The mycorrhizal status of Phragmites australis in several polluted soils and sediments of an industrialised region of Northern Portugal

Roots of Phragmites australis from three polluted soils and sediments (a periodically flooded stream bank containing organic pollutants, a high-pH drying sedimentation pond and an acidic, periodically flooded sand polluted by industrial effluents) were sampled over a 1-year cycle of plant growth to assess the degree of colonisation by arbuscular mycorrhizal fungi (AMF). At the dry sedimentation pond, root samples of Juncus effusus and Salix atrocinerea were also taken to assess the presence of AMF throughout the year. Root colonisation was low (<5% root length colonised) but arbuscule presence peaked in P. australis during the spring and autumn prior to flowering. These changes in arbuscule abundance were also seen in a parallel greenhouse trial using seed taken from one of the sites. Roots of J. effusus contained mainly vesicular colonisation but arbuscule activity peaked during the winter months (December–March). S. atrocinerea roots were found to be ectomycorrhizal throughout the year but the fine feeder roots were colonised by AMF. The results confirm that semi-aquatics, like P. australis, can become arbuscular mycorrhizal but that this status changes during the year depending on soil moisture content and plant phenology. The influence of AMF in these polluted soils is uncertain but the potential exists to establish a more diverse plant ecosystem during the landscaping of these areas (phytostabilisation) by management of adapted plant and AMF ecotypes. Accepted: 6 November 2000     

Quercus rubra-associated ectomycorrhizal fungal communities of disturbed urban sites and mature forests

The presence and quality of the belowground mycorrhizal fungal community could greatly influence plant community structure and host species response. This study tests whether mycorrhizal fungal communities in areas highly impacted by anthropogenic disturbance and urbanization are less species rich or exhibit lower host root colonization rates when compared to those of less disturbed systems. Using a soil bioassay, we sampled the ectomycorrhizal fungal (EMF) communities associating with Quercus rubra (northern red oak) seedlings in soil collected from seven sites: two mature forest reference sites and five urban sites of varying levels of disturbance. Morphological and polymerase chain reaction–restriction fragment length polymorphism analyses of fungi colonizing root tips revealed that colonization rates and fungal species richness were significantly lower on root systems of seedlings grown in disturbed site soils. Analysis of similarity showed that EMF community composition was not significantly different among several urban site soils but did differ significantly between mature forest sites and all but one urban site. We identified a suite of fungal species that occurred across several urban sites. Lack of a diverse community of belowground mutualists could be a constraint on urban plant community development, especially of late-successional woodlands. Analysis of urban EMF communities can add to our understanding of urban plant community structure and should be addressed during ecological assessment before pragmatic decisions to restore habitats are framed.     

Red mud (RM)-Induced enhancement of iron plaque formation reduces arsenic and metal accumulation in two wetland plant species

Human activities have resulted in arsenic (As) and heavy metals accumulation in paddy soils in China. Phytoremediation has been suggested as an effective and low-cost method to clean up contaminated soils. A combined soil-sand pot experiment was conducted to investigate the influence of red mud (RM) supply on iron plaque formation and As and heavy metal accumulation in two wetland plant species (Cyperus alternifolius Rottb., Echinodorus amazonicus Rataj), using As and heavy metals polluted paddy soil combined with three rates of RM application (0, 2%, 5%). The results showed that RM supply significantly decreased As and heavy metals accumulation in shoots of the two plants due to the decrease of As and heavy metal availability and the enhancement of the formation of iron plaque on the root surface and in the rhizosphere. Both wetland plants supplied with RM tended to have more Fe plaque, higher As and heavy metals on roots and in their rhizospheres, and were more tolerant of As and heavy metal toxicity. The results suggest that RM-induced enhancement of the formation of iron plaque on the root surface and in the rhizosphere of wetland plants may be significant for remediation of soils contaminated with As and heavy metals.     

Heavy-Metal Phytostabilizing Potential of Agrostis castellana Boiss. & Reuter

The soils of many abandoned mine sites in the central region of Spain are heavily polluted with a number of different metals. Having frequently found Agrostis castellana growing at these old mine sites, this study was designed to assess its remediation capacity for this type of setting. In an initial field study, plant specimens were collected from 4 abandoned mine sites to determine pollutant concentrations in their roots and shoots. This was followed by a 4-year bioassay in a controlled environment in which soils collected from the mines were used to set up microcosms. Maximum root concentrations of the most polluting elements present in the bioassay were 3625 mg kg^?1 Zn, 2793 mg kg^?1 Cu, 13042 mg kg^?1 Pb, 49 mg kg^?1 Cd and 957 mg kg^?1 As. These concentrations represent root bioaccumulation indices of over 1 and usually >2. In contrast, indices of transfer to above-ground phytomass were always < 1, indicating this species is a good candidate for use as a phytostabilizer. However, the high metal concentrations that could reach the above-ground mass of this plant determines a need for close monitoring and avoiding the use of areas under restoration for hunting or grazing.     

Establishment of arbuscular mycorrhizal plants originating from xerothermic grasslands on heavy metal rich industrial wastes–new solution for waste revegetation

Industrial waste substrata, rich in heavy metals, are poorly suited for plant growth. Efforts are made to establish an appropriate plant cover to reduce erosion and further contamination. Grasses are the usual solution, as they grow fast, thrive on poor substrata and have well-developed root systems. Some of them are also highly dependent on mycorrhizal symbiosis that supports their growth especially on poor and polluted soils. However, the commercially available grasses often meet a lack of well established mycorrhiza on the site and the introduced plant populations dramatically decrease with time, despite large financial input including covering the substratum with soil and intensive watering. The aim of this paper was to select proper plants together with mycorrhizal fungi that could accelerate the establishment of the vegetation and improve its diversity under these extreme conditions, minimizing the financial costs of the reclamation (no use of soil layering and watering). The experiments were carried out under field and laboratory conditions. The plant seeds used originated from dry calcareous grasslands. The seeds were germinated under field conditions or in pots filled with soil supplemented with substratum from the industrial wastes. The seedlings were inoculated with AM fungi and introduced on the field plots a few weeks after germination. The inoculum consisted of either crude inoculum harvested from the dry calcareous grasslands or strains originating from polluted areas. Plants colonized by mycorrhizal fungi established well in the experimental plots. The results suggest that inocula from dry calcareous grasslands are potentially useful in revegetation of industrial wastes. Although in several cases the photosynthetic activity of plants was lower than at the natural sites, almost all plants survived and formed seeds. In all experiments the plant vitality was estimated on the basis of chlorophyll a fluorescence and was useful to show differences between waste substrata, inocula and coexisting plant species. The interactions between mycorrhizal and non-mycorrhizal plants were studied under greenhouse conditions and at least no negative effect of this coexistence was found.     

Varietal differences in mungbean (Vigna radiata) for growth, yield, toxicity symptoms and cadmium accumulation

Increased cadmium (Cd) contamination of soils resulting from industrial activities is critical to crop production. The objective of this study was to find varietal differences for foliar chlorosis and necrosis, growth and Cd accumulation in mungbean (Vigna radiata). Despite substantial varietal differences, increased Cd levels reduced the shoot and root dry weight and the number and area of leaves at different growth stages. Applied Cd stress produced the foliar symptoms such as marginal and intervein chlorosis and scattered necrotic spots on younger leaves while accelerating the senescence of older leaves. Slope of regression equation and correlations of shoot Cd content with foliar Cd toxicity revealed that leaf chlorosis was more damaging than necrosis. At maturity, number of pods per plant and seeds per pod were maximally reduced to 37% and 26%, while 100‐seed weight, seed yield and harvest index showed 61%, 79% and 54% reduction, respectively, as a result of Cd toxicity. Results suggested that although varietal difference exists, the accumulated Cd is mainly toxic to the mesophyll tissue, most probably by interfering with the uptake of essential nutrients, thereby reducing growth and yield at various stages. Therefore, selection programmes based on foliar toxicity criteria may be beneficial for better utilisation of Cd‐polluted soils.     

Biodegradation of pentachlorophenol in natural soil by inoculatedRhodococcus chlorophenolicus

Rhodococcus chlorophenolicus PCP-1, a mineralizer of polychlorinated phenols, was inoculated into natural sandy loam and peaty soils with pentachlorophenol (PCP) at concentrations usually found at lightly and heavily polluted industrial sites (30 to 600 mg PCP/kg). A single inoculum of 10⁵ to 10⁸ cells per g of peat soil and as little as 500 cells/g sandy soil initiated mineralization of¹⁴C-PCP. The mineralization rates of PCP were 130 to 250 mg mineralized per kg soil in 4 months in the heavily (600 mg/kg) polluted soils and 13 to 18 mg/kg in the lightly (30 mg/kg) polluted soils. There were no detectable PCP mineralizing organisms in the soils prior to inoculation, and also there was no significant adaptation of the indigenous microbial population to degrade PCP during 4 months observation in the uninoculated soils. The inoculum-induced mineralization continued for longer than 4 months after a single inoculation. Uninoculated, lightly polluted soils (30 mg PCP/kg) also showed loss of PCP, but some of this reappeared as pentachloroanisol and other organic chlorine compounds (EOX). Such products did not accumulate in theR. chlorophenolicus-inoculated soils, where instead EOX was mineralized 90 to 98%.R. chlorophenolicus mineralized PCP unhindered by the substrate competition offered by the PCP-methylating bacteria indigenously occurring in the soils or by simultaneously inoculated O-methylatingR. rhodochrous.     

Variations of Abundance and Community Structure of Ammonia Oxidizers and Nitrification Activity in Two Paddy Soils Polluted by Heavy Metals

While microbial nitrogen transformations are sensitive indicators of trace metal toxicity in soils, studies that quantify the impacts of heavy metal pollution in polluted rice soils on microbial communities and their activities remain limited. We examined changes in the abundance, composition and activity of ammonia oxidizing communities in two paddy fields that have been polluted by metal mining and smelting activities for more than three decades. The results showed a shift in the community structure of ammonia oxidizing archaea (AOA) and, to a lesser extent, of ammonia oxidizing bacteria (AOB) under metal pollution in the soils. All the retrieved AOB sequences in this study belonged to the genus Nitrosospira. Among them, the species in Cluster 3 a.1 seemed to be more sensitive to heavy metal pollution. Both AOB abundance and nitrification activity were not affected by heavy metal pollution in the two sites; whereas, AOA abundance increased. Our results suggested an effect of metal pollutants on communities of ammonia oxidizers, the degree of which varied in accordance with the amount of metal pollution. Therefore, it is difficult to quantify the relationship between the AOB/AOA communities and nitrification activity in the polluted soil.     

Influence of Phenol and Phenanthrene on the Growth of Phalaris arundinacea and Phragmites australis

In constructed wetlands for the treatment of industrial effluents and in contaminated waterlogged soils, wetland plants (helophytes) are exposed to toxic chemicals. Hence, the plants' resistance to contaminants is an important prerequisite for applying phytoremediation to solve these environmental problems. For toxicity tests on the germination and growth of various helophytes (Phalaris arundinaceae and Phragmites australis), phenol, phenanthrene, and a mixture of both were used as examples of chemicals from the petrol- and coal-processing industries. The germination rate, shoot length, root length, and influence on leaves, young shoots, and dry weight were studied. Although an increase in contaminant concentration decreased plant growth (dry weight, shoot length); interestingly, the number of young shoots rose. Low contaminant concentration (about 50 mg/l in case of phenol) stimulated the plant growth. The cress seed germination test was less susceptible compared with plantlet exposure in the case of phenol and phenanthrene. Due to its low bioavailability, solid phenanthrene (without solutizer) did not significantly affect plant growth.     

Productivity differences between dandelion (Taraxacum officinale; Asteraceae) clones from pollution impacted versus non-impacted soils

Common dandelions (Taraxacum officinale Weber, sensu lato; Asteraceae) introduced to North America form an assemblage of asexual (agamospermous), clonal lineages derived from Eurasian mixed sexual and asexual populations. We investigated whether selection for more pollution tolerant clonal lineages occurs at polluted sites and selection for more pollution intolerant lineages occurs at unpolluted sites. We tested the above hypothesis by performing reciprocal greenhouse productivity experiments in which unique dandelion clones (12 clones, identified by DNA fingerprinting, from each site type) sampled from two unpolluted and two polluted (moderately enhanced Cu, Pb and Zn soil concentrations) sites were grown pairwise in both unpolluted (nutrient solution only) and polluted (nutrient solution + Cu, Pb and Zn) media (n?=?48 paired tests for each media type). Dandelion clones from polluted sites produced fewer and smaller leaves, shorter roots and smaller root diameters, reduced shoot and root dry weights, and reduced total biomass compared to clones from unpolluted sites when clones were grown in unpolluted-media (P?≤?0.05). In contrast, clones taken from unpolluted sites were shown to produce significantly fewer and shorter leaves, shorter roots and smaller root diameters, reduced shoot and root dry weights, reduced total biomass, a reduced shoot : root biomass ratio, and have much lower survival compared to clones from polluted sites when both were grown in polluted-media (P?≤?0.05). These results reveal that there was increased selection against unpolluted-site clonal lineages in polluted-media and against polluted-site clonal lineages in unpolluted-media. Across all treatments, clones from unpolluted sites growing in unpolluted-media had the highest proximate measures of fitness. Overall, these findings provide insight into the relationships among anthropogenic environmental contamination and the consequent effects of selective forces acting on dandelion clones and their population genetic architecture.     

Cloning and characterisation of polymorphic heterochromatic segments of Brachycome dichromosomatica

After selective enrichment and differential hybridisation of C_ot-1 DNA fractions of plants with and without polymorphic heterochromatic segments, a repetitive sequence (called Bds1) specific to the polymorphic chromosome segments of Brachycome dichromosomatica (Brachyscome dichromosomatica) was isolated. A single repeat unit of Bds1 is 92 bp long and is organised in tandem arrays at three different polymorphic segment sites on the chromosomes of cytodeme A2. Although all three sites showed extensive polymorphism between plants, the karyotypes of all analysed mitotic root cells were stable within a single plant. Electron microscopy revealed heavily condensed chromatin structures at the most obvious polymorphic site. The mechanisms that generate and maintain the observed chromosome structure polymorphisms are discussed. Received: 16 March 1999; in revised form: 28 September 1999 / Accepted: 11 November 1999     

Natural Occurrence of Enantiomers of Organic Compounds Versus Phytoremediations: Should Research on Phytoremediations Be Revisited? A Mini‐review

Decontamination of polluted soils using plants is based on the ability of plant species (including transgenic plants) to enhance bioavailability of pollutants in the rhizosphere and support growth of pollutant‐degrading microorganisms via root exudation and plant species‐specific composition of the exudates. In this work, we review current knowledge of enantiomers of low‐molecular‐weight (LMW) organic compounds with emphasis on their use in phytoremediation. Many research studies have been performed to search for plants suitable for decontamination of polluted soils. Nevertheless, the natural occurrence of L‐ versus D‐enantiomers of dominant compounds of plant root exudates which play different roles in the complexation of heavy metals, chemoattraction, and support of pollutant‐degrading microorganisms were not included in these studies. D‐enantiomers of aliphatic organic acids and amino acids or L‐enantiomers of carbohydrates occur in high concentrations in root exudates of some plant species, especially under stress, and are less stimulatory for plants to extract heavy metals or for rhizosphere microflora to degrade pollutants compared with L‐enantiomers (organic acids and amino acids) or D‐carbohydrates. Determining the ratio of L‐ versus D‐enantiomers of organic compounds as a criterion of plant suitability for decontamination of polluted soils and development of other types of bioremediation technologies need to be subjects of future research. Chirality 26:1–20, 2013. © 2013 Wiley Periodicals, Inc.     

Synergistic plant-microbes interactions in the rhizosphere: a potential headway for the remediation of hydrocarbon polluted soils

Soil pollution is an unavoidable evil; many crude-oil exploring communities have been identified to be the most ecologically impacted regions around the world due to hydrocarbon pollution and their concurrent health risks. Several clean-up technologies have been reported on the removal of hydrocarbons in polluted soils but most of them are either very expensive, require the integration of advanced mechanization and/or cannot be implemented in small scale. However, “Bioremediation” has been reported as an efficient, cost-effective and environment-friendly technology for clean-up of hydrocarbon”s contaminated soils. Here, we suggest the implementation of synergistic mechanism of bioremediation such as the use of rhizosphere mechanism which involves the actions of plant and microorganisms, which involves the exploitation of plant and microorganisms for effective and speedy remediation of hydrocarbon”s contaminated soils. In this mechanism, plant”s action is synergized with the soil microorganisms through the root rhizosphere to promote soil remediation. The microorganisms benefit from the root metabolites (exudates) and the plant in turn benefits from the microbial recycling/solubilizing of mineral nutrients. Harnessing the abilities of plants and microorganisms is a potential headway for cost-effective clean-up of hydrocarbon”s polluted sites; such technology could be very important in countries with great oil producing activities/records over many years but still developing.     

Linking of microorganisms to phenanthrene metabolism in soil by analysis of (13)C-labeled cell lipids

Phenanthrene-metabolizing soil microbial communities were characterized by examining mineralization of [(14)C]phenanthrene, by most-probable-number (MPN) counting, by 16S-23S spacer DNA analysis of the numerically dominant, culturable phenanthrene-degrading isolates, and by examining incorporation of [(13)C]phenanthrene-derived carbon into sterols and polar lipid fatty acids (PLFAs). An unpolluted agricultural soil, a roadside soil diffusely polluted with polycyclic aromatic hydrocarbons (PAHs), and two highly PAH-polluted soils from industrial sites were analyzed. Microbial phenanthrene degraders were not detected by MPN counting in the agricultural soil and the roadside soil. In the industrial soils, phenanthrene degraders constituted 0.04 and 3.6% of the total number of CFU. 16S-23S spacer DNA analysis followed by partial 16S DNA sequencing of representative isolates from one of the industrial soils showed that one-half of the isolates belonged to the genus Sphingomonas and the other half were closely related to an unclassified beta-proteobacterium. The (13)C-PLFA profiles of the two industrial soils were relatively similar and resembled the profiles of phenanthrene-degrading Sphingomonas reference strains and unclassified beta-proteobacterium isolates but did not match the profiles of Pseudomonas, Mycobacterium, or Nocardia reference strains. The (13)C-PLFA profiles of phenanthrene degraders in the agricultural soil and the roadside soil were different from each other and different from the profiles of the highly polluted industrial soils. Only in the roadside soil were 10me/12me18:0 PLFAs enriched in (13)C, suggesting that actinomycetes metabolized phenanthrene in this soil. The (13)C-PLFA profiles of the unpolluted agricultural soil did not resemble the profiles of any of the reference strains. In all of the soils investigated, no excess (13)C was recovered in the 18:2omega6,9 PLFA, suggesting that fungi did not contribute significantly to assimilation of [(13)C]phenanthrene.     

IS THE NUCLEAR DNA CONTENT OF MATURE ROOT CELLS PRESCRIBED IN THE ROOT MERISTEM?

Cells of the mature root exhibit arrest within the G1 and G2 periods of the mitotic cycle. The number of cells arrested with a 2C or 4C DNA amount in mature tissue was compared with that in meristems of excised primary root tips deprived of carbohydrate. Results from four plant species are described. Cells in mature tissue of seedling roots of Vicia and Pisum exhibited arrest predominately at the 4C while those of Triticum and Helianthus arrested preponderantly at the 2C DNA level. The proportion of cells arrested at the 2C and 4C levels in mature root tissue was specific for each species tested. In each species the cycle stage where most cells arrested was the same in carbohydrate-deficient root meristems as in mature root tissue; consequently, most meristematic cells are preconditioned or predetermined to arrest in a specific mitotic period. A test system was developed in Pisum in which the predominant period of arrest was altered by the removal of the cotyledons. The predominant arrest period changed from 4C to 2C in both mature root tissue and carbohydrate-deficient root meristems with cotyledon removal and indicated that mature root cells are preconditioned while meristematic as to where they will eventually arrest in the mitotic cycle.     

Ecotoxicological evaluation of municipal sludge

Municipal wastes originating from urban and industrial areas have become a major source of soil, ground and surface water pollution. These undesirable agents in our environment significantly interact with our flora and fauna. The aim of this study was to test samples of municipal sludge (MS) for their ecotoxicological potential by using sensitive bioassays involving a plant, Vicia faba, and the earthworm, Eisenia foetida. A 10% leachate of MS was prepared for the experiments, and V. faba seedlings were exposed to three leachate concentrations (2.5%, 5% and 10%) for 5 days. The findings revealed chromosome aberrations during the metaphase as well as the anaphase of cell division, and inhibition of the mitotic index, which reflects that MS originating from domestic and other human activities may be genotoxic to the living organisms of the ecosystem. Abnormalities in chlorophyll content, plant growth, root length, shoot length and root/shoot length ratio in V. faba clearly indicated the toxicity of the sludge. Behavioural and reproduction studies with E. foetida also provided evidence for the toxic nature of the MS.     

16S rDNA Pyrosequencing Analysis of Bacterial Community in Heavy Metals Polluted Soils

Soil contamination with heavy metals is a widespread problem, especially prominent on grounds lying in the vicinity of mines, smelters, and other industrial facilities. Many such areas are located in Southern Poland; they are polluted mainly with Pb, Zn, Cd, or Cu, and locally also with Cr. As for now, little is known about most bacterial species thriving in such soils and even less about a core bacterial community—a set of taxa common to polluted soils. Therefore, we wanted to answer the question if such a set could be found in samples differing physicochemically and phytosociologically. To answer the question, we analyzed bacterial communities in three soil samples contaminated with Pb and Zn and two contaminated with Cr and lower levels of Pb and Zn. The communities were assessed with 16S rRNA gene fragments pyrosequencing. It was found that the samples differed significantly and Zn decreased both diversity and species richness at species and family levels, while plant species richness did not correlate with bacterial diversity. In spite of the differences between the samples, they shared many operational taxonomic units (OTUs) and it was possible to delineate the core microbiome of our sample set. The core set of OTUs comprised members of such taxa as Sphingomonas, Candidatus Solibacter, or Flexibacter showing that particular genera might be shared among sites ~40 km distant.     

Inoculation with remnant prairie soils increased the growth of three native prairie legumes but not necessarily their associations with beneficial soil microbes

Restoring the diversity of plant species found in remnant communities is a challenge for restoration practitioners, in part because many reintroduced plant species fail to establish in restored sites. Legumes establish particularly poorly, perhaps because they depend on two guilds of soil microbial mutualists, rhizobial bacteria and arbuscular mycorrhizal (AM) fungi, that may be absent from restored sites. We tested the effect of soil microorganisms from remnant and restored prairies on legume growth by inoculating seedlings of Lespedeza capitata, Amorpha canescens, and Dalea purpurea with soil from 10 restored prairies and 6 remnant (untilled) prairies from southwest Michigan. We generally found support for the hypothesis that restored prairie soils lack microbes that enhance prairie plant growth, although there was variation across species and mutualist guilds. All three legumes grew larger and two legumes (Lespedeza and Amorpha) produced more nodules when inoculated with soil from remnant prairies, suggesting that low quantity and/or quality of rhizobial partners may limit the establishment of those species in restored prairies. In contrast, no legume experienced greater root colonization by AM fungi in remnant prairie soils, suggesting equivalent quantity (but not necessarily quality) of fungal partners in remnant and restored prairie soils. We detected no evidence of spontaneous recovery of the community of beneficial soil microbes in restorations. These results suggest that the absence of rhizobia, a largely overlooked component of prairie soils, could play a strong role in limiting restored prairie diversity by hindering legume establishment. Active reintroduction of appropriate rhizobial strains could enhance prairie restoration outcomes.     

A preliminary study on the effect of Cu,Pb and Zn contamination of soils on community structure and certain life-history traits of oribatids from urban areas

The effect of pollution of urban soils by traffic exhausts on oribatid mites was studied along a traffic gradient of the city of Thessaloniki. Although the population density of the main orbatid species appeared increased in polluted areas, the total orbatid numbers were reduced due to the reduction in species richness. The highest species diversity was recorded in moderately polluted areas. The morphometric characteristics as well as certain life-history traits did no correlate with the level of traffic influence. Nevertheless, these characteristics were considered important for the understanding of the pollution impact on life in soils. Moderate body size, sexual reproduction, increased reproductive effort and wide habitat preferences characterize species in urban sites. Scheloribates latipes and Tectocepheus sarekensis can be used as bioindicators for Pb and Zn pollution of soils, respectively.     

Evaluation of three herbaceous index plant species for bioavailability of soil cadmium, chromium, nickel and vanadium

Uncultivated plants growing on disturbed sites may be useful for assessing the bioavailability of some metals in soils, and thus the potential for metal mobilization up the terrestrial food chain, an important element in ecological risk assessment. A planted chicory cultivar (Cichorium intybus L. var. foliosum Hegi.) and the uncultivated plants horseweed (Canada fleabane) (Erigeron canadensis L.) and dogfennel (Eupatorium capillifolium (Lam.) Small) were evaluated for their ability to act as index plant species for soil Cd, Cr, Ni, and V at two field sites where these metals had been applied five yr previously to two highly weathered sandy Ultisols. Soil Cd was available to all analyzed plant tissues of all three plant species at both sites, particularly on the sandier Blanton soil. Chicory was an effective index plant for Cd on the finer textured Orangeburg soil but functioned as an indicator plant (toxicity symptoms were observed) on the sandier Blanton soil. Horseweed and dogfennel were effective index plants for Cd in both contaminated soils. Soil Cr, Ni, and V were less bioavailable than soil Cd and plant metal uptake was more sensitive to residual soil Cr, Ni, and V than was soil extraction with double acid. Horseweed and chicory may have potential as index plants for soil Cr. Chicory may have potential as a Ni index plant. Chicory and dogfennel may have potential as V index plants.