Assessment of structure and function in metal polluted grasslands using Terrestrial Model Ecosystems

Department of Animal Ecology, Vrije Universiteit, Amsterdam, The Netherlands.
Ecotoxicology and Environmental Safety (Impact Factor: 2.76). 07/2008; 72(1):51-9. DOI: 10.1016/j.ecoenv.2008.03.016
Source: PubMed

ABSTRACT Ecosystem effects of metal pollution in field situations are hard to predict, since metals occur often in mixtures and links between structural (organisms) and functional endpoints (ecosystem processes) are not always that clear. In grasslands, both structure and functioning was suspected to be affected by a mixture of copper, lead, and zinc. Therefore, the structural and functional variables were studied simultaneously using Terrestrial Model Ecosystems (TMEs). Comparing averages of low- and high-polluted soil, based on total metal concentrations, did not show differences in structural and functional variables. However, nematode community structure (Maturity Index) negatively correlated with metal concentrations. Next to that, multivariate statistics showed that enchytraeid, earthworm and, to lesser extent, nematode diversity decreased with increasing metal concentrations and a lower pH in the soil. Bacterial CFU and nematode biomass were positively related with decomposer activity and nitrate concentrations. Nitrate concentrations were negatively related to ammonium concentrations. Earthworm biomass, CO(2) production and plant yield were not related to metal concentrations. The most metal-sensitive endpoint was enchytraeid biomass. In all analyses, soil pH was a significant factor, indicating direct effects on organisms, or indicating indirect effects by influencing metal availability. In general, structural diversity seemed more positively related to functional endpoints than structural biomass. TMEs proved valuable tools to assess the structure and function in metal polluted field situations. The outcome feeds modeling effort and direct future research.

Download full-text


Available from: Matty P. Berg, Sep 29, 2015
60 Reads
  • Source
    • "A. Ghanem et al. Kools et al. 2009; Roig et al. 2012; Skrbic and urisic-Mladenovic 2007). The analysis of variance (ANOVA) using the suitable general linear mixed (GLM) model offers an efficient method to assess the influence of different factors on the characteristics of TME using a reduced number of replications. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The use of sludge as soil amendment is widely encouraged by its high contents in organic matter and plant nutrients. Nevertheless, agrochemicals potentially present in sludge could be harmful to terrestrial ecosystems. The present work aimed to apply standard statistical methods for suitable assessment of the ecotoxicological impacts of sludge amendments on soil, involving the following factors: the type of treated sludge, their application dose, and their contents in agrochemicals. Terrestrial Model Ecosystems were used to assess the effects of sludge amendments on endpoints from different trophic levels of the soil ecosystem, including an in vitro estrogenic bioassay on soil leachates. Here, we show the significant negative effects of the highest dose of sludge in most of the soil bioassays. Thermally dried sludge increased significantly the microbial activity leading to lower contamination of leachates with endocrine disrupting molecules. Agrochemicals contents of sludge have only significant impacts on increasing the delay of germination of plant seeds. Soil bioassays are thus complementary to sludge chemical analysis when the impacts of its application on soil should be assessed: significant negative impacts were related to the intrinsic composition of sludge rather than its agrochemicals contents. We conclude that standard statistical methods are relevant tools for the analysis of complex data generated from this type of experiment.
    Toxicological and Environmental Chemistry 03/2013; 95(1):4. DOI:10.1080/02772248.2012.744021 · 0.83 Impact Factor
  • Source
    • "ARTICLE IN PRESS of different plant species or artificial root exudates on soil microbial community structure and activity (for example: Baudoin et al., 2003; Sö derberg et al., 2004; Renella et al., 2007; Singh et al., 2007), the capacity of root exudates to influence rhizosphere microbial communities in trace element polluted soils is less well understood. On the other hand, the analysis of nematode community has been successfully used in many occasions to determinate the effect of trace element pollution in soils (Bongers, 1990; Nagy, 1999; Kools et al., 2009). Also differences in nematode community associated to soil with different plant species rhizospheres has been published (Bais et al., 2006; Hofmann and Grundler, 2007). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Re-vegetation of trace element contaminated soils can alter the pH and chelating capacity in the rhizosphere, increasing the mobility of pollutants, which, in turn, may impact on rhizosphere ecology. In this study a short-term pot experiment was carried out in order to investigate the multi-factorial effects of: buffering capacity (sandy-loam and loam soils); pollutant load (0%, 1.3%, and 4% of pyrite sludge), and the presence/absence of plant (Lolium perenne L. and Medicago sativa L.) on the mobility of trace elements, soil biochemical functionality (hydrolase activities), and biological diversity (bacterial and nematode communities). The experiment was carried out with representative soils from the Guadiamar basin (SW Spain), an area where the Aznalcóllar mining spill affected over 4000ha. Results indicated that the development of rhizospheres in polluted soils (coarse-textured) increases the mobilization of trace elements. In general the presence of roots has stimulatory effects on soil quality indicators such as hydrolase activities and both bacterial and nematode communities. However, the presence of high amount of metals interferes with these beneficial effects. This study provided evidence about the complexity of the impact of growing plants on trace element polluted soils. Trace element mobilization, hydrolase activities and bacterial and nematode communities in the rhizosphere are dependent on plant species, soil type, and pollution dose.
    Ecotoxicology and Environmental Safety 04/2010; 73(5):970-81. DOI:10.1016/j.ecoenv.2010.01.013 · 2.76 Impact Factor
  • Source
Show more