Ecogenesis and primary soil formation on the East European Plain. A review

Numerous published studies have shown that soil formation, including primary pedogenesis, is closely connected functionally, energetically and operationally with ecogenesis as a key biogenic exploration mechanism of the Earth’s surface by living organisms. The ontogenetic stage of soil evolution, especially in the initial phases, is determined by geogenic conditions and the intensity and trends of biogenic-accumulative processes in the developing ecosystem. Primary soils are considered critical in the rapid development of the initial ancient biosphere, supporting multiple environmental possibilities for ecosystems in that stage of their formation. Currently, similar models of correlated soil formation and ecogenesis are actualised when new substrates appear suitable for biogenic-abiogenic interactions, which occur in both natural and anthropogenic landscapes. Biotic factors during primary pedogenesis have accumulative and transformative effects on the edaphic component complex. At this stage, the initial pedon is a key functional stage in the evolution of terrestrial ecosystems (biogeocenosis). When restoration of natural ecosystems occurs during the independent growth of exposed substrates, the natural regeneration mechanisms normally occur. These processes are based on the biogenic development of the substrate through the accumulation and transformation of organic matter.

Triangulopteris lacunata gen. et sp. nov. (Centroplasthelida), a New Centrohelid Heliozoan from Soil †

A new genus and species of centrohelid heliozoans, Triangulopteris lacunata gen. et sp. nov. (Pterocystidae Cavalier-Smith and Heyden, 2007), from four geographically remote locations (the Crimean Peninsula, the Dnieper Lowland (the East European Plain), Franz Josef Land, and the Kolyma Lowland (North–Eastern Siberia) was examined using light and electron microscopy. The novel centrohelid is characterized by round shape, 4.3–16.3 μm in diameter, covered with two types of scales: 1.06–4.54 μm long triangular spine scales and 1.22–2.05 μm oval plate scales. Studied centrohelid heliozoan possesses a unique spine scale morphology. The base of scales is represented by a horse hoof-shaped basal plate. The inner surface and lateral wings of spine scales have numerous radial ribs with two ‘pockets’ that are located on both sides of the spine shaft. These pockets are formed by the lateral wings and ends of the basal plate. The cyst formation and transition to a spicules-bearing stage were noted. Additionally, phylogenetic tree was constructed based on SSU rRNA sequences including the strain HF-25 from the permafrost of Kolyma Lowland. The resulting phylogeny recovered it within the clade Pterista, while forming a separate sister lineage to H2 clade, which only had included freshwater environmental sequences.

NEW PALEOLITHIC FINDS IN THE LOWER DON REGION

Изучение среднего и нижнего палеолита юга Восточно-Европейской равнины до сих пор во многом связано с редкими памятниками, расположенными в Северо-Восточном Приазовье (Герасимовка, Рожок I, Носово) и в нижнем течении р. Северский Донец (Хрящи, Михайловское), поэтому любые сведения о новых комплексах этих эпох представляют большой интерес. В статье впервые представлены материалы нового местонахождения каменного века Батай III, открытого более сорока лет назад, расположенного в дельте Дона в устье р. Койсуг. На строительной площадке в перемещенном грунте аллювиального генезиса (рис. 1: 2,3) была собрана коллекция кремневых изделий, состоящая в основном из артефактов среднепалеолитического облика. Основой для них послужил местный галечный кремень. Цвет сырья буро-коричневый (рис. 2: 1b). Патина варьирует от желто-коричневой до красновато-бурой. Коллекция включает нуклевидные изделия, пренуклеусы, небольшой плоско-выпуклый бифас миндалевидной формы (рис. 3: 1a, b), остроконечник (рис. 3: 4a), различные сколы. Наиболее близкие аналогии происходят из местонахождения палеолита у х. Михайловское - недалеко от впадения р. Северский Донец в Дон. So far the studies of the Middle and Lower Paleolithic in the South of the East European Plain have been linked to rare sites located in the northeastern of Azov Sea region (Gerasimovka, Rozhok I, and Nosovo) and the downstream of the Severskiy Donets river (Khryashchi, and Mikhaylovskoe); that is why, any information on new assemblages dating to these historical periods are of great interest. Materials from Batay III, which is a new Stone Age location discovered more than forty years ago, are described for the first time. This site is located in the Don estuary in the mouth of the Koysug river. An assemblage of flint items made up mostly of the Middle Paleolithic artifacts was collected in alluvial soil removed from the construction site (Fig. 1: 2, 3). Local pebbles were used as the main source material. The raw material is reddish-brown (Fig. 2: 1b). The patina varies from yellow-brown to reddish-black. The assemblage includes core-like items, pre-cores, a small almond-shaped plano-convex biface (Fig. 3: 1а, b), a point (Fig. 3: 4а), and various flakes. The closest analogies come from a Paleolithic location near the village of Mikhaylovskoe not far from the place where the Severskiy Donets joins the Don.

Characteristics and process controls of statistical flood moments in Europe – a data-based analysis

Many recent studies have sought to characterize variations of the annual maximum flood discharge series over time and across space in Europe, including some that have elucidated different process controls on different statistical properties of these series. To further support these studies, we conduct a pan-European assessment of process controls on key properties of this series, including the mean annual flood (MAF) and coefficients of variation (CV) and skewness (CS) of flood discharges. These annual maximum flood discharge series consist of instantaneous peaks and daily means observed in 2370 catchments in Europe without strong human modifications covering the period 1960–2010. We explore how the estimated moments MAF, CV and CS vary due to catchment size, climate and other controls across Europe, where their averages are 0.17 m3 s−1 km−2, 0.52 and 1.28, respectively. The results indicate that MAF is largest along the Atlantic coast, in the high-rainfall areas of the Mediterranean coast and in mountainous regions, while it is smallest in the sheltered parts of the East European Plain. The CV is largest in southern and eastern Europe, while it is smallest in the regions subject to strong Atlantic influence. The pattern of the CS is similar, albeit more erratic, in line with the greater sampling variability of CS. In the Mediterranean, MAF, CV and CS decrease strongly with catchment area, suggesting that floods in small catchments are relatively very large, while in eastern Europe this dependence is much weaker, mainly due to more synchronized timing of snowmelt over large areas. The process controls on the flood moments in five predetermined hydroclimatic regions are identified through correlation and multiple linear regression analyses with a range of covariates, and the interpretation is aided by a seasonality analysis. Precipitation-related covariates are found to be the main controls of the spatial patterns of MAF in most of Europe except for regions in which snowmelt contributes to MAF, where air temperature is more important. The Aridity Index is, by far, the most important control on the spatial pattern of CV in all of Europe. Overall, the findings suggest that, at the continental scale, climate variables dominate over land surface characteristics, such as land use and soil type, in controlling the spatial patterns of flood moments. Finally, to provide a performance baseline for more local studies, we assess the estimation accuracy of regional multiple linear regression models for estimating flood moments in ungauged basins.

Mechanical resistance of Quercus robur L. at the environmental boundary of the species distribution in the steppe

The paper studies the mechanical resistance of old-age pedunculate oak trees which grow at the environmental boundary of the species distribution in the steppe. The trees of the studied species growing in the south of the East European Plain (Donetsk Ridge) can be about 200 years old and still be viable (good condition) and have a high mechanical resistance (critical mass (mcr)=105 kg, and flexural stiffness=9.8·107 N·m2) even under unfavourable environmental conditions. A strong dependence of the morphometric parameter of the ratio was established between the tree trunk diameter and its height on the parameters of the trunk bending stiffness, its critical mass, and the relative resistance to bending. The obtained results of statistical analysis can be used to monitor oak forests and scattered trees of Quercus robur L. in order to single out plants with low mechanical resistance with the help of the d/l parameter which serves as a morphometric marker of the tree resistance.

S.М. Solovyov’s Conception of the “Struggle between the Forest and the Steppe”: “For” and “Against”

Based on works by representatives of the Marxist and the Eurasian direction, the article considers arguments “for” and “against” S. M. Solovyov’s conception of the “struggle between the forest and the steppe” as an important part of his historiological and philosophical-historical doctrine. This essay shows that the main arguments against Solovyov’s conception are connected to the interpretations of historical facts corresponding to the theoretical positions of the Marxist and Eurasian paradigms of history. They include: the thesis about the class character of the Russian state and of the state enslavement of the population; that of the subordination of the course of a nation’s history to the action of universal historical laws; that of the decisive role of geographical and ethnic factors; that of the mutual influence of the “forest” and the “steppe” on the formation of the Eurasian state. To determine the balance of arguments “for” and “against” the conception of the “struggle between the forest and the steppe,” the author proposes to use the model of a structural and hierarchical history, where there are stable and dynamic levels in space and time. The essay concludes that the geohistorical fact of the division of the East European plain into forest and steppe belts, which makes it possible to theoretically explain the premises behind the conception of the “struggle between the forest and the steppe, raises no objections from any of the critics of such a struggle. At the same time, historical facts concerning the understanding of the nature of social integrity, on the level at which the struggle took place, lead to fundamentally different theoretical interpretations. Even more discrepancies are found concerning the causes of the changes that determine the historical dynamics. As the real course of history shows, in a changing and interconnected world, such causes can actually become a global conflict of cultures.

Contemporary Trends in River Flow, Suspended Sediment Load, and Soil/Gully Erosion in the South of the Boreal Forest Zone of European Russia: The Vyatka River Basin

Recent decades in the north of the East European Plain have been characterized by significant changes in climate and land use/cover, especially after the collapse of the USSR in 1991. At the same time, the hydrological consequences of these changes, especially changes in erosion processes and river sediment load, have been studied insufficiently. This paper partially covers this existing knowledge gap using the example of the Vyatka River basin. Draining an area of 129,000 km2, the Vyatka River is among the largest rivers in the boreal forest zone of European Russia. Cultivated land occupies about one-fifth of the river basin area; about three-fourths is covered by taiga forest vegetation. The results of state long-term hydrometeorological monitoring and information on land use/cover made it possible to reveal contemporary (since the 1960s) hydrological and erosion-intensity trends and their drivers within the greater (96%) part of the river basin. There has been a statistically insignificant increase in water discharge in the Vyatka River basin during recent decades. This is due to a statistically insignificant increase (for the entire basin studied) in the spring snowmelt-induced floodwater flow and a statistically significant rise in the discharge in the year’s warm and cold seasons. The main reason for the detected trends is increased precipitation, including heavy rainfall during the warm season. In contrast to this, the total annual suspended sediment load of the river (especially that which was snowmelt-induced) and, consequently, soil/gully erosion intensity have experienced a significant decrease in recent decades (up to 58% between 1960–1980 and 2010–2018). Land-use/-cover changes (a reduction of cultivated land area and agricultural machinery, a decline of livestock in pastures) following the collapse of the Soviet Union are considered the main reasons for this decrease. The most noticeable changes in water discharge, suspended sediment load, and erosion intensity were observed in the most agriculturally developed southwest and south parts of the Vyatka River basin. All the above trends may be considered with a high probability to be representative for the south sector of the taiga zone of the East European Plain.