Articles

The features of vegetation and terrestrial detritus within the boundaries of the Chashnikovo UOPEC in the upper reaches of the Klyazma River have been studied, theses ecosystems corresponding with coniferous-deciduous forests conditions. Based on the ecological scales of L.G. Ramensky and E. Landolt, as well as the ecological-cenotic classification of A.A. Nitsenko, a grouping of terrestrial ecosystems differing in trophic and humidification levels was obtained by the method of main components. Within the studied territory, based on the ecological and cenotic structure of living ground cover, three groups of phytocenoses were identified — moderately wet forest phytocenoses with a predominance of spruce, wet forests with a predominance of small–leaved species, as well as phytocenoses of dryland and floodplain meadows. For all sampling points, the classification and stocks of litter, as well as their spatial distribution within the phytocenosis, were assessed. The studied ecosystems vary significantly in litter stocks from high values in the tree trunk spaces of spruce forests – about 5 kgm-2 – to extremely low values – less than 0.5 kgm-2 — in upland and floodplain meadows, which determines the high heterogeneity of potential carbon accumulation within the territory. The typological affiliation of litter is interconnected with stocks only at the biogeocenotic level in relation to spruce forests, but this pattern does not work at a higher level when considering ecosystems at the landscape level.

Approximately one third of the scientific publications dedicated to digital soil mapping includes morphometric variables as predictors for soil cover models. For each specific territory with its own set of specific landforms, a unique set of significant morphometric variables is needed to describe the features of such a complex system as soil cover, selected directly with the research tasks. Thus, the aim of this research is to find relationships between soils taxa as vell as its morphological features determining soil diagnostic at different taxonomic levels, and morphometric variables in the case study for the farmlands soil cover on the left bank of the Don River in the Voronezh region, Liskinsky district. Soil cover consists not only of bleached, leached, and typical chernozems, but also chernozem-like meadow soil. Methods of parametric and nonparametric statistics confirm that the most important morphometric variables influencing all analyzed soil properties with diagnostic importance for determining soil allocations are  catchment area, vertical curvature and minimum curvature. The largest number of correlations between morphometric variables and soil properties occurs at maximum level of model generalization in the range of 17 m, 51 m, 102 m, 306 m.

The article analyses the historical development of ecotoxicology as a young interdisciplinary branch of environmental sciences that uses the entire arsenal of knowledge of natural and exact sciences to create its theoretical framework, terms, tasks, and research methods. The paper describes the achievements, current trends and actual directions of development of ecotoxicology considering their theoretical and practical significance. Nowadays ecotoxicology has formed a set of data on effects and behaviors of ecotoxicants in populations and communities of terrestrial and aquatic ecosystems. This set of data is at the heart of the theoretical foundation of the doctrine on functioning of biosystems under ecotoxicological stress, assessment of systems conditions by bioindication and bioassay techniques, approaches to develop of ecotoxicants regulation within the framework of the concept of acceptable environmental impact on ecosystems. Special attention is paid to multi-vector nature of ecotoxicological research, its cooperation with other areas of science and technology and contribution to the solution of environmental, economic and political challenges of our time.

The features of soil and hydrological conditions of the solonetzic complex of the semi-desert of the Northern Caspian region, a long-standing object at 70-year monitoring of their natural and anthropogenic transformations, were studied at the Dzhanybek Research Station of the Institute of Forest Science of the Russian Academy of Sciences. The classical works of Professor A.A. Rode  and the research led by Professor T.A. Sokolova  became the standard for comparison when conducting it at the present stage. The soils of virgin areas and meadow-chestnut soils of micro- and mesorelief depressions under separated forest stand and massive forest plantation, mainly of pedunculate oak and squat elm, were studied. The data of weather and climatic conditions were analyzed, the coefficient of humidification of the territory was calculated, the dynamics of groundwater levels, their chemical composition and mineralization were traced, the composition of water extract from soils was determined and supplies of easily soluble salts and chlorine ion by half-meter layers were calculated. Three significantly different periods of changes in soil and hydrological conditions caused by fluctuations of the groundwater table and changes in moisture content in the region have been identified. The modern stage, which began in the early 2000s, turned out to be the driest with a moisture coefficient of 0.24±0.07. Against this background, the rise of the groundwater level characteristic of the early 80s of the XXth century was replaced by its lowering. Under meadow-chestnut soils of virgin depressions at a groundwater level of 5.6±0.2 m and their average mineralization of 3.41±0.27 gl-1, at the present stage, the previously appeared tendency of their salinization has been preserved due to the accumulation of Cl-, Ca2+, Na+ ions in them. In the depressions of the micro- and mesorelief under the separated and massive forest stands, there is an increase in groundwater mineralization caused by high evapotranspiration of the trees, but due to the additional accumulation of snow by forest strips and the periodically flushing type of water regime with limited desuction, a root-accessible desalinated zone with a thickness of 350 and 250 cm, respectively, persists there now. The revealed patterns, covering a 70-year period of observations, allow a more reasonable approach to the creation of demanded landscaping in such unfavorable climatic conditions.

Anthropogenic factors of soil acidification/alkalinization change the natural protolytic balance of soils. The degree and direction of such changes are determined by the magnitude of the acid/alkaline load and soil stability - acid-base buffering capacity. The article summarizes the results of a study of the sources of buffering capacity of taiga soils in the European north-east of Russia. It is shown that the buffering capacity of soils developing in the same climatic conditions, as well as similar in lithological features, depends on the hydrological conditions of the microrelief elements, and accordingly on the composition and functioning of biocenoses. The variability of the nature and structure of soil buffering is revealed in the thickness of the most active action of biotic factors - in organogenic and eluvial horizons. The similarity of illuvial horizons of genetically different and geographically isolated soils is due to their insignificant transformation by soil processes, which is manifested in the absence or reduced content of direct products of soil formation - organic, Al-, Fe-organic compounds, minerals of the soil chlorite group. The materials can be used for soil-chemical monitoring and for predicting soil changes under the influence of pollution by acidic and alkaline compounds.

The article is dedicated to the blessed memory of the outstanding scientist, teacher-mentor, professor, doctor of biological sciences Tatyana Alekseevna Sokolova. The scientific community knows and will always remember Tatyana Alekseevna as an authoritative specialist in the field of soil science and mineralogy. The scope of her interests in the scientific and educational system is wide and diverse. One of the fundamental areas of work is the problems of soil acidity. The presented material contains some components of the creative heritage of T.A. Sokolova in the aspect of current research and prospects for its development. In particular, attention is drawn to the nature of the acidity of highly acidic soils (pHKCl <3.3, pHH2O <4.4). The specificity of the formation of the acid-base state of these objects is shown using soils of different genesis as an example. The reasons for the low accuracy and reproducibility of the results of measuring the exchangeable acidity of highly acidic soils are revealed. Recommendations for improving the quality of measurements are given.

We tracked the effect and two-year aftereffect of potassium fertilizers with a single application under beet in rates of 70-240 kg∙ha-1 K2O in six farming trails of the Central Federal District, conducted in the Voronezh and Lipetsk Regions with sugar beet on soils with increased and high soil potassium levels. The contribution of potassium to the yield increase on average over three years was 14-15%. The content of exchangeable potassium during the experiments corresponded to a higher level of potassium supply compared to the available form, by one or two classes. The use of the potassium balance indicator for calculating the rates of fertilizers applied is advisable in years favorable for crop development. Calculation of optimal rates of potassium fertilizers obtained using multi-criteria estimation allows to consider 140 kg∙ha-1 K2O with a possible increase to 210 kg∙ha-1 in years favorable for crop development as the optimal for application to sugar beet in the Voronezh Region, and from 210 to 280 kg∙ha-1 K2O in the Lipetsk Region. A promising approach to determine potassium rates to jointly take into account the indicators of the effect and after-effect of fertilizers in terms of yield growth, economic efficiency, and the possibility of achieving a positive balance. The use of calculations based on only one of the above criteria, as well as on classes or direct assessments of soil potassium supply levels based on standard methods, leads to a significant overestimation or underestimation of the results due to the temporal instability of the determined indicators. Existing methods for calculating rates of potassium fertilizers require both the correction of the proposed classes of potassium availability and the consideration of the emerging potassium balance.

The study objects are represented by calcareous and weakly differentiated soils underlain by the hard carbonate-silicate rocks (red-colored and without reddish pigment ones) that have formed in the cold, continental environment of the southern part of the Lena-Angara plateau, Eastern Siberia. The study aimed to investigate the autochthonous/ allochthonous nature of the loose calcareous substrate underlain by the hard rock using data of clay mineralogy. Intensive leaching of carbonates in the soil profiles led to decrease of the pH values simultaneously with increase of the proportions of dithionite extractable iron in the topsoils. The clay mineral association is the same in the red-colored soil and calcareous hard rock. It represented by chlorite and dioctahedral mica (illite), and a small proportion of the mixed-layer illite-smectite (vermiculite) structures with < 50% of smectite (vermiculite) layers. The latter increases slightly in the soil horizons compared to the hard rock. Oppositely, clay mineralogy in the profile on the non reddish colored rock differs from that in the silicate part of the hard rock. Dioctahedral smectite, talc, dioctahedral mica, chlorite, and mixed-layer chlorite-vermiculite (smectite) were identified in the silicate part of the calcareous hard rock. In the soil horizons the decrease of the proportions of talc and smectitic clay was occurred. Besides, appearance of kaolinite in the soil horizons that is absent in the hard rock can be an indicator of the allochthonous substrate occurrence. The studied soils are illustrated two variants of pedogenesis on the loose calcareous substrate underlain by hard carbonate-silicate rocks: (i) on the eluvium of hard rock (red-colored profile) and (ii) with admixture of allochthonous loose substrate in the profile underlain by hard calcareous rock.