cm (without the litter horizon) was performed in September and October. To calculate the soil-ecological index, both soil (physicochemical and agrochemical) and climatic characteristics were taken into account. Its values for fallow, cropland, and urban ecosystems averaged 70.2, 72.8, and 64.2 points (n = 90, 17, and 24, respectively). For the soils of forest ecosystems, the average value of the soil-ecological index was lower (54.4; n = 151). At the same time, the micro-biological characteristics of the studied forest soils were generally higher than those in the soils of fallow, cropland, and urban ecosystems. In this context, to estimate the soil quality in different ecosystems on the basis of the soil-ecological index, the use of a correction coefficient for the biological properties of the soils (the C_mic content) was suggested. The ecological substantiation of this approach for assessing the quality of soils in different ecosystems is presented in the paper.     

Biomass and respiration activity of soil microorganisms in anthropogenically transformed ecosystems (Moscow region)

In the forest, meadow, arable, and urban ecosystems (recreational, residential, and industrial zones) of Sergiev Posad, Shatura, Serpukhov, and Serebryanye Prudy districts of Moscow region, spatially separated sites (3–5 points per site) have been randomly selected and soil samples have been taken from the 0–10 (plant litter excluded) and 10- to 150-cm layers (a total of 201 samples have been taken). In the samples, the microbial biomass carbon (C_mic), the rate of the basal (microbial) respiration (BR), and the physical parameters (the particle size distribution (PSD), organic carbon (C_org), pH, heavy metals, and nutrients (NPK)) have been determined. High spatial variability has been revealed for C_mic and BR in all the ecosystems and the functional zones of the studied districts, and a clear tendency of a decrease in these parameters has been shown in the arable soils (by 1.4–3.2 times) and the industrial zone (by 1.7–3.3 times) compared to the natural analogues and other corresponding functional zones. It has been shown that the spatial distribution of the microbiological parameters is significantly (p ≤ 0.05) affected by the physicochemical properties of the soil (C_mic by the PSD and PSD × C_org; BR by the pH and pH × NPK; contributions of 40 and 63%, respectively), as well as by the type of ecosystem and the region of study (the contribution of the sum of these factors to the C_mic and BR was 56 and 67%, respectively). A tendency toward the deterioration of the functioning of the microbial community under the anthropogenic transformation of the soil has been shown. The contribution of the urban soils as a potential source of CO₂ emission to the atmosphere has been calculated and discussed.     

The spatial-temporal dynamics of the structure of bacterial complexes on the Medvenka River floodplain (Moscow oblast)

The distribution of bacteria in separate tiers of the floodplain ecosystem was studied by the methods of direct luminescent microscopy and inoculation onto agar media. The maximum concentration of bacteria was determined in the litter horizon; the bacterial population gradually decreased in the phylloplane and in the soil horizons. The taxonomic structure of the bacterial complexes changed in the vertical direction (in separate tiers) and from season to season. The effect of the floodplain process was seen in the specific composition of bacterial communities in the lower soil horizons; the latter were enriched in the bacterial forms derived from the flood water (spirilla, slipping bacteria, and coryneform bacteria).     

长期施肥对植烟土壤微生物的影响

【目的】微生物是土壤的重要组成分,与土壤养分转化供应密切相关。本研究利用12年肥料定位试验研究了云南植烟土壤可培养微生物数量、微生物量碳氮、标记性磷脂脂肪酸（PLFAs）、微生物种群特征及有益微生物的变化。【方法】试验设置不施肥（CK）、单施化肥（CF）和化肥配施有机肥（CFM）处理,在烟株旺长期,采集020 cm耕作层土壤,测定了微生物量碳、氮含量,微生物标记磷脂脂肪酸（PLFAs）含量和可培养微生物数量;鉴定自生固氮菌、磷细菌和钾细菌的数量;根据PLFAs计算了微生物种群特征值。【结果】有机无机肥配施处理的土壤中,可培养细菌比不施肥土壤增加了6.14倍、 真菌增加了2.30倍、 放线菌增加了1.56倍,增幅显著高于化肥处理;施肥显著提高土壤微生物量碳、氮量。化肥和有机无机肥配合处理土壤的微生物量碳分别比CK增加了71.8%和246%;不同施肥处理土壤微生物量碳/氮比值显著不同,分别为14.8（CK）、13.3（CF）和11.2（CFM）。微生物标记性PLFAs含量以化肥有机肥配合处理最高,化肥处理次之,CK最低。化肥、化肥配施有机肥处理土壤细菌PLFAs比对照分别增加了25.41%和87.66%,真菌PLFAs分别增加了15.59%和39.24%,化肥处理代表放线菌的PLFAs降低了24.63%,化肥配施有机肥处理增加了83.86%,表明施肥尤其是化肥配施有机肥改善了土壤环境,促进了微生物的生长繁殖,并改变了土壤微生物种群结构;施肥处理土壤中微生物群落多样性指数上升,化肥处理还提高了微生物的优势度指数,说明施肥有益于增加微生物的种群数量, 化肥配施有机肥处理显著提高了无机磷细菌和钾细菌的数量,两者分别比对照增加了1.15倍和1.02倍,化肥处理则相反,自生固氮菌和无机磷细菌数量分别比CK降低了56.69%和41.30%;化肥配施有机肥处理土壤中的自生固氮菌、磷细菌和钾细菌共有20个属,CK土壤有19个属,化肥处理土壤仅16个属。 【结论】CFM促进微生物生长繁殖,增加种群多样性,有益于微生物固氮、溶磷、解钾,对于提高肥料利用率和保持土壤健康有重要意义。在烟叶栽培过程中,提倡化肥与有机肥配合施用很有必要。     

Carbon dioxide,methane, and nitrous oxide fluxes in soil catena across the right bank of the Oka River (Moscow oblast)

The flux rates of carbon dioxide, methane, and nitrous oxide in the soils on autonomous, transitional, transitional-accumulative, and accumulative positions of a catena on the Oka River’s right bank (Moscow oblast) were assessed using the chamber method. The lowest rate of C-CO₂ emission (18.8–29.8 mg/m² per hour) was found for the gray forest soil in the autonomous position, and the highest rate (52.4–66.1 mg/m² per hour) was found for the alluvial meadow soil of the accumulative landscape. In the summer, the uptake of methane from the atmosphere exceeded its release from the soil at all the points of the catena (9–38 μg/m² per hour). The highest rate of the C-CH₄ uptake was observed for the soil in the transitional position. In the fall, the soils in the autonomous, transitional, and transitional-accumulative positions served as a sink of C-CH₄, and the soil of the accumulative position was a source of methane emission. The rate of the N-N₂O emission from the catena soils increased when going from the autonomous position to the accumulative one (0.41–11.2 μg/m² per hour). The spatial variation of the C-CO₂, C-CH₄, and N-N₂O fluxes within the catena was 33, 172, and 138%, respectively. The upper (0- to 10-cm) soil layer made the major contribution to the emission of carbon dioxide. This soil layer was characterized by its C-CH₄ uptake, and the emission of methane was typical for the deeper (0- to 20-cm) layer. The layers deeper than 10 and 20 cm emitted more N-N₂O than the surface layer.     

Epibiotic microorganisms associated with microcrustaceans in overlying water of Philippine paddy fields

Epibiotic microorganisms associated with micro crustaceans in the overlying water of Philippine paddy fields were examined by scanning electron microscopy, and their associations were compared with those observed in Japanese paddy fields (Soil Sci. Plant Nutr., 43, 633-641, 651-664, 1997). Various types of microorganisms, including bacteria, protozoa, and algae, colonized microcrustaceans and their kinds and colonizing patterns varied depending on the kinds of microcrustaceans. Common associations between epibionts and respective micro crustaceans were observed in the Philippines and in Japan: e.g., rodshaped bacteria on Cyclopidae and Cypridopsidae; no microorganisms on Simocephalus spp.     

Selective phytoamelioration of soils in Kursk oblast

Data on zinc accumulation by saperda mustard and common barley grown on typical chernozem (Voronic Chernozems) and gray forest soil (Greyic Phaeozems Albic) in Kursk oblast are given. The revealed high phytoextraction capability of saperda mustard on gray forest soil depends on the content of total and available zinc. It has been found that the accumulation capability of common barley is similar on both soil types. The phytoextraction rate of the root systems of the studied plants is greater than that of their sprouts. Biological removal of zinc from soil by plants is up to 4.46 kg/ha. Saperda mustard and common barley are potential phytoremediation plants for zinc-contaminated gray forest soil and typical chernozem.     

Biofiltration of methane by soil and soil-like constructions and specifics of their functioning

Methane consumption in constructions is driven by its intense biofiltration which differs by seasons according to the general specifics of the functioning of methanotrophs. Three stages of methane biofiltration were identified—adaptation, optimum, and stress. It was established that methane biofiltration in soil construction is 1.5–2.0 times higher than in soil-like constructions. The biofiltration process under intense methane inflow leads to filtrate acidity increase; the Eh value drops in the summer period in constructions and grows during the winter season; a significant increase in microbial community stability is observed.     

Humic substances in agro-stratozems of Leningrad oblast

Chemical properties and some parameters of the humus status of agro-stratozems developed in Leningrad oblast from different parent materials and with different histories of agricultural use were studied. The stability of the elemental composition of humus in the studied soils was found. The group and fractional composition of humus was more sensitive to agricultural impacts. In response to the application of manure, lime, and mineral fertilizers, humate-fulvate humus changed into fulvate-humate humus and the content of the agronomically most valuable HA-2 fraction increased, in some cases, to predominance. Exclusion from land use for 15 years decreased the humus content and changed its composition; it became more similar to that in zonal soddy-podzolic soils, which are the natural analogues of the agro-stratozems studied.     

Fractional composition of lead compounds in soils of Moscow and Moscow region

Sequential fractionation of lead compounds from the urban and suburban soils of Moscow and eastern Moscow region was performed using the Tessier method. It was found that strongly bound lead compounds retained by Fe and Mn hydroxides were predominant in the background (reference) soils of the Meshchera Lowland in Moscow oblast. The content of almost all the lead fractions, except for the hydroxide fraction, increased in the contaminated soils. The quantitative proportions of the particulate fractions varied depending on the distance from the city, the physicochemical properties of the soils, and the land use. The profile distribution of the lead was of accumulative character; the metal was fixed on the biogeochemical barrier, where the lead compounds of the fourth fraction bound to organic matter are mainly accumulated.