Soils with the second humus horizon, paleochernozems, and the history of pedogenesis at the border between forest and steppe areas

We consider the history of studies, systematization, geographic distribution, and modern properties of the SHH. On the basis of the analysis of Holocene paleosols, we try to characterize the prototype of the SHH, to estimate its age, and to trace stages of its development in the Holocen

On the question of studyng dust-like formations in urban ecosystems

According to the World Health Organization, more than 80% of urban residents are at risk due to unsatisfactory air quality and air pollution, which causes approximately 4.2 million deaths per year. The purpose of the work is to give an overview of scientific articles related to the dustiness of the city’s natural environments. The articles of foreign and Russian researchers were analyzed - the definition of urban road dust was given; the primary technogenic and natural sources of dust particle generation in the city, thephysical and chemical properties of road dust, their dependence on climate, the type of roads and city architecture, the effect of photolysis on physicalchemical characteristics of dust particles are reviewed as well. Particular attention is paid to the negative impact of dust particles PM2.5 and PM10 on human health and the environment. The question of the absence in Russian scientific practice an officially recognized methodology for the settled dust sampling with updating the regulatory documentation on the methodology for the sampling of fine particles suspended in the air is considered. Recommendations are given on the creation of the regulatory framework governing the sampling and analysis of road dust, which is confirmed by the numerous conclusions of both foreign and some domestic researchers as an environmental geo-indicator

Biochar influence on the development of spring wheat (Triticum aestivum L.) and acidity of soddy-podzolic soil in Western Siberia

The paper purpose was to establish the effect of applying biochar obtained from various organic wastes of agriculture (cow manure, straw), woodworking (pine sawdust) and food industry (pine nut shell), which are typical of Western Siberia, on the morphometric characteristics of plants (using spring wheat (Triticum aestivum L.) as the example) and the soddy-podzolic soil properties. The assessment of biochar influence was performed by a series of vegetation experiments using climatic chambers. As a result, it was found that the introduction of all the noted biochar types into the soil layer leads to a significant (p < 0.05) increase in the morphometric characteristics of spring wheat. For example, when applying the straw biochar to the soil, it results in growing the plant height to the node by 19%, while the number of leaves increased by 8% compared to the control variant. The introduction of biochar from manure leads to the increased length of the spring wheat root by 35%. Moreover, straw and manure biochars contribute to the reduction of soil acidity (increase in pH values from 7.1 to 7.4 and 7.8, respectively). The results of the comprehensive analysis indicate that the agronomic advantages of application of biochars obtained from wheat straw and cattle manure are better compared to biochars from pine sawdust and pine nut shells, which is due to higher concentration of nutrients and substances with alkaline reaction (carbonates and oxides) in the former. The results obtained are useful from the point of view of assessing the environmental risks when applying biochar ameliorants in soils typical of the boreal bioclimatic zone. Subsequent experiments, including studies of the joint application of biochars and fertilizers to the soil, will make it possible to develop recommendations for applying the thermal conversion technology for recycling the regional organic waste into ameliorants that improve soil quality and increase its fertility

New faunistic and taxonomic data on oribatid mites (Acari: Oribatida) of Mexico

This study is based on oribatid mite materials collected from leaf litter in secondary semi- evergreen tropical forests in Mexico; 85 species from 64 genera and 37 families are found; of these, 15 species are recorded for the first time in Mexico, and three species are recorded for the first time in the Neotropical region. A new species of the genus Mucrobates (Schelor- ibatidae) – Mucrobates solidarensis sp. n. – is described. An identification key to the known representatives of Mucrobates is presented

Soils with the second humus horizon, paleochernozems, and the history of pedogenesis at the border between forest and steppe areas

We consider the history of studies, systematization, geographic distribution, and modern properties of the SHH. On the basis of the analysis of Holocene paleosols, we try to characterize the prototype of the SHH, to estimate its age, and to trace stages of its development in the Holocen

Development of surficial deposits on Belyi Island (Kara Sea) during the Last 40,000 Years

A series of radiocarbon (14C) dates of peat and other materials, containing organic matter, were obtained from Belyi Island. We have identified a large group of dates associates with MIS 1, as well as a significant group of dates associated with the Kargin (MIS 3) period (40-31 ka cal BP). A large number of dates from the Late Glacial period and from the Early Holocene (MIS 1 - ca. 14-9 ka cal BP) point to this time interval being associated with warm climate conditions (the Holocene thermal maximum). The climate cooled off significantly during the Middle and Late Holocene, and the intensity of peat accumulation declined. The dates from the MIS 2 period are missing, due to the conditions of this period being extremely unfavorable for the accumulation of peat, as well as of other materials suitable for 14C dating. © 2018 by the Arizona Board of Regents on behalf of the University of Arizona

Development of an experimental plant and a numerical model of an axial magnetic rotor suspension

This article presents the results of the work on the creation of an experimental plant, its testing, as well as the development of a computational model of a rotor magnetic suspension with the use of axial electromagnets. The main purpose of producing the plant was to test the results of the developed numerical finite element model. An automatic control system was developed for the experimental installation. The electrical circuit was assembled on the basis of a ESP32 microcontroller with a clock frequency of 240 MHz and a PWM with a capacity of 10 bits. A PID-regulator program was developed. The coefficients kP, kD, kI used in the code of the electronic control system program (PID-controller) were selected. An experimental study of the bearing capacity of the axial active magnetic bearing under the influence of an external axial force was conducted. The required power of the axial active magnetic bearing was determined. The maximum load-bearing capacity of the installation for the selected coefficients of the PID-controller was determined. An axisymmetric finite-element model of the axial active magnetic bearing was created in the open-source program FEMM 4.2. The load-bearing capacity of the installation for a given current intensity value was calculated. The results of the numerical modelling were compared with the experimental data obtained. The basic principles of creation and operation of the experimental plant and its numerical model are outlined

The organic matter of the buried peat soils on bely island (kara sea)

The organic matter composition of buried peat horizons from the west coast of White lake (Kara Sea) was investigated using the method of dency-metric fractionation. Considerable amount of peat in studied buried horizons, the amount of which increases with depth was revealed. According to radiocarbon dating of peat was formed in the early Holocene. Great ancientry of organic matter in studied buried horizons indicates a very slow humification process. This is due to the extreme environmental conditions: lower average temperatures and short duration period of positive temperatures. The presence of a larger number poorly decomposed plant residues in the composition of the light fractions in low part of the buried horizon indicates the difference between the conditions of the decomposition of organic matter in the period of 8950-8580 years ago, namely, the less favorable conditions for microbial activity in low horizon. This could be due to the change of the local hydrological conditions that influenced the change in the rate of humification of plant residues during this relatively short period of time

Floristische Zusammensetzung und bestimmende Umweltfaktoren in Kiefernwäldern in der hemiborealen Zone West-Sibiriens

Despite their vast distribution ranging from Central Europe to Siberia, hemiboreal oligotrophic pine forests remain poorly studied. Though they dependence on low productive soils, they are widespread on sandy deposits or in bogs. This study aims to classify and ecologically describe the vegetation of oligotrophic pine forests in the south of Western Siberia. In total 50 relevés from nutrient-poor sandy substrates and bogs were sampled in the pre-Taiga zone of the Tyumen province covering the whole range from dry to wet habitats. Five vegetation types were defined by hierarchical clustering. Phi coefficient of association was calculated for groups and their combination, resulting in a high number of species with high fidelity to clusters. Floristic composition ranged from xero-mesophytic vegetation with high frequency of the tribe Pyroleae on dry sandy soils to pine-sphagnum-communities on bogs. The strongest environmental gradients influencing the floristic composition were soil humidity, nutrient supply and fire. Higher nutrient supply due to loamy subsoil increased vascular plant species richness, enabling common plants of hemiboreal birch forests to grow. Surface fires turned out to be a key process in dry pine forests, resulting in a destroyed bryophyte layer and to a partly altered vascular plant species composition. Fire regime plays an important role in maintaining the floristic composition and habitat structure over time. West-Siberian dry oligotrophic pine forests are ecologically, structurally and floristically quite similar to Central-European pine communities of the Peucedano-Pinetum.Einleitung: Hemiboreale (boreonemorale) Wälder sind in West-Sibirien in der Übergangszone zwischen Sub-Taiga im Norden und Wald-Steppe im Süden zu finden (ERMAKOV et al. 2000). Auf-grund des humiden, stark kontinentalen Klimas dominieren lichtbedürftige Baumarten wie Betula pendula et pubescens, Populus tremula und Pinus sylvestris. Wegen ihrer offenen Kronen-Struktur ist die Bodenvegetation sehr artenreich. Ein Großteil der Arten ist ebenfalls in West- und Mitteleuropa verbreitet (ERMAKOV & MOROZOVA 2011), was durch den Begriff "eurosibirischer Vegetationskreis" verdeutlicht wird. Von Pinus sylvestris dominierte Wälder kommen wie in Europa auf azonalen Sandböden natürlich vor, wie sie vor allem an den Terrassen großer Flüsse zu finden sind. Diese Standorte sind sehr trocken und nährstoffarm, außerdem sind schwache Oberflächenfeuer ein häufiges Phänomen. Allerdings sind diese Wälder im Vergleich zu mesischen Standorten nur wenig untersucht. Methoden: Im Juni und Juli 2014 wurden 50 Vegetationsaufnahmen in von Pinus sylvestris dominierten Wäldern auf Mineral- sowie auf Torfböden entlang der Flüsse Tura und Tobol im Oblast Tyumen (Abb. 1) durchgeführt. Auf 100 m² wurden alle Gefäßpflanzenarten, Moose und Flechten notiert und ihre Deckung geschätzt (VAN DER MAAREL 1979). Moose und Flechten konnten zum Teil nur auf Gattungs-Niveau bestimmt werden. Zusätzlich wurden Boden-, Struktur- und Brandparameter aufgenommen (Tab. 2). Aus den Vegetationsaufnahmen wurden mit hierarchischer Clusteranalyse (Methode "flexible beta") fünf Vegetationstypen abgegrenzt (Abb. 2). Für die Typen wurden mit dem phi coefficient of association (TICHÝ & CHYTRÝ 2006) diagnostische Arten ermittelt. Die Beziehung zwischen Umweltgradienten und Artenzusammensetzung wurde mit einer DCA untersucht. Ergebnisse: Insgesamt wurden 105 Gefäß-, 10 Moos- und 5 Flechtenarten erfasst. Die mittlere Artenzahl pro Aufnahme lag bei 22 (Minimum: 9; Maximum: 43). Die Artenzusammensetzung der Vegetationstypen (Tab. 1) wurde in erster Linie durch die Bodenfeuchte bestimmt. Folglich bildeten die Typen einen Gradienten von sehr trockenen, oligotrophen Standorten auf Krypto-Podsolen mit geringer Humusauflage bis hin zu niedrigwüchsigen Kiefernwäldern im Randbereich ombrotropher Hochmoore. Die bessere Wasser- und Nährstoffverfügbarkeit in Böden mit lehmigen Sanden um Unterboden führte zu höherer Produktivität und Diversität der Feldschicht (Abb. 5). Oberflächenfeuer, natürlich oder anthropogen verursacht, entfernten die Moosschicht nahezu völlig. Diskussion: Bodenfeuchte, Nährstoffe und Feuer sind die drei bestimmenden Umweltfaktoren in oligotrophen Kiefernwäldern im südlichen West-Sibirien. Die feuchtesten Standorte sind Moor-Kiefernwälder der Klasse Vaccinio uliginosae Pinetea Passarge et G. Hofmann 1968 mit moortypischen, circumboreal verbreiteten Arten. Auf sehr trockenen, nährstoffarmen Sanden bildet sich eine Wärme und Trockenheit liebende Pflanzengesellschaft aus mit Arten wie Chimaphila umbellata, Solidago virgaurea und einem großen Anteil von Pyroloideaen (ERMAKOV et al. 2000). Die nährstoffreicheren Ausbildungen weisen einen höheren Anteil mesischer Arten wie Cnidium dubium und Rubus saxatilis auf und stellen den Übergang zu Betula pendula dominierten Wäldern dar. Diese Gesellschaften werden durch wiederkehrende, schwache Oberflächenfeuer offen gehalten, sodass die Humusauflage gering bleibt und konkurrenzkräftigere Arten wie Vaccinium spp. zurückgedrängt werden. In Struktur und Artenzusammensetzung sind sie ähnlich zum Peucedano-Pinetum W. Matuszkiewicz 1962 (Beilage S1), das in Mitteleuropa wegen hoher Stickstoffimmissionen und Streuakkumulation nur noch reliktisch zu finden ist (HEINKEN 2008a, REINECKE et al. 2014). Für den Naturschutz bedeutet dies, dass die Erhaltung von Pyroloidae-reichen Kiefernwäldern nur durch grobe Maßnahmen wie regelmäßige Bodenfeuer oder Streurechen möglich ist

Peculiarities of Elemental Composition of the Pyrogenic Tundra Soils in Pur-Taz Watershed

В статье рассмотрен состав тундровых почв Пур-Тазовского междуречья на участках пожаров с разным сроком давности (2 года и 28 лет). Определение валового содержания химических элементов проведено с использованием метода спектрометрии с индуктивно связанной плазмой (ICP). Отмечено, что почвы отличаются низким содержанием практически всех элементов, в том числе физиологически важных для растений Zn, Cu, Ni. Выявлено изменение состава пирогенных почв. Непосредственно после пожара в почву поступают элементы, накопленные растениями (цинк, фосфор, кадмий). Затем в ходе послепожарного восстановления элементы-биофилы интенсивно поглощаются растениями, что вызывает обеднение почв. По истечении 28 лет после пожара в поверхностном горелом горизонте значительно, почти вдвое по сравнению с ненарушенными почвами, снизилось содержание P2O5, Cd, S, Hg, Ag. Использование микроудобрений будет способствовать быстрейшему восстановлению растительного покрова на гарях и участках техногенных нарушений.This article analyzes the composition of tundra soils of the Pur-Taz watershed in the areas of fires with different periods of limitation (2 and 28 years, respectively). Determination of the total content of chemical elements was performed using inductively coupled plasma (ICP) spectrometry. The authors note that the soils lack almost all the elements, in particular, such physiologically important for plants ones as Zn, Cu, and Ni. The study has revealed a change in the composition of pyrogenic soils. Immediately after the fire, elements accumulated by plants (zinc, phosphorus, and cadmium) enter the soil. Then, in the course of post-fire recovery, elements-biofilms are intensively absorbed by plants, which causes depletion of soils. After 28 years, in the surface burned horizon, the content of P2 O5 , Cd, S, Hg, and Ag decreased significantly (almost twice compared to undisturbed soils). The use of micronutrients will contribute to the rapid restoration of vegetation cover in the fires and areas of technogenic disturbances