Steppe Zone Research Articles

Morphological variability and vitality of Rindera tetraspis (Boraginaceae) in the South Urals and Western Kazakhstan

Population studies of Rindera tetraspis Pall., a rare endemic species of the steppe zone of the European part of Russia and Kazakhstan, were carried out. The study of the habitats of 11 populations in the Orenburg Region and the Republic of Kazakhstan has shown that the species is confined to various variants of calciphyte steppes on chalk substrates or sandstones. In terms of most morphometric indicators, the northern coenopopulation “Rodnichny” is the leader; the minimum values are noted in the coenopopulation “Verkhnechebendinskie Chalk Mountains, northern extremity”. The discriminant analysis has revealed morphostructural differences between individuals from the majority of coenopopulations. In terms of vitality, four coenopopulations are prosperous, seven ones are depressed. The optimal conditions for the species growth are in the northern part of its range, in more favorable climatic conditions in terms of temperature and humidity, mainly on soils of sand origin. When moving southward, a decrease in size parameters of individuals is observed, associated with insufficient moisture, while their morphological diversity increases. The state of R. tetraspis coenopopulations is stable, but the species is not provided with proper protection measures, so further monitoring of its habitats and improvement of conservation measures are necessary.

Rosaceae in the Mountain-Xerophyte and Steppe Vegetation of Shahbuz District, Current Status of the Woody Species

Rosaceae spreading in mountain-xerophytic and steppe vegetation of Shahbuz district flora, is presented in the article. Information is given on the taxonomic composition, life forms, ecological groups, geographical area types and classes of woody species of the family. According to the researches conducted by us, when we characterized the woody species of the mountain-xerophyte and steppe zone of the Shahbuz district flora belonging to the Rosaceae family by genera, it was found that Rosa — 21 (37.5%), Crataegus — 7 (12.5%), Pyrus — 7 (12.5%), Prunus — 6 (10.71%), Sorbus — 5 (8.92%), Cotoneaster — 4 (7.14%), Rubus and Spiraea — 2 (3.57%), Malus and there is — 1 (1.78%) species of the Pyracantha genus. Shrub plants, especially woody species of the Rosaceae family, occupy an important place in the structure of Shahbuz district flora. They are part of the bush steppes, form independent groups and form unique formations.

Agroecological assessment of arable soils in the southwestern part of the foreststeppe zone of the forest steppe zone of the Central Black Earth region of Russia

Agroecological assessment of arable soils in the southwestern part of the foreststeppe zone of the forest steppe zone of the Central Black Earth region of Russia

Yield, grain quality and morphological characteristics of new early maturing varieties of soybean [Glycine max (L.) Merrill] from domestic breeding

Purpose. To carry out a comprehensive study and evaluation of new varieties of soybean [Glycine max (L.) Merrill] of the early maturity group (vegetation period – 91–110 days) by morphological characteristics and the main economic indicators: yield, oil and protein content. Methods. Field stu­dies on the qualification examination of soybean varieties were carried out during 2022–2023 in ten branches of the Ukrainian Institute for Plant Variety Examination (UIPVE) within the soil and climatic zones of the Steppe, Forest­Steppe and Polissia. The process was based on the existing methods of qualification examination of plant varieties for their suitability for distribution in Ukraine (VCU), determination of quality indicators of crop production and compliance of varieties with the criteria of distinctness, uniformity and stability (DUS). Results. The morphological characteristics, yield and grain quality of new early maturing varieties of Ukrainian breeding, included in the State Register of Plant Varieties Suitable for Distribution in Ukraine, were evalua­ted. Namely: ‘Zlatopilska’, ‘Kobuko’, ‘AFC Tempo’, ‘AFC Fest’, ‘Hospodynia’ and ‘Sunrise’. The most productive varieties in all soil and climate zones were ‘AFC Tempo’ (Steppe – 3.25 t/ha, Forest­Steppe – 3.64, Polissia – 3.63 t/ha) and ‘Kobuko’ (Steppe – 3.03 t/ha, Forest­Steppe – 3.68, Polissia – 3.42 t/ha). At the same time, ‘Zlatopilska’, ‘Kobuko’, ‘AFC Tempo’, ‘AFC Fest’ and ‘Sunrise’ produced the highest yields in Forest­Steppe [from 2.89 t/ha (‘Zlatopilska’) to 3.68 t/ha (‘Kobuko’)] and ‘Hospodynia’ – in Polissia (2.83 t/ha). ‘Zlatopilska’ (38.4–40.3%) and ‘Sunrise’ (37.9–40.6%) had the highest protein content in the grain and ‘AFC Fest’ (23.3–24.3%) the highest oil content. Conclusions. According to the results of the qualification examination, varieties of soybean ‘Zlatopilska’, ‘Kobuko’ and ‘AFC Tempo’ are recommended for cultivation in all soil and climatic zones; ‘Sunrise’ – in the Steppe and Forest­Steppe; ‘Hospodynia’ – in the Steppe and Polissia; ‘AFC Fest’ – only in the Steppe. Seeds produced in the Forest­Steppe zone have the best quality indicators in terms of protein content, and in terms of oil content – in the Steppe zone. The studied varieties of soybeans meet the criteria of distinctness, uniformity and stability, as well as the requirements for suitability for distribution in Ukraine.

Quality indicators of new sunflower (Helianthus annuus L.) varieties for high oleic and oilseed use under different growing conditions

Purpose. To study the influence of steppe and forest-steppe climatic conditions on the yield, oil content in seeds and fatty acid composition of oil in new sunflower varieties of high oleic and oilseed use. Methods. The research was conducted in accordance with “Methods of qualification examination of plant varieties for their suitability for distribution in Ukraine (general part)” and “Methods of qualification examination of plant varieties for their suitability for distribution. Methods of determining quality indicators of plant production”. The following methods were used in the research: laboratory, comparison, generalisation, mathematical statistics, analysis and synthesis to draw conclusions. Results. The fatty acid composition of the seeds of new varieties of sunflower (Helianthus annuus L.) of high oleic and oilseed use, grown in different soil and climatic conditions, was studied. According to the results of the analysis in the steppe zone, the variety ‘LG50648’ has the highest economic and value characteristics: oil content (51,0%), oleic acid (85.1%), yield (3.11 t/ha); varieties ‘SULIANO’ and ‘MAS 908HOCP’ – yield (3.40 and 3.91 t/ha) and oleic acid content (85.8 and 86.1%) regardless of the gro­wing conditions. It was found that high oleic sunflower varieties ‘MAS 908HOCP’, ‘LG50648’, ‘SULIANO’ grown under steppe and forest-steppe conditions yielded higher quality oil. The maximum content of oleic acid in 2022–2023 was characteristic of the seeds of the varieties ‘MAS 908HOCP’ (86.1% in the steppe and 85.8% in the forest steppe) and ‘SULIANO’. The hi­ghest linoleic acid content was obtained in the seeds of the oilseed use varieties ‘STK104’ (62.9% in the steppe and 58.5% in the forest steppe) and ‘STK103’ (61.2% in the forest steppe). Among the high oleic varieties, the best results were obtained with ‘LG50648’ (5.7% in the steppe and 5.9% in the forest steppe). Conclusions. Oil content of sunflower varieties and fatty acid composition are determined by varietal characteristics of sunflower and environmental conditions. Modern sunflower varieties, which are included in the State Register of Plant Varieties of Ukraine, have high yield potential and can provide a large yield of vegetable oil per unit area. Agroclimatic conditions have different effects on the gross seed yield and oil quality in the conditions of the forest steppe and steppe of Ukraine.

Ecological Capacity and Bioenergy Potential of Agrocenoses as a Way of Sustainable Agriculture

Background: Calculation of bioenergy potential and ecological capacity are promising methods for assessing the state of an agro-landscape, allowing us to promptly respond to changes in its sustainability. The article presents the results of soil research and calculation of bioenergy potential of the farm territory in the zone of dry steppe on chestnut soils. Methods: Assessment of anthropogenic load on agricultural landscape is based on ecological standards and point system of relative fertility. The determination of the ecological capacity by BEPT of an agrocenosis occupied by winter wheat and sunflower was carried out according to the method of V.M. Volodin, R.F. Eremina, N.F. Mikhailova. Determination of erosion and geomorphological characteristics of the research object was carried out using geoinformation technologies. The basis for creation of digital elevation model (DEM) is the data of radar survey of the Earth surface (SRTM4). Result: Soils of the research object have low and average humus content. Nitrogen level in the soil varies from very low to good; nitrogen availability in the fields is average. Provision with mobile phosphorus is average. Soil potassium content is mostly high. As a result of calculations, it was found that in the conditions of the dry steppe zone, the bioenergy potential of the agrolandscape area occupied by winter wheat is 2735.72 GJ/ha, sunflower-2647.4 GJ/ha. At the same time, the ecological capacity of the field occupied by winter wheat is 2764.6 GJ/ha and sunflower-2676.8 GJ/h.

The impact of technologies for the development and use of virgin, fallow lands on agroecological stability and soil fertility

Relevance. The research was carried out in order to analyze the impact of technologies for the development of virgin and fallow lands on erosion processes in the steppe zone in the 60s and modern conditions.Methods. The analysis of approaches to the prevention of soil degradation and desertification of the territory is carried out based on materials obtained in the steppe zone of the Republic of Khakassia in the second half of the XX century and in modern conditions. We used the results of the application of technologies for the development of virgin and fallow lands of Tselinnoye LLC in different periods. Information about dust storms was taken from data from the Bey and Shire weather stations. In 1954–1960 when plowing the chernozem of the southern virgin lands, technology was used using plows, huskers and other tillage tools. The lack of adapted ways of developing and using new lands has led to an outbreak of wind erosion of soils over large areas, including in the south-east of the country.Results. The dump system of soil treatment during the mass development of virgin and fallow lands in the 60s, without taking into account soil, climatic and other conditions, led to a strong development of wind erosion. The number of days with dust storms in Khakassia reached up to 4.8–11.6 per year. In modern conditions, the removal of highly ventilated soils from arable lands and the use of strip placement of crops and minimal tillage on the rest of the arable land contribute to increasing the erosion resistance of agricultural landscapes. The use of the Tornado 500 herbicide in August during the development of the deposit reduces the erodibility by 2.5 times, compared with the technology with its introduction in early summer.

Modelling fields of hydrological cycle characteristics in the Nizhnekamskoye Reservoir watershed of the Volga River basin under climate change

The assessment of trends in averaged over the watershed area hydroclimatic characteristics and changes in the fields of the hydrological cycle components in the XXI century in large river basin of the Nizhnekamskoye reservoir was carried out on the basis of a model approach combining regional space distributed hydrological model and GCMs. It is shown that a slight decrease by 8% is expected in the area-averaged specific runoff by the end of the century according to the RCP8.5 scenario. However, in various parts of the watershed both a slight increase by 3-6% and a significant decrease in the mean annual runoff by 22% can occur, depending on physiographic conditions. Moreover, climatic changes can increase contrasts in the ecological status of the territory: warm regions in the steppe zone become even hotter and more arid, and the moisture availability of wetter territories in the center and east of the basin increases even more.

Effect of detrital subsidy on the Collembola community structure in winter wheat agroecosystems

Mulch is widely used for improving soil quality and maintaining crop productivity. The effects of mulch use in agroecosystems can be assessed by the state of the soil biota. Springtails (Collembola) are a representative group of soil animals in agroecosystems that survive well under agricultural field conditions. We assessed the effect of adding a detrital subsidy with different carbon to nitrogen ratio (C:N) on springtails in a 4-year series of field experiments in winter wheat agroecosystems located in two agroecological zones (broad-leaved forest and steppe). The mulch effect depended on weather conditions. In dry years, the addition of mulch led to an increase in the proportion of epedaphic (upper-litter dwellers) springtails in the broad-leaved forest zone and to an increase in the proportion of atmobiotic forms (mostly inhabiting macrophytes) in the steppe zone. These changes begin to manifest approximately 1.5 months after the detrital subsidy addition. In general, mulch application had a positive and stabilizing effect on the springtail community structure in winter wheat agroecosystems, regardless of the agroecological zone. Our study showed that the addition of detrital subsidy helps to increase the abundance and stabilize the diversity of the springtail community. Changes observed in the structure of the Collembola community can be an indicator of improved soil health, and springtails can be used in assessing the effectiveness of agricultural practices.

Диэлектрическая модель влажных почв для территории юга Западной Сибири в диапазоне частот 3 МГц – 1 ГГц

The wet soil's dielectric model whose input parameters are frequency, volumetric moisture content, and physical clay content are presented. This model was developed based on statistical analysis of dielectric permettivity data for five soil samples with differ partical size distribution from steppe and forest-steppe climate zones within the territory of southern Western Siberia. A comparison of dielectric data obtained empirically and calculated using the model for one type of soil is carried out. The obtained results will find application in assessing the radiophysical characteristics of the underlying surface in the frequency range from 3 MHz to 1 GHz.

ОЦЕНКА СОВРЕМЕННОЙ ЛАНДШАФТНОЙ СТРУКТУРЫ ЗАПАДНО-КАЗАХСТАНСКОГО РЕГИОНА

The article presents an assessment of the modern landscape structure of the Western Kazakhstan region, based on the developed map of modern landscapes, made at a scale of 1:1 500,000. Based on the assessment, it was established that in the landscape structure of the entire region, the largest areas are occupied by landscape types of elevated stratal plains (17.8 % of the region’s area) and structural plateaus (14.6 %). Qualitative and quantitative analysis of landscape structure and assessment of dynamic trends in landscape transformation made it possible to establish that within the steppe and dry-steppe zones of the studied region, anthropogenically transformed natural-territorial complexes (NTC) take place in almost all identified types of landscapes and occupy 51.2 and 42.6 % of the NTC area in ​​these zones. Within the natural complexes of semi-arid and arid natural zones, 29.9 and 23.2 % of their area are anthropogenically transformed. On the basis of the regional assessment of the modern landscape structure, environmental standards for anthropogenic loads and approaches to organizing a system of rational environmental management, aimed at the sustainable functioning of natural and economic systems, are developed.

Revisiting the Issue of Attribution of Some Catacomb Monuments Groups from the South of Eastern Europe in the Late 3rd – early 5th Centuries

The catacomb funerary ritual had a widespread occurrence among the southern Eastern European population in late Roman times and at the beginning of the Great Migration Period. The Alan culture monuments of the 2nd – 4th centuries AD from the North Caucasus and the “Alans-Tanaites” nomadic culture of the late 3rd – 4th centuries AD feature the burial ritual most widely and vividly. Evidently, the migration occurred in a westerly direction from the “Alan-Tanaitian” culture area in the late 3rd century, resulting in the appearance of a group of under-kurgan burials in the steppe zone of the Dniester-Danube interfluve. It is possible that the people who left these kurgans in the 4th century were assimilated by the Chernyakhov culture bearers and switched to a sedentary lifestyle, having lost the kurgan funeral ritual (Belen’koe burial ground) but retained the catacomb burial structure of almost predominantly type II. The catacomb burials under the kurgans graphically feature the Alans-Tanaites fate after the encounter with the Huns, who defeated and subjugated the Alans-Tanaites, partly incorporating the vanquished population into their military and political union. The Alans-Tanaites took part in the campaign in Transcaucasia and Western Asia as part of the Hunnic army (395–398), as evidenced by the specific forms of the catacombs in the kurgans of the Palasa-Syrt burial ground from the Western Caspian region. A group of kurgan catacombs in the Middle Don and the Left Bank of the Dnieper features the partial outflow of the Alans-Tanaites from the Volga-Don steppes under the pressure of the Huns in the course of their expansion. A part of the Alans-Tanaites participated in the movement of the Huns to the west, as evidenced by the catacombs in the Budzhak steppe dating back to the last quarter of the 4th century.

A High-Status Middle Sarmatian Burial from the Kovalevka Burial Complex in the Volgograd Region

The article is devoted to the archaeological materials publication from the kurgan 25 excavations of the Kovalevka burial complex. The accompanying inventory, marking a high status of the buried, was found in an individual burial made in the tradition of the Middle Sarmatian funeral rite. The bronze cauldron broken in antiquity and placed upside down was found in the cache. Cauldrons of this type existed in the first century AD. Iron bits with two-hole psalms, widespread among the nomads of the steppe zone starting from the turn of the eras and silver-plated iron plaques from the horse bridle jewelry lay nearby. The set of three phalars, which can be functionally defined as breast and shoulder plates of a horse harness, was found on the other side of the cauldron. The phalars made of forged silver sheet traces of gilding on the surface. The multi-figure compositions of animals, birds and floral ornaments were depicted on the obverse, in low relief. Such phalars in Sarmatian monuments were widespread since the turn of the era and exist within the first half of the first century AD. On both sides of the cauldron there were two gray-clay pottery jugs made in Kuban pottery centers. They became widespread in the burial grounds of the Kuban and the Lower Don starting from the turn of the eras, although they were occasionally encountered at the end of the Early Sarmatian time. Two paired long militant knives were placed along the right leg; these finds are well known in the Sarmatian burials of the turn of the first centuries AD, and are found, as a rule, in high status complexes along with horse harness, bronze cauldrons and other prestigious items. All of the above allows us to assert that the buried individual belonged to the nomadic elite, whose burials during that period were concentrated in the Volga-Don interfluve.

РОЛЬ КРОЮЩИХ ТРИХОМ В БИОХИМИЧЕСКОЙ АДАПТАЦИИ И ИНДИКАЦИИ ЭКОЛОГИЧЕСКИХ УСЛОВИЙ МЕСТООБИТАНИЙ РАСТЕНИЙ

Covering trichomes serve the functions of physical protection of plants (reduction of transpiration, protection against overheating, etc.). In connection with the weak knowledge of their participation in other mechanisms for the formation of stress-tolerance, the purpose of the study was to clarify the role of the leaf-ups on the example of the type of the Boraginaceae family ( Echium Vulossum Officinale, Symphytum Caucasicum, S. Asperum ) in biochemical adaptation in biochemical adaptation Indication of environmental growing conditions. The collection of plant material was produced in two experimental sites in the foothill and steppe zones of the Kabardino-Balkarian Republic, which are related respectively to the environmental optimum (moderate air temperature, sufficient soil moisture) and stress (elevated temperature, lack of moisture). The density of the tricho governing on both surfaces of the leaf plate E. vulgare and C. Officinale in the environmental optimum exceeds the similar indicator of S. asperum and S. caucasicum leaves by 1.3-4.2 times. With a decrease in the favorableness of the growing conditions, the density of the trichium protruding increases in E. vulgare and C. Officinale in 1.2-1.4, in S. Asperum and S. caucasicum -2.0-4.4 times. In favorable conditions, the specific weight of the Trich with peroxidase changes from 20-45 % ( Symphytum) to 67-71 % ( E. Vulgare and C. Officinale ). The activity of peroxidase in plant leaves decreases among: E. vulgare> C. Officinale> S. asperum> S. caucasicum . In favorable conditions of growth, a high correlation was noted between the activity of peroxidase, the content of the tannins and the number of tricho protruding, showing peroxidate activity; With the deterioration of thermal and water regimes, the correlation is moderate. The results obtained indicate an important role of the leaves protruding in biochemical adaptation, the indication of the environmental conditions of growth and the diagnosis of stability of the types of the Boraginaceae family to stress conditions according to the variability of peroxidious activity and the content of the tannins.

Effectiveness of the use of chickpea collection samples in breeding

Aim. To determine the breeding value the large number of collection chickpea (Cicer arietinum L.) varieties obtained from the International Crops Research Institute for the Semi-Arid Tropics (India, Patancheru, ICRISAT) and the National Center for Plant Genetic Resources of Ukraine (Kharkiv) was evaluated in 1995-2022 under the conditions of the steppe zone of Ukraine. Methods. Standard field and laboratory methods (phenological observations, hybridization, structural analysis, biochemical analysis of protein content in seeds according to the Kjeldahl method), statistical analysis. Results. Donors and sources of such economically valuable features as early maturity, increased productivity, protein content in seeds, large-seeded, resistance against pathogens on an artificially created infectious background were identified. The set of 12 varieties of chickpea were developed by artificial hybridization, which are recommended for cultivation in all zones of Ukraine. Conclusions.The characteristics of the created varieties are given, the most valuable collection genotypes for use in crossing programs are recommended.

ИКОНОГРАФИЯ ТЕТРОБОЛА ФЕОДОСИЙСКОЙ ЧЕКАНКИ С ИЗОБРАЖЕНИЕМ АРЕСА И АФРОДИТЫ АРЕИ

The article presents new finds of Theodosian coins issued in 480-470 BC. The coins were found in ancient settlements of the steppe zone of Southeastern Crimea and are tetroboles with images of Ares on the obverse and Aphrodite Ares on the reverse. It is assumed that their release was associated with the victorious completion of the first stage of the Bosporan-Feodosian war, in which Theodosia, with the help of Heraclea of Pontus, defeated Bosporus. Given the religious beliefs of the time and the deceptive actions of navarch Tinnich, the Theodosians could associate this significant event with the divine help of Ares and Aphrodite. This was reflected in the iconography of the coins with the placement of marked mythological characters on them. The deities are represented with unusual hairstyles: Ares with long hair, Aphrodite with short hair, which indicated past military events. Both deities depicted on the tetrobol were part of the pantheon of the Feodosian polis.

МОНИТОРИНГ ПОТОКОВ ДИОКСИДА УГЛЕРОДА НА РАЗНОВОЗРАСТНЫХ ЗАЛЕЖАХ В РАЗЛИЧНЫХ ПРИРОДНО-КЛИМАТИЧЕСКИХ ЗОНАХ ЮГА ЗАПАДНОЙ СИБИРИ

The paper reflects the spatial and temporal variability of CO2 fluxes on fallow lands. The aim was to determine the soil CO2 emissions from fallow lands of different ages, taking into account the natural and climatic zones of the south of Western Siberia. The research was carried out in three natural and climatic zones of the Omsk region: steppe, forest-steppe, subtaiga; in each zone, three sites with different age fallow lands were identified: 5-10, 10-20 and older than 20 years. The soil CO2 emission was measured using exposure chambers with determination on a gas chromatograph. When comparing the intensity of CO2 emissions from fallow lands, depending on the natural and climatic zone, it can be noted that in the warm season the maximum level was in the subtaiga zone (on average for May-September 54.1 g of CO2 ∙ m-2 ∙ day-1), followed by the magnitude of flows in the forest-steppe zone (29.4), the minimum It was observed in the steppe zone (25.0). At the same time, the maximum value of the flows was observed in the subtaiga zone in July, in the forest–steppe and steppe zone in June. Younger deposits are characterized by a large amount of soil carbon dioxide emissions compared with older ones: in the subtaiga zone, the average seasonal emission of deposits 5-10 years old is 1.30 times higher than deposits older than 20 years, in the forest–steppe zone, respectively, 1.51, steppe – 1.63 times. The daily dynamics of soil CO2 fluxes has an increased level in the morning and afternoon hours, decreased in the evening and night hours, regardless of the zone.

Bark Thickness of Forest-forming Species: Modeling and Comparative Analysis

The need to assess the carbon-depositing capacity of a stand, an individual tree and its components is constantly emphasized in the world literature, since mitigation of the effects of climate change has become the highest priority. Since the carbon concentration differs in different tree species and in different components of the tree, including in the stem wood and bark, it is necessary to develop species-specific mathematical models for estimating the proportion of bark in trunks to improve the accuracy of knowledge about the carbon balance of forests. The relationship of bark thickness with both age and diameter of the tree trunk is known, but with respect to its regional variability, the data are contradictory. According to the actual data from 1100 model trees of five forest-forming species, allometric models of a mixed type have been developed. They include as independent variables the age and diameter of the trunk, as well as a binary variable characterising the influence of the growing area itself on the bark thickness of Scots pine, silver birch and Siberian larch, as well as the difference in the thickness of the bark between Siberian spruce and Siberian fir in case of joint growth in mature stands of the taiga zone. At a statistically significant level, it was found that the bark thickness of Scots pine and silver birch trees in the steppe zone is significantly greater compared to the taiga zone, and the bark thickness of Siberian larch trees in the forest-tundra is significantly greater compared to the steppe zone. The bark thickness of Siberian spruce trees is significantly less than that of Siberian fir trees. The ranking of species by bark thickness is included in the paper.

Spatial organisation of the soil macrofauna community of an oak forest in the steppe zone of Ukraine

Background. Environmental impact assessments and the development of measures for the protection and sustainable use of ecosystems should take into account that not only steppe ecosystems but also forest, marsh, salt marsh and meadow ecosystems are referenced for the steppe zone. A comparative approach requires the study of reference ecosystems to understand how much a particular ecosystem has been transformed or how far it is from natural patterns in the restoration process. The soil macrofaunal community of the forest ecosystem of the right bank of the Samara River can be considered a reference for many forest ecosystems in the region. The aim of this study was to identify patterns of spatial organization of the soil macrofaunal community of an oak forest on the right bank of the Samara River. Materials and Methods. A study was conducted in a deciduous woodland located in an oak forest on the right bank of the Samara River. The study area was divided into 5 transects, each consisting of 20 sampling points with a 2 m distance between rows. The samples of the soil macrofauna were taken from a single block of soil that was 25×25×30 cm deep and removed quickly. Vascular plant species lists were recorded for each 2×2 m subplot. The soil penetration resistance and electrical conductivity were measured. Soil faunal trophic activity was assessed by means of a bait lamina test. Results and Discussion. The spatial structure of the community is complex in terms of hierarchy. The driver of the broad-scale component of spatial variation in the community is the properties of the topsoil, mainly the density of the litter. Vegetation cover forms a broad component of the spatial variation in soil macrofauna. An important factor in structuring ecological space is the location of trees. The pure spatial pattern is represented by broad-, medium-, and fine-scale components. Conclusion. The soil macrofaunal community of an oak forest on the slope of the right bank of a steppe river has a high level of abundance and taxonomic and ecological diversity. The spatial distribution of trees forms a broad-scale component of variation in the soil macrofaunal community, and herbaceous cover forms a medium-scale component. The fine-scale component of community variation is due to neutral factors.

Late Holocene morphosedimentary and palaeoenvironmental study of the Middle Drâa river basin (southeastern Morocco)

The alluvial filling of the middle basin of the Drâa River (southeastern Morocco) has recorded hydrogeomorphological responses to environmental changes. A systematic study of the Holocene fluvial terraces along an upstream-downstream section of about a hundred kilometers, combined with a sedimentary multiproxy study, was carried out on the alluvial archives of the Drâa's river. The stratigraphic field studies, combined with granulometric and geochemical X-ray Fluorescence analyses and radiocarbon dating, enable us to propose, for the first time, a reconstruction of the major stages in the morpho-hydrodynamic and paleo-environmental evolution of the middle Drâa river over the past 3500 years. Our results highlight six morpho-hydrodynamic and paleoenvironmental phases. Between 3500–2700 and 1800–1600 cal BP, the Drâa river was highly active, associated with torrential activity, reflecting arid climatic conditions. The lack of sedimentary record observed between 2800 and 2350 cal BP points either to a phase of erosion, or to a minimal and discontinuous activity that left no traces in the studied archives. The periods 2350–1800 (Roman Warm Period) and 1600–550 cal BP (Medieval Climate Anomaly) are characterized by strong fine and more regular alluviation punctuated by episodes of low energy of the Drâa floodplain, sometimes favoring fluviosols development that showed similar characteristics in the three outcrops studied. Finally, from 550 cal BP the fluvial records generally shows signs of anthropization, marked by the formation of anthrosols characteristic of fluvial oasis construction, and associated with the presence of ceramics and hearths, in which eolization features are frequent. The comparison of Drâa evolution in a broader paleohydrological and climatic context, integrating other Moroccan studies and regional data, shows solid connection with the river, lakes, and marine archives from the southern Mediterranean to the Western Sahelian steppe zones, revealing a clear response of this large hydrosystem to regional climatic variations.