首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 906 毫秒
1.
In the year 2000, the elemental composition of mosses collected from 528 French sites has been studied as part of the 2000 European Moss Survey. Five moss species were collected: Scleropodium purum (56%), Pleurozium schreberi (18%), Hypnum cupressiforme (18%), Thuidium tamariscinum (4.5%.) and Hylocomium splendens (3.5%). Mosses were kept whole for analysis, including green and brownish parts. Summary statistics on element concentrations (Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Na, Ni, P, Pb, Rb, Sr, V and Zn), and comparisons made with data from the other 27 participating European countries are shown here. The sources of these elements are identified using calculations of enrichment factors (EF) and principal component analysis (PCA). Finally, the spatial distribution in France of 10 elements is also shown, using maps underscoring areas showing highest concentration levels for each metal.  相似文献   

2.
Concentrations of the elements Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V and Zn were measured in the moss Pleurozium schreberi from the Tatra National Park, one of the most protected regions in Poland. The moss samples were collected at different elevations between 860 and 2220 m a.s.l. P. schreberi was used as bioindicator for long range transported atmospheric pollution investigating the hypothesis that elevation influences the concentrations of elements in this moss. Principal component and classification analysis (PCCA) distinguished between mosses from the highest and the lowest elevations and mosses from West/East oriented valleys. P. schreberi from the highest elevations contained the highest concentrations of Cd, Cu, Cr, Fe, Mn, Pb, V and Zn. P. schreberi from the lowest elevation contained the highest concentration of K. P. schreberi from West/East oriented valleys contained the highest concentrations of Ni and Co. P. schreberi from the Tatra National Park, one of the most protected areas in Poland, receives metals originating from long distance aerial transport.  相似文献   

3.
Trace Metals in Mosses in the Estonian Oil Shale Processing Region   总被引：1，自引：0，他引：1  
Electric energy production and most heavy industry in Estonia are concentrated in the north-eastern part of the country. Thermoelectric power plants (total maximal capacity over 3 GW), cement and chemical industries are fueled by Kukersite oil shale, mined nearby. The mineral part of oil shale is rich in trace metals that can accumulate in the local ecosystem. Samples of epigeic mosses Pleurozium schreberi and Hylocomium splendens were taken in 1992, 1997 and 2002 from sites 1 km to 30 km from the main air pollution sources and analysed for Cd, Cr, Cu, Fe, Ni, Pb, V and Zn. For background data collection, analogous measurements within the national monitoring programme were used. Raster maps of concentrations were generated from the measurements, using the Kriging algorithm. These maps were compared with the model-estimated (AEROPOL model) maps of fly ash and cement dust deposit from the past. The concentration of trace metals in mosses is highly (Cr, Fe, Ni, V) or moderately (Cd, Cu, Pb, Zn) affected by the airborne emissions of the oil shale industry. During the past decade the uptake of the first group of elements in the industrial zone has decreased 3–4 times in proportion to emissions.  相似文献   

4.
The first systematic study in Romania of atmospheric pollution from heavy metals and other toxic elements based on moss analysis was undertaken as a Romanian–Russian–Norwegian collaboration, primarily in order to assess the general state of heavy metal pollution in Romania. An additional goal was to contribute to the European heavy metals in mosses survey, conducted under the auspices UNECE ICP Vegetation which reports to the Working Group of Effects of the Long-range Transboundary Air Pollution Convention. Samples of the moss species Hypnum cupressiforme, Hylocomium splendens and Brachytechium salebrosum and B. rutabulum were collected during the period 1995–2001. A total of 40 elements were determined using NAA and AAS. The total concentrations of arsenic, cadmium, copper, nickel, vanadium and zinc are presented in the form of contour maps. Generally, the observed concentrations in Romania are markedly higher than those observed in most other countries of Europe using the moss technique.  相似文献   

5.
Goal and Scope. The UNECE heavy metals in Mosses Surveys provide data on the accumulation of metals in naturally growing mosses throughout Europe. Using Germany as an example, this article concentrates on the elaboration and application of methods of data analysis that are necessary for a comprehensive interpretation of spatial and temporal trends in metal accumulation.Methods and Results. The sampling of mosses, and the chemical analysis of Cr, Cu, Fe, Ni, Pb, Ti, V and Zn in 1990, 1995 and 2000 are summarized briefly. The variogram analyses detect distinct autocorrelation structures in the sample data which may consequently be estimated for all sites in Germany without monitoring metal accumulation by means of ordinary kriging. A procedure for the geostatistical detection of spatial outliers was developed and applied and, after the elimination of the spatial outliers, several measurements were seen to indicate an adequate quality of the geostatistical estimations. The cluster analyses of the z-transformed estimation data result in a nominal multi-element index that indicates regional metal accumulation types over time. Percentile statistics serve for computation of an ordinal, scaled, multi-element accumulation index which is spatially differentiated over time in terms of multivariate, statistically defined ecoregions. The integrative statistical analysis reveals, from 1990 to 2000, that the metal accumulation declines up to 80% in some of the ecoregions. Hot spots of metal accumulation are mapped and interpreted by means of metadata analysis.Conclusions. Dot maps depict the spatial structure of the metal accumulation without spatial bias. This information, detailed with respect to metal species and space, should be generalized for better supporting the interpretation. The combination of geostatistical analysis and estimation, percentile and multivariate statistics is suitable for the calculation of indices that serve for a comprehensive mapping of metal accumulation in the ecoregions over time, for quantifying the bias of the surface estimation, and for mapping spatial outliers and hot spots of metal accumulation.  相似文献   

6.
Data on deposition density of Ag, Al, As, B, Ba, Bi, Br, Ca, Cd, Co, Cr, Cs, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Si, Sn, Sr, Th, Tl, U, V, Zn, Cl?, NO 3 ? , and SO4 4 2? in atmospheric precipitation were derived at 11 observation stations in the northern part of the European territory of Russia (ETR). Three sets (factors) of chemical indices that are mutually independent and determine the precipitation chemical content over that territory were revealed by using the hierarchical factor analysis of deposited density of chemical ingredients studied. These are two first-order factors: one is presented with the elements of a “marine” origin; the second is associated with biogenic elements. The second-order factor is formed by the ingredients characteristic of the combustion products of different fossil fuels. The structure and space-time distribution of factors are considered. The discriminant and cluster analyses allowed to classify the observation stations considered by the atmospheric precipitation chemistry and to show that Amderma, Vorkuta, Arkhangelsk, and Kargopol stations mostly differ from each other.  相似文献   

7.
This work attempts to characterize metallic elements associated with atmospheric particulate matter on a dry deposition plate, a TE-PUF high-volume air sampler and a universal air sampler. Dry deposition fluxes of particulates and concentrations of total suspended particulate, fine (PM2.5) and coarse (PM2.5–10) particulate matters were collected at Taichung harbor sampling sites from August 2004 to January 2005. Chemical analyses of metallic elements were made using a flame atomic absorption spectrophotometer coupled with hollow cathode lamps. Concentrations of metal elements in the forms of coarse particles and fine particles as well as the coarse/fine particulate ratios were presented. Statistical methods such as correlation analysis, principal component analysis and enrichment factor analysis were performed to compare the chemical components and identify possible emission sources at the sampling sites. Metallic elements of Cu, Zn, Pb, Cr, Ni and Mg had higher EFcrust ratios in winter and spring than in summer and autumn. Diurnal and nocturnal variations of metallic element concentrations in fine and coarse particles were also discussed.  相似文献   

8.
Biomonitoring of atmospheric deposition loads of 13, 14 and 35 elements and their compounds through moss analysis was carried out in the Czech Republic (CZ) in 1991, 1995 and 2000, respectively. The last biomonitoring campaign revealed very high contents of typical soil elements and lanthanides in southern Moravia. The variations in current element contents in moss, which can be explained by the action of six factors, were correlated with altitude, with total biennial precipitation, and with the bedrock types in the sampling plots. The element contents in moss samples repeatedly collected from the identical plots showed a steady decrease in atmospheric deposition loads in the CZ in the last decade of the 20th century. The main reasons for this phenomenon are listed. The results of cluster analyses and PCAs have found no substantial changes in the qualitative element composition of atmospheric deposition in CZ in recent years. Isoline maps are presented, which document changes in the distribution of Cd, Pb and S contents in moss in 1995 and 2000. An estimate of absolute deposition loads (g m–2 year–1) for given areas of the CZ can be made, using the list of bulk deposition indices.  相似文献   

9.
In order to investigate the chemical characteristics of atmospheric aerosols in a regional background site, PM2.5 and PM10 were collected at Mount Gongga Station once a week in 2006. The concentrations of fifteen elements including Na, Mg, Al, K, Ca, V, Fe, Ni, Cu, Zn, As, Ag, Ba, Tl, and Pb were detected by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The results showed that Na, Mg, Al, K, Ca, Fe were the major components of elements detected in PM2.5 and PM10, occupied 89.5% and 91.3% of all the elements. Crustal enrichment factor (EF) calculation indicated that several anthropogenic heavy metals (Ni, Cu, Zn, As, Ag, Tl, Pb) were transported long distances atmospherically. The concentrations of all elements (except Na) measured in PM2.5 and PM10 in spring and winter were higher than those in summer and autumn. The backward air mass trajectory analysis suggests that northeast India may be the source region of those pollutants.  相似文献   

10.
《Atmospheric Research》2005,73(1-2):87-100
Coarse (>2.2 μm) and fine (<2.2 μm) atmospheric particulate material samples were collected from an urban area (Al-Hashimya, Jordan), from August 2000 to August 2001 using a “GENT” stack filter unit (SFU). Collected samples were analyzed for 19 elements using inductively coupled plasma mass spectrometry (ICP-MS). The crustal elements exhibit atmospheric concentrations that are comparable to those in urban and industrial areas. The anthropogenic elements, on the other hand, are clearly less abundant in Al-Hashimya than in other industrial regions. Results indicated that, elements of crustal origin are associated with the coarse particles, while elements of anthropogenic origins are more associated with fine particles. Concentrations of crustal-derived elements were higher in summer and those of anthropogenic elements were higher in winter. Crustal enrichment factor calculations showed that concentrations of Pb, Zn, Cd, Sb and Ag are highly enriched and of As, Cu, Co, Ca and Ni are moderately enriched. Factor analysis calculations permitted the identification of four source groups for the fine fraction, namely oil combustion, crustal and urban dust, smelting industries and motor vehicles.  相似文献   

11.
At four industrial regions, heavy metal concentrations and calculated depositions were investigated by sampling and analysing mosses. In each region, a special spatial pattern of heavy metal concentrations was detected, reflecting the industrial processes. Metals most likely originating from the industrial sites showed an exponential decrease of concentrations and depositions with increasing distance from the pollution source. The exponential deposition pattern was in some cases modified by a series of natural factors, like the main direction of winds or orographic conditions. The distance at which deposition dropped to background values was up to 20 km. Beside the fact that the moss-metho is a useful tool for deposition measurement in the vicinity of stationary sources, some improvements for using this method are discussed, highlighting factors such as a proper calculation of deposition from concentrations, or the better knowledge of correlations between heavy metal concentrations in mosses and effects on human health.  相似文献   

12.
Total suspended particulates(TSP)samples were collected using low pressure impactors(Andersen Series 20-800,USA)on typical clear,hazy and foggy days in Beijing in order to investigate the characteristics of size distributions and elemental compositions of particulate matter(PM)in different weather conditions. The concentrations of sixteen elements,including Na,Mg,Al,K,Ca,Mn,Fe,Ni,Cu,Zn,As,Se,Cd,Ba,Tl and Pb were detected using inductively coupled plasma mass spectrometry(ICP-MS).The results showed that Ca,Al,Fe,Mg and Ba on foggy days were 2.0-2.6 times higher than on clear days,and 2.3-2.9 times higher than on hazy days.Concentrations of Cu,Zn,As,Se and Pb on foggy days were 163.5,1186.7,65.9,32.0 and 708.2 ng m-3,respectively,in fine particles,and 68.1,289.5,19.8,1.6 and 103.8 ng m-3,respectively,in coarse particles.This was 1.0-8.4 times higher and 1.4-7.4 times higher than on clear and hazy days,respectively.It is then shown that Mg,Al,Fe,Ca and Ba were mainly associated with coarse particles,peaking at 4.7-5.8μm;that Cd,Se,Zn,As,Tl and Pb were most dominant in fine particles,peaking at 0.43-1.1μm;and that Na,K,Ni,Cu and Mn had a multi-mode distribution,with peaks at 0.43-1.1μm and 4.7-5.8μm.The enrichment factors indicated that coal combustion along with vehicle and industry emissions may be the main sources of pollution elements.  相似文献   

13.
A biomonitoring survey using the moss species Hypnum cupressiforme Hedw. was performed in the North of Navarra (Spain) in 2006. The levels of V, Cr, Mn, Ni, Cu, Zn, As, Zr, Cd, Hg and Pb, and the total nitrogen content were determined in the samples by means of ICP-MS, CV-AA, and the Kjeldahl method. PCA analysis showed a differentiation between lithogenic (V, Cr, Mn, Ni, As and Zr) and anthropogenic elements (Mn, Cu, Zn, Cd, Hg and Pb). Spatial distribution maps were drawn using the kriging method, in order to identify the most affected areas and the main pollution sources. A similar spatial distribution was observed for the elements belonging to each group separated by the PCA, showing an important contribution from metal industries located in the Basque Country, as well as influence of long-range transboundary pollution processes. Background levels were also determined for the study area, along with the contamination factor for the different elements analysed. Mosses seemed to be good biomonitors of N deposition in areas of accumulation.  相似文献   

14.
Gross primary production (GPP) plays a crucial part in the carbon cycle of terrestrial ecosystems. A set of validated monthly GPP data from 1957 to 2010 in 0.5° × 0.5° grids of China was weighted from the Multi-scale Terrestrial Model Intercomparison Project using Bayesian model averaging (BMA). The spatial anomalies of detrended BMA GPP during the growing seasons of typical El Ni?o years indicated that GPP response to El Ni?o varies with Pacific Decadal Oscillation (PDO) phases: when the PDO was in the cool phase, it was likely that GPP was greater in northern China (32°–38°N, 111°–122°E) and less in the Yangtze River valley (28°–32°N, 111°–122°E); in contrast, when PDO was in the warm phase, the GPP anomalies were usually reversed in these two regions. The consistent spatiotemporal pattern and high partial correlation revealed that rainfall dominated this phenomenon. The previously published findings on how El Ni?o during different phases of PDO affecting rainfall in eastern China make the statistical relationship between GPP and El Ni?o in this study theoretically credible. This paper not only introduces an effective way to use BMA in grids that have mixed plant function types, but also makes it possible to evaluate the carbon cycle in eastern China based on the prediction of El Ni?o and PDO.  相似文献   

15.
Methane(CH4) is an important greenhouse gas second only to CO2 in terms of its greenhouse effect. Vegetation plays an important role in controlling soil CH4 fluxes, but the spatial variability of soil CH4 fluxes during vegetation restoration in Loess Hilly Region(LHR) is not fully understood. The effects of different plant community types [Medicago sativa grassland(MS); Xanthoceras sorbifolium forestland(XS); Caragana korshinskii bushland(CK); Hippophae rhamnoide...  相似文献   

16.
Improving our ability to predict the impact of climate change on the carbon (C) balance of boreal forests requires increased understanding of site-specific factors controlling detrital and soil C accumulation. Jack pine (Pinus banksiana) and black spruce (Picea mariana) stands along the Boreal Forest Transect Case Study (BFTCS) in northern Canada have similar C stocks in aboveground vegetation and large woody detritus, but thick forest floors of poorly-drained black spruce stands have much higher C stocks, comparable to living biomass. Their properties indicate hindered decomposition and N cycling, with high C/N ratios, strongly stratified and depleted δ13C and δ15N values, high concentrations of tannins and phenolics, and 13C nuclear magnetic resonance (NMR) spectra typical of poorly decomposed plant material, especially roots and mosses. The thinner jack pine forest floor appears to be dominated by lichen, with char in some samples. Differences in quantity and quality of aboveground foliar and woody litter inputs are small and unlikely to account for the contrasts in forest floor accumulation and properties. These are more likely associated with site conditions, especially soil texture and drainage, exacerbated by increases in sphagnum coverage, forest floor depth, and tannins. Small changes in environmental conditions, especially reduced moisture, could trigger large C losses through rapid decomposition of forest floor in poorly drained black spruce stands in this region.  相似文献   

17.
一种新的El Niño海气耦合指数   总被引：6，自引：1，他引：5  
利用1980～2010 年月平均Hadley中心海表温度、美国全球海洋资料同化系统(GODAS)海洋温度和NCEP/NCAR 大气环流再分析资料,通过对2 个海洋要素(海表温度SST、上层热含量HC)和5 个大气要素(海平面气压SLP、850 hPa 风场、200 hPa 速度势和对外长波辐射OLR)的多变量经验正交函数展开(multivariate EOF,简称MV-EOF)探讨了热带太平洋的主要海气耦合特征。结果表明,MV-EOF 分析的前两个耦合模态分别很好地对应了传统型El Ni?o 和El Ni?o Modoki 的海气耦合特征:传统型El Ni?o 期间,伴随着赤道中东太平洋SST 的异常增温,HC、SLP、200 hPa 速度势等要素总体呈东西反相的“跷跷板”变化,低层850 hPa 赤道中太平洋出现较强西风距平,西北太平洋上空为反气旋性异常环流;El Ni?o Modoki 期间,SST 持续增温和HC 正异常中心均显著西移至中太平洋,低层SLP 和高空200 hPa 速度势均呈现纬向三极型异常分布,低层异常强西风向西移至暖池东部,西北太平洋上空呈现气旋性异常环流。两类El Ni?o 的海气耦合特征存在显著差异,较优的El Ni?o 指数应不仅可以客观描述和区分El Ni?o 现象本身,更要紧密联系两类事件所产生的大气响应。以往定量表征El Ni?o 年际变化的指标大多立足于SST 或SLP,本文选取HC 作为研究指标,定义了一组新的El Ni?o 指数HCEI 和HCEMI。较以往基于SST 的El Ni?o 指数,HCEI 和HCEMI 不仅能更清楚地表征和区分两类El Ni?o(如1993 年的传统型El Ni?o 和2006 年的El Ni?o Modoki),而且能更好地反映和区分两类El Ni?o 与大气间的海气耦合特征,为El Ni?o的监测和短期气候预测工作提供了一个新工具。  相似文献   

18.
Studies on pine ecosystem functioning were carried out in different climates along a W–E transect extending more than 1500 km across Central-Eastern Europe (Germany-Poland-Belarus). Decomposition of litter in litter bags, measured at 13 locations simultaneously during 1995 and 1996 was correlated with components of climate: long-term annual temperature (TANN), temperature amplitude (TAMP) defined as the difference between temperatures of the warmest and coldest months, annual precipitation (PANN) and precipitation amplitude (PAMP). The content of eight metallic elements (Mn, Fe, Zn, Cu, Ni, Cr, Pb, Cd) was determined in litters from the same stands and correlations with decomposition rates were estimated. In those 13 pine stands influenced by gradually changing thermoclimate, the role of chemical factors was evaluated. It is suggested that similar interactions between decomposition, thermoclimate and metallic elements can occur in the case of climate change. In the warmer year, 1995, statistically significant correlations between decomposition rate and metal content or climatic factors were more frequent. Among the four fractions of litter analysed, needle litter responds most to the presence of climate and metals as regards its decomposition. Results from the calculation of partial correlations excluding the influence of various climatic factors suggest that a synergistic interaction might exist between two groups of factors driving decomposition processes, i.e. climate (in this case TANN, TAMP and CONT) and litter chemistry.  相似文献   

19.
This study aims to examine the effect of El Nino and La Nina on the monthly and seasonal climate of Hong Kong against the ENSO-neutral situation from a statistical perspective. Monthly and seasonal temperature and rainfall of Hong Kong and monthly number of tropical cyclones (TCs) coming within 500 km of the city over the 59-yr (1950-2008) period are examined under three ENSO situations, namely El Nino, La Nina, and ENSO-neutral. It is found that, compared with the ENSO-neutral situation, El Nino tends...  相似文献   

20.
Heavy Metal Concentrations in European Mosses: 2000/2001 Survey   总被引：3，自引：0，他引：3  
The heavy metals in mosses survey was originally established in 1980 as a joint Danish–Swedish initiative under the leadership of Åke Rühling, Sweden and has, since then, been repeated at five-yearly intervals with an increasing number of countries and individuals participating. Twenty-eight European countries, almost 7000 sites and about 100 individuals have been involved in the most recent survey in 2000/2001. The survey provides data on concentrations of 10 heavy metals (arsenic, cadmium, chromium, copper, iron, lead, mercury, nickel, vanadium, zinc) in naturally growing mosses throughout Europe. The technique of moss analysis provides a surrogate measure of the spatial patterns of heavy metal deposition from the atmosphere to terrestrial systems, and is easier and cheaper than conventional precipitation analysis. The aims of the survey are to determine patterns of variation in the heavy metal concentration of mosses across Europe, identify the main polluted areas, produce regional maps and further develop the understanding of long-range transboundary pollution.As in previous surveys, there was an east/west decrease in heavy metal concentrations in mosses, related in particular to industrial emissions. Former industrial sites and historic mines accounted for the location of some high concentrations in areas without contemporary industries. Long-range transboundary transport appears to account for elevated concentrations of heavy metals in areas without emission sources, such as lead in southern Scandinavia (presumably from emission sources elsewhere in Europe).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号