bluuebunny/crossref_metadata_2025 huggingface dataset:
Revision of Permian Ray-Finned Fishes from the Kazankovo-Markino Formation of the Kuznetsk Basin
Authors: Bakaev A. S.
Published: April 2024

A revision of the systematic composition of Permian ray-finned fishes from freshwater deposits of the Kazankovo-Markino Formation (Middle Permian, Kazanian Stage) of the Kuznetsk Basin is presented. Eurynotoides (“Heterolepis”) multa belongs to the Eurynotoidiformes and is the first member of this order to be found outside European Russia. Mitinolepis costulata (reidentified Usolia sp.), Marmoratolepis obruchevi (reidentified cf. Sludalepis sp.), Heterolepis tomiensis (reidentified Elonichthidae gen. indet.), Tenuislepis unica (reidentified Eurynotoididae gen. indet.) and Nitidalepis trisecta (reidentified Acrolepididae gen. indet.) are too poorly preserved; the characters available are not sufficient to distinguish new taxa, and they can only be identified to the genus or family-level. The previously used generic name Heterolepis is a junior homonym and is replaced. The new discovery confirms the existence of non-marine paleogeographic migration routes between Siberia and European Russia in the Permian.
The First Finds of the Most Ancient Oyster-Like Bivalves of the Genus Prospondylus Zimmermann (Pectinidae, Prospondylidae) in the Lower Permian of the Southern Cis-Urals (Russia)
Authors: Biakov A. S. , Mazaev A. V.
Published: April 2024

For the first time in the Lower Permian deposits (Upper Asselian–Sakmarian stages) of the Southern Cis-Urals, the most ancient representatives of oyster-like bivalves of the genus Prospondylus Zimmermann were found, reliable findings of which were previously known only in the Lower-Middle Permian deposits of North America and the Upper Permian deposits of Germany. A description of the new species Prospondylus shakhtauensis Biakov, sp. nov. is given.
A New Genus of the Zooproblematics of the Family Siphogonuchitidae
Authors: Demidenko Yu. E.
Published: April 2024

A new genus and species Monoshanites dentatus gen. et sp. nov. of asymmetric sclerites of problematic animal organisms belonging to the family Siphogonuchitidae is described from the Khevte–Tsakhir–Nuruu section of Western Mongolia (Tommotian Stage, Beds with Halkieria amorpha, Bayangol Formation). The microstructure of sclerites with a double wall was studied: the inner layer is lamellar, the outer layer is columnar.
A New Species Martinothyris pseudolineatus (Spiriferida) from the Late Famennian of Northeastern Iran
Authors: Baranov V. V. , Nasiri Y. , Gharaie M. H. M. , Nikbakht S. T. , Hadi M.
Published: April 2024

A new species Martinothyris pseudolineatus (Spiriferida) is described from the Upper Famennian (Khoshyeilagh Formation) of the Siaheh Mountain, northeastern Iran. The first appearance and ways of dispersal of representatives of the genus Martinothyris Minato, 1953 are considered.
New Species of the Genus Oryctocephalus Walcott from the Middle Cambrian of the Siberian Platform
Authors: Korovnikov I. V.
Published: April 2024

Two new species of trilobites of the Oryctocephalus Walcott, 1886 from the Amgan Stage of the Middle Cambrian of the Siberian Platform were described: Oryctocephalus doliformis sp. nov. and O. molodoensis sp. nov. wich were found in the middle part of the Kuonamka Formation in the Molodo and Muna Rivers sections.
Shell Microstructure and Microornamentation of the Three Lingulate Genera of the Families Discinidae and Trematidae from the Famennian of Novosibirsk Islands
Authors: Smirnova T. N. , Gatovsky Yu. A. , Zhegallo E. A.
Published: April 2024

The organophosphatic brachiopod assemblage from the Famennian deposits of Novosibirsk Islands was described firstly. There is the new information of shell microstructure of the genus Opatrilkiella. It is supplemented information about microornamentation of genera Orbiculoidea and Schizobolus.
The First Artropod Trackways in the Lower Triassic of Eastern Europe from the New Locality Mansurovo, Orenburg Region
Authors: Uliakhin A. V. , Sennikov A. G. , Novikov I. V.
Published: April 2024

A description is given of trace fossils from the Lower Triassic Gostevskaya Formation of the Mansurovo locality, Orenburg Region, represented by counterimpressions on the lower contact of sandstone with wave ripples. The ichnological characteristics of the trackways and their individual imprints are similar to the ichnospecies Diplichnites triassicus (Linck, 1943), which is widespread in fluvial and lake sediments of the Carboniferous-Triassic of Europe and North America. For D. triassicus most likely the trace maker from the group of branchiopod arthropods Notostraca, which moved in the aquatic environment. Most likely, the microbial mat developed on the surface of the sand substrate acted as a trace carrier, and the subsequent preservation and burial of arthropod trackways took place with the direct participation of the microbial mat.
A New Species of Nucleolites (Echinoidea, Cassiduloida) from the Lower Albian of Russian Plate
Authors: Kalyakin E. A. , Barsukov L. S.
Published: April 2024

A new species of Nucleolites from the Lower Albian deposits (Arcthoplites jachromensis Zone) of the Pavlovskoye section (Yuriev-Polsky district, Vladimir region) was described based on eight specimens. The species characterizes the late stages of the phylogeny of the genus and significantly expands its paleogeography. The taphonomic features of the burial made it possible to trace the structure of the jaw apparatus of the cassiduloid type in adult Nucleolites. For the first time in the Albian deposits of the Russian Plate, an extensive echinoderm assemblage, which is the most representative for the Lower Cretaceous deposits of the region as a whole, was established.
On the Late Paleozoic Subfamily Neopronoritinae Weyer (Pronoritidae, Ammonoidea)
Authors: Leonova T. B.
Published: April 2024

Modern views on the systematics of Pronoritidae are considered. The division of the family into two subfamilies, Pronoritinae and Neopronoritinae, proposed by Weyer (1972) is discussed, the composition and the phylogenetic relationships of Neopronoritinae are clarified. The endemic genus Shikhanites Ruzhencev is proposed to be a paedomorphic member of the subfamily Uddenitinae (family Medlicottiidae Karpinsky). The genera Neopronorites Ruzhencev and Sakmarites Ruzhencev were revised, based mainly on species of these genera from the Early Permian of the Shakhtau quarry (Bashkortostan). Of the 15 species previously assigned to the genus Neopronorites, 12 are recognized as valid, ten of them are Early Permian. The genus Sakmarites includes six species, three of which were found in Shakhtau.
Pleistocene Walrus (Odobenus rosmarus L., 1758) Discovered in the Northern European Russia (Pechora River)
Authors: Ponomarev D. V. , Kryukova N. V. , Andreicheva L. N. , Puzachenko A. Yu. , Vorobyev N. N. , Marchenko-Vagapova T. I. , Van Kolfschoten T. , Van der Plicht J.
Published: April 2024

A fragment of a walrus skull of Neopleistocene age was found at a distance of about 340 km from the mouth of the Pechora River. The skull presumably belonged to a mature male of Atlantic walrus 13–14 years old. The radiocarbon date of the walrus bone shows the age over the method’s limit (45 ka). Nitrogen and carbon isotope data from skull collagen are discussed. The reason for the appearance of the walrus far from the modern sea shore was, presumably, the Rodionovo (Shklov, MIS 7) or boreal Sula (Mikulino, MIS 5e) marine transgression into the area of the latitudinal part of the Pechora River. The relatively good preservation of bone testifies in favor of the Sula marine transgression. The Rodionovo age of the walrus can be assumed on the basis of the presence of shallow water marine deposits lying between two Middle Pleistocene moraines—Pechora (Dnieper, MIS 8) and Vychegda (Moscow, MIS 6).
Results of Morphological and Physico-Chemical Investigations of Compressions of the Ancient Coal-Forming Plants
Authors: Telnova O. P. , Gomankov A. V. , Kocheva L. S. , Karmanov A. P.
Published: April 2024

Orestovia-like plants are соаl-forming for some of the most ancient in the history of the Earth, Devonian coals. Their complex study has been being completed without using the possibilities of chemosystematics for the Palaeozoic fossil plants. The morphology and material composition of plant compressions are described. EPR spectroscopy has shown the presence of paramagnetic properties in the studied compressions, a specific feature of lignins and products of their transformation. The method of pyrolytic chromato-mass spectrometry established the aromatic nature of organic matter, structurally similar to lignin and built exclusively from p‑coumaric units.
Ultrastructural features of the body wall of the helminth Heterakis dispar (Schrank, 1790) (Nematoda, Heterakidae)
Authors: Rzayev F. H
Published: April 2024

The structure of the body wall (cuticle, hypoderm, and muscle layer) of the nematode Heterakis dispar (Schrank, 1790) from the family Heterakidae was studied using light and electron microscopy methods and compared with other species of the same family. The cuticle of the adult nematode H. dispar consists of 8 layers: 1 - an outer membrane layer or epicuticle; 2, 3 - outer and inner cortical layers; 4, 5 - outer and inner homogeneous or middle layers; 6, 7 - outer and inner fibrous or fibrillar layers; 8 - basement membrane. The cortical, homogeneous and fibrillary layers constitute 12.4, 45.3 and 42.3% of the all cuticle, respectively. The homogeneous layer of the cuticle in the lateral ridges in both male and female and near the bursa of the male is several times as thick as other parts of the helminth cuticle. Unlike other species of the family, males of H. dispar possess 3 different forms of cuticular structure in different parts of the body. In the basal layer of the cuticle, sustaining structures consisting of dense fibrils and microtubules were found, which were not previously noted in other species of the family. It is likely that they provide strength to the body wall of the helminth. In the hypodermis of the nematode, dorsal, ventral, and 2 lateral ridges are traced, the lateral ridges being twice as large as others. Ultrastructural features of the excretory channels and nerve cords located in the hypodermal ridges, were also revealed. The nervous system of the helminth is orthogonal. The ventral nerve cord is wider than the dorsal one. Muscle layer is of the polymyar type, number of muscle cells arranged in groups varies from 17 to 26, depending on the sex and body part of the helminth.
IV international parasitological symposium “Modern problems of general and private parasitology” (St. Petersburg, december 7-9, 2022)
Authors: Leonovich S. A
Published: April 2024

The fourth regular international parasitological symposium, organized by the agricultural Ministry of russian Federation, St. petersburg state university of veterinary medicine, Zoological Institute of the russian academy of Sciences, and peter the First academy of sciences and arts has been held in St. Petersburg in early december. More than 100 communications devoted to different aspects of general and private parasitology were presented. the spectrum of participants was rather wide. together with participants from russian Federation, parasitologists from Belarus (6 communications), Armenia (4 communications), Azerbaijan (3 communications), and also from Kazakhstan and Rwanda took part in the symposium. russian parasitologists represented virtually all the regions of russian Federation (together with Moscow and St. Petersburg, colleagues from Pskov, Yakutsk, Ulan-ude, Voronezh, Kemerovo, Petrozavodsk, Ekaterinburg, Stavropol, Tumen, Kaliningrad, Rostov, Orenburg, Ryazan, Murmansk, Perm, Izhevsk, Monchegorsk, Kostroma, Rostov-on-Don, Surgut, Vologda, Novosibirsk, and Tomsk talked at the symposium.
Reconstruction of Derogenes varicus miracidium (Digenea: Derogenidae): first ultrastructural description of spines on the surface of Hemiurata larvae
Authors: Smirnov P. A , Krupenko D. Y
Published: April 2024

We performed the detailed ultrastructural reconstruction of the “passive” miracidium of Derogenes varicus - the species from Hemiurata group. The miracidium is highly miniaturized and simplified in comparison with the “active” miracidia. For the first time we elucidate the nature of the spines on the surface of hemiuroid larva: they are derivatives of the epithelial plates. The anterior end of the larva is equipped with three epithelial plates, that bear both spines and cilia. The major part of the miracidial surface is formed by tegument. The nervous and excretory systems of the D. vari cus miracidium are extremely reduced. Single undifferentiated cell comprises the germinal material of the miracidium. We discuss the trends of evolution of hemiuroid miracidia that are associated with transition to passive strategy of infection.
Fleas (Siphonaptera) of mammals and birds of the southern part of the Caspian sandy natural plague focus
Authors: Ermolova N. V , Artyushina Y. S , Lazarenko E. V , Bammatov D. M , Grigoriev M. P , Klimova L. I , Surkhaev D. B , Halidov A. H
Published: April 2024

The data on the taxocenoses of fleas of rodents, other mammals and birds of the Stavropol part of the Caspian sandy natural plague focus (43) for the period 1990-2015 are presented. As a result of long-term (more than 25 years) observations, it was possible to identify a more complete composition of flea taxocenoses in the plague focus, confined to individual feeders. The conducted studies prove the possibility of the existence of a complex parasitic system with the participation of secondary (additional) and accidental vectors and carriers of the causative agent of the plague, which may have important epizootological significance.
Findings of ticksHaemaphysalis japonica douglasi Nuttall et Warburton, 1915 (Acari, Ixodidae) in Irkutsk surroundings
Authors: Vershinin E. A , Mel'nikova O. V
Published: April 2024

The genus Haemaphysalis includes 168 tick species recorded in Europe, Asia, Africa and Australia. Within the Russian Federation 15 species of Haemaphysalis genus are endemic to different forested habitats in the south of European part and south of the Far East. H. japonica tick is common in Japan and on the continental part of South-Eastern Asia, including the Russian Maritime Territory. The continent al population is referred to the subspecies H. japonica douglasi. In Russia it is common in Amur Region and Primorye. This communication is devoted to five findings of the tick in Irkutsk region (East Siberia). The findings were recurrent during the same season and the same route, suggesting the idea of micropopulations of H. japonica douglasi existing in our region.
Flea morphotypes (Insecta, Siphonaptera)
Authors: Medvedev S. G
Published: April 2024

Combinations of structural characters previously used to substantiate various classifications of the order Siphonaptera are analyzed. Adaptive and phyletic morphotypes marking assemblages or phylogenetically closely related groups of flea families are considered.
An annotated checklist of mite species (Mesostigmata, Gamasina) associated with small mammals, birds and reptiles in Saratov province
Authors: Porshakov A. M , Korneev M. G , Kondratev E. N
Published: April 2024

In this paper, we provide a catalogue of mite species (Gamasina) recorded in Saratov Province in 1929-2022. As a result of the analysis of the currently available information, an electronic dataset has been created on mites, which includes information about 38 districts of Saratov Province. The database contains materials (81 species, 41 genera and 20 families) on the habitats and locations where mites occurred and provides a comprehensive list of literature related to the fauna of Saratov Province.
A record of Ixodes ricinus (L., 1758) (Acari, Ixodinae) above the northern border of the range in Republic of Karelia, Russian Federation
Authors: Fedorov D. D , Grigoryeva L. A
Published: April 2024

A female of I. ricinus was found above the generally accepted northern boundary of the range (the White Sea biological station of RAS “Cape Kartesh” (66°20.230ʹ N, 33°38.972ʹ E). The possibility of the existence of independent populations of the sheep tick in the conditions of the northern taiga is discussed.
The first finding of Ixodes lividus Koch, 1844 (Ixodidae) in Komi Republic
Authors: Selivanova N. P , Danilova E. V
Published: April 2024

The tick Ixodes lividus Koch, 1844, a parasite of the sand martin (Riparia riparia (Linnaeus, 1758), was found for the first time in Komi Republic. A single nymph and several larvae were found in nests and burrows in the nesting colony of birds. The colony was located in the bank of the Sysola River (a tributary of the Vychegda River; 61°36´ N, 50°48´ E). Findings of hungry nymph and larvae of I. lividus prove the successful distribution of this species in Komi Republic up to 61° N. The wide distribution and high abundance of the tick host in Komi Republic suggest the distribution of I. lividus as far as 66° N.
Assessment of the Ecological Status of Soils Contaminated by the Copper Mining Industry in Chile: Earthworms to the Rescue
Authors: Neaman A. , Yáñez C.
Published: April 2024

Soil fauna can serve as an excellent tool for ecological assessment of soil quality. The earthworm Eisenia fetida L. is widely used as a bioindicator organism to assess the toxicity of metals, metalloids, and other pollutants. Many studies have shown that the concentrations of metals and metalloids toxic to earthworms are an order of magnitude lower in artificially contaminated soils than in industrially contaminated soils. The novelty of this study is that toxicity estimates were made using native industrially contaminated soils. The results of the two experiments demonstrate the potential use of earthworms for ecological assessment of soils contaminated with metals and metalloids due to copper mining activities in central Chile. The main contaminant in these soils was copper, but arsenic, commonly found in copper ore, was also present in the contaminated soils. In the short-term bioassay, E. fetida earthworms avoided the soil in response to increasing copper content. However, in long-term experiments, arsenic proved to be more toxic to earthworm reproduction, while copper had little effect. In this study, we present toxicity thresholds for copper and arsenic to E. fetida in industrially contaminated native soils.
Transfer and Accumulation of Biophilic Elements in Pasture Ecosystems of the Northern Caspian
Authors: Kulakova N. Yu. , Suvorov G. G.
Published: April 2024

The scale and consequences of the transfer of biophilic elements from pasture ecosystems to sheep farms in the clayey semidesert of the Northern Caspian Sea region under the method of pastoralism accepted in the region (on the example of Stepnovsky settlement of Pallasovsky district of Volgograd region) were estimated. For the calculations, we used data on the chemical composition of dominant plants and sheep faeces, the long-term average productivity of phytocenoses, information on the rate of consumption of pasture forage by animals, etc. Soils of pastures and the reserve area, and soils on the sheep farm (in sheep corrals and in their resting places) were investigated. At least 17 t C, 600 kg Ca, 260 kg N, 100 kg Mg, 50 kg K, 40 kg P and 1 kg S were transferred to farms (0.1% of the area) from 1 ha of pasture (15% of the area) during the 6 months grazing season. The long-term stocks of faeces on farms (more than 1 thousand t in the example under consideration) are practically excluded from the circulation in the landscape. Small areas of farm soils are enriched with C, N, P and K. Compared with soils of the protected area, stocks of water soluble K increase (in the 0–30 cm layer) by two orders of magnitude, exchangeable K increases by 12–16 times, C by 8 times, N by 3 times, mobile P by 2 times. In grassland meadow-chestnut soils a decrease in the content of C (1.3 times) and exchangeable forms of K (1.6 times) relative to soils of the reserve area, in solonets on pastures decrease in the concentration of elements is not noted. The absence of statistically significant differences in the stocks of biophilic elements between the pasture soils and the soils of the protected area is partially explained by an increase in soil density by 0.08 g/cm3 in the 0–50 cm layer of the pasture soils. With the existing farming method, it is necessary to control the balance of biophilic elements in pasture soils.
Effect of Moisture on CO2 Flux of the Palsa Mire Soils (North of Western Siberia)
Authors: Matyshak G. V. , Chuvanov S. V. , Goncharova O. Yu. , Trifonova V. A. , Timofeeva M. V. , Isaeva A. V. , Tarkhov M. O.
Published: April 2024

The effect of the moisture content on peat soils has been studied in discontinuous permafrost area in the north of the Western Siberia (Nadym region). СО2 flux was measured in palsa mire soils (Cryic Histosol) and surrounding bogs (Fibric Histosol) using the closed chamber method for 4 years at the peak of the growing season (August). Despite a significant difference in soil moisture (34.8 ± 13.2 and 56.2 ± 2.1% on average), no significant difference in CO2 emission between these ecosystems was found in any of the observation years (on average 199.1 ± 90.1 and 182.1 ± 85.1 mg CO2 m–2 h–1, respectively). Experimental wetting or drying (with two times difference in moisture content) of peat soil plots by transplantation method showed no significant effect on CO2 emission even 3 years after the experiment start. The absence of significant differences in CO2 flux between ecosystems and experiments was explained by the presence of permafrost and the influence of many multidirectional factors mitigating changes in CO2 production by soils. CO2 flux enhancing from the soils of the bog is possible due to the additional contribution of the methanotrophic filter, as well as the lateral runoff of dissolved CO2 over the permafrost table from palsa mire surrounding the bogs. The absence of a response of CO2 emission to a significant change in moisture may indicate a wide optimum of this parameter for microbiological activity in peat soils of the studied region. The results indicate that, in the study of cryogenic soils of hydromorphic landscapes, it is necessary, in addition to biogenic sources, to take into account additional factors, often of a physical nature, that change the balance of CO2 fluxes and CO2 emission by soils, respectively.
Soil Microbiome in the Impact Zone of the Pechenganikel Plant Emissions (Murmansk Region)
Authors: Korneykova M. V. , Nikitin D. A.
Published: April 2024

The microbial parameters in Albic Podzol soil were analyzed along the pollution gradient (3, 16, 30, 50 km) with Pechenganickel plant emissions (Murmansk region). The amount and structure of the prokaryotes and fungi biomass were assessed by the method of luminescent microscopy; the content of microorganism’s ribosomal genes copies was determined by real-time PCR; the taxonomic diversity and abundance of culturable soil microfungi were studied. An increase in the number of genes copies of bacteria, archaea, and fungi close the source of emissions compared to remote areas was revealed. In all plots, the highest number of ribosomal genes copies was found for bacteria (from 3.21 × 1010 to 12 × 1010 per g of soil). For fungi and archaea, the number varied from 0.53 × 1010 to 1.59 × 1010 per g of soil and from 0.55 × 1010 to 11.41 × 1010 gene copies/g of soil, respectively. A significant increase in the actinomycetes biomass close the plant was noted, while the biomass of bacteria and fungi remained practically unchanged at different distances from the emission source. Mycelium and fungal spores in all areas are mainly represented by small forms with a diameter of 2–3 microns. The length of the fungal mycelium varied from 51.2 m/g near the plant to 397 m/g in remote areas, with no regularities in its distribution along the contamination gradient. A decrease in the diversity of soil microfungi at the level of genera and higher taxa along the pollution gradient with plant emissions was noted. A change in the structure of communities from polydominant (background site) to monodominant (near the plant) was revealed. The species Penicillium raistrickii dominated in all plots. Fungi Trichoderma viride, dark-colored yeasts Torula lucifuga (3 km) and Aureobasidium pullulans (16 km) also dominated in the zone 16 km from the emission source. In the background area, representatives of the orders Mucorales and Umbelopsidales were dominant.
Activity of СО2, N2 Fixation and Denitrification in the Course of Decay of Coarse Woody Debris Decay of Norway Spruce in the South Taiga
Authors: Yevdokimov I. V. , Kostina N. V. , Bykhovets S. S. , Kurakov A. V.
Published: April 2024

The activity of CO2 efflux, N2 fixation, and denitrification, as well as the physiological state of the community of microorganisms-destructors were assessed depending on the decay stage of the coarse woody debris (CWD) in the incubation experiments with the coarse woody debris of Norway spruce (Picea abies L.) and podzolic soil (Retisol). The coarse woody debris and soil were sampled at the experimental sites of the Central Forest State Reserve (Tver Region, Russia). Maximal CO2 emissions caused by CWD decomposition was associated with the decay stages III and IV. Also, the latter two showed maximal values of such sound indices of microbial activity as substrate induced respiration (SIR, 50 μg С–СО2/(g h)), percentage of easily decomposable С in organic matter (А1, 66%) and metabolic quotient qCO2 (0.78). Unlike the СО2 emission, maximal activity of N2 fixation was at the earlier decay stage II. The values of N2 fixation and denitrification activities indicate a gradual and complicatedly regulated transition process from the properties of bacterial and fungal communities of CDW to those in the soil during stages II, III and IV. The dramatic, more than 3-fold decrease was found only for C : N in CWD during the stages III–IV transition. СО2 emission at the stage V increased dramatically. Nevertheless, the CWD organic matter even at this latest decay stage had lower sustainability than organic matter of podzolic soil.
Soil Properties as Indicators of Soil Moisture Regime Parameters (a Review)
Authors: Smirnova M. A. , Kozlov D. N.
Published: April 2024

The water movement in soils contributes to the formation of a number of specific soil properties; their interpretation allows for to characterization of the features of both individual hydrological processes and the soil water regime, which is especially important due to the limited possibilities of soil wetness monitoring. The review considers the diagnostic indicators of mineral soils, determined in the field and laboratory conditions, characterized by different formation times and resistance to changes in environmental factors. Field methods for diagnosing soil moisture regime parameters make it possible to formulate hypotheses about the features of water behavior within the soil profile, which can later be confirmed or refuted as a result of laboratory diagnostic methods, regime observations, and physical and mathematiqcal modeling. In particular, on the basis of a standard field description of soils, it is possible to identify the zone of the greatest moisture turnover, areas of the soil profile, which are characterized by constant and periodic moisture stagnation, as well as determining the level of occurrence of the capillary fringe. Clay coats, root burrows, and soil animals paths mark the preferental flows. Laboratory diagnostic methods are aimed at assessing the quantitative ratio of hydrological processes in the soil; basically, they allow to characterize the source, duration and intensity of the period of soil overmoistering. The Schwertman criterion is the most commonly used analytical indicator for diagnosing soil overmoistering, the possibility and effectiveness of which has been shown for a wide range of soils. Verification of the results of hydrological modeling by soil properties is potentially possible for the processes of downward and lateral runoff, physical evaporation of moisture, transpiration, evapotranspiration and capillary rise.
Natural 13C Abundance of Organic Matter in Water-Stable Aggregates of Haplic Chernozem under Conditions of Contrasting Land Uses
Authors: Artemyeva Z. S. , Zazovskaya E. P. , Zasukhina E. S. , Tsomaeva E. V.
Published: April 2024

Natural 13C abundance of different organic matter (OM) pools in water-stable macro- and free microaggregates of Haplic Chernozem in contrasting land use variants (steppe and long-term bare fallow) are described. Fractionation of 13C at certain stages of the formation of OM pools is relatively constant, regardless of the level of structural organization. This is demonstrated by the presented conceptual scheme, which allows one to quantify the fluxes of carbon (C) in the system of aggregate/OM pool. It was revealed that the main C fluxes in the OM pools go from the free OM (LFfr) to the Residue fraction through microaggregates within water-stable aggregates (mWSA), the components of which are the occluded OM (LFocc) and the Clay. With a high degree of probability, C flows from macroaggregates (WSAma) to free microaggregates (WSAmi). At the same time, the higher probability of the C flux into the Residue from the mWSA as compared to the direct C fluxes from the LFocc and the Clay, testifies in favor of the hypothesis that the Residue is represented, to a large extent, by parts/fragments of disintegrated mWSAs of 50–1 μm in size. Regardless of the size, the WSA contains a labile OM (as the components of mWSA, along with LFfr – only in macroaggregates) and a stable OM (Residue). Labile OM (LFocc and Clay) within WSAmi is characterized by a lower degree of microbial processing (“lighter” isotopic signature) compared to that within WSAma, which is due to its greater “physical” protection against microbial attacks. However, the most stable OM pool, concentrated in the Residue within WSAmi is enriched in 13C compared to that within WSAma. Considering that the Residue determines the total isotopic composition of C in WSA, the organic matter of free microaggregates is characterized by a higher degree of microbial processing in comparison with that of macroaggregates. Free microaggregates are parts of disintegrated macroaggregates.
Effects of the Composition and Properties of Soils and Soil-Sand Substrates Contaminated with Copper on Morphometric Parameters of Barley Plants
Authors: Pinsky D. L. , Shary P. A. , Mandzhieva S. S. , Minkina T. M. , Perelomov L. V. , Maltseva A. N. , Dudnikova T. S.
Published: April 2024

In a multifactorial vegetation experiment, the effect of the composition and properties of soils and soil-sandy substrates contaminated with various doses of copper acetate on the morphometric parameters of spring barley seedlings was studied. It has been shown that the germination and vigor of seed germination, as well as the length of roots, aboveground parts, and dry biomass of plants depend in a complex way on the concentration of Cu in soils and substrates, as well as their buffering capacity to heavy metals. The presence of two mechanisms of Cu influence on plant development was established: metabolic at СCu 500 mg/kg of soil and diffusion at СCu 500 mg/kg. Using methods of regression analysis on experimental data, a multiple regression equation was obtained that combines morphometric parameters of plants, concentration of Cu in the substrates, and the buffering capacity of soils to heavy metals. On its basis, in the coordinates of soil buffering capacity – Cu concentration, a curve of values f the maximum permissible concentration of Cu in soils in the concentration range from 17 to 2047 mg/kg. It makes the possibility to separate the zone of permissible development of barley plants (reduction of morphometric parameters by no more than 15%) from the zone of exceeding the accepted value of maximum permissible concentration of Cu. Thus, maximum permissible concentration of Cu is considered not as a fixed value, but as a function of Cu concentration, soil buffering capacity, and plant species.
Microbiological Parameters of Sod-Podzolic Soil and Rhizosphere in a Half-Century Field Experiment with Different Fertilizer Systems
Authors: Semenov M. V. , Ksenofontova N. A. , Nikitin D. A. , Tkhakakhova A. K. , Lukin S. M.
Published: April 2024

The regular application of mineral and organic fertilizers is one of the essential components of the agricultural intensification. The applied fertilizers lead to artificial enrichment of the soil environment with readily available substrates and biophilic elements, which can have a significant impact on the soil and rhizosphere microbiome. The aim of the study was to investigate the effect of different fertilizer systems on the quantitative parameters of various microbial groups in soddy-podzolic soil (Umbric Albic Retisol) and the rhizosphere of potatoes and barley. The study was carried out on a long-term field experiment, in which mineral (NPK), organic (manure) and mixed (NPK + manure) fertilizer systems have been applied since 1968. The application of organic fertilizers increased the microbial biomass carbon (Cmic) in the bulk soil and the rhizosphere by 25–100% compared to the soil without fertilizers, while the use of mineral fertilizers, on the contrary, decreased it by 10–30%. Basal respiration and respiratory coefficient (qСО2) increased in the row: without fertilizers NPK NPK + manure manure. The gene copies number of bacteria, archaea, and fungi significantly increased (1.5–2.5 times) under organic fertilizers and decreased (2–2.5 times) under NPK. The varied from 32 to 100 and from 0.10 to 0.92 by the luminescent microscopy and quantitative PCR, respectively. The lowest fungi/bacteria ratios were revealed for variants with NPK, and the highest fungi/bacteria ratios were in variants with manure. Thus, the applied doses of mineral fertilizers must be compensated by the introduction of fresh organic matter in order to maintain the stability of the soil-microbe-plant system.
Soil of the Ray-Iz Mountain Ridge (Polar Urals)
Authors: Zhangurov E. V. , Korolev M. A. , Dubrovskiy Yu. A. , Shamrikova E. V.
Published: April 2024

Based on the profile-genetic approach, we made the diagnosis and the classification position of previously little-studied soils of larch woodlands, mountain tundras and a belt of cold glacial deserts of the Polar Urals, formed in different landscape-geomorphological conditions. We studied morphological, physico-chemical and chemical characteristics of the soil profiles formed on rocks of basic and ultrabasic composition. We revealed that the main background of the soil cover under the larch forests are sub-burs (podzolic and illuvial-humus). Both soils are Entic Podzol (Skeletic) according to WRB-2015. In the mountain tundras, gleyzems of humus oxidized gley or Reductaquic Gleysol (Thixotropic) and gray-humus soils or Skeletic Phaeozem are formed. In the extreme soil formation conditions of the cold glacial desert belt (900–1033 m a.s.l.), different subtypes of gleyzems (Reductaquic Gleysol and Turbic Gleysol (Abruptic) occupy local areas. We also found that the surface, predominantly ground-depositional input of plant litter and its slow mineralisation resulted in coarse-humus and peaty upper horizons with a wide C/N molecular ratio.
Effect of Long-Term and Short-Term Droughts on the Hydrolytic Enzymes in Haplic Luvisol
Authors: Yakushev A. V. , Zhuravleva А. I. , Kuznetsova I. N.
Published: April 2024

The transformation of organic matter in the soil is largely determined by hydrolytic enzymes. Under the conditions of climate change, understanding the mechanisms of microbial response is of particular importance for predicting the carbon cycle. Until now, the effect of drought duration and frequency on soil hydrolytic enzymes has been little studied. A multifactorial field manipulation experiment was carried out, simulating in the presence of plants and without them: two short-term droughts, a long-term drought, and an optimal level of soil moisture. The maximum reaction rate Vmax, Michaelis constant Km, and catalytic efficiency Ka of five groups of enzymes involved in the carbon cycle (cellobiase, glucosidase, xylanase), phosphorus (phosphatase), and nitrogen (chitinase) were determined. In phosphatases, glucosidases, and xylanases, Vmax decreased during short-term drought. During prolonged drought, the Vmax value of phosphatases, cellobiohydrolases, and xylanases decreased and increased in chitinases, while remaining unchanged in glucosidases. Both long-term and short-term droughts led to an increase in Km and a decrease in catalytic efficiency (Ka) for almost all enzymes. Short-term droughts were not a “weakened version” of a long-term drought, but had their own specifics – a decrease in Km in glucosidases, which led to an increase in Ka. Long-term drought was characterized by an increase in Vmax of chitinases and spatial variability of Vmax of phosphatases and glucosidases. The influence of the presence of plants was secondary and affected only during short droughts. The reversibility of the effect of drought on Vmax, Km, Ka decreased in the series first short-term drought second short-term drought long-term drought due to an increase in the total duration of the stress impact.
Soils of Agricultural Terraces on Clay Shales in the Mid-Mountain Zone of the Eastern Caucasus
Authors: Pinskoy V. N. , Idrisov I. A. , Kashirskaya N. N. , Yeltsov M. V. , Borisov A. V.
Published: April 2024

The article considers the chemical properties and biological activity of soils of agricultural terraces on clay shales in the mid-mountain zone of the Eastern Caucasus. It is established that the area of terraced plots in the southern zone of Shale Dagestan is about 264 km2 of the territory. These soils are currently in a fallow state but represent a significant reserve of highly fertile erosion-resistant soils, the cultivation of which, unlike soils on consolidated rocks, is possible with the help of modern technology. The influence of slope exposure, steepness, terrace size, duration of the plowing period on the chemical properties and biological activity of soils has been studied. It is shown that for background soils outside the terracing zone, the slope exposure has a decisive influence. For terraced areas, the impact of exposure is less pronounced. The formation of a vertical terraced surface led to a change in the thermal regime, as a result of which the differences in chemical and microbiological properties of soils on the slopes of the northern and southern exposures became less pronounced. The leveling effect of terracing is most noticeable on relatively gentle slopes (12°–18°), where the width of the terraced canvas is greatest. On steep slopes (20°) with narrow terraces, the influence of slope exposure on soil properties remains. At the same time, factors such as the duration of soil functioning and the features of agricultural technology have no less significant impact on soil properties. The regularities of changes in soil properties within the body of any single terrace have been established. The most fertile area within one terrace is the instrument part, where the profile depth is greatest. As we approach the rear seam of the terrace, a natural decrease in a number of biological and chemical indicators is observed.
Laboratory Study of the Effect of Ammonium and Lanthanum Salts on Methane Oxidation and the Composition of Microbial Communities in Sod-Podzolic Soil
Authors: Kravchenko I. K. , Sizov L. R. , Lysak L. V.
Published: April 2024

One of the promising approaches to solving the issues of ecosystem resilience to stress is to assess the response of microbial communities of soils performing important ecological and biospheric functions to natural or anthropogenic impacts. In a model experiment with sod-podzolic soil (Eutric Albic Retisols (Abruptic, Loamic), the inhibitory effect of ammonium and the stimulating effect of lanthanum on the oxidation of methane by soil microorganisms were established. The addition of ammonium and lanthanum reduced the taxonomic diversity of the bacterial community of the soil and changed its structure: the relative content of Gram-positive bacteria of the phylum Actinobacteriota and Bacillota decreased, while the proportion of gram-negative bacteria of the phylum Pseudomonadota increased. The introduction of lanthanum significantly, by several orders of magnitude, increases the relative content in the community of methanotrophs of the genus Methylobacter and obligate methylotrophs of the genus Methylotenera. The results of the work can be used to develop approaches for regulating the activity of the soil “methane filter” and the accompanying microbiota.
Phosphorus Sorption by Saline Soils of Western Transbaikalia
Authors: Sosorova S. B. , Merkusheva M. G. , Boloneva L. N. , Lavrentieva I. N.
Published: April 2024

The sorption of phosphorus by salt marshes of the dry-steppe zone of the Republic of Buryatia from an aqueous solution of KN2PO4 in the concentration range from 0.25 to 5.0 mM/L (mmol/L) was studied under static conditions. The interaction time is 24 hours with a soil: solution ratio of 1 : 10. The amount of sorbed phosphorus was calculated from the difference in its content in the initial solutions and in the filtrates of soil suspensions. Based on experimental data, phosphorus adsorption isotherms were constructed by soil and sorption parameters were calculated using the Langmuir and Freundlich equations. Typical and quasi-clay Solonchaks have relatively high sorption properties with respect to phosphorus. The value of the maximum adsorption capacity (Amax) in the humus horizons of these soils varied in the range of 23.04–42.74 mM P/kg, in the underlying horizons 16.26–30.39 mM P/kg. In general, all soils, with the exception of the sorov Solonchaks, had an Amax value in the range of 17.70–42.74 mM P/kg. A low sorption value of phosphorus was found in the Solonchaks of sorovy. The Langmuir adsorption constant (KL) varied in the range of 0.3–14.0 l/mmol. Solonchaks dark and typical most strongly bind phosphorus. The Freundlich coefficient (KF) in the studied soils varied in the humus horizon from 5.34 to 63.43 mM P/kg, in mineral from 1.74 to 22.68 mM P/kg. The distribution coefficient (Kd) ranged from 1.95–145.04 l/kg with high values for quasi-clay Solonchaks and low for sorov Solonchaks. The correlation between Kd and Amax was estimated as average (r = 0.51), Kd and KL – high (r = 0.84, p ≤ 0.05). The studied soils according to the values of SPR (the amount of phosphorus that must be sorbed by the soil to maintain a concentration of P = 0.2 mg/kg (0.0065 mM/l) in soil solution) from (0.0723 to 3.4836 mM/kg) refer to weakly absorbing phosphorus. According to the ability to sorb phosphorus, soils form the following decreasing series: quasi-glay solonchaks typical solonchaks dark solonchaks glay solonchaks alluvial light humus saline sorov solonchaks.
Sizes and Ratios of Organic Carbon Pools in Gray Forest Soil under Long-Term Application of Mineral and Organic Fertilizers
Authors: Semenov V. M. , Lebedeva T. N. , Zinyakova N. B. , Sokolov D. A.
Published: April 2024

Soil organic matter (SOM) is proposed to subdivide into structural and process pools. Structural pools include particulate organic matter (CPOM) and mineral-associated organic matter (CMAOM), and process pools include microbial biomass (Cmic) and potentially mineralizable organic matter (C0). The studies were carried out in a long-term microfield experiment on gray forest soil (Luvic Retic Greyzemic Phaeozems (Loamic)). Mineral (N 90–360, P2O5 75–300 and K2O 100–400 kg/ha) and organic (fresh cattle manure from 25 to 100 t/ha) fertilizers in increasing doses were applied annually for 9 years. The increasing in soil organic carbon (Corg) stocks from NPK and manure was 5–10 and 38–83%, respectively. The application of extreme doses of manure (700 to 900 tons/ha in 9 years) led to saturation of the soil with organic carbon. SOM pools sizes decreased in the sequence CMAOM CPOM C0 Cmic, amounting to 7.91–12 g/kg (50–84% of Corg), 0.76–12 g/kg (8–50%), 0.32–1.71 g/kg (2.8-13.7%) and 0.09-0.56 g/kg (0.8-3.7%), respectively. CPOM pool size depended mainly on the dose of mineral and organic fertilizers, and CMAOM depended on the duration of fertilizer application. Both Cmic and C0 pools increased with the manure dose and decreased with the NPK dose. The long-term manuring did not produce a cumulative accumulation of C0 in the soil. It is emphasized that the separation of structural and process pools can be used for monitoring of SOM quality and functions.
Cyanobacteria in Hypolithic Horizons of Soils in the Larsemann Hills, East Antarctica
Authors: Velichko N. V. , Rabochaya D. E. , Dolgikh A. V. , Mergelov N. S.
Published: April 2024

The research is devoted to the analysis of biodiversity of Antarctic soil cyanobacteria in hypolithic organo-accumulative horizons of the Larsemann Hills (East Antarctica). Studying of fouling glasses by the methods of light and confocal microscopy, as well as fluorescent in situ hybridization, has shown that filamentous forms predominate among cyanobacteria in the upper layers of Antarctic hypolithic microbial communities. To clarify the taxonomic status, strains of the genera Nostoc, Halotia, Leptolyngbya, Plectolyngbya, Phormidesmis, as well as some new and previously undescribed representatives of Antarctic cyanobacteria were isolated from corresponding soil samples. The strains of the unique collection of soil cyanobacteria that we formed for the first time were described according to modern methods of polyphasic taxonomy based on analysis of the complex of morphological and molecular-genetic characters. The results of phylogenetic analysis of the primary sequence of 16S rRNA gene and peculiarities of organization of secondary structures of internal transcribed spacers of ribosomal operon allowed to identify new taxa of potentially endemic cyanobacteria among the studied strains. The high level of similarity of 16S rRNA gene sequences of soil cyanobacteria with those previously detected in the water bodies of the Larsemann Hills confirms their ability to spread beyond the limits of individual ecological niches and to adapt flexibly to contrasting environmental conditions.
Magnesium in Saline Gypsum-Containing Soils of Russia
Authors: Chernousenko G. I. , Khitrov N. B. , Pankova E. I.
Published: April 2024

Statistical analysis of 3802 samples of saline soils from different regions of Russia made possible to substantiate observations of a higher proportion of magnesium in soils containing gypsum compared to saline soils without gypsum. Gypsum is not a toxic salt and its presence does not lead to an increase in salinity. The increase of the salinity degree is mainly associated with sodium and magnesium salts, with the proportion of sodium more often than the proportion of magnesium. The article statistically substantiates that in the studied saline soils that do not contain gypsum, among the cations in the water extract (1 : 5), sodium most often dominates at any degree of salinity. The appearance of gypsum in the soil profile is accompanied by a significant increase in the proportion of magnesium. With a low and medium degree of salinity in horizons containing more than 1% gypsum, according to the median, as well as the arithmetic mean, upper quartile and maximum, the proportion of magnesium from the sum of sodium and magnesium in the water extract (1 : 5) is often more than 50%. Even at a strong and very strong degree of salinity, the proportion of magnesium in gypsum-containing horizons is significant and amounts to 43 and 31%, respectively, on the median, which is 5.8–6.7 times higher than the proportion of magnesium in gypsum-free horizons of the same degree of salinity.