N. D. Ananyeva’s research while affiliated with Russian Academy of Sciences and other places

The introduction of resource-saving technologies into the practice of agriculture is one of the approaches to preserving soil fertility and increasing the reserves of organic carbon (Сorg). One of such technologies is zero tillage, which has been actively used all over the world since the middle of the twentieth century. However, there is still insufficient information about the effectiveness of this technology for the accumulation and preservation of Сorg in the agro-soils of our country. The paper estimates the rate of accumulation of Сorg by agrochernozems with zero tillage in the conditions of the Middle Volga region. On the territory of agricultural farms (Pokhvistnevsky district of the Samara region), 2 agricultural fields with 5- and 8-year zero tillage (88 and 161 hа, respectively) and a field with non-fallow plowing (42 hа) were selected. 30 study points were selected in each field, from which soil samples of the upper (0–10 cm) and lower (10–30 cm) layers of humus-accumulative and partially illuvial horizons were selected. The paper presents the main physic-chemical parameters of the soil and calculated the reserves of Сorg. A significant increase in sorghum reserves in the upper soil layer was shown at 5- and 8-year zero tillage (on average by 0.57 and 0.45 kg/m2) compared with those during plowing, but no significant differences were found for the lower layer. The total sorghum reserves for the 0–30 cm soil layer at zero tillage increased by 0.61 and 0.34 kg/m2 relative to those during plowing. Consequently, as a result of the application of zero processing, the rate of accumulation of Сorg reserves in the agrochernozems of the Middle Volga region can reach 1.22 and 0.43 t/ha per year, which is 1.3–41 times more than the recommended program “4 ppm” for agricultural lands of our country (from 0.03 to 0.33 t/ha per year).

In six forest parks of Moscow and four suburban forests (5 plots each, n = 50), soil physical, chemical, and microbial properties of the upper 10-cm layer were assessed in combination with vegetation properties. The contents of carbon (C), nitrogen (N), and phosphorus (P) in soil and microbial biomass were determined. It was revealed that soil bulk density; pH value; and contents of N-NO3–,Ca, and heavy metals (Pb, Cu, Ni, Zn) increase in forest parks of Moscow in comparison with those in suburban forests. In the soils of forest parks, a decrease in the microbial biomass C (Cmic) content, basal respiration (BR), and microbial C and N availability (Cmic/C, Nmic/N, BR/C) took place. The changes in soil microbial properties were mainly driven by the decrease in abundance of leaf litter and the available soil C content (13–35% of the explained variance). The microbial response of soil microorganisms to input of low molecular weight organic substrates (carbohydrates, carboxylic and phenolic acids, amino acids, amino sugars) in forest parks and suburban forests did not differ significantly. In the soils of forest parks, no changes in microbial mineralization and immobilization of P (Pmic, Pmic/P) were found. The impact of urbanization on the forest ecosystems led mainly to a decrease in the intensity of soil C and N cycles. Apparently, these changes were caused by the recreational activity and management practices applied to green spaces in the city, which led, in particular, to a decrease in the amount of forest litter in urban parks compared to suburban forests.

In six forest parks of Moscow and four rural forests (5 plots each, n = 50), soil physical, chemical and microbial properties of the upper 10 cm layer were assessed in combination to vegetation properties. The content of carbon (C), nitrogen (N), and phosphorus (P) in soil and microbial biomass was determined. It was revealed that soil density, pH value, content of N–${\text{NO}}_{3}^{ - },$ Ca and heavy metals (Pb, Cu, Ni, Zn) increase in forest parks compared to rural forests. In the soil of the forest parks, a decrease in the content of microbial biomass C (Cmic), its basal respiration (BR), and microbial C- and N-availability (Cmic/C, Nmic/N, BR/C) was noted. The changes of soil microbial properties are mainly driven by the abundance of leaf litter and the content of available soil C (13–35% of the explained variance). The microbial response to the soil enrichment by low molecular weight organic substrates (carbohydrates, carboxylic and phenolic acids, amino acids, amino sugars) in forest parks and rural forests did not differ significantly. In the soils of forest parks, no changes in microbial mineralization and immobilization of P (Pmic, Pmic/P) were found as well. The impact of urbanization on the forest ecosystems has led mainly to a decrease in the intensity of processes associated with soil C and N cycles. Apparently, such changes are caused by the recreational activity and the management practice of green spaces in the city, which leads, in particular, to a decrease in the amount of forest litter in parks compared to rural forests.

Quantifying response of the soil heterotrophic and autotrophic respiration (RH and RA) to environmental changes is necessary to improve the carbon cycle models of terrestrial ecosystems. Using substrate-induced respiration (SIR) technique, we separated soil respiration (RS) into RH and RA components in subtaiga (mixed forest, meadow) and forest-steppe (broad-leaved forest, steppe) ecosystems of European Russia during the growing season of 2015 (May–October). The RH and RA rates varied 35–200 and 19–534 mg C m–2 h–1 for the subtaiga, 29–216 and 10–227 mg C m–2 h–1 for the forest-steppe. In both vegetation zones, the season average RH was the dominant component of RS in the forests (60–79%), while its contribution in the grasslands was close to 50%. Both RH and RA variations in the forest-steppe ecosystems were better predicted by soil temperature than in the subtaiga ones (R2 = 0.89 vs. R2 = 0.09–0.61). The RA component for the growing season generally exhibited a higher temperature sensitivity than RH. Soil water content significantly affected either RH or RA of the forests, while this relation was not found in the grasslands. The SIR technique showed the RH and RA contributions into RS, the values of which coincide with those of other studies. Using this technique for the dry soil might result in the overestimation of RH and RA.

An altitudinal gradient in the mountains constitutes a unique ‘open-lab’ to examine environmental hypotheses and analyse the expected effects of global warming. The distribution of carbon (C)-, nitrogen (N)-, and phosphorus (P)-acquiring enzyme activity, microbial catabolic activity as represented by a community-level physiological profile (CLPP), and microbial functional diversity (HCLPP) within mountainous ecosystems consisting of mixed, fir and deciduous forests, as well as subalpine and alpine meadows (1260–2480 m a.s.l., Mt. Tkachiha, the Northwest Caucasus, Russia) has been studied. Concerning potential drivers, vegetation (plant projective cover, plant functional group composition, plant richness and diversity) and edaphic (soil nutrients: total and available C and N, total P, pH, texture, temperature, microbial biomass C) and topographic (elevation, slope, mean annual temperature calculated using biannual monitoring data) properties have been considered. The distribution patterns of the studied hydrolytic enzymes along an altitudinal gradient cannot be explained solely by elevation change and soil nutrient content. The activity of soil leucine aminopeptidase depends on vegetation type and graminoid abundance. β-D-glucosidase activity was mainly driven by the quality of soil organic matter (SOM), demonstrating a significant relation with the soil C:N ratio. The chitinase and phosphatase turned out soil temperature-sensitive enzymes. The CLPP depends on the available N content in the soil. The HCLPP distribution with altitude was driven by available N and forbs abundance represented by the widest spectrum of plant families and species. An altitudinal gradient determines the spread of the vegetation zone. In turn, vegetation properties, such as plant functional group composition, species richness and diversity, play a significant role in the distribution of soil microbial activity along an altitudinal gradient that controls the decomposition of SOM and nutrient cycling. Thus, the significant role of vegetation in the distribution of soil microbial activity across a wide range of natural ecosystems and in consideration of topographic and edaphic factors has been demonstrated.

Urbanization results to a wide spread of Technosols. Various materials are used for Technosols’ construction with a limited attention to their ecosystem services or disservices. The research focuses on the integral assessment of soil-like materials used for Technosols’ construction in Moscow megalopolis from the ecosystem services’ perspective. Four groups of materials (valley peats, sediments, cultural layers, and commercial manufactured soil mixtures) were assessed based on the indicators, which are integral, informative, and cost-effective. Microbial respiration, C-availability, specific respiration, community level physiological profile, and Shannon’ diversity index in the materials were compared to the natural reference to assess and rank the ecosystem services and disservices. The assessment showed that sediments and low-peat mixtures (≤30% of peat in total volume) had a considerably higher capacity to provide C-sequestration, climate regulation and functional diversity services compared to peats and high-peat mixtures. Urban cultural layers provided ecosystem disservices due to pollution by potentially toxic elements and health risks from the pathogenic fungi. Mixtures comprising from the sediments with minor (≤30%) peat addition would have a high potential to increase C-sequestration and to enrich microbial functional diversity. Their implementation in urban landscaping will reduce management costs and increase sustainability of urban soils and ecosystem.

In mountain areas, one of the noticeable results of modern climate change is rapid shift of treelines to subalpine and alpine meadows. Such vegetation shifts is associated with a change in quality of the plant residues entering the soils, which in turn can affect the mineralization activity (basal respiration) and functional diversity of the soil microbial community. Therefore, the study was aimed at assessing the soil microbial (basal respiration and functional diversity) and chemical (C, N, C/N, pH) properties (0-10 cm) along the reserved and grazed forest-meadow transects of the Northwestern Caucasus (Karachay-Cherkess Republic), as well as evaluating an effect of vegetation type and land use on variation of these soil properties. It was found that the C and N contents (for both land usees), pH and basal respiration (reserved slope) significantly increase from forest to meadow soils. In contrary, the microbial functional diversity decreased from forest to meadow soils, which might be due to less diverse organic compounds entering the soil only with grass residues than their combination with forest litter. Two-way ANOVA showed that soil microbial functional diversity, pH, C and N along the studied forest-meadow transects was mostly associated with vegetation type (1439 % of the explained variation), and C/N and basal respiration - with land use (3336 % of the explained variation). Thus, a land use change will have a more significant effect on the mineralization activity of soil microbial community than a treeline shifts.

An important element of the urban environment is soil, the balanced functioning of which largely depends on the soil microbiome. The state of the microbiome can be identified by different microbial indicators. However, there is still no answer to the question: which microbial indicators can most informatively reflect the functioning of urban soils and be useful in planning and landscaping urban areas? Databases eLibrar-y.ru, Web of Science, and Scopus were used to collect Russian and foreign papers published in the past 25 years on the study of the soil microbial properties in different cities of the world. It is revealed that the main attention in the study of urban soils is directed to the assessment of the microbial taxonomic structure, its gases’ production and enzymatic activities, the content of microbial biomass, its ecophysiological status, microbial functional diversity, cell morphology, and the presence of pathogenic and opportunistic microorganisms. The criteria of various microbial indicators (reproducibility, selectivity, cost, standardization, interpretation and understanding, recognition by the scientific community) are proposed to illustrate their acceptability and informative value for assessing the functions of urban soils and ecosystem services. The highest correspondence with such criteria was found for the soil microbial activity and the ecophysiological status, and the lowest belongs to the abundance of functional genes and “key groups” of microorganisms. The necessity of studying the relationship of the taxonomic diversity of the microbiome of urban soils with their main functions and the interpretation of experimental results in terms of ecosystem services is justified.