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1.
Four Scythian kurgans of the burial site Beloe Lake-3 were studied in the Turan–Uyuk Depression in the Republic of Tyva. They were constructed about 2565–2390 calendar years ago (calibrated with deviation 1 σ). Soil formation after 2500 yrs of the construction of the kurgans was examined in the interkurgan area. The properties of the background surface and ancient buried soils have much in common, and the difference between the soils of the four kurgans is small. This attests to the fact that the paleoclimatic conditions in the period of the necropolis construction remained stable and were similar to the modern climatic conditions. According to palynological data, the climate at the stage of the construction of the first two kurgans was a little more humid in comparison with the modern climate; it became somewhat drier after 95 years, during the construction of the third kurgan (2425 cal. BP) and again tended to humidification at the final stage of the necropolis creation. These changes in the paleoclimatic conditions are indicated by variations in the structure and composition of associations of xerophytes, mesophytes, hydrophytes, and ruderal plants. At the Uyuk stage, the area was mainly occupied by steppe phytocenoses with a predominance of xerophytes over mesophytes, and hydrophilous vegetation was allocated to moistened habitats near water reservoirs. Larch forests grew near water bodies. The variable anthropogenic impact on the landscape was stronger at the initial and final stages of the construction of the Uyuk culture necropolis. 相似文献
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Sara E. Gallego Ríos Claudia M. Ramírez Beatriz E. López Sara M. Macías Jenny Leal Claudia M. Velásquez 《Water, air, and soil pollution》2018,229(8):275
The concentrations of mercury, lead, cadmium, and arsenic were evaluated in 96 samples, 12 by each one of the following eight fish species: snook (Centropomus undecimalis), crevalle jack (Caranx hippos), Serra Spanish mackerel (Scomberomorus brasiliensis), southern red snapper (Lutjanus purpureus), blue runner (Caranx crysos), Atlantic tarpon (Megalops atlanticus), ladyfish (Elops saurus), and Atlantic goliath grouper (Epinephelus itajara), which were collected during 1 year in the Atrato River Delta in the Gulf of Urabá, Colombian Caribbean. Three fish were caught from each of the following sites the community usually uses to catch them (known as fishing grounds): Bahía Candelaria, Bahía Marirrío, Bocas del Roto, and Bocas del Atrato. The quantification of metals was performed by microwave-induced plasma-optical emission spectrometry. The Pb concentration fluctuated from 0.672 to 3.110 mg kg?1, surpassing the maximum permissible limit (MPL?=?0.3 mg kg?1) for human consumption for all species. The Hg concentration ranged between < Limit of detection and 6.303 mg kg?1, and in the crevalle jack and Atlantic tarpon, concentrations exceeded the MPL (0.5 mg kg?1). The levels of Cd and As were not significant in the studied species and did not exceed the MPL (0.05 mg kg?1). 相似文献
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Tomáš Matys Grygar Jitka Elznicová Tereza Lelková Timea Kiss Márton Balogh Ladislav Strnad Tomáš Navrátil 《Journal of Soils and Sediments》2017,17(11):2596-2609
Purpose
The Oh?e River has received contamination from metal mining and metallurgy (mainly Cu, Pb, Sn, U, Zn) over the previous five centuries. This contamination history has been poorly documented. Contamination has entered the river system in its middle reach, where the channel is incised and bedrock confined, which impedes overbank deposition. Our objective was to locate and describe a sedimentary record in this unfavourable depositional setting.Materials and methods
Three former channel bars that have coalesced with the riverbank were revealed by examination of historical and current maps and a digital terrain model. Manual coring in the bar and in situ (handheld) X-ray fluorescence (XRF) spectroscopy provided data for developing a contamination chemostratigraphy, which was correlated with the mining history in the region. Detailed topographic examination of the bar and valley edge was important to understanding the evolution of one of the bars. Optically stimulated luminescence (OSL) dating was used to verify the timing of deposition.Results and discussion
Handheld XRF for in situ analysis of element composition is efficient for studying contaminated sediment bodies with complex stratigraphy, which require extensive coring and stratigraphic correlation. Despite the unfavourable settings, the channel bars trapped sufficient sediment to produce a record that correlates with the history of contamination in the drainage basin. In the bar studied in greatest detail, we observed a surprising amount of contamination passing through the Oh?e River channel (up to 300 mg kg?1 of Cu, 340 mg kg?1 of Pb and 630 mg kg?1 of Sn in fine sand and silt deposits) associated with a pollution climax in the sixteenth and seventeenth centuries. Modern contamination (Hg and U deposited in the nineteenth and twentieth centuries) was entrapped with low efficiency based on comparable concentrations of Hg and U located 90 km downstream.Conclusions
The efficacy of the use of historical maps and detailed fieldwork was demonstrated by identification of unique depositional meso-environments, which are rare in bedrock-confined fluvial systems. The contamination chemostratigraphy of the bar deposits was correlated with the local mining and pollution history and contributed to an understanding of the bar evolution. The approach used in our study may be applicable to other montane rivers with historic ore mining and processing in their basins.5.
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Contamination levels of the organic horizon of Al–Fe-humus podzols (Albic Rustic Podzols) in the zone affected by atmospheric emissions of the Severonikel smelter (Murmansk oblast) within a 20-yearlong period are compared. The spatiotemporal changes in the total content of heavy metals in the soils in response to a decrease in aerotechnogenic loads have a complicated pattern. As the content of heavy metals in the soils varies widely, the correlation between their amount in the organic soil horizon and the distance from the contamination source is absent. In response to the ninefold decrease in the amount of atmospheric emission of Ni compounds, the bulk content of Ni in the organic horizons of podzols reliably decreased by 2.5 times. The threefold decrease in the emission of Cu compounds proved to be insufficient for a significant decrease in the Cu content in the soils. In 2016, the content of heavy metals in some sampling points even increased in comparison with the earlier periods. The Ni-to-Cu ratio in the soil samples changed significantly. In 1989–1994, bulk forms of heavy metals in the soil samples formed the sequence Ni > Cu > Co; in 2016, it changed to Cu > Ni > Co, which corresponds to the proportions of these metals in the aerial emissions. Under conditions of the continuous input of heavy metals from the atmosphere, the contamination of the organic horizons of podzols with heavy metals remains at the high or very high levels. 相似文献
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Rosa Devesa-Rey M. Luz Iglesias Rogelio Pérez-Moreira Francisco Díaz-Fierros M. Teresa Barral 《Journal of Soils and Sediments》2013,13(5):932-942
Purpose
This work explores the application of the use of Zn, Cu, and Pb relative contents as a new type of normalization method for geochemical properties of soils and sediments in an Atlantic Basin (Anllóns River, NW Spain). The method is based on the conservative behavior of these elements, which exhibit a certain concentration ratio that remains stable as long as there are no human disturbances.Materials and methods
The average relative contents of Zn, Cu, and Pb were calculated by dividing the concentration of each metal in soils or sediments, in the <63-μm fraction, by the sum of Zn, Cu, and Pb, expressed as a percentage. The evaluation of the sum of the average relative concentrations of Zn, Cu, and Pb (Ri), together with three standard deviations for each element, namely, Ri ± 3Si, allows a hexagon to be constructed, represented in ternary diagrams of Zn:Cu:Pb. Following the method proposed by Weng et al. (Environ Geol 45:79–85, 2003), those samples falling outside the hexagon must be considered outliers.Results and discussion
Results obtained confimed the conservative behavior between the relative contents of Zn, Cu, and Pb in surficial samples (soils, bed, and suspended sediments). Only sediment cores displayed nonconservative behavior, showing a marked Pb enrichment, with respect to the surficial samples. When Zn, Cu, and Pb relative contents were plotted in ternary diagrams, outliers were best classified when the hexagon was drawn with standard deviations of samples from the study area. The hexagon drawn with an international database of soils and sediments showed a poorer classification of outliers.Conclusions
The results showed that total Zn, Cu, and Pb relative contents may be employed to investigate anthropogenic disturbances of these elements in soils and sediments of the Anllóns River Basin, thus corroborating that this type of normalization may be employed as a tool to assess outliers in a contaminated area. 相似文献8.
Brian Moss 《Biological conservation》1977,12(2):95-114
The Norfolk Broads and rivers of eastern England (Fig. 1) comprise an area hitherto farmed for the diversity of its wildlife and submerged aquatic plant communities. The latter have progressively disappeared since the early 1950s, until only four sites currently retain more than remnants of the original sub-aquatic macrophyte flora and its associated invertebrate fauna. Increases in turbidity of the water have been associated with the loss of macrophytes, and these increase have been variously attributed to phytoplankton and to disturbance of sediment by the many boats of visiting tourist and residents. Synoptic surveys of turbidity were carried out in the navigable waterways of Broadland in summer and winter 1973, and of phytoplankton in summer 1973. The differential distribution of phytoplankton is discussed in terms of the nutrient loadings on, and flushing coefficients of, the waterway. Highly significant correlations were obtained between phytoplankton numbers and turbidity in the system as a whole and Broads and rivers considered separately. A very weak correlation between boat activity and turbidity was shown to be non-causative. It is concluded that increase in turbidity is a function of increased nutrient loading from human activities in the catchment area and that boat disturbance does not contribute significantly to the sustained turbidity. 相似文献
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《Biological conservation》1987,41(4):279-289
The causes of the recent heavy elephant mortality in the Tsavo ecosystem between 1975 and 1980 were investigated. Poaching and drought conditions were thought to be the main reason.Whether the cause of death was poaching or other factors was ascertained from the examination of carcasses in the field. In the former case the front part of the cranium was cut while those of the unpoached animals were intact. Rainfall data were analysed to assess whether drought conditions occurred during this period, which might have caused the recent mortality. Other possible causes of mortality were assessed from interviews with park wardens and rangers and from records on poaching incidents and ivory recoveries.The overall results of this study show that the recent heavy elephant mortality in Tsavo ecosystem was caused mainly by poaching preceded by drought. It is therefore recommended that future conservation measures for the remaining elephant population require control of poaching, especially in wet season dispersal areas which are not under park management. 相似文献
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Inmaculada Riba Enrique García-Luque Alejandra Maz-Courrau María Luisa González de Canales Tomás Ángel DelValls 《Water, air, and soil pollution》2010,212(1-4):329-336
This study assesses the effect of salinity in bioavailability and toxicity of Zn by means of laboratory bioassays by observing contamination in both sediment and water, accumulation of Zn in biological tissues, and histopathological damage in the gills and guts tissues of Ruditapes philippinarum clams, which were exposed to different types of sediments from the Gulf of Cádiz (SW Spain) as well as two dilutions of toxic mud coming from an accidental mining spill. With this objective, the coefficients of distribution (K D) for Zn between overlying water and sediments were calculated, the histopathological frequencies in the tissues of the gills and guts of clams were determined, and the biota-sediment bioaccumulation factors as well as the bioaccumulation factors were quantified in the different stations. Results showed that the greatest histopathological damages appeared when the salinity values decreased. Statistical results showed that salinity was inversely correlated with histopathological damage (p?<?0.01) for the lesion index for gills. The most outstanding results were observed in the two dilutions of toxic mud (0.3% and 7.9%) at a salinity value of 10. Salinity was inversely correlated with the concentration of Zn in biological tissues (p?<?0.05) and inversely correlated with the concentration of Zn in water and sediment. Zn mobilization to the overlying water is produced when salinity values decrease. 相似文献
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J. Van de Wauw G. Baert J. Moeyersons J. Nyssen K. De Geyndt Nurhussein Taha Amanuel Zenebe J. Poesen J. Deckers 《CATENA》2008
Though knowledge about the distribution and properties of soils is a key issue to support sustainable land management, existing knowledge of the soils in Tigray (Northern Ethiopian Highlands) is limited to either maps with a small scale or with a small scope. The goal of this study is to establish a model that explains the spatial soil variability found in the May-Leiba catchment, and to open the scope for extrapolating this information to the surrounding basalt-dominated uplands. A semi-detailed (scale: 1/40 000) soil survey was conducted in the catchment. Profile pits were described and subjected to physico-chemical analysis, and augerings were conducted. This information was combined with information from aerial photographs and geological and geomorphologic observations. The main driving factors that define the variability in soil types found were: 1) geology, through soil parent material and the occurrence of harder layers, often acting as aquitards or aquicludes; 2) different types of mass movements that occupy large areas of the catchment; and 3) severe human-induced soil erosion and deposition. These factors lead to “red-black” Skeletic Cambisol–Pellic Vertisol catenas on basalt and Calcaric Regosol–Colluvic Calcaric Cambisols–Calcaric Vertisol catenas on limestone. The driving factors can be derived from aerial photographs. This creates the possibility to extrapolate information and predict the soil distribution in nearby regions with a comparable geology. A model was elaborated, which enables the user to predict soil types, using topography, geomorphology, geology and soil colours, all of which can be derived from aerial photographs. This derived model was later applied to other catchments and validated in the field. 相似文献
14.
Lu Zhang 《Compost science & utilization》2019,27(1):46-60
This research determined whether addition of β-cyclodextrin (β-CD; 0, 0.15, or 0.25%) improved the two-stage composting of green waste (GW). The following parameters were measured during composting or in the final product: moisture content; volume; biochemical and chemical oxygen demand; humic substances; C/Nsolid and C/Nsoluble; microbial numbers (culturable bacteria, actinomycetes, and fungi); enzyme activities (pectinase and xylanase); microbial biomass carbon and nitrogen; degradation of organic components; contents of phosphorus (available and total), potassium, sodium, calcium, and magnesium; and toxicity to germinating seeds. The two-stage composting of GW was optimal with the addition of 0.15% β-CD. A mature and stable compost was obtained in only 28?days with the optimized two-stage composting rather than in the 90–270?days typically required for traditional composting. 相似文献
15.
Abstract Two types of soils (Brown Lowland soil and Ando soil), which were artificially enriched with different amounts of Cu, were incubated with or without pulverized orchard grass for 12 weeks at 25°C. For both soils with and without orchard grass amendment, the amount of CO2 evolved over the 12-week period of incubation decreased by the enrichment with Cu at a concentration exceeding 1,000 mg kg?1 soil. The decrease of the mineralization of added orchard grass in the Cu-enriched soil was conspicuous especially during the initial period of incubation. The amount of microbial biomass C at the end of the incubation was significantly reduced by the Cu enrichment regardless of the amendment with orchard grass. The relative decrease of the soil microbial biomass was much greater than that of the soil respiration. The amount of biomass C was negatively correlated with the amount of 0.1 M CaCl2-extractable Cu as a logarithmic function. On the other hand, the β-glucosidase activity at the end of the incubation was not significantly affected by the presence of Cu in the soils without orchard grass amendment and increased with the increase in the amount of enriched Cu in the orchard grass-amended soils. 相似文献
16.
《European Journal of Soil Biology》2008,44(4):373-380
Prosopis laevigata and Parkinsonia praecox are the most abundant perennial shrubs in the Tehuacán Desert, forming ’islands of fertility’ that dominate the alluvial terraces. Both species exhibit very similar phenology, with the timing of litter foliage being the only difference between them. P. praecox litter occurs shortly after the rains, while P. laevigata maintains its leaves until the next wet season. As degradable organic matter (OM) is one of the leading factors determining soil biota composition and activity, because of the OM provided by littering, we expected that the vertical distribution of the microbial community in the vicinity of the root zone of P. praecox would be higher in comparison to P. laevigata. One soil sampling was performed; during the rainy season in August, soil samples were collected from a 0–50-cm depth at 10-cm intervals, in the vicinity of the root canopy of four individual plants of each species and the interspaces between them. Soil moisture, organic matter, and counts of bacteria and fungi under shrubs were found to decrease from the upper to deeper layers. Respiratory activity was higher in the deeper layers (p < 0.01) in all three sampling sites. Total bacterial, fungal, and heterotrophic diazotrophs were found to be significantly (p < 0.001) more numerous under shrubs than in the interspace soil. No nitrogen-fixing bacteria were isolated from interplant soils in comparison to the soil samples collected beneath the shrubs. Heterotrophic diazotrophs significantly (p < 0.01) reduced more acetylene under P. praecox (29.0 nmol/g soil) than under P. laevigata (20.1 nmol/g soil). Although the microbial numbers were unaffected by differences in plant phenology, greater nitrogenase activity under P. praecox may influence nitrogen distribution in this arid environment. Due to the fact that only one sampling was undertaken, this study elucidates the differences in the microbial community between the two shrubs, but the dynamics in the above community could not be shown. 相似文献
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Eurasian Soil Science - A new view on the genesis and properties of soils in landscapes of the taiga–steppe ecotone in the Selenga Mountains of western Transbaikalia is suggested with due... 相似文献
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Water, Air, &; Soil Pollution - Lake E?irdir is one of the most important freshwater resources in Turkey. The lake is located at the border of Isparta province in South West Turkey, an area... 相似文献
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Eurasian Soil Science - To determine the distribution, migration, and accumulation characteristics of heavy metal pollution in the Youjiang River basin in South China, 71 shallow soil samples were... 相似文献
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V. S. Anisimov L. N. Anisimova L. M. Frigidova D. V. Dikarev R. A. Frigidov Yu. N. Korneev A. I. Sanzharov S. P. Arysheva 《Eurasian Soil Science》2018,51(4):407-417
The mobility and migration capacity of Zn in the soil-plant system were studied in a series of pot experiments with barley as a test plant. The parameters of Zn accumulation depending on the metal concentrations in soils and soil solutions were estimated by soil and water culture methods. Experiments with barley in water culture were performed on a nutrient (soil) solution extracted from soddy-podzolic soil (Albic Retisol (Loamic, Ochric)) to which Zn2+ was added to reach working concentrations increasing from 0.07 to 430 μM. Different responses of barley plants to changes in the concentration of Zn in the studied soil were identified. Ranges of the corresponding concentrations in the soil and aboveground barley biomass were determined. Parameters of Zn accumulation by test plants were determined depending on the metal content in soddypodzolic soil and the soil solution. A new method was proposed for evaluating the buffer capacity of soils with respect to a heavy metal (Zn) using test plants (BCS(P)Zn). The method was used to evaluate the buffering capacity of loamy sandy soddy-podzolic soil. The considered methodological approach offers opportunities for using data obtained during the agroecological monitoring of agricultural lands with heavy metals (HMs), including the contents of exchangeable HMs and macroelements (C and Mg) in soils and concentrations of HMs and (Ca + Mg) in plants, in the calculation of the buffering capacity of the surveyed soils for HMs. 相似文献