The effects of dissolved heavy metals on attached diatoms in the Uintah Basin of Utah,U.S.A.

The relationships of diatom species to dissolved heavy metals in the streams of the Uintah Basin of Utah were studied through four seasons of 1977–1978. Niche center gradient analysis, cluster analysis and correlation analysis were performed.Achnanthes minutissima, Cyclotella meneghiniana, Cymbella minuta, Gomphonema parvulum, Navicula secreta var.apiculata, Nitzschia frustulum, Nitzschia frustulum var.perminuta, Nitzschia frustulum var.perpusilla, Nitzschia palea, andSynedra ulna appear to be indicator species of high or low heavy metal concentrations. Several other species also showed meaningful relationships to high or low heavy metal concentrations.Dept. of Physics and Astronomy, Brigham Young UniversityDept. of Physics and Astronomy, Brigham Young University     

EFFECTS OF METAL AND PETROLEUM HYDROCARBON CONTAMINATION ON BENTHIC DIATOM COMMUNITIES NEAR CASEY STATION,ANTARCTICA: AN EXPERIMENTAL APPROACH1

The effects of metals and petroleum hydrocarbons on benthic marine diatom communities were assessed using a manipulative field experiment at Casey Station, Antarctica. Uncontaminated, metal contaminated, and petroleum hydrocarbon contaminated sediments were deployed for 11 weeks during the 1999 austral summer. The treatments were deployed at three different locations: Brown Bay, which has elevated levels of anthropogenic contaminants, and two uncontaminated reference locations, O'Brien Bay and Sparkes Bay, the latter of which has naturally occurring high concentrations of some heavy metals. At each location, significant differences between the composition of diatom communities recruiting to control and petroleum hydrocarbon contaminated treatments were observed. Navicula directa (Smith) Ralfs occurred at lower abundances in the petroleum hydrocarbon contaminated treatments than in the control treatments. In contrast, Navicula cancellata Donkin occurred at higher relative abundances in both contaminated treatments relative to the control treatment. Interactions between treatment and location were also observed for several species, including Navicula glaciei Van Heurck. Significant differences in the overall community composition of diatom communities between control and metal contaminated treatments and metal contaminated and petroleum hydrocarbon contaminated treatments were only observed within Brown Bay. The location of deployment also had a significant influence on the composition of diatom communities. Brown Bay had higher abundances of Achnanthes brevipes Agardh but lower abundances of Navicula aff. cincta (Ehrenberg) Van Heurck than either reference locations. This experiment demonstrated that benthic diatom communities are sensitive to sediment contamination and would be suitable for future monitoring work within this and other areas of Antarctica.     

Cadmium and lead toxicity on tropical freshwater periphyton communities under laboratory-based mesocosm experiments

Periphyton constitutes an important community that is useful for assessment of ecological conditions in lotic systems. The objective of this study was to assess the effects of different mixtures of Cd and Pb on periphyton growth as well as Cd and Pb mixtures toxicity to diatom assemblages in laboratory mesocosm experiments. A natural periphyton community sampled from the Monjolinho River (South of Brazil) was inoculated into five experimental systems containing clean glass substrates for periphyton colonization. The communities were exposed to mixtures of dissolved Cd and Pb concentrations of 0.01 and 0.1 mg l⁻¹ Cd and 0.033 and 0.1 mg l⁻¹ Pb. Periphyton ash-free dry weight, growth rate, diatom cell density and diatom community composition were analyzed on samples collected after 1, 2 and 3 weeks of colonization. High Cd concentration (0.1 mg l⁻¹) has negative effects on periphyton growth while high concentration of Pb (0.1 mg l⁻¹) decreased the toxic effects of Cd on periphyton growth. Shifts in species composition (development of more resistant species like Achnanthidium minutissimum and reduction of sensitive ones like Cymbopleura naviculiformis, Fragilaria capucina, Navicula cryptocephala, Encyonema silesiacum, Eunotia bilunaris, and Gomphonema parvulum), decreases in species diversity of diatom communities with increasing Cd and Pb concentrations and exposure duration have been demonstrated in this study making diatom communities appropriate monitors of metal mixtures in aquatic systems.     

Cleaning up of heavy metals-polluted water by a terrestrial hyperaccumulator Sedum alfredii Hance

Sedum alfredii Hance is a terrestrial zinc/cadmium （Zn/Cd）-hyperaccumulating and lead （Pb）-accumulating plant. Previous studies on S. alfredii were mostly focused on its physiological mechanism of heavy metal uptake and the application in phytoextraction of metals from contaminated soils. In this study, we evaluated the application potential of S. alfredii in the cleanup of heavy metals from contaminated lake water. Our research revealed that changing pH in lake water would not make particular difference on the final accumulation amount of heavy metals, because the acidic water environment negatively affected plant growth compared with the neutral and alkaline environments, but was more conducive for heavy metal absorption and accumulation. In addition, S. alfredii showed an increase of approximately 2.2-fold in dry weight （DW） when cultured with lake water for 25 d. At the same time, it accumulated approximately 5.0 mg/kg DW of Cd and 41.4 mg/kg DW of Pb. The absorption of heavy metals was highly effective during the first 10 d of culture. Also, the quality of lake water was greatly improved after only 2-d cleanup by S. aifredii. In general, this hyperaccumulator exhibits great potential for application in the cleanup of heavy metals-polluted waters.     

Effects of Cd or/and Pb on soil enzyme activities and microbial community structure

Heavy metals could have long-term hazardous impacts on the health of soil ecosystems and adverse influences on soil biological processes. A study of Cd or/and Pb effects on soil enzyme activities and microbial community structure was undertaken with brown soil in a greenhouse for a period of 10 weeks. The experiment results showed that urease, acid phosphatase and dehydrogenase activities were significantly lower (p < 0.05) in Cd or/and Pb treatments than in control. Three enzyme activities decreased with the increasing metal concentrations. The effects of Cd and Pb combined on enzyme activities were higher than Cd or Pb alone. The soil microbial populations were far lower in heavy metal treatments than in control, and soil microbial populations under different heavy metals levels showed a significant difference (p < 0.05). The PCR-DGGE banding patterns confirmed that the addition of metals had a significant impact on microbial community structure.     

Bioaccumulation and translocation of heavy metals by nine native plant species grown at a sewage sludge dump site

In the present study, nine native plant species were collected to determine their potential to clean up nine heavy metals from soil of a sewage sludge dump site. Almost all nine plant species grown at sewage sludge dump site showed multifold higher concentrations of heavy metals as compared to plants grown at the reference site. All the investigated species were characterized by a bioaccumulation factor (BF) > 1.0 for some heavy metals. BF was generally higher for Cd, followed by Pb, Co, Cr, Cu, Ni, Mn, Zn, and Fe. The translocation factor (TF) varied among plant species, and among heavy metals. For most studied heavy metals, TFs were <1.0. The present study proved that the concentrations of all heavy metals (except Cd, Co, and Pb) in most studied species were positively correlated with those in soil. Such correlations indicate that these species reflect the cumulative effects of environmental pollution from soil, and thereby suggesting their potential use in the biomonitoring of most heavy metals examined. In conclusion, all tissues of nine plant species could act as bioindicators, biomonitors, and remediates of most examined heavy metals. Moreover, Bassia indica, Solanum nigrum, and Pluchea dioscoridis are considered hyperaccumulators of Fe; Amaranthus viridis and Bassia indica are considered hyperaccumulators of Pb; and Portulaca oleracea is considered hyperaccumulator of Mn.     

Vertical concentration gradients of heavy metals in Cladonia lichens across different parts of thalli

Certain lichens of the genus Cladonia are effective heavy-metal-tolerant colonisers of strongly contaminated and disturbed sites. Among them, Cladonia cariosa, Cladonia pyxidata and Cladonia rei are the major components of specific cryptogamic assemblages proven to be bioindicators of soil pollution. This study examines the bioaccumulation capacity and heavy metal accumulation pattern of these species in the context of element concentration levels in various parts of their thalli at various vertical distances from the ground. The content of Zn, Pb, Cd, As and Cu in primary squamules, lower and upper parts of secondary thalli (podetia), and fruiting bodies (apothecia), as well as the corresponding substrate, was analysed using the AAS method. The substrate turned out to be the main source of heavy metals in the examined Cladonia lichens. Element accumulation in particular parts of thalli greatly depends on metal enrichment in the immediate vicinity while Cu/Zn ratios for both substrate and lichen samples were very low and comparable within the species. Concentration levels in thalli usually decrease significantly with distance from the substrate. The exception is copper, which content was frequently higher in apothecia than in the upper parts of podetia. Low bioaccumulation factors calculated for the examined Cladonia specimens classified these lichens as weak accumulators of heavy metals. Even given an extremely high level of contaminants in the substrate, the upper parts of thalli are not greatly affected. Consequently, fruticose and erect growth form, in combination with low accumulation capacity and a remarkable decrease in metal content along a vertical gradient, may be an important attribute of Cladonia lichens in the colonisation of a highly contaminated substrate. The content of elements differs significantly between particular parts of Cladonia thalli; this should be taken into account whenever burdens of heavy metals are used as indicators in biomonitoring studies.     

南京市14种绿化树种对空气中重金属的累积能力

分析了南京化工厂（污染区）和江苏省林科院（对照区）不同绿化树种叶片重金属元素（Pb、Cd和Cu）的含量,揭示了14种绿化树种对3种重金属污染物的累积能力。结果表明,城市绿化树种对大气重金属污染物具有一定的吸收净化能力,并依重金属和树种的不同具有明显差异;同种植物对不同重金属的累积量也有很大差别,其中对Cu的累积量最高;采样区植物叶片重金属含量明显高于对照区;对Pb累积量高的树种有：杨树、广玉兰、女贞和紫叶李; Cd累积量高的树种为杨树;Cu累积量高的树种为构树;累积3种重金属综合能力最强的树种有杨树、构树、雪松、广玉兰、悬铃木、栾树。     

湖南石门、冷水江、浏阳3个矿区的苎麻重金属含量及累积特征

对湖南省石门、冷水江、浏阳3个矿区土壤和苎麻体内重金属进行测定和分析。结果表明,石门雄黄矿区As污染严重,伴随Cd、Sb污染和轻微的Pb污染;冷水江锑矿区Sb为主要污染物,伴随Cd、As、Pb污染;浏阳七宝山矿区Cd污染严重,伴随Pb、Zn、Cu污染。15个采样点的苎麻群落生长繁茂,Sb和As在苎麻不同部位间的分布次序为叶片中含量最高,根茎中次之,其余重金属在部位间分布没有规律。所有采样点苎麻地上部的Cd含量比一般植物的Cd含量大2-10倍,As含量大9.9-147.5倍,Sb含量大1.2-338.4倍;Cd富集系数和转移系数最高值为2.07和3;As富集系数和转移系数最高值为1.04和12.42,Sb富集系数和转移系数最高值为1.91和9.04。3个矿区苎麻地上部生物量分别为3.47,14.3,15.7 t/hm²,地上部Cd、Pb、As、Sb、Zn和Cu的累积量分别高达0.11、1.17、0.72、7.97、6.71,1.69 kg/hm²,兼具一定的经济价值和观赏性,适合用作矿区重金属污染土壤的环境治理和修复。     

Biomonitoring Heavy Metal Pollution Using an Aquatic Apex Predator,the American Alligator,and Its Parasites

Monitoring the bioaccumulation of chemical elements within various organismal tissues has become a useful tool to survey current or chronic levels of heavy metal exposure within an environment. In this study, we compared the bioaccumulations of As, Cd, Cu, Fe, Pb, Se, and Zn between the American alligator, Alligator mississippiensis, and its parasites in order to establish their use as bioindicators of heavy metal pollution. Concomitant with these results, we were interested to determine if parasites were more sensitive bioindicators of heavy metals relative to alligators. We found parasites collectively accumulated higher levels of As, Cu, Se, and Zn in comparison to their alligator hosts, whereas Fe, Cd, and Pb concentrations were higher in alligators. Interestingly, Fe levels were significantly greater in intestinal trematodes than their alligator hosts when analyzed independently from other parasitic taxa. Further analyses showed alligator intestinal trematodes concentrated As, Cu, Fe, Se, and Zn at significantly higher levels than intestinal nematodes and parasites from other organs. However, pentastomids also employed the role as a good biomagnifier of As. Interestingly, parasitic abundance decreased as levels of As increased. Stomach and intestinal nematodes were the poorest bioaccumulators of metals, yet stomach nematodes showed their ability to concentrate Pb at orders of magnitude higher in comparison to other parasites. Conclusively, we suggest that parasites, particularly intestinal trematodes, are superior biomagnifiers of As, Cu, Se, and Zn, whereas alligators are likely good biological indicators of Fe, Cd, and Pb levels within the environment.     

Multiple Heavy Metal Tolerance of Soil Bacterial Communities and Its Measurement by a Thymidine Incorporation Technique

A thymidine incorporation technique was used to determine the tolerance of a soil bacterial community to Cu, Cd, Zn, Ni, and Pb. An agricultural soil was artificially contaminated in our laboratory with individual metals at three different concentrations, and the results were compared with the results obtained by using the plate count technique. Thymidine incorporation was found to be a simple and rapid method for measuring tolerance. Data obtained by this technique were very reproducible. A linear relationship was found between changes in community tolerance levels obtained by the thymidine incorporation and plate count techniques (r = 0.732, P < 0.001). An increase in tolerance to the metal added to soil was observed for the bacterial community obtained from each polluted soil compared with the community obtained from unpolluted soil. The only exception was when Pb was added; no indication of Pb tolerance was found. An increase in the tolerance to metals other than the metal originally added to soil was also observed, indicating that there was multiple heavy metal tolerance at the community level. Thus, Cu pollution, in addition to increasing tolerance to Cu, also induced tolerance to Zn, Cd, and Ni. Zn and Cd pollution increased community tolerance to all five metals. Ni amendment increased tolerance to Ni the most but also increased community tolerance to Zn and, to lesser degrees, increased community tolerance to Pb and Cd. In soils polluted with Pb increased tolerance to other metals was found in the following order: Ni > Cd > Zn > Cu. We found significant positive relationships between changes in Cd, Zn, and Pb tolerance and, to a lesser degree, between changes in Pb and Ni tolerance when all metals and amendment levels were compared. The magnitude of the increase in heavy metal tolerance was found to be linearly related to the logarithm of the metal concentration added to the soil. Threshold tolerance concentrations were estimated from these linear relationships, and changes in tolerance could be detected at levels of soil contamination similar to those reported previously to result in changes in the phospholipid fatty acid pattern (Å. Frostegård, A. Tunlid, and E. Bååth, Appl. Environ. Microbiol. 59: 3605-3617, 1993).     

Application of in situ cage cultures of phytoplankton for monitoring heavy metal pollution in two Norwegian fjords

A simple apparatus for in situ use of the cage culture technique for growing planktonic algae has been developed and used to follow growth and metal uptake of three diatoms in two Norwegian fjords polluted by heavy metals. Continuous pumping of sea water through a chelating resin and continuous water sampling was used to obtain average values for dissolved and particulate heavy metal content at the various test sites. The metals investigated (zinc, copper, lead, cadmium, and mercury) showed differences in the proportion of dissolved to particulate fractions.The three species of diatoms tested gave systematic growth responses to heavy metal pollution in the moderately polluted fjord; one alga died, one showed reduced growth rate at the more contaminated site compared with those at less polluted sites, while the most tolerant alga was apparently not affected. In the heavily polluted fjord only the most tolerant alga survived, showing decreasing growth rate with increasing pollution.Uptake of heavy metals increased generally with increasing heavy metal content in the sea water. The contents in the algae grown in the most polluted fjord were much higher than those obtained in the less polluted fjord, which were higher than the contents reported for algae from non-contaminated areas.     

Association of Microbial Community Composition and Activity with Lead, Chromium, and Hydrocarbon Contamination

Microbial community composition and activity were characterized in soil contaminated with lead (Pb), chromium (Cr), and hydrocarbons. Contaminant levels were very heterogeneous and ranged from 50 to 16,700 mg of total petroleum hydrocarbons (TPH) kg of soil⁻¹, 3 to 3,300 mg of total Cr kg of soil⁻¹, and 1 to 17,100 mg of Pb kg of soil⁻¹. Microbial community compositions were estimated from the patterns of phospholipid fatty acids (PLFA); these were considerably different among the 14 soil samples. Statistical analyses suggested that the variation in PLFA was more correlated with soil hydrocarbons than with the levels of Cr and Pb. The metal sensitivity of the microbial community was determined by extracting bacteria from soil and measuring [³H]leucine incorporation as a function of metal concentration. Six soil samples collected in the spring of 1999 had IC₅₀ values (the heavy metal concentrations giving 50% reduction of microbial activity) of approximately 2.5 mM for CrO₄²⁻ and 0.01 mM for Pb²⁺. Much higher levels of Pb were required to inhibit [¹⁴C]glucose mineralization directly in soils. In microcosm experiments with these samples, microbial biomass and the ratio of microbial biomass to soil organic C were not correlated with the concentrations of hydrocarbons and heavy metals. However, microbial C respiration in samples with a higher level of hydrocarbons differed from the other soils no matter whether complex organic C (alfalfa) was added or not. The ratios of microbial C respiration to microbial biomass differed significantly among the soil samples (P < 0.05) and were relatively high in soils contaminated with hydrocarbons or heavy metals. Our results suggest that the soil microbial community was predominantly affected by hydrocarbons.     

Heavy metals contamination and accumulation in submerged macrophytes in an urban river in China

Deteriorating urban water quality has attracted considerable attention in China. We investigated the contamination levels and distribution of heavy metals (As, Cd, Cu, Ni, Pb, and Zn) in Yuxi River water and sediments, and assessed the heavy metal accumulation capability of five species of submerged macrophytes: Vallisneria natans (Lour.) Hara, Potamogeton pectinatus L., Hydrilla verticillata (L. f.) Royle, Myriophyllum spicatum L., and Potamogeton crispus L. Samples were collected from upstream and downstream locations in different season. The results showed that the levels of heavy metals in the downstream areas were higher than in the upstream areas. Heavy metal concentrations in the river water during the dry seasons were higher than those during the rainy seasons, and the opposite results appeared in sediments and submerged macrophytes. In general, the river was slightly contaminated by heavy metals, and the concentrations of Pb and Ni in this river should serve as a warning, while Cd and Zn pollution in the sediments desperately needs to be removed. Furthermore, Potamogeton pectinatus L. showed a higher accumulation capacity for these metals among the five native submerged macrophytes and could be defined as a hyperaccumulator for Cd. Therefore, the potential use of native aquatic plants in contaminated rivers is worth further exploration.     

贵州水银洞金矿紫茎泽兰重金属元素测定与分析

利用原子吸收法对贵州水银洞金矿紫茎泽兰及其基质中Cr、Pb、Zn、Cd、Hg和As含量进行了测定和分析。结果表明,贵州水银洞金矿废水处理区土壤Hg(12.575 mg·kg^-1)和As(501.374 mg·kg^-1)已严重超标,Hg和As的平均含量分别是国家土壤环境质量三级标准(GB15618-1995)的8.383倍和12.534倍,污染极为严重;紫茎泽兰对该矿区不同的重金属富集能力不同,尤其对该矿区Cr有较强的富集作用,具有一定的Cr污染修复潜力。紫茎泽兰对所测定的6种重金属元素的吸收转移能力有较大的差异,整个植株对Pb、Zn 和Cr具有很强的吸收转移能力。其茎、叶对不同的重金属元素的吸收转移能力也呈现出很大的差异,紫茎泽兰茎对Cr、Pb和Cd具有很强的吸收转移能力,而叶对Zn、Pb和Hg具有很强的吸收转移能力。除As外,紫茎泽兰对Cr、Pb、Zn、Cd和Hg都具有不同程度的耐受能力,对该矿区的生态恢复具有重要的作用。     

黄河口盐地碱蓬湿地土壤-植物系统重金属污染评价

以黄河口盐地碱蓬湿地为例,评价了淹水和非淹水区湿地表层土壤As、Cd、Cu、Cr、Pb和Zn 6种重金属的污染程度及其在土壤-植物系统中的迁移、富集特征,分析了不同积水深度和土壤理化性质对研究区土壤重金属含量的影响.研究结果表明,与土壤或沉积物质量标准相比,黄河口盐地碱蓬湿地土壤受As和Cd污染最严重,而其它重金属污染较轻;非淹水土壤Cd、Cr和Zn含量高于淹水湿地,而As、Cu和Pb则较低;而且淹水土壤As含量随积水深度增加而呈下降趋势,但积水深度对其他重金属含量的影响不明显.相关性分析结果表明,按照受土壤关键影响因子的不同重金属(除As外)可以分为两类:第一类为Cd、Cr和Zn,这些重金属含量受土壤pH值和盐分影响较大,且相互间存在显著正相关关系,表明它们可能有相同的来源;第二类为Pb和Cu,它们受土壤pH值、盐分和有机质的影响,且Pb和Cu之间存在显著正相关关系.除Cr、Cu和Zn外,重金属在盐地碱蓬的根系内一般不发生显著富集,但绝大多数重金属都表现出地上部分的含量比根系更高的现象.     

德兴铜矿尾矿重金属污染对土壤中微生物多样性的影响

【目的】为更好地了解重金属污染与微生物多样性之间的相互作用关系,以江西德兴铜矿4#尾砂库为研究对象,采集野外实地样品共16件进行分析(包括尾砂样品以及周围农田和菜地土壤样品)。【方法】一方面对样品中可培养异养细菌进行平板计数,一方面采用变性梯度凝胶电泳(Denaturing gradient gel electrophoresis,DGGE)对样品中可培养和不可培养微生物分子生态多样性进行研究;同时采用PCA(Principle component analysis)方法分析样品理化性质、重金属及主要元素与可培养细菌数量及微生物多样性之间的相互关系。【结果】元素分析结果表明该尾矿区样品受到不同程度重金属Cu、Cd、Zn、Ni、Pb和Cr的污染;可培养异养细菌在尾砂样品中数量最少,在菜地和农田土壤样品中有明显增加;多样性指数(Shannon-Weaver index H)计算结果发现H最大值出现在距离尾矿中等距离、重金属浓度在中等程度的样品中。PCA分析结果表明可培养异养菌数量与理化性质如有机碳、有机质、含水率等相关性较大,重金属影响不明显;而多样性指数H除与上述理化性质相关性较大外,还受到重金属Ag、Zn、As、Pb、Ni、Cr等的影响,而在样品中含量普遍比较高的重金属如Cu、Cd等并不成为影响微生物多样性的主要因素。【结论】从这些长期受重金属污染的野外实地样品来看,以上结果说明不同重金属浓度对微生物多样性的影响可能并不是实验室研究的简单的线性关系。     

Soil Microbial Community Responses to Additions of Organic Carbon Substrates and Heavy Metals (Pb and Cr)

Microcosm experiments were conducted with soils contaminated with heavy metals (Pb and Cr) and aromatic hydrocarbons to determine the effects of each upon microbial community structure and function. Organic substrates were added as a driving force for change in the microbial community. Glucose represented an energy source used by a broad variety of bacteria, whereas fewer soil species were expected to use xylene. The metal amendments were chosen to inhibit the acute rate of organic mineralization by either 50% or 90%, and lower mineralization rates persisted over the entire 31-day incubation period. Significant biomass increases were abolished when metals were added in addition to organic carbon. The addition of organic carbon alone had the most significant impact on community composition and led to the proliferation of a few dominant phylotypes, as detected by PCR-denaturing gradient gel electrophoresis of bacterial 16S rRNA genes. However, the community-wide effects of heavy metal addition differed between the two carbon sources. For glucose, either Pb or Cr produced large changes and replacement with new phylotypes. In contrast, many phylotypes selected by xylene treatment were retained when either metal was added. Members of the Actinomycetales were very prevalent in microcosms with xylene and Cr(VI); gene copy numbers of biphenyl dioxygenase and phenol hydroxylase (but not other oxygenases) were elevated in these microcosms, as determined by real-time PCR. Much lower metal concentrations were needed to inhibit the catabolism of xylene than of glucose. Cr(VI) appeared to be reduced during the 31-day incubations, but in the case of glucose there was substantial microbial activity when much of the Cr(VI) remained. In the case of xylene, this was less clear.     

黔西北铅锌矿区植物群落分布及其对重金属的迁移特征

重金属耐性植物和超富集植物的筛选、鉴定和驯化是植物修复技术研究与发展的关键。以黔西北4个不同恢复年限的铅锌矿为研究对象,通过群落生态调查利用聚类分析方法筛选出研究区域中重金属耐性植物优势种,并分析其对重金属Pb、Zn、Cu、Cd的迁移富集能力。结果表明:4个矿区共发现高等植物22种,分属13科21属,筛选出9种重金属耐性植物优势种,其中转运系数大于1的植物有:黄花蒿(Cu)、珠光香青(Zn)、大叶醉鱼草(Zn/Pb/Cd)、野艾蒿(Cu/Zn/Pb/Cd);没有富集系数大于1的植物。其中大叶醉鱼草具有耐贫瘠、耐旱、生物量大等优势,可将其作为典型的重金属耐性先锋植物,用于矿区废弃地的植物修复。