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Collembola have been proposed for several decades as a good model organisms to survey soil biodiversity; but most of the studies focused on taxonomic endpoints. The main objectives of this study are to compare the effects of the different land uses, including urban and industrial land uses, while using both collembolan functional and taxonomic biodiversity approaches. We collected data on 3,056 samples of Collembola communities across 758 sites in various land uses throughout France. The types of land use considered included all types of human activity from forestry to urban, industrial, traffic, mining and military areas, agricultural grassland, arable land, vineyards and urban vegetable gardens. In order to study functional and taxonomic biodiversity, we used community-weighted means, functional indices, species richness and density. When looking at collembolan functional diversity, urban and industrial soils appear clearly less diversified than when considering the taxonomic diversity. We suspect here a functional homogenization effect commonly reported in the literature for various organisms in urban ecosystems. Our study provides range of values for different taxonomic and functional indices of Collembola communities in a wide land use classification across France.

Wood ash contains much heavy metal and may therefore be considered toxic to the soil system and its organisms. We evaluated this at several levels of description from simple toxicity tests to field tests with ash application in an acid plantation of Norway spruce. In pot studies ash stimulate plant growth, equally because of the pH increase and the nutrients added. The pH increase stimulates decomposition activity. Soil carbon availability is not permanently increased with ash amendment, however, which may suggest that decomposition increase is coupled to primary production increase. Plantation organisms changed markedly with ash. Moss cover change, enchytraeid worms decrease, and the bacterial food chain increase without a reduction in fungal activity. The bacterial communities also change. Ash did not affect ectomycorrhiza, probably because it remains in the upper cm after surface application. Wood ash increase plantation soil Cd, and so did Cd in grass although at a very low level, Cd in lichens and Cd in the small biomass of earthworms. The toxicity of Cd is regulated by metal binding to soil being several orders of magnitude lower than in pure liquid. Ash is toxic towards microarthropods in farmland soil, not in plantation soil being an effect of pH not of heavy metals. Cd toxicity was reduced when applied with ash, and available Cd and plant uptake even decrease with increased ash to soil. Tolerance of bacteria to Cd does not increase with ash also suggesting low availability of Cd in ash. Other more abundant cations like Zn regulate Cd uptake. Mycorrhiza reduce Cd uptake in several plants. In barley Cd gradually decrease from root via stem to seeds. In conclusion for ash amounts up to 10 t/ha, we do not find metal toxicity of ash or evidence for bioaccumulation of metals in soil organisms. Neither CO2 output nor exchange of N2O and CH4 in the plantation was changed with ash, and nitrogen leaching did not increase. So, even though marked changes occur in the soil biota following ash amendment, no adverse effects within the system were observed and polluting outputs from the system were not increased. By addressing the in part contrasting results at description levels between simple toxicity tests, pot studies with organisms, ash and heavy metals under control, and field studies we got a system understanding of the ash effects on soil organisms and processes.

Dette projekt har undersøgt vekselvirkninger mellem to pesticider og hhv. jordbearbejdning (direkte sået eller pløjet jord) og gødskning (handels- eller husdyrgødning) med hensyn til effekter på regnorme, mikroleddyr og mikrobielle indikatorer og på udvalgte økosystem-tjenester (funktioner).

ECOGEN is a project funded by the EU under the 6th Framework Programme. Based on results obtained from soil biodiversity studies and economic evaluations, ECOGEN assessed the impact on soil organisms of different agricultural management practices, including those involving genetically modified (GM) crops. Soil organisms form a complex ecosystem that is crucial to the productivity of agricultural soils. ECOGEN evaluated the diversity and function of soil organisms in various agricultural soils using selected parameters. Soils from fields where GM maize was grown were compared to soils from fields where non-GM conventional maize (8 different varieties) was planted. In addition, economic assessments of the GM crop were performed by quantifying the differences in variable costs, revenues and external effects in comparison with the conventional variety. The implications for the EU Common Agriculture Policy were then evaluated. These two major factors - ecological and economic - were then integrated into decision support models for predicting the overall consequences of introducing GM crops into an agricultural system. Bt-maize line MON 810, resistant to a widespread insect pest called the European corn borer, was chosen as the model GM crop since it has been approved for planting in the EU and been available to growers in Europe since 2003 (introduced first in Spain), with commercial plantings being conducted in five Member States in 2006 on more than 63,000 ha. MON 810 maize was first commercialised in the US in 1998 and has been planted on millions of hectares worldwide since then. In the ecological assessment, the effects of Bt maize were assessed at three levels of increasing complexity: Laboratory tests on single species: the main groups of soil organisms covered were bacteria, protozoa, nematodes, springtails, mites and earthworms; Green-house model ecosystem or mesocosm studies to analyse ecological interactions; Field studies in three climatic zones of Northern and Southern Europe where Bt-maize management was compared with conventional management (that included insecticides) for possible ecological effects. Different soil tillage programmes were included.In the economic assessment, an extended social benefit cost analysis was used, where social benefits and costs (reversible, irreversible, private and public) were considered (Figure 2). As mentioned above, the ecological and economic results were integrated into a decision support model to facilitate the assessment of the impact of various cropping systems on soil quality and economics.In conclusion, the ECOGEN results indicate no difference of biological relevance in the impact on soil organisms between Bt-maize line MON 810 and conventional non-GM maize. These results are in line with other research findings obtained over the past ten years since first commercialization. The few differences observed were inconsistent and within the natural variation expected for maize crops. Soil type, plant growth stage and the use of pesticides have a higher impact on soil organism diversity and function than the type of maize crop grown (GM or conventional). Furthermore, the adoption of reduced tillage technologies, facilitated in certain types of GM crops, may contribute to preserving the quality of agricultural soil. The economic analyses indicate that the EU corn growing farmers would forego direct economic benefits in the area of 150 million Euro per year by postponing the full introduction of MON 810. The direct economic benefits are high enough to compensate for possible but highly unlikely irreversible costs of full introduction. Authors continued: Scatasta, S., Gomot-De Vaufleury, A., Caul, S., Birch, A.N.E., Andersen, M.N., Sausse, C., Fernandez, S.

Udgivelsesdato: 29 January

The biodiversity of, and processes performed by soil organisms make up a crucial part of the natural basis for agricultural production and, therefore, have subsequent economic consequences. ECOGEN was a research initiative funded under the European Commission Framework 5 programme, designed to integrate the combined soil ecological and economic effects of introducing systems including genetically modified (GM) crops by performing data mining and building decision support systems. The project involved eight academic partners from five EU countries and an input from Monsanto. Maize expressing an insecticidal protein from Bacillus thuringiensis (Bt-maize) was chosen as the model GM crop due to its availability, while studies using GM herbicide tolerant (HT) maize were initiated in the latter stages of the project.

Increasing amounts of environmental data are being collected. With environmental data, we often encounterthe situation of having to predict several target variables of similar type, such as biomasses of differentspecies. This situation is usually handled by computing an aggregate target variable (like total biomass ora biodiversity measure) and then predicting the aggregate variable. An other possible (but rarely taken)approach is to model all target variables and then calculate the aggregate variable from the model outputs.In this paper, we try to answer the question whether the simpler approach of producing one model for theaggregate target variable is worse than the more complex approach of producing multiple models and thencalculating the aggregate variable from the model outputs. We do this by taking a dataset describing theagricultural events and soil biological parameters as independent variables and a set of microarthropodspecies biomasses as dependent variables. We calculated several aggregate target variables such as totalbiomass, Shannon biodiversity and species richness from the original data. We build models to predictthese directly, and also build separate predictive models for the biomass of the microarthropod species andcalculate the aggregate target variables from the outputs of these models. We compared the aggregatevariables calculated from the measured data, the aggregate variables predicted directly and the aggregatevariables calculated from the outputs of the models for individual species using the Parson correlation coefficientand two additional error measures. Our results show, that in most cases first calculating the aggregatevariables, and then learning models to predict these directly yields better results than modeling individualspecies and then calculating the aggregate variables from the predictions of these models.

The Department of Terrestrial Ecology at the Danish National Environmental Research Institute (NERI) include a Contract Research Organization (CRO) offering a suite of ISO and OECD field and laboratory tests needed in risk assessment for the soil environment. All tests are performed in compliance with Good Laboratory Practice (GLP). Our test programme includes earthworms, collembolans, enchytraeids, mites, organic matter decomposition and plants. We offer close co-operation with clients, and deliver scientifically based reporting and interpretation of data. Our tests have been developed and refined during several years of R&D programme activities. In-house risk assessors and taxonomical and ecological expertise support the conduction and reporting of test results.

Field trials were established at three European sites (Denmark, Eastern France, South-West France) of genetically modified maize (Zea mays L.) expressing the CryIAb Bacillus thuringiensis toxin (Bt), the near-isogenic non-Bt cultivar, another conventional maize cultivar and grass. Soil from Denmark was sampled at sowing (May) and harvest (October) over two years (2002, 2003); from E France at harvest 2002, sowing and harvest 2003; and from SW France at sowing and harvest 2003. Samples were analysed for microbial community structure (2003 samples only) by community-level physiological-profiling (CLPP) and phospholipid fatty acid analysis (PLFA), and protozoa and nematodes in all samples. Individual differences within a site resulted from: greater nematode numbers under grass than maize on three occasions; different nematode populations under the conventional maize cultivars once; and two occasions when there was a reduced protozoan population under Bt maize compared to non-Bt maize. Microbial community structure within the sites only varied with grass compared to maize, with one occurrence of CLPP varying between maize cultivars (Bt versus a conventional cultivar). An overall comparison of Bt versus non-Bt maize across all three sites only revealed differences for nematodes, with a smaller population under the Bt maize. Nematode community structure was different at each site and the Bt effect was not confined to specific nematode taxa. The effect of the Bt maize was small and within the normal variation expected in these agricultural systems. Field trials were established at three European sites (Denmark, Eastern France, South-West France) of: genetically modified maize expressing the cry1Ab Bacillus thuringiensis protein (Bt), the near-isogenic non-Bt cultivar, a conventional maize cultivar and grass. Soil from these trials was sampled at sowing (May) and harvest (October) over two years (2002, 2003) and analysed for: microbial community structure by community-level physiological-profiling (CLPP) and phospholipid fatty acid analysis (PLFA), protozoa and nematodes. Individual differences within a site resulted from: greater nematode numbers under grass than maize on three occasions; different nematode populations under the conventional maize cultivars once; and two occasions when there was a reduced protozoan population under Bt maize compared to non-Bt maize. Microbial community structure within the sites only varied with grass compared to maize, with one occurrence of CLPP varying between maize cultivars (Bt versus a conventional cultivar. An overall comparison of Bt versus non-Bt maize across all three sites only revealed differences for nematodes, with a smaller population under the Bt maize. Nematode community structure was different at each site and the Bt effect was not confined to specific nematode taxa. The effect of the Bt maize was small and within the normal variation expected in these agricultural systems.

The acute toxicity of dimethoate was examined on different life stages (larvae, protonymph, deutonymph, male and female) of the predatory mite Hypoaspis aculeifer. The mites were exposed for 7 days in an artificial soil to 0, 2, 4, and 6 mg kg-1. A comparison of LC50 values ranked the sensitivity of the life stages to be: Larvae (LC50 = 3.8) > protonymph (LC50 = 5.3) > male (LC50 = 5.6) > deutonymph (LC50 = 7.1) > female (LC50 = 7.6). A life table response analysis may show how the results affect the population dynamics of H. aculeifer.

The effect of eight polycyclic aromatic compounds (PACs) on the seed emergence and early life-stage growth of three terrestrial plants (Sinapsis alba, Trifolium pratense and Lolium perenne) were studied in a greenhouse, using a Danish agricultural soil with an organic carbon content of 1.6%. After three weeks of exposure, seed emergence and seedling weight (fresh weight and dry weight) were determined. Exposure concentrations were veri.ed with chemical analysis. The substances tested were four polycyclic aromatic hydrocarbons (.uoranthene, pyrene, phenanthrene and .uorene), the N-, S-, and O-substituted analogues of .uorene (carbazole, dibenzothiophene and dibenzofuran, respectively), and the quinoline representative acridine. Seedling growth was a far more sensitive endpoint than seed emergence for all substances. Concentrations estimated to give a 20% reduction of seedling fresh weight (EC20-values) ranged from 36 to 290 mgkg_1 for carbazole, 43 to 93 mgkg_1 for dibenzofuran, 37 to 110 mg kg_1 for dibenzothiophene, 140 to 650 mg kg_1 for .uoranthene, 55 to 380 mgkg_1 for .uorene, 37 to 300 mg kg_1 for phenanthrene, and 49 to 1300 mg kg_1 for pyrene. For acridine, no toxicity was observed within the concentration range tested (1-1000 mg kg_1). As illustrated by the EC20-values, there was a rather large di.erence in sensitivity between the species, and T. pratense was the most sensitive of the species tested.

The effects of the Cry1Ab toxin from Bacillus thuringiensis (corn variety Cascade Bt MON810 and DeKalb variety 618 Bt) were studied on survival and reproduction of the soil collembolan Folsomia fimetaria, Folsomia candida, the collembolan predator mite Hypoaspis aculeifer and enchytraeids Enchytraeus crypticus. The toxicity was observed in Petri dishes with plaster of Paris substrate and in a soil-litter microcosm toxicity test system on both single species and in a predator-prey interacting test system. In petri dishes, roots and leaves of young plants (three weeks) were fed to F. candida for 16 days, dried leaves of mature plants collected after harvest and artificial food (mixture of dried leaves with yeast) were fed to F. fimetaria for 21 days. In the single species soil test system, F. fimetaria and E. crypticus were exposed for 21 days to increasing concentrations of young Bt plant material, max. 40 g kg-1 soil, and increasing concentrations of dried mature Bt plant material, max. 10g kg-1 soil. H. aculeifer and its prey F. fimetaria were used in the predatory-prey two species test system. They were exposed to increasing concentrations of dried mature Bt plant material of max. 20 g kg-1 soil for 21 days. Cry1Ab toxin was analysed by ELISA (PSB 05500 Agdia). After 16 day exposure to young plant, the reproduction of F. candida fed Bt roots was significantly reduced, while there was no statistical difference between the reproduction of F. candida fed Bt and non-Bt leaves. There was a weak significant reduction by 30% on the reproduction of F. fimetaria fed Bt corn in Petri dishes for 21 days. Likewise there was a weak significant reduction by 40% of the reproduction of H. aculeifer by Bt corn in amounts corresponding to 20 g plant material kg-1 soil in the two species soil-litter microcosm systems. There were no effects of Bt corn materials on the reproduction of F. fimetaria and E. crypticus in the single species soil-litter microcosms. No effects of Bt corn materials on mortality of all the 4 species were observed in all treatments. The tendency of effects of the Bt corn on the reproduction of F. fimetaria, F. candida and H. aculeifer is discussed.

Effective use of organic wastes for agricultural production requires that risks and benefits be documented. Two types of sewage sludge, household compost and solid pig manure were studied under field and greenhouse conditions to describe their fertilizer value and effects on soil properties and soil biota, the fate of selected organic contaminants, and their potential for plant uptake. A 3-year field trial on two soil types showed no adverse effects of waste amendment on crop growth, and a significant fertilizer value of one sludge type. Accumulation of N and P-i was indicated, as well as some stimulation of biological activity and micro-arthropod populations, but these effects differed between soil types. There was no detectable accumulation of polycyclic aromatic hydrocarbons (PAH), di(2- ethy Ihexyl)phthal ate (DEHP), nonylphenol and ethoxylates (NP + NPE) or linear alkylbenzene sulfonates (LAS) after three repeated waste applications, and no plant uptake was suggested by analysis of the third crop. A plot experiment with banded sludge was conducted to examine sludge turnover and toxicity in detail. Less than 5% of NP or LAS applied in organic wastes was recovered after 6 months, and less than 6% of DEHP applied was recovered after 12 months. Potential ammonium oxidation (PAO) at 0-1 cm distance from the banded sludge was stimulated despite toxic concentrations in the sludge, which suggested that contaminants were degraded inside sludge particles. Phospholipid fatty acid (PLFA) profiles suggested a gradual shift in the composition of the microbial community within sludge, partly due to a depletion of degradable substrates. A pot experiment with sludge-amended soil and soil spiked with contaminants showed no plant uptake of NP, DEHP or LAS. Degradation of LAS and NP added in sludge was delayed and the degradation of DEHP was faster than when the contaminants were added directly to the soil. In conclusion, adverse effects of organic waste application on soil or crop were not found in this study, and for some waste products positive effects were observed. (C) 2003 Elsevier Science B.V. All rights reserved.

Recent research has documented soil microorganisms to be rather sensitive to linear alkylbenzene sulfonates (LAS), which may enter the soil environment in considerable quantities following sewage sludge disposal. We here report field effects of LAS on selected microbial populations present in a sandy soil surrounding well-defined sludge bands spiked with high but realistic LAS levels (7.1 or 31.3 g/kg). Surprisingly, LAS had no effect on heterotrophic respiration in the sludge compartment per se but stimulated activity and metabolic quotient (microbial activity per unit of biomass) in the surrounding soil. By contrast, autotrophic ammonia oxidation was initially inhibited in the LAS-spiked sludge. This led to dramatic transient increases of NH+4 availability in the sludge and surrounding soil, subsequently stimulating soil ammonia oxidizers. As judged from a Nitrosomonas europaea bioluminescence toxicity assay, however, LAS or other sludge components never accumulated to toxic levels in the soil compartments and the LAS tolerance of the indigenous microbes further remained unchanged following LAS exposure. LAS effects on the investigated microbial populations largely occurred during the first two months and were confined to soil closer than 30 mm from LAS-spiked sludge. Our results strongly suggest that disposal of LAS-contaminated sludge does not pose a major risk to the function of the soil microbial community under field conditions.

Udgivelsesdato: AUG

Veterinary pharmaceutical products such as antibacterial agents and antiparasitics are widely used to control diseases and promote production in the agricultural sector. Exposure of non- target organisms are a likely result of using manure from treated live stocks or from dung dropped on the field by grazing animals. The aim of this study was to determine the toxic threshold levels of three antibacterial agents (tiamulin, olanquindox and metronidazole) and one anthelmintic (ivermectin) to two species of soil dwelling organisms (springtails and enchytraeids), that are often found in bio- solids such as manure or dung. The antibacterial agents were not toxic to adults and effects on reproduction occurred generally above concentrations normally found in soil or dung. The threshold values for toxicity (10% reduced reproduction or EC10 values) were in the range of 61-111 mgkg(-1) dry soil for springtails and 83-722 mgkg-1 dry soil for enchytraeids. Ivermectin was significantly more toxic with EC10 values of 0.26 mgkg(-1) dry soil for the springtails and 14 mgkg(-1) dry soil for the enchytraeids. A comparison of these results with rough estimates of likely and worse case environmental concentrations indicates a potential risk of ivermectin to non- target species such as springtails and enchytraeids, whereas direct toxic effect of antibacterial agents is very unlikely to occur at environmental realistic concentrations. However, indirect effects of antibacterial agents driven through changes in the food web cannot be abolished at this stage. (C) 2002 Elsevier Science Ltd. All rights reserved.