Humus Horizons of Soils in Urban Ecosystems

The origin, structure, composition, and properties of soil humus horizons in functional zones of St. Petersburg have been studied. The radiocarbon age of organic matter in the humus horizons varies from 500 to 2700 years, which attests to the natural origin of humus. The structure of microbiomes in the humus horizons of soils under different plant communities has its specific features. The taxonomic structure of microbial communities at the phylum level reflects both genetic features of natural soils and the impact of anthropogenic factors, including alkalization typical of the studied urban soils. Tomographic studies have shown that the transporting system of humus horizons is less developed in the anthropogenically transformed soils in comparison with the natural soils. It can be supposed that the intensity of water and gas exchange in the anthropogenic soils is much lower than that in the natural soils. The fractional and group composition of humus in the urban soils is specified by the long-term pedogenesis, on one hand, and by the impact of metabolic products of the city and the factors of soil formation in the megalopolis, on the other hand. Bulk density of the humus horizon in the urban soils is higher than that in the natural soils; the portion of overcompacted humus horizons in the urban soils reaches 44%. Humus horizons of the lawns along highways are most contaminated with heavy metals: Pb, Zn, and Cu. There are no definite regularities in the distribution of major nutrients (NPK) in the humus horizons of anthropogenic soils.     

Physical properties of soils in Rostov agglomeration

Physical properties of natural and anthropogenically transformed soils of Rostov agglomeration were examined. The data obtained by conventional methods and new approaches to the study of soil physical properties (in particular, tomographic study of soil monoliths) were used for comparing the soils of different functional zones of the urban area. For urban territories in the steppe zone, a comparison of humus-accumulative horizons (А, Asod, Ap, and buried [A] horizons) made it possible to trace tendencies of changes in surface soils under different anthropogenic impacts and in the buried and sealed soils. The microtomographic study demonstrated differences in the bulk density and aggregation of urban soils from different functional zones. The A horizon in the forest-park zone is characterized by good aggregation and high porosity, whereas buried humus-accumulative horizons of anthropogenically transformed soils are characterized by poor aggregation and low porosity. The traditional parameters of soil structure and texture also proved to be informative for the identification of urban pedogenesis.     

Fungal communities in the soils of early medieval settlements in the taiga zone

The difference between the mycobiota in anthropogenically transformed soils of the settlements of the 9th–14th centuries and in the background zonal Podzols and umbric Albeluvisols of the middle and southern taiga subzones in the European part of Russia is demonstrated. The mycological specificity of anthropogenically transformed soils with a cultural layer (CL) in comparison with the background soils is similar for all the studied objects. Its characteristic features are as follows: (1) the redistribution of the fungal biomass in the profile of anthropogenically transformed soils in comparison with zonal soils, (2) the lower amount of fungal mycelium in the CL with the accumulation of fungal spores in this layer, (3) the increased species diversity of fungal communities in the CL manifested by the greater morphological diversity of the spore pool and by the greater diversity of the fungi grown on nutrient media, (4) the change in the composition and species structure of fungal communities in the CL, (5) the replacement of dominant species typical of the zonal soils by eurytopic species, and (6) the significant difference between the fungal communities in the CL and in the above-and lower-lying horizons and buried soils of the same age. Most of the mycological properties of the soils of ancient settlements are also typical of modern urban soils. Thus, the mycological properties of soils can be considered informative carriers of soil memory about ancient anthropogenic impacts.     

Anthropogenic Soils on the Territory of the New Jerusalem Monastery,Moscow Region

The soil cover inside the walls of the New Jerusalem Monastery (in the city of Istra, Moscow region) has been completely transformed during the long history of anthropogenic loads on the local landscape. Specific anthropogenic soils have been formed from the technogenic deposits on the top and slopes of the monastery hill. These soils contain numerous artifacts; in their upper part, horizons with characteristic features of the modern humus-accumulative process have been developed. The major types of anthropogenic soils on the territory of the monastery—urbiagrostratozems, soddy urbistratozems, and soddy-calcareous urbistratified soils—have been described. The composition of technogenic deposits determines the shift of pH values towards the alkaline reaction, the high content of available phosphorus compounds, and the soil contamination with heavy metals. The post-alluvial gray-humus soils close in their morphology and chemical properties to the natural soils of the floodplain predominate in the soil cover of the park zone adjacent to the walls of the monastery in the Istra River valley.     

Anthropogenic transformation of soils in the Pokrovskoe-Streshnevo Park (Moscow) and adjacent residential areas

The diversity of soils within the specially protected natural territory of Pokrovskoe-Streshnevo in Moscow is discussed. The soils of this large park are not affected by the modern construction activities that delete the features inherited from the early stages of the anthropogenic transformation of soils in Moscow. They are characterized by the book-like type of soil memory, which makes it possible to trace several sequences of the anthropogenic soil transformation. The background natural soils-rzhavozems (Chromic Cambisols)—have been transformed into agrogenic soils (agrosols) and postagrogenic soils (postagrosols) under abandoned plowlands, into urbo-soils and urbanozems in the areas of former or modern settlements, and into techno-soils in the areas of active excavation works and engineering reclamation. The change in the character of the land use without the accumulation of osediments on the surface leads to the development of polygenetic soil horizons.     

Anthropogenic transformation of soils in the northern Ergeni Upland (studies at the first experimental plot of the Arshan’-Zelmen Research Station)

The results of soil studies performed in 2005–2009 at the first experimental plot of the Arshan’-Zelmen Research Station of the Institute of Forest Science of the Russian Academy of Sciences are discussed. The post-reclamation state (about 55 years after reclamation) of the soils under forest shelterbelts and adjacent croplands in the rainfed agriculture was studied. The long-term efficiency of forest reclamation and crop-growing technologies developed in the 1950s by the Dokuchaev Soil Science Institute and the Institute of Forest to reclaim strongly saline solonetzic soils was proved. In 55 years, strongly saline sodic solonetzes with sulfate-chloride and chloride-sulfate composition of salts were replaced by agrogenic soils with new properties. Under forest shelterbelts, where deep (40–60 cm) plowing was performed, the soils were transformed into slightly saline solonetzic agrozems with slight soda salinization in the upper meter and with dealkalized plowed and turbated horizons (0–20(40) cm). Under the adjacent cropland subjected to the influence of the shelterbelts on the soil water regime, strongly saline solonetzes were transformed into solonchakous agrosolonetzes with slight soda salinization in the upper 50 cm. In the plow layer, the content of exchangeable sodium decreased to 4–12% of the sum of exchangeable cations. An increased alkalinity and the presence of soda were found in the middle-profile horizons of the anthropogenically transformed soils.     

Soil Cover of the Svetloyarsk Irrigation System after 50 Years of Reclamation Practices

The state of irrigated soils of the Svetloyarsk irrigation system (Volgograd oblast) after 50 years or irrigation and ameliorative impacts has been assessed with the use of published and new field data, cadastral materials, and remote sensing materials. In the recent two decades, the area of regular irrigation and the volume of irrigation water have decreased, which has led to the lowering of the groundwater level to the depth of 5 m and more. The pattern of sown areas is characterized by a rise in the portion of winter cereals. Surface planing during the construction of the irrigation system led to a considerable transformation of the soil cover. On convex elements, solonetzic and other topsoil horizons were almost completely cut off. In many areas, they were replaced by a mixture of different horizons, including carbonaceous material. There are now significant areas of soils of different geneses with carbonates from the surface. Former solonchakous and slightly solonchakous soils are now at the stage of deep desalinization: soluble salts in them have been washed to the second meter, where slightly or moderately saline horizons with a predominance of sulfates have been formed. Irrigated areas on satellite images are specified by spotty patterns differing from those of natural solonetzic soil complexes because of the significant transformation of the soil cover during the construction and operation of irrigation system. The anthropogenically transformed soils can be mapped. Soil maps reflecting the modern state of the of soil cover of irrigated areas are given.     

Morphological diagnostics of pedogenesis on the anthropogenically transformed floodplains in Moscow

At present, many parts of river valleys, including floodplains, are being actively used for urban construction. This leads to the disturbance of normal functioning of the valleys; alluvial deposits and soils become buried under the thickness of various anthropogenic materials. Four profiles of typical urban soils (urbanozems) developed on the floodplain of the Moskva River and its small tributaries have been studied. The macro- and micromorphological characteristics (including data of submicroscopic studies) and the chemical and physicochemical properties of these soils are analyzed. It is shown that the influence of ground-water on the anthropogenically transformed soils of floodplains and low terraces is preserved even upon the cessation of regular flooding. The substitution of urban pedosedimentogenesis for alluvial pedosedimentogenesis has a gradual character with a transitional stage of simultaneous occurrence of both processes. Clayey and clayey-calcareous infillings in the middle-profile horizons and newly formed phosphates of iron and calcium in the lower horizons affected by the groundwater can be considered typical diagnostic features of the urban-alluvial pedogenesis.     

Soils of the Istra River valley within the New Jerusalem monastery and its surroundings

The paper studies the soils of the New Jerusalem monastery complex, which covers a vast area in the Istra River valley and has been significantly changed since the foundation of the monastery (in 1656). The main types of anthropogenically transformed and natural soils are identified; their morphological peculiarities and physical and chemical properties are characterized. The regularities of the spatial soil distribution, which are determined by both natural and anthropogenic factors, are ascertained. The results of the study can be used in implementing the restoration of the monastery and reconstruction of the historical landscape.     

Modern Azerbaijani soil classification system

A new soil classification system is elaborated on the basis of the legend to the soil map of Azerbaijan on a scale of 1: 100 000. The classification system includes above-type categories and a detailed list of anthropogenically transformed soils. It is based on the profile-genetic and evolutionary concepts. The soil classes (the highest taxon) include naturally developed, anthropogenically modified, and technogenically disturbed soils. The lists of soils of the first two classes are similar to those of the new Russian soil classification system, contrary to the class of technogenically disturbed soils, which is subdivided into soil orders with respect to the particular kinds of soil disturbance. The concept of soil types is generally preserved in the new classification. The diagnostics of soil types are based on the sequences of genetic horizons (types of soil profiles). The latter are used for finding proper correlation of the distinguished soil types with analogous soils in the WRB system.     

Changes in the biochemical characteristics of soils in the impact zone of the Kostomuksha Ore-Dressing enterprise

Special soil studies in the impact zone of the Kostomuksha Ore-Dressing enterprise were performed for the first time. The influence of the aerial pollution on the contents and composition of the free amino acids in the organic (forest litter) and mineral (podzolic) soil horizons was examined. An increase in the content of free amino acids in the soils near the pollution source was revealed. The content of amino acids in the organic soil horizons varied in dependence on the distance from the enterprise. The results obtained in this study may be used for the purposes of the biological diagnostics and monitoring of soils in the anthropogenically disturbed ecosystems of eastern Fennoscandia.     

Electrical resistivity as a possible indicator cultivation of arable sandy soils of the humid zone

It is established that soils with different degrees of cultivation have distinctions not only in the morphological structure of a profile, but also in the capacities of anthropogenically transformed (arable) horizons, properties of soils that are reflected in the amounts of electrical resistivity of the soils defined both on a profile and in a vulgar measurement with the use of horizontal electrical resistivity. Accurate reduction of the amounts of electrical resistivity of soils with term increase cultivation is revealed in the middle of a range (0?C100 years) reflected in fertility improvement. The express method of electrical resistivity mapping is rather promising for evaluating changes in properties of sandy soils in humid zone during anthropogenic agricultural transformation.     

Dynamics of the dispersity of model soddy-podzolic soils in a long-term lysimetric experiment

Changes in the particle-size composition and specific surface area were considered for soddy-podzolic soils in large lysimeters of the Soil Research Station of Moscow State University, which simulated anthropogenically modified soils with different sequences of genetic horizons in a long-term (1961–2002) experiment. Changes were detected in the degree of dispersion of the soil horizons occurring under conditions inadequate for their genesis: a decrease in the clay content by 7% and in the external specific surface area from 28.9 to 7.4% in the illuvial horizon placed on the surface and the accumulation of colloidal mineral fractions in the Ap horizon buried at a depth of 80–100 cm. The degree of change depended on the occurrence depth of the buried horizons and increased with approaching the surface. The changes in the dispersity of the model soddypodzolic soils in the lysimetric experiment were primarily due to the translocation of the fine fractions with vertical water flows. The long-term experiment carried out under completely controlled conditions showed that, at the initial functioning stages of the soils with anthropogenically modified profiles, this process was well detectable and significant for the monitoring studies.     

The mycological properties of medieval culture layers as a form of soil ‘biological memory’ about urbanization

Background, aim, and scope  The mycological properties of soil can offer information about ancient human–landscape interaction, including urbanization. This preposition has been confirmed in our study of the habitation deposits in the medieval Russian settlements (eighth to fourteenth centuries A.D.). Materials and methods  The mycobiota of profiles of anthropogenically transformed soil of excavated medieval settlements were examined in different climate conditions in the European part of Russia. The fungal biomass and biomass structure were evaluated using luminescent microscopy. The isolation and enumeration of microfungi were performed using the method of serial dilutions of soil samples and plating them out on the number of solid media. The isolation of keratinolytic microfungi was performed by hear-bite technique. Results  It was established that in ancient urban soils, the mycobiota may have properties different from those of zone fungal communities. The examined cultural layers of ancient settlements differ from the horizons of the surrounding natural soils because of a bigger rate of fungal spores in fungal biomass, more mosaic distribution of microfungal communities, different species composition and dominant microfungal species, increased incidence of some ecological, and trophic fungal groups (for example, keratinophilic, potentially pathogenic microfungi). Discussion  The mycological characteristics of anthropogenic deposits in the excavated medieval settlements were found to be mainly similar to mycological properties of modern urban soils. Conclusions  These properties of habitation deposits can be interpreted as a kind of “soil mycological memory” of the ancient urban impact. Recommendations and perspectives  Soil mycological characteristics could be used in paleoecological reconstructions and biomonitoring of urban impacts     

Schätzung der nutzbaren Feldkapazität und Luftkapazität von anthropogenen Bodenhorizonten aus einfach zu bestimmenden Kennwerten

Estimating soil water and air capacity from physical properties in anthropogenic substrate horizons Up to now there is no appropriate method available to estimate soil water and air capacity in anthropogenic substrate horizons. The “Bodenkundliche Kartieranleitung” (German soil classification key) was developed for natural soils and can be applied to anthropogenic soils only with limited validity. For developing an estimation system, a data base of 197 anthropogenic substrate horizons was established, consisting of soil characterizations gained from own investigations and from literature. By using multiple linear regression analysis, estimating models were developed to calculate soil water and air capacity derived from values of soil bulk density, texture, amount of skeleton and content of organic matter. Though every regression model proved to be highly significant, some gained coefficients of determination less than 50%. Absolute mean standard errors of estimate vary between 3.4 and 9.1 Vol%.     

The effects of agricultural use on the structure and physical properties of three soil types

This investigation was carried out to determine the influence of the use of soils on their morphological structure and properties. Three soil types (i.e. Haplic Phaeozem derived from loess, Orthic Luvisol derived from loess and Orthic Luvisol derived from sandy loam) were involved. In each soil unit, profiles lying at a small distance from one another were taken for detailed examination. The main difference between the soils within each unit was the use to which they were put. The following soils were selected for evaluation: (A) soil from natural forest habitat; (B) soil cultivated in farms with a very low level of mechanisation; (C) soil cultivated in farms which had been completely mechanised for many years; (D) soil used for many years in a vegetable garden, similar to hortisol.

In the selected profiles the morphological features, soil structure in all genetic horizons, granulometric composition, humus content, pH, density, air and water capacity and air permeability were analysed.

It was found that the transition from forest soil management to agricultural use leads not only to the formation of an arable-humus horizon and to changes in structure but also to changes of the physico-chemical properties of soils. Soils under agricultural use manifest a lower level of acidification than forest soils, as well as a different distribution of organic matter. In all agricultural soils, increased compaction of humus horizons was observed, compared with the corresponding horizons of forest soils, as well as changes in other physical features. The use of heavy machines over many years in field operations results in increased density of the soil and deterioration of soil structure. This effect is greater in soils with low colloids and organic matter contents.     

The mineral background of the anthropogenic soils of landscape architecture objects

During the creation of landscape architecture the mineral background of natural soils is transformed and new artificial soils are created. The mineral content and the grain texture of an anthropogenic changed soil of the Arkhangelskoe manor museum were studied as an object of a landscape architecture. The degree of transformation of the natural soils was evaluated. The features of constructozems were determined: the significant sandiness of the upper part of the profile, high variability of distribution of soil grain fractions, the changes in concentrations of the share participation of minerals and their distribution, and also the mismatch between the degree of weathering of the mineral component and the absolute soil age. According to the data we obtained, practical suggestions for forming of organic-sandy mixtures, which are used for anthropogenic soil construction, were made.     

Soil cover of gas-bearing areas

Natural soils with disturbed functioning parameters compared to the background soils with conservative technogenic-pedogenic features were distinguished on vast areas above the artificial underground gas storages in the zones of spreading and predominant impact of hydrocarbon gases. The disturbance of the functioning parameters is related to the increase in the methane concentration, the bacterial oxidation intensity and destruction, and the complex microbiological and physicochemical synthesis of iron oxides. The technogenic-pedogenic features include neoformations of bacteriomorphic microdispersed iron oxides. The impurity components consist of elements typical for biogenic structures. New soil layers, horizons, specific anthropogenically modified soils, and soil-like structures were formed on small areas in the industrial zones of underground gas storages due to the mechanical disturbance, the deposition of drilling sludge, and the chemical contamination. Among the soils, postlithogenic formations were identified—chemotechnosols (soddy-podzolic soils and chernozems), as well as synlithogenic ones: strato-chemotechnosols and stratochemoembryozems. The soil-like bodies included postlithogenic soil-like structures (chemotechnozems) and synlithogenic ones (strato-chemotechnozems). A substantive approach was used for the soil diagnostics. The morphological and magnetic profiles and the physical, chemical, and physicochemical properties of the soils were analyzed. The micromorphological composition of the soil magnetic fraction was used as a magnetic label.