Soil contamination in the impact zone of mining enterprises in the Bashkir Transural region

The results of long-term studies of the contents of bulk forms of metals (Cu, Zn, Fe, Ni, Pb, Mn, Co, and Cd) and their mobile compounds in soils of background and human-disturbed areas within the Krasnoural’sk–Sibai–Gai copper–zinc and Baimak–Buribai mixed copper mineralization zones in the Bashkir Transural region are discussed. It is shown that soils of the region are characterized by abnormally high natural total contents of heavy metals (HMs) typomorphic for ore mineralization: Cu, Zn, and Fe for the Sibai province and Cu, Zn, and Ni for the Baimak province. In the case of a shallow depth of the ores, the concentrations of HMs in the soils are close to or higher than the tentative permissible concentration values. The concentrations of mobile HM compounds in soils of background areas and their percentage in the total HM content strongly vary from year to year in dependence on weather conditions, position in the soil catenas, species composition of vegetation, and distance from the source of technogenic contamination. The high natural variability in the content of mobile HM compounds in soils complicates the reliable determination of the regional geochemical background and necessitates annual estimation of background parameters for the purposes of the ecological monitoring of soils. The bulk content of Cu and Zn content in soils near mining enterprises exceeds the regional geochemical background values by 2–12 times and the tentative permissible concentrations of these metals by 2–4 times. Anthropogenic contamination results in a sharp rise in the content of mobile HM compounds in soils. Their highest concentrations exceed the maximum permissible concentrations by 26 times for Cu, 18 times for Zn, and 2 times for Pb. Soil contamination in the impact zone of mining enterprises is extremely dangerous or dangerous. However, because of the high temporal variability in the migration and accumulation of HMs in the soils, the recent decline in the ore mining activities, and the construction of purification facilities, no definite temporal trends in the contents of HMs in the soils have been found in the studied region for the period from 1998 to 2015.     

Lanthanides in soils of the Cherepovets steel mill impact zone

Contents of different lanthanide forms in soddy-calcareous soils at different distances from the Cherepovets steel mill (Vologda oblast) have been studied. Increased contents of Pr and Tb are found in soils near the pollution source. Less manifested increases in the contents of other lanthanides (from La to Gd) are also observed. Along with the increase in total content, technogenic pollution increases the content of acid-soluble lanthanides and affects their degree of extraction. The residual fraction strongly bound to aluminosilicates contains 80 to 95% of lanthanides. Soil processes result in the partial binding of lanthanides with organic matter (5–18% of their total content) and Fe and Mn (hydr)oxides (0.1–5% of the total content). The individual properties of lanthanides are clearly manifested in their interaction with these soil components. The highest share of the fraction bound to organic matter contains medium lanthanides, and the highest share of the fraction bound to Fe and Mn (hydr)oxides contains heavy lanthanides.     

Modern state of the soils of flood irrigation systems in the semidesert zone

The data of two soil and vegetation surveys of flood basins of the Mamai irrigation system performed in 1987 and 2012 are compared. This irrigation system is found within the Caspian Lowland in Western Kazakhstan oblast of Kazakhstan. The thickness of the humus horizon decreased by 4 cm on the average attesting to the first-second stages of soil degradation. The humus content in the A + B1 horizons decreased by 0.3% on the average with variations corresponding to the first-third degradation stages. From 1987 to 2012, the area of saline soils and the content of exchangeable sodium in them also increased attesting to the development of desertification in the studied zone. The flooded portion of flood basins decreased from 84% in 1987 to 69% in 2012, and the groundwater level rose from 3.6–4.0 to 1.8–3.1 m. Soil degradation processes, together with adverse anthropogenic impacts, resulted in a decrease in the projective cover of valuable plant species and the productivity of herbs grown in flood basins.     

Assessment of the biological activity of soils in the subtropical zone of Azerbaijan

The enzymatic activity; the microbial population; and the intensities of the nitrification, ammonification, CO₂emission, and cellulose decomposition were studied in gray-brown, meadow-sierozemic, meadow-forest alluvial, and yellow (zheltozem) gley soils in the subtropical zone of Azerbaijan under natural vegetation, crop rotation systems with vegetables, and permanent vegetable crops. On this basis, the biological diagnostics of these soils were suggested and the soil ecological health was evaluated. It was shown that properly chosen crop rotation systems on irrigated lands make it possible to preserve the fertility of the meadow-forest alluvial and zheltozem-gley soils and to improve the fertility of the gray-brown and meadow-sierozemic soils.     

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.     

Assessment of changes in the physical properties of plowed loamy soddy-podzolic soils in the nonchernozemic zone of European Russia under the impact of anthropogenic loads

The main physical characteristics of the plow layer of medium and heavy loamy soddy-podzolic soils were assessed. These soils were subdivided into the groups of degrading and improving soils. Permissible and critical values of the physical characteristics of the plow layer upon multiple anthropogenic impacts on it and the development of degradation processes were determined. A forecast of changes in the physical properties of the plow layer in soddy-podzolic soils upon their technogenic compaction was given.     

Algological and mycological assessments of the soil state in the impact zone of the Kirovo-Chepetsk Chemical Plant

The chemical and microbiological (on the basis of algae and micromycetes) analysis of the soils was carried out in the region of the Kirovo-Chepetsk Chemical Plant. It has been shown that the complex soil contamination resulted in essential changes in the algal-mycological complexes: the species diversity of the phototrophs decreased, nitrogen-fixing cyanobacteria practically disappeared from the algocenoses, and melanic forms of fungi dominated in the structure of the micromycetal communities. The higher sensitivity of the mycological indication method to the soil contamination was found in comparison with the methods of biotesting on the basis of protozoa and coliform bacteria.     

Assessment of the state of vegetation and soils on the basis of remote sensing data

An interpretation of remote sensing data based on an analysis of NDVI values and spectral reflectance curves has been performed for two neighboring catchments of the Koloksha and Peksha rivers in central Russia. The phytomass productivity in the Koloksha catchment is higher; at the same time, this area is subjected to more considerable anthropogenic loads and more active erosional processes in comparison with the Peksha catchment.     

丘陵平原过渡区不同土地利用方式土壤DDTs残留及潜在风险

滴滴涕(DDTs)曾作为杀虫剂被广泛使用,对土壤造成很大的污染,已成为土壤中主要化学污染负荷的重要组成之一[1]。我国自20世纪50年代开始使用DDTs到停止生产和大规模使用DDTs的30多年间,累计使用量40多万t,占国际用量的20%[2]。目前国内外有关土壤DDTs残留污染的研究报道不计其数[3～6],对于指导无公害农产品生产发挥着巨大作用。但我国地域辽阔、土地利用类型多样,已有的土壤中OCPs残留和迁移特征的研究还不能满足我国农业清洁生产的需要。四川省乐山市五通桥区位于长江上游,是典型的丘陵平原过渡区,不仅是人口稠密区,而且具有长期的农耕历史,土地利用方式多样,农药和化肥等的施用可能对该     

Accumulation of polycyclic aromatic hydrocarbons in soils and plants of the tundra zone under the impact of coal-mining industry

Thirteen polycyclic aromatic hydrocarbon (PAH) compounds were identified in organic horizons of tundra surface-gleyed soils ( Histic Stagnosols (Gelistagnic) and plants. The total content of PAHs in contaminated soils exceeded the background values by three times. Concentrations of low-molecular weight hydrocarbons in soils at different distances from the coalmines were relatively stable. Concentrations of highmolecular weight hydrocarbons had a distinct maximum at a distance of about 0.5 km from the source of emission. The increased values of correlation coefficients were found between PAH concentrations in organic soil horizons, plants, and coal of the Vorkutinskaya mine. Mostly low-molecular weight structures predominated in the organic soil horizons and in the studied plant species. The maximum capacity for the biological accumulation of PAHs was displayed by Pleurozium schreberi and the minimum capacity was displayed by Vaccinium myrtillus. Mosses and lichens actively absorbed polyarenes from the surface; most of the PAHs were transported into the plants. This phenomenon was not observed for Vaccinium myrtillus Concentrations of PAHs on the surface and in plant tissues decreased with an increase in the distance from the mine. Distribution of polyarenes in plant organs was nonuniform. Insignificant excess of concentration of polyarenes was found in dead part of Pleurozium schreberi in comparison with its living part. The accumulation of polyarenes in the leaves of Vaccinium myrtillus was higher than that in its stems and roots.     

Agrogenic transformation of soils in the dry steppe zone under the impact of antique and recent land management practices

Virgin, cultivated, and old-arable soils have been studied in the area of Olbia, one of the antique poleis in the northern part of the Black Sea region. It is shown that the soils cultivated during the antique time still preserve some features differing them from their virgin analogues. In the course of agrogenic evolution, progressive changes in the morphology of dry steppe soils are not accompanied by the improvement of soil aggregation at lower levels. Macromorphological indices attest to the enhanced development of humification processes and leaching of carbonates and soluble salts in the soils cultivated during the antique time. At the same time, a number of soil degradation processes are vividly manifested in the cultivated soils. It is suggested that this process can be referred to as the soil allopseudomorphosis.     

Assessment of the functional state of soils in Moscow Zoo on the basis of microbiological parameters

The functional state of soils in the Moscow Zoo was assessed on the basis of the indices of intensity of the main biological processes. Studies of the carbon and nitrogen cycles in the soils, the soil enzyme activity, the microbial biomass, and the functional diversity of soil microorganisms (using the method of multisubstrate testing) were performed in aviaries, open-air animal enclosures, and on public parts of the Moscow Zoo. Against the background of relatively favorable physical properties of the soils (soil density and soil air, water, and temperature regimes), their biological activity was very low. The highest values of the biological activity were found in the soils of enclosures with the white-tailed gnu (Connochaetes gnou) and the cassowary (Casuarius casuarius). No significant differences in the biological activity of the soils within the aviaries and animal enclosures and on the public territories were found.     

Emission of CO2 by soils in the impact zone of the Severonikel smelter in the Kola subarctic region

The intensity of the in situ soil respiration in the background northern taiga spruce forests of the Kola subarctic region reaches 120–290 mg C-CO₂/m² per h. In the impact zone of the Severonikel smelter, it decreases to 90–140, 30, and 15–30 mg C-CO₂/m² per h at the stages of spruce defoliation, spruce-birch woodland, and technogenic barrens of the technogenic succession, respectively. For the first time, the impact of the industrial pollution on root respiration has been assessed, and the dependences of the CO₂ emission, the contribution of mineral soil horizons to this process, the microbial biomass, and root respiration on the concentrations of available nickel and copper compounds have been determined. The efficiency of two remediation technologies applied to technogenic barrens near the smelter has been evaluated on the basis of four parameters of the soil biological activity. The results indicate that remediation with the creation of a new filled soil layer is more efficient than chemical and phytoremediation methods.     

Changes in the properties of soils and soil biota in the impact zone of the aerotechnogenic emissions from the Kandalaksha aluminum smelter

A comparative analysis of the changes in the properties of the soils and soil biota in the past ten years along the gradient of pollution with aerotechnogenic emission from the Kandalaksha aluminum smelter in response to a decrease in the emission volume has been performed. The concentrations of fluorine compounds (the priority pollutant) in the emissions and in the organic soil horizons in the impact zone significantly decreased in 2011 relative to 2001. The concentrations of Al decreased only in close vicinity to the smelter (up to 2 km). The concentrations of F, Ca, and Mg in the liquid phase were higher than those in the solid phase, and these elements migrated to greater distances from the source of the contamination (up to 15–20 km). The elements Si, Al, Fe, and P were contained mostly in the solid phase and were mainly deposited within the 5-km zone. The acidity of the litter near the smelter decreased by almost by two pH units in the nearest zone (<2 km). The decrease in the amount of contaminants in the emissions resulted in the narrowing of the zone of the maximum soil contamination from 2.5 to 1.5 km from the emission source; the zones of strong and moderate contamination narrowed by 5 km. The regularities of the changes in the numbers and biomasses of the main groups of microorganisms in the soils of the permanent sampling plots did not change during the past ten years. The emissions inhibited the development of the fungal biota. The prokaryotic part of the soil microbiota and, particularly, the actinomycetes proved to be tolerant to the emitted contaminants. It was suggested that the changes in the structure of the fungal and actinomycetal communities should be used to monitor the state of the soil ecosystems affected by the emissions from the aluminum smelter.     

The structural state of buried and surface soils of solonetzic complexes in the dry steppe zone of the Lower Volga basin

The structural state of modern (surface) soils and the soils buried under Anna Ioannovna??s rampart (1718?C1720) was studied. These soils are the components of solonetzic soil complexes in the southern Privolzhskaya Upland. The dehumification and the high content of calcium in the exchange complex determine the state of the macrostructure of the chestnut soil buried about 300 years ago. The dehumification drastically lowers the water stability of the soil aggregates, and the predominance of calcium ions in the soil exchange complex prevents the destruction of the chestnut paleosol aggregates and preserves their aggregate state upon moistening. For the last 300 years, no significant changes in the macrostructure of the solonetzes have been observed.     

Establishment of a landfill impact zone on soils using structural and functional modifications of microbial communities

A number of structural and functional parameters of microbial communities have been applied for ecological monitoring of soils located in nearby landfills. The difference in sensitivities to pollution between different microbial indices was shown. A landfill impact zone in the direction of pollution migration was established using the total disturbance index of habitat microbial communities.     

Assessment of the state and biological production potential of soddy-podzolic soils in the Sudogda River basin of Vladimir oblast

Soddy-podzolic soils of the Sudogda River basin (Vladimir oblast) are studied. Data on the properties of these soils and phytomass productivity are presented. Weak development of podzolization and its morphological vagueness depend on the low humidity of soils due to the qualities of soil-forming rock. The low stock of aboveground phytomass depends on the composition of vegetation growing in this territory and indirectly confirms the influence of the low moisture content in the soil.     

Perchlorate biodegradation in contaminated soils and the deep unsaturated zone

In the United States, perchlorate has been officially recognized as an environmental contaminant. In Israel, widespread perchlorate contamination has been found in the 40-m deep vadose zone near an ammonium perchlorate manufacturing plant north of Tel Aviv, above the central part of Israel's coastal aquifer, with peak concentrations of 1200 mg kg_sediment^?1. In this study, we examined the perchlorate-reduction potential by native microbial communities along this deep contaminated vadose zone profile. We analyzed the effect of various concentrations of nitrate on perchlorate reduction and determined whether perchlorate concentrations in the profile are toxic to the native microbial population. All experiments were performed in soil slurries with sediments taken from the contaminated site. Perchlorate was reduced to chloride in three (1, 15 and 35 m) of the four examined sediment samples taken from different depths (1, 15, 20, and 35 m below surface). No activity was observed in the sediment sample from 20 m below land surface, suggesting low viable microbial communities and water content, and high perchlorate concentrations. In the presence of nitrate, the lag time for perchlorate degradation was inversely correlated to nitrate concentration. We found no perchlorate degradation as long as nitrate was present in the system, and perchlorate degradation initiated only after all the nitrate had been reduced. Nitrate-reduction rates were correlated to the initial concentrations of nitrate and no lag period was observed for nitrate reduction. Viable microbial populations were observed at both high concentrations (10,000 mg l^?1 and 20,000 mg l^?1) and with no addition of perchlorate, at levels of 2.35 × 10⁵, 4.01 × 10⁵, and 3.41 × 10³ CFU ml^?1, respectively; these results were well correlated to those found by PCR amplification analysis of chlorite dismutase. We suggest that the microbial community has adapted to the conditions of high perchlorate concentrations in the unsaturated zone over 30 years of exposure. When no external carbon source was added to the slurry of soil from land surface, all perchlorate was removed after 134 days of incubation. The average perchlorate-reduction rate using natural organic matter as a carbon source was 0.45 mg day^?1, while the average rate using acetate as an external carbon source was 7.2 mg day^?1.     

Heavy metal contamination of soils in a mining area in South Africa and its impact on some biotic systems

In soils, animals and plants from selected sites in the Rustenburg mining area, a part of the South African ore belt, the heavy metal burden was examined. These sites belong to different soil types and are characterized by different land-use (agriculture, grassland). The heavy metal contamination of the soil samples is relatively high and is dominated by chromium and nickel, metals, which are extracted in the mine near the sampling sites. These high heavy metal concentrations had no clear inhibitory influence on micro-organisms or the enzyme activity of soils. It appears that the high clay content of the soils may counteract the influence of heavy metals. On the other hand, tolerant microbial populations may have been established. In addition, the investigated culture plants there was no correlation between the heavy metal content of the soils and the concentrations in roots and shoots. The dangerous, potential contamination of organs in humans seems to be modest, with the exception of tobacco leaves. The heavy metal content of tissues in the examined animals reflect the environmental habitat in situ with no obvious influence on the health of the animals.     

Assessment of the state of soil microbial cenoses in the forest-tundra zone under conditions of airborne industrial pollution

The quantitative and functional responses of soil microbial cenoses in the forest-tundra zone to pollution have been studied in the area exposed to emissions from the Norilsk Mining and Metallurgical Works. The strongest structural and functional disturbances of the soil biota have been recorded on the plots with completely destroyed vegetation. A decrease in the content of microbial carbon and an elevated respiration rate in the technogenically transformed soils provide evidence for the functioning of the microbial communities under stress caused by the continuous input of aggressive pollutants. The degree of transformation and the contents of technogenic elements (Ni, Cu, Co, Pb, and S) in the organic horizons of the forest-tundra soils are the major factors affecting the development and functioning of the soil microbial cenoses.