Ecotoxicity of dust was assessed for different functional zones in three Moscow districts. Ecotoxicity was estimated by the reaction of higher plants using a new approach to the implementation of biotesting method and by changes in the biomass and respiration of microorganisms in residential and transport zones as compared to recreational zones. The proposed method of assessing urban dust toxicity upon modeling dust transfer to soil-like substrates allowed us to solve the main methodological problem, i.e., the choice of control. By the example of perennial ryegrass (Lollium perenne L.), it was found out that annual volume of dust deposition upon a high load within a one-meter zone from the road surface does not manifest toxicity, whereas a three-year volume suppresses plants up to 27

Microbial production and CO2 emissions were studied in Albic Retisol (Loamic) and Albic Retisol (Aric, Loamic) of the Chashnikovo carbon polygon (Moscow oblast) of Lomonosov Moscow State University at the peak of vegetation activity. The objects were monitoring sites in two natural ecosystems (secondary spruce forest and mixed-grass meadow) and two agroecosystems (perennial grasses and bare fallow). The soils differed in the carbon stocks of organic matter (Corg), microbial carbon (Cmic), and potentially mineralizable carbon (Cpm). The highest values of microbial indicators and carbon content were observed in the upper 30 cm, with a maximum in the upper 10 cm. Corg stocks in the 0- to 30-cm layer were 1.1–1.3 times higher in agrosoils (72.7–75.6 t ha–1) than in natural soils (59.4–65.0 t ha–1) due to the difference in soil density. The contribution of the Cmic stock to the Corg stock in meadow soils and agrosoils covered by perennial grasses (1.8 and 1.4

Цель работы заключалась в поиске солеустойчивой культуры высших растений для измерения токсичности водных вытяжек из твердых материалов (почвы, отходы и др.), а также для вод на фоне среднего уровня солености. В экспериментах с модельными водно-солевыми растворами исследовали пять видов культурных растений (тест-культур) из классов двудольных (горчица белая, люцерна изменчивая) и однодольных (житняк гребневидный, ячмень яровой и овес посевной) с помощью планшетной системы «Фитоскан». На основании сравнения чувствительности ростовых тест-откликов (длина корней, длина ростков и энергия прорастания) к повышенному солесодержанию (1–6 г/дм3) сделан вывод о наибольшей пригодности горчицы белой (Sinapis alba L.) для измерений токсичности среднеминерализованных водных сред, отходов и водных экстрактов засоленных почв. Результаты исследования составили основу новой методики измерения токсичности по изменению длины корней S. alba. The purpose of the work was to search for a salt-tolerant culture of higher plants to measure the toxicity of aqueous extracts from solid materials (soil, waste, etc.), as well as for waters at an average level of salinity. In experiments with model water-salt solutions, fi ve plant species (test crops) from the classes of dicotyledons (Sinapis alba, Medicago polymorpha) and monocotyledons (Agropyron cristatum, Hordeum vulgare and Avena sativa)) were studied using the «Fitoscan» tablet system. Based on a comparison of the sensitivity of growth test responses (root length, sprout length and germination energy) to increased salinity (1–6 g/dm3), it was concluded that white mustard (Sinapis alba) is most suitable for measuring the toxicity of medium-mineralized aquatic environments and waste and aqueous extracts of saline soils.

There are only few studies in the world on ecotoxicity of urban dust as its ability to cause adverse effects to living organisms. The aim of the research is to assess the ecotoxicity of dust by the reaction of higher plants using a new approach, as well as to analyze the differentiation of microbial reaction on dust from recreational, residential and transport functional areas of three Moscow districts. The proposed approach of the urban dust ecotoxicity assessment by the modeling of dust transfer on urban soils proved its consistency and resolved the main methodological difficulty of biotesting – the issue of control choosing. Applying ryegrass (Lollium perenne L.), it was found that the annual volume of dust deposition on soils in Moscow does not perform toxicity, while a three-year volume suppresses plants up to 27% relative to the control. No significant differences between the phytotoxicity of dust in different functional areas was found, and phytotoxicity did not correlate with any of the studied properties of dust (organic carbon content, pH, electrical conductivity, moisture capacity, particle size distribution). In contrast to plants, the parameters of the vital activity of microorganisms in dust revealed differences between functional areas. Basal respiration and microbial dust biomass were maximal in the recreational areas of the city (3.1–7.2 μg C–CO₂g–1 h–1 and 314–435 μg g–1 respectively), decreasing by 27–71% in residential and 76–81% in the transport ones. Significant correlations of basal respiration and microbial biomass with organic carbon content were observed.

Application of mineral fertilizers to regulate microbial respiration and carbon dioxide emissions from urban lawn soils was evaluated due to the need to develop technologies for reducing CO 2 emissions and for increasing the C-absorption capacity of natural and anthropogenic ecosystems. The studies were performed in the Botanical Garden of Moscow State University on Leninskie Hills in a small-plot experiment with the fractional application of four types of complex fertilizers (NPKS 27 : 6 : 6 : 2, NPKS 21 : 10 : 10 : 2, NPK 15 : 15 : 15 and NPK 18:18:18 + 3 MgO + trace elements (TE)) at the doses of 60 and 120 kg N/ha during the growing season. We studied the basal respiration (BR) of soils, carbon content of microbial biomass (C mic ) by substrate-induced respiration, and the CO 2 emission from soils by the method of closed static chambers. C mic in soil of the control plot in the summer period was 1300–1450 µg/g. Application of NPKS 21 : 10 : 10 : 2 and NPK 18 : 18 : 18 + 3 MgO + TE at a low dose increased C mic by 12–35% within the first two weeks, and then it dropped. All types of fertilizers applied for a short period of time increased BR of soils and CO 2 emission maximum on the sixth day. After two weeks and onwards, their growth decreased or their intensity dropped to the control values (500 mg CO 2 m 2 /h –1 and 1.5 μg C–CO 2 g/h, respectively) and lower. The lowest intensity of CO 2 emission, a rise in basal respiration, and an increase in microbial biomass were recorded after the application of fertilizer NPKS 21 : 10 : 10 : 2. The change in the functioning of the soil microbial community detected by the maximal q CO 2 was the greatest in case of NPKS 27 : 6 : 6 : 2 application. The dynamics of CO 2 emission from the soils of the small-plot experiment from April to October correlated with the soil temperature ( r S = 0.66, p < 0.05, n = 135). Emissions of CO 2 were minimal for the plot with NPKS 21 : 10 : 10 : 2 in all periods of the study.

The methodology for biodiagnostics of the ecological state of soils and other environmental objects involves the use of two approaches: bioindicative observations in situ and biotesting of samples, carried out according to standard methods in controlled laboratory conditions ex situ. An integrated assessment of soils based on an interdisciplinary approach in accordance with the international standard ISO19204-2017 makes it possible to diagnose of the “health” of soils based on biotic parameters in the course of observations of the natural environment and ecotoxicity indicators, which are supplemented by the results of quantitative che-mical analysis (TRIAD methodology). For soils, indicators of the state of higher plants and microbial communities, especially in agroecosystems, are of paramount importance. This article analyzes the advantages and limitations of well-known methods of phytoindication, laboratory phytotesting, soil respiration, structural and functional indicators of microbiota diversity, and bacterial biosensors. The responses of living systems to the same pollutant content largely depend on the carbon content of organic matter. The existing regulatory framework for the ecological assessment of the biological state of soil ecosystems practically does not take into account this, as well as the level of mineralization and pH of the analyzed objects. For an adequate assessment of the ecological quality of soils, it is proposed to improve the methods of measuring toxicity by more targeted recommendations for application (for example, for certain gradations of humus content, mineralization, and pH).

The regularities and factors of methane and carbon dioxide emission from soils were investigated in the settlement of Kommunarka (New Moscow) in the areas built up in 1938–2014 and in the recreational zone. It has been shown that the intensity of the formation and oxidation of methane and, as a consequence, the content of this gas in soils and emissions into the atmosphere, depend on the time of creation of Urbic Technosols (Folinovic) and on the age of other urban soils. In summer, the emission of methane from soils of the residential zone was absent according to median values or did not exceed 0.01 mg CH 4 m –2 h –1 . Methane was absorbed from the atmosphere. However, local CH 4 emission from some soils was observed. During the period with sufficient moisture, maximal emission from the youngest Urbic Technosols (Folinovic) reached 5.25 mg CH 4 m –2 h –1 and decreased by an order of magnitude from soils near houses built in 2001 and older. During the dry period, the local emission from young Urbic Technosols (Folinovic) was only 0.03 mg CH 4 m –2 h –1 and decreased three times near houses built in 1938. Waterlogged urban soils, containing household waste, were the most dangerous source of methane to the atmosphere. The maximal CH 4 emission from them was 57.15 mg CH 4 m –2 h –1 . The content of carbon dioxide in the technogenic horizons of Urbic Technosols (Folinovic) and Urbic Technosol (Someriumbric) decreased contrary to the building age. The carbon dioxide emission depended more slightly on the period of soil formation as compared to methane. Nevertheless, the CO 2 emission under conditions of sufficient humidification was maximal from young Urbic Technosols (Folinovic) (to 3606 mg CO 2 m –2 h –1 ). Under conditions of insufficient moisture, the CO 2 emission was maximal from soils of older microdistricts (to 664 mg CO 2 m –2 h –1 ) and from Folic Gleyic Fluvisol (to 1901 mg CO 2 m –2 h –1 ).

Bioassay is a popular method for assessing the ecotoxicological state of different components of urban ecosystems: soils, water bodies, and air. However, little is known about the potential of bioassay application to determine the ecotoxicity of urban dust, which is a complex heterogeneous medium composed of natural and technogenic particles. Many components of urban dust are known to have toxic effects on living organisms. The purpose of this paper is to review the existing practices for assessing the ecotoxicity of urban dust and identifying the key trends in the development of the bioassay method. Analysis of the existing studies has revealed a high potential of bioassay methods, since they are sensitive to a wide range of pollutants that are contained in dust and can selectively reflect dust toxicity depending on environmental factors and be implemented using organisms of different trophic levels. The following dust characteristics should be taken into account for proper choice of the bioassay method: sample weight, wettability, pH, and content of water-soluble ions and organic matter. Due to the complexity of the composition of urban dust and different potentials for the transition of its components into water extracts, it is recommended to prioritize contact bioassay based on solid dust substrates instead of extracts. For comprehensive assessment of dust impact on an urban ecosystem, it is reasonable to test a set of organisms of different trophic levels. Standards should be developed for dust bioassay to unify the results of different studies. One of the most important methodological questions is the choice of the control sample.

The response of the microbial community (microbial biomass carbon (Cmic), basal respiration (BR), and functional diversity (FD)) of agrosoddy-podzolic soil (Albic Glossic Retisols (Loamic, Aric Cutanic, Ochric)) to pollution by heavy metals (HMs: Cu 660, Zn 1100, Pb 650 mg/kg) and carbon-containing preparations (5% of biochar and 0.25% of lignohumate) was studied in model experiment (30 days). Soils with different organic carbon contents (Corg 3.86 and 1.30%) were sampled at two sites (Chashnikovo, Moscow oblast). We determined Cmic by the substrate-induced respiration method and FD by multisubstrate testing (47 substrates). It was found that HMs application reduced Cmic on average by 49–57%, BR by 23–52%, and FD by 45%, but, on the contrary, increased the microbial metabolic quotient (qCO2 = BR/Cmic) by 9–46%. The changes of these properties were most significant in the soil with low Corg content (1.30%). Carbon-containing preparations did not contribute to variations in Cmic, BR, and qCO2 in both soils with HMs, but increased their FD. It is concluded that the studied microbiological parameters may be used as indicators for optimal assessment of soil quality: FD and Cmic are the more sensitive to HMs than BR and qCO2.

Статья посвящена актуальным вопросам эмиссии парниковых газов в атмосферу в городской среде и выявлению роли почв в регулировании этого процесса. Исследовано три типа потенциально газогенерирующих объектов: территории над погребенными стихийными свалочными телами, участки строительства на засыпанной переувлажненной речной пойме и рекультивированные поля фильтрации сточных вод. На каждом объекте определялись типы доминирующих почв, их физические, химические свойства, способность образовывать и окислять метан, продуцировать углекислый газ. Показано, что более развитые урбисерогумусовые техногенные почвы и урбаноземы техногенные, а также созданные в ходе благоустройства реплантоземы более эффективно утилизируют аллохтонные потоки метана, чем литостраты, органолитостраты и слаборазвитые почвы. Эмиссии метана в атмосферу из первой группы почв не наблюдается, но они служат более мощным источником углекислого газа в атмосферу по сравнению с литостратами и органолитостратами. Запечатывание, переуплотнение, засоление, подтопление городских почв снижают их окислительную способность и повышают вероятность эмиссии метана в атмосферу.В связи с ростом индустриализации города приобретают больший вес в естественном круговороте веществ в природе. Города являются источниками парниковых газов, выделяемых промышленностью, автотранспортом, полигонами ТБО, а также городскими почвами. В связи с увеличением плотности населения застраивается все больше территорий с неблагоприятными свойствами: переувлажненные поймы рек, засыпанные овраги и балки, погребенные несанкционированные свалки, рекультивированные поля фильтрации. Городские почвы над такими территориями являются источником и стоком метана и углекислого газа. Данное исследование важно для понимания вклада городских почв в выбросы парниковых газов в атмосферу. Полученные результаты могут быть задействованы при разработке более рациональных рекомендаций по рекультивации потенциально опасных в газогеохимическом отношении территорий, используемых под строительство.

93 Effects of lignohumate and biochar on microbial communities in agricultural soils differing in organic matter content Terekhova V.A., Fedoseeva E., Pukalchik M.A., Ivanova A.E., Verkhovtseva N.V., Pozdnyakov L.А., Kulachkova S.A., Gorlenko M.V., Karpukhin M.M., Yakimenko O.S. Lomonosov Moscow State University, Moscow, Russia, vterekhova@gmail.com Severtsov Institute of Ecology and Evolution, Moscow, Russia Pirogov Russian National Research Medical University, Moscow, Russia Skolkovo Institute of Science and Technology, Moscow, Russia

The purpose of this research was to study the generation, sink, and emission of greenhouse gases by soils on technogenic parent materials, created at different stages of the Moskva River floodplain development (1—construction and 2—landscaping of residential areas). Field surveys revealed the spatial trends of concentration and emission of the greenhouse gases in following groups of soils: Retisols (RT-ab-ct) and Fluvisols (FL-hu, FL-hi.gl) before land engineering preparation for the construction, Urbic Technosols Transportic (TC-ub-ar.tn and TC-ub-hu.tn) at stage 1 and Urbic Technosols Folic (TC-ub-fo) at stage 2. CO2 and CH4 concentration in soils and their emission were determined using subsurface soil air equilibration tubes and the closed chamber method, respectively. Bacterial methane generation rate (MGR) and methane oxidation rate (MOR) were measured by kinetic methods. In natural soils MOR is caused only by intra-aggregate methanogenesis. The imbalance of methane generation and oxidation was observed in FL-hi.gl. It caused CH4 accumulation in the profile (7.5 ppm) and its emission to the atmosphere (0.11 mg CH4 m−2 h−1). RT-ab-ct acted as the sink of atmospheric methane. CO2 emission was 265.1 ± 24.0 and 151.9 ± 37.2 mg CO2 m−2 h−1 from RT-ab-ct and FL-hi.gl, respectively. In Technosols CH4 concentration was predominantly low (median was 2.7, 2.9, and 3.0 ppm, in TC-ub-ar.tn, TC-ub-hu.tn, and TC-ub-fo, respectively), but due to the occurrence of peat sediments under technogenic material, it increased to 1–2%. Methane emission was not observed due to functioning of biogeochemical barriers with high MOR. In TC-ub-ar.tn and TC-ub-hu.tn, the barriers were formed at 60-cm depth. In TC-ub-fo, the system of barriers was formed in Folic and Technic horizons (at 10- and 60-cm depth). CO2 emission was 2 times lower from TC-ub-ar.tn and TC-ub-hu.tn and 1.5 times higher from TC-ub-fo than from natural soils. Greenhouse gas generation, sink, and emission by natural soils and Technosols in floodplain were estimated. CO2 and CH4 content in Technosols varied depending on the properties of parent materials. Technosols at stage 1 did not emit CH4 due to formation of biogeochemical barriers—soil layers of high CH4 utilization rates. Urbic Technosols (Folic) at stage 2 performed as a source of significant CO2 emission.

The first inventory and zoning of the emission and sink of methane and carbon dioxide in the urban structure of greenhouse gases from soils and surface technogenic formations (STFs) (Technosols) on technogenic, recrementogenic, and natural sediments have been performed with consideration for the global warming potential under conditions of different formation rate of these gases, underflooding, and sealing. From gas geochemical criteria and anthropogenic pedogenesis features, the main sources of greenhouse gases, their intensity, and mass emission were revealed. The mass fractions of emissions from the sectors of waste and land use in the inventories of greenhouse gas emissions have been determined. New sources of gas emission have been revealed in the first sector, the emissions from which add tens of percent to the literature and state reports. In the second sector, emissions exceed the available data in 70 times. Estimation criteria based on the degree of manifestation and chemical composition of soil-geochemical anomalies and barrier capacities have been proposed. The sink of greenhouse gases from the atmosphere and the internal (latent) sink of methane in soils and STFs have been determined. Ecological functions of soils and STFs have been shown, and the share of latent methane sink has been calculated. The bacterial oxidation of methane in soils and STFs exceeds its emission to the atmosphere in almost hundred times.

Intensive urbanization leads to the use of ecologically unfavorable areas for construction. Expensive remediation may not produce the desired results. Risks of boundary ecosystems include pollution, reducing biodiversity, and human health deterioration remains. This applies to the reclaimed sewage filtration fields. The main factor of their environmental hazard before remediation is the sludge rich in organic matter whose decomposition under reducing conditions leads to methane and carbon dioxide accumulation in soils and emission to the atmosphere.

Methane biofiltration is based on gas transformation to carbon dioxide and water by methanotrophic microorganisms. Biofilter performance has been thoroughly investigated under climatic conditions of Western Europe, but not those of Russia. Therefore, this study was conducted to analyze methane biotransformation performance of soil and soil-like biofilters in Moscow.