祁连山不同海拔氮磷循环细菌数量变化特征

祁连山植被的水源涵养作用对于维持黑河的流量至关重要,地下微生物参与生态系统的物质和能量循环,维持了地上植被的稳定,因而具有重要的生态作用. 研究分析了祁连山冰沟流域不同海拔梯度上硝化细菌、反硝化细菌、固氮细菌、解磷细菌和植酸矿化细菌的数量随土壤深度的变化规律. 结果表明：随土壤深度的增加,氮磷循环细菌的数量下降;随海拔升高,硝化细菌相对减少,而反硝化细菌和固氮细菌呈增多的趋势. 典范对应分析（CCA）显示,硝化细菌的数量变化主要受地下生物量和土壤pH值的影响,而反硝化细菌、固氮细菌、解磷细菌和植酸矿化细菌主要受植被盖度、地上生物量和土壤含水量的影响. 聚类分析表明,低海拔（E1-2 905 m和E2-3 128 m）浅层土壤（0~40 cm）聚类,而其深层土壤（60 cm）与高海拔（E3-4 130 m）土壤聚类,说明高海拔处土壤发育与低海拔处深层土壤的早期发育相类似. 研究表明,高山地区氮磷循环细菌数量的变化受到海拔主导下植被和土壤理化因子的共同作用.     

The polycyclic aromatic hydrocarbon concentrations in soils in the Region of Valasske Mezirici, the Czech Republic

The polycyclic aromatic hydrocarbon (PAH) contamination of urban, agricultural and forest soil samples was investigated from samples obtained in the surroundings of Valasske Mezirici. Valasske Mezirici is a town located in the north-east mountainous part of the Czech Republic, where a coal tar refinery is situated. 16 PAHs listed in the US EPA were investigated. Organic oxidizable carbon was also observed in the forest soils. The PAH concentrations ranged from 0.86-10.84 (with one anomalous value of 35.14) and 7.66-79.39 mg/kg dm in the urban/agricultural and forest soils, respectively. While the PAH levels in the urban/agricultural soils are within the range typically found in industrialized areas, the forest soils showed elevated PAH concentrations compared to other forest soils in Western and Northern Europe. The PAH concentrations and their molecular distribution ratios were studied as functions of the sample location and the meteorological history. The soils from localities at higher altitudes above sea level have the highest PAH concentrations, and the PAH concentrations decrease with increasing distance from the town.     

Total organic carbon in soils and its relation with manganese concentrations in soils and vegetation close to an abandoned manganese mine

This study aimed at quantifying the total organic carbon (TOC) present in soils within the proximity of the Kgwakgwe Mn oxide ore abandoned mine, Botswana, and establish its relationship with Mn concentrations in soils and vegetation based on multivariate and Geographical Information Systems (GIS) analytical techniques. Four hundred soil samples and 200 vegetation set samples were obtained from a 4 km² area close to the abandoned mine. The TOC in soil samples were determined using a carbon/hydrogen/moisture determinator, and Mn concentrations in soils and vegetation by atomic absorption spectrophotometry. Results were processed using the statistical package for social science (SPSS), GIS, and Remote Sensing (RS) techniques with the Integrated Land and Water Information System (ILWIS), Geosoft Oasis Montaj and ArcGIS software packages. The values for TOC in the soil samples from the study area ranged from 0 wt % to 7.91 wt %, with a mean of 1.90 wt %, and at the control area, from 4.07 wt % to 4.86 wt %. The range of concentrations of Mn in soils was from 36 mg/g to 24908 mg/g and for Mn concentrations in the vegetation samples from 26 mg/g to 3611 mg/g with a mean of 598 mg/g. Results of correlation coefficients depicted very weak negative association except Mn in soils/Mn in leaves which was weak but positive. The statistical data yielded four clusters as follows: cluster one consisted mainly of Mn in leaves, cluster two was constituted of Mn in soils, and cluster four had TOC. Cluster three was dominated by the three parameters but with negative t statistic. The spatial presentation of data presented revealed little or no vegetation in the south eastern area and those close to the mine workings, and some significant vegetation in the north western part of the study area. The low TOC in the soils is associated to low vegetation cover which is considered to have been influenced by the soil clay fraction mineralogy and high concentrations of Mn.     

Soil moisture dynamics under different land uses on karst hillslope in northwest Guangxi,China

Temporal and spatial dynamics of soil moisture are little known on karst hillslope with shallow soil in subtropical region. The objectives of this paper were (1) to investigate the temporal dynamics of soil moisture at depth of 0–10 cm under different land uses; and (2) to understand the relationship between mean and coefficient of variation (CV) of moisture contents on karst hillslope in northwest Guangxi, China. Soil moisture contents had a moderate variation (CV 17.5–30.3%) over an 8-month period and they had a significant difference among different land uses at the 0.01 level with a decreasing order: native scrubland > abandoned cropland and sloping cropland > economic forestland. There were higher mean and lower CV of moisture contents in rainy season than those in drought season. Mean and CV of moisture contents had a significant negative linear relationship except in abandoned cropland with higher soil and vegetation heterogeneity. This suggested that spatial variability of soil moisture within sampling sites would decrease when soils were wet and increase when soils were arid. Compared with rainy season, more soil samples may be needed and the interval for sampling should be shortened in drought season. Such information provided some insights to better understand the dynamics and variability of soil moisture at a larger scale in karst region of southwest China.     

The development and nature of soils on Rakata

The properties and development of soils derived from pumiceous tuff of the 1883 Krakatau eruption were studied on Rakata island during 1983 and 1989. Field observations on soil profiles of different altitude and topography, and laboratory data, revealed that in a period of 100 years soil development has resulted in the formation of a pronounced A-horizon of 5–15 cm thickness underlaying an AC or weak B horizon. Solum development commonly reaches to a depth of approximately 25 cm. The dominant process of soil formation was decomposition of organic matter and aggregation of soil particles in the surface horizon. There was also a slight indication of iron and fine clay translocation but base cations were accumulating in the surface horizon. Soils at 600 m altitude and higher commonly contained lower base saturation, pH, and weatherable minerals, and higher exchangeable A1 and H than those at lower altitudes. The dominant clay minerals were montmorillonite, kaolinite and other layer silicate clays. It is believed that the clays were not formed pedogenically. Some pedons at higher altitudes were dominated by amorphous material in the clay fraction.Presented at the XVII Pacific Science Congress, May 27–June 2, 1991. Honolulu, Hawaii, USA     

Geochemistry and genotoxicity of the heavy metals in mine-abandoned areas and wasteland in the Hetai goldfields,Guangdong Province,China

The article presents the geochemical and biogeochemical characteristics of heavy metal elements within the soil–plant system in the Hetai mine-abandoned areas and wasteland, China. The cytogenetic toxic effects of gold mine wastelands environment on the chromosome and micronucleus were analyzed by genetic methods. The results showed that abundances of Au and Au-associated heavy metal elements such as Cu, As, Cd, Pb and Hg in soils, plants and the pigments in those abandoned mine areas were much higher than those in the background region. The cell structures of the plants in the abandoned mine areas were anomalous and aberrant, and there were many nano-metal particles diffused in the cells. Moreover, the heavy metal elements in those abandoned mine areas had entered the ultrastructure and caused toxicities to the organism.     

Effects of sewage sludge and nitrogen fertilizer on herbage growth and soil fertility improvement in restoration of the abandoned opencast mining areas in Shanxi, China

A field trial was conducted to investigate the effects of application of sewage sludge and nitrogen fertilizer on herbage growth and fertility improvement of raw mixed-loess soils at the west waste dump of Antaibao surface mine (ATB) in Shanxi, China. Four indigenous species present in mining areas, including Kentucky bluegrass, Erect milkvetch, Alfalfa and Alfalfa–ryegrass mixture were selected as the herbaceous plants in the field trial. The results showed that applying sewage sludge and nitrogen fertilizer, biomasses of all the four grasses were significantly increased when compared with those in the control group. After 100 days growth, applying sewage sludge had the greatest effects on biomass increasing for Kentucky bluegrass (17.54 times in the overground yields and 13.94 times in underground yields when compared with the control group) or Alfalfa–ryegrass mixture (5.34 and 7.20 times, respectively); meanwhile, the combined application of sewage sludge and nitrogen fertilizer also had the best effects. It was concluded that Kentucky bluegrass is the best pioneer species for quickly establishing vegetation in ATB abandoned opencast mining areas; municipal sewage sludge is an effective bio-fertilizer for the fertility improvement of raw mixed-loess soils; and the combined application of sewage sludge and nitrogen fertilizer in plots revegetated with Alfalfa–ryegrass mixture is the best strategy to help quickly establish a self-sustaining vegetation system during the primary stage of reclamation in ATB abandoned opencast mining areas in China.     

Geological impact of some tailings dams in Sardinia,Italy

This article deals with the results of a survey carried out in Sardinia on both active and abandoned tailings dams, and we also discuss the geological impact of tailings dams of two mines: the Masua mine, a large syngenetic Pb-Zn deposit located in Cambrian limestones, and the Montevecchio mine, a Pb-Zn vein deposit near a Hercynian granite intrusion. The characteristics and metal content of material in the dams were analyzed. A high contamination of heavy metals (Pb, Zn, Cd, Cu) was found both in the soils and water of Rio Montevecchio, a stream draining the tailings dams and other mining operations in the area.The study indicates that a control plan to minimize heavy metal pollution must be drawn up for all mines of the area, whether active or abandoned.     

The lateglacial lakes of Glens Roy,Spean and vicinity (Lochaber district,Scottish Highlands)

This paper summarises the evidence for glacial ice advance into lower Glen Spean during the Loch Lomond Stadial which involved the blockage of westward-flowing drainage to form a series of ice-dammed lakes, the former surfaces of which are marked by prominent shorelines. Detailed mapping of glacigenic landforms and instrumental levelling of the shorelines reveals a dynamic interplay between the glacier margins and lake formation. Subsequent deglaciation led to lowering of the lake levels, at times by catastrophic drainage beneath the ice (jökulhlaup). The abandoned shorelines have been warped and dislocated in numerous places as a result of glacio-isostatic deformation, faulting and landslip activity. The pattern of retreat of the ice can be deduced from the mapped distributions of retreat moraines and the levelled altitudes of numerous kame and fluvial terrace fragments. The sequence of events outlined in this paper provides important context for understanding the evolution of the landscape of the Glen Roy area during the Loch Lomond Stadial, and a prelude to more recent studies reported in other contributions to this thematic issue.     

Effects of natural and calcined oyster shells on Cd and Pb immobilization in contaminated soils

In Korea, soils adjacent to abandoned mines are commonly contaminated by heavy metals present in mine tailings. Further, the disposal of oyster shell waste by oyster farm industries has been associated with serious environmental problems. In this study, we attempted to remediate cadmium (Cd)- and lead (Pb)-contaminated soils typical of those commonly found adjacent to abandoned mines using oyster shell waste as a soil stabilizer. Natural oyster shell powder (NOSP) and calcined oyster shell powder (COSP) were applied as soil amendments to immobilize Cd and Pb. The primary components of NOSP and COSP are calcium carbonate (CaCO₃) and calcium oxide (CaO), respectively. X-ray diffraction, X-ray fluorescence and scanning electron microscope analyses conducted in this study revealed that the calcination of NOSP at 770°C converted the less reactive CaCO₃ to the more reactive CaO. The calcination process also decreased the sodium content in COSP, indicating that it was advantageous to use COSP as a liming material in agricultural soil. After 30 days of incubation, we found that the 0.1 N HCl-extractable Cd and Pb contents in soil decreased significantly as a result of an increase in the soil pH and the formation of metal hydroxides. COSP was more effective in immobilizing Cd and Pb in the contaminated soil than NOSP. Overall, the results of this study suggest that oyster shell waste can be recycled into an effective soil ameliorant.     

Hazard assessment on arsenic and lead in soils of Castromil gold mining area,Portugal

Castromil is one of the Au mining areas in Portugal that has been abandoned since 1940. Due to the lack of regulations and environmental education, Castromil is now a residential area suffering from the considerable consequences of poorly regulated mining activities; tailings, shafts and adits are present. Geochemical data related to environmental studies in old mining areas frequently show extremely high values and very skewed distributions that need to be properly addressed. Agricultural soils from this region have high concentrations of As and Pb. In this study, the Box–Cox transformation and geostatistics were applied to study heavy element (As and Pb) concentrations in soils in order to characterize the hazard posed by them in the area. This provides a decision support tool to define the areas where remedial action is needed in light of the risks to humans and ecosystems and for contaminant migration. The results discussed here take into account the hazard-based standards for soils as target and intervention values.     

Enrichment of metals in soils subjected to different land uses in a typical Mediterranean environment (Murcia City, southeast Spain)

Industrialization, urbanization, and agricultural practices are 3 of the most important sources of metal accumulations in soils. Concentrations of Cr, Mn, Ni, Cu, Pb, Zn and Cd were determined in surface soils collected under different land uses, including urban (UR), industrial (IN-1 and IN-2), agricultural (AG), abandoned unused (AB), and natural (NA) sites to examine the influence of anthropogenic activities on metals in soils formed in a typical Mediterranean environment. The highest concentrations of Cr, Cd, and Pb observed in the NW industrial area (IN-2) were 63.7, 3.34 and 2330 mg metal kg⁻¹ soil, for each metal, respectively. The SW industrial area (IN-1) contained the highest Zn content at 135 mg kg⁻¹. However, soils with the highest concentrations of Ni and Cu were located in AG sites at 30.9 and 64.9 mg kg⁻¹ soil, respectively. Sampling locations with the highest concentrations of Mn were identified in AB sites. Using the concentrations of metals at the NA sites as the baseline levels, soils collected from all other land uses in the study area exhibited significantly higher total contents of Zn, Mn, Cr and Ni. Metal enrichment was attributed to fertilizer and pesticide applications, industrial activities, and metal deposition from a high volume of vehicular traffic (for Pb and Cd). High concentrations of Mn in some samples were attributed to parent materials. The study demonstrated that anthropogenic activities associated with various land uses contribute to metal accumulation in soils and indicated a need to closely monitor land management practices to reduce human and ecological risks from environmental pollution.     

Pilot-scale field investigation of ex situ solidification/stabilization of soils with inorganic contaminants using two novel binders

Recently, two novel binders, one by-product-based binder named as GM and one phosphate-based binder named as KMP, have emerged that can stabilize soils spiked with mixed lead and zinc contaminants. However, field evaluations of the stabilization of actual soils that contaminated with mixed zinc (Zn) and inorganic chloride (Cl^?) using GM and KMP have not been performed yet. This study presents a pilot-scale field test to evaluate the performance of GM and KMP to stabilize these inorganic contaminants in soils at two locations in an abandoned industrial plating plant site. The field soils were stabilized and cured for 1, 3, 7, and 28 days and tested for dry density, dynamic cone penetration, soil pH, and leachability. Laboratory unconfined compression tests were performed, and the relationship between unconfined compressive strength and dynamic cone penetrometer index was assessed. The results showed that the strength of both the GM- and KMP-stabilized soils after 28-day curing improved significantly, and the leached Zn and Cl^? concentrations were well below the corresponding remediation limits. In general, the KMP-stabilized soil demonstrated superior performance in terms of higher dry density, unconfined compressive strength, average dynamic cone penetration resistance, lower dynamic cone penetrometer index in the early curing stage (7 days), and lower leached Zn concentration under all curing times. In contrast, the GM exhibited superior immobilization of Cl^? in the contaminated soil irrespective of the curing time. The results demonstrate that GM and KMP are promising binders for treating Zn- and Cl^?-contaminated soils at plating and other industry sites with similar contaminants.

     

Geochemical assessment of an arsenic mine adjacent to a water reservoir (León, Spain)

A water reservoir constructed for production of hydraulic energy and drinking water in the Riaño valley (León, northern Spain) receives leachates from polluted soils and spoil heaps from a site where small-scale As mining and smelting operations have been developed in the first half of the twentieth century. Water of the upper catchments of the Esla, Yuso and Orza Rivers is stored in this reservoir. The location of these abandoned mine works within the reservoir drainage basin suggested that the stored water could contain high As concentrations. In order to evaluate possible environmental risks, a preliminary soil and surface water geochemical survey has been carried out downstream of the Santa Águeda Mine. Total As concentrations in soils reach 23,800 mg kg^?1 in soils and increase with depth, at least up to a depth of 80 cm. Total As concentrations in surface waters reach 890 μg l^?1. Despite the fact that there is an important As input to the water reservoir, the water flow from the mine catchment is a negligible contribution when compared with the total volume of water inside the dam (0.07%). This fact considerably decreases the environmental risk associated with the presence of untreated spoil heaps containing As-rich minerals at Santa Águeda mine site.     

南宁外环膨胀土路基处治技术及设计方案研究

拟建南宁外环路穿越膨胀土分布区,若实施刚性支挡难以保证开挖边坡稳定,沿用弃土换填方案填筑路堤至少需废240万方,使工程投资大增并严重破坏生态环境,为此,研究运用膨胀土处治新技术进行路基工程设计。通过系统土性、填料性质试验,论证了物理处治技术修建膨胀土路堤的可行性;采取FLAC和极限平衡分析,获得实施柔性支护前后典型膨胀土堑坡的稳定性。基于试验、理论分析并借鉴交通部西部膨胀土项目的成功经验,提出两种封闭包盖措施填筑南宁膨胀土下路堤、不同边界条件下的路堑边坡柔性支护设计方案。对比分析表明,采用新技术效益明显,能实现南宁外环高速路安全、经济、节能环保的修建目标     

Comparison of elements of environmental concern in regular and reclaimed soils,near abandoned coal mines Ptolemais–Amynteon,northern Greece: Impact on wheat crops

A comparative study related to the concentrations of trace elements especially those of environmental concern, occurring in regular and reclaimed soils on abandoned coal mines as well as on their respective wheat crops has been undertaken in the vicinity of Ptolemais–Amynteon, Greece. The aim was to assess the impact of land reclamation on the crops.The results of elemental analysis show that the concentration of As is 1.5 to 1.7 times higher in the regular soils than in the reclaimed ones, similarly Co is 2.4 to 2.6 times higher, Cr is 1.7 to 2.8 times higher, Ni is 1.9 to3.1 times higher, Pb is 0.8 to 4.6 times higher, and Hg is equal to or 1.7 times higher. Cu, Cd and Se have the same concentration in both kind of soils and Mo and U are 1.7 to 2.0 times lower in the regular soils as compared to the reclaimed soils. Nevertheless, all concentrations are within the reported range for regular soils.Moreover, the concentrations of the studied elements in wheat grains harvested from both types of soils are approximately the same. The reason for the uniform uptake of elements by the plants is the very low solubility of the elements in the soil solutions. This is attributed to the high soil pH and the nature of the occurrence or bonding of the elements in soil minerals.     

Soil,archaeological, biotic,and climatic relationships for the late holocene of the Wyoming basin: The case of the Garrett Allen (Elk Mountain) site (48CR301)

Soils at the Garrett Allen (Elk Mountain) site (48CR301) along Quealy Spring in Carbon County, Wyoming, indicate nearly continuous, although episodic, meadow soil formation during much of Neoglacial or post-Altithermal time at a mountain-basin edge (elev. 2237 m) of the Wyoming Basin. Seven relict and buried meadow soils now under sagebrush (Haplaquents or Fluvaquents, Haplaquolls, and Argiaquolls) of the T₁ terrace date less than 200 B.P. as well as around 200, 600, 900, 1700, and two soils at greater than 3100 B.P. Composite-superposed soils of two or more of the individual soils are common. Some soils have E horizons and the older ones have intensely gleyed cambic or argillic subsoils. Development of meadow soils and deposition of their respective parent materials seem to coincide with glacial episodes in the region when the climate may have been somewhat humid. Occupations of the meadow by Archaic and younger cultural groups, whose artifacts occur mainly in A(O?) horizons of meadow soils, appear to coincide with these humid–glacial climates when the meadow grew and flourished. Changes in subsistence and settlement of these peoples may have been partly influenced by humid climates during glacial episodes when rangeland and habitat were able to support large human and animal populations. However, four major erosional unconformities separate some soils. These unconformities may coincide with times of lessened glacial activity when the climate may have become drier and the meadow decreased in size. During these times, human groups may have abandoned the meadow, left the region, or only sparsely occupied the plains and basins. The youngest unconformity developed when Quealy Spring cut from T₁ to the T₀ level in the last century. This appears to coincide with sagebrush invasion across portions of the meadow, although a small relict meadow still exists. Sagebrush invasion and downcutting of the drainage may relate to climatic drying in the last century. Fluvents are now forming in alluvium of the T₀ level along the Quealy Spring drainage.     

Late Pleistocene and Holocene History at Mubwindi Swamp, Southwest Uganda

Deposits beneath Mubwindi Swamp provide a partial record of vegetation history since at least 43,000 yr ago. We studied pollen from two cores and obtained nine radiocarbon ages from one of these cores and three radiocarbon ages from the other. Pollen deposited before and soon after the last glacial maximum represents vegetation very different from the modern vegetation of the Mubwindi Swamp catchment. Although species now associated with higher altitudes were dominant some elements of moist lower montane forest persisted, possibly because of favorable soils or topography. The pollen data provides evidence for a late glacial montane forest refuge near Mubwindi Swamp. Moist lower montane forest became much more widespread soon after the glacial maximum. The only irrefutably Holocene sediments from Mubwindi Swamp date to the past 2500 yr. During this time a combination of climatic and human-induced changes in vegetation can be seen in the pollen records.     

不同耕作类型下土壤-农作物系统中汞、砷含量与生态健康风险评价

针对废弃矿山遗留生态环境问题,选择贵州丹寨废弃金汞矿为研究区,基于野外系统样品采集,通过原子荧光法和电感耦合等离子体质谱法分析了区内土壤和农作物中的汞(Hg)、砷(As)浓度,采用单指标污染标准指数法、单因子污染指数法、潜在生态危害指数法和目标危险系数法评价了区内Hg、As污染程度及生态健康风险.结果显示:旱地土壤Hg...     

垂直地带性岩溶生态环境特征初探——以金佛山国家自然保护区为例

由于特殊的地理环境,金佛山自然保护区的垂直地带性岩溶生态特征明显.通过研究发现,金佛山在不同海拔地质背景基础上,土壤、物种多样性和山上山下两种不同特征的岩溶动力系统.土壤分带性主要表现为：从山下向山顶依次为黄壤、暗黄壤、黄棕壤和棕壤.物种多样性主要表现为：植被种类繁多,动物类型复杂多样,是同类地区所罕见的,大大丰富了我国野生生物基因库.岩溶动力系统主要表现为：土壤CO₂和水化学特征的差异显著,从而形成了山上山下两个不同特征的岩溶动力系统,山下岩溶作用明显强于山顶.