We evaluated how root-induced changes in rhizosphere pH varied and interacted with Cu availability and bioavailability in an acidic soil. Rape was grown on a Cu-contaminated acidic soil, which had been limed at 10 rates. Soil Cu bioavailability was not influenced by liming. However, liming significantly decreased CaCl2–extracted Cu for pH between 3.7 and 5.1. Little effect was found for pH above 5.1. For soil pH < 4.4, CaCl2–Cu contents were smaller in rhizosphere than uncropped soil. Rhizosphere alkalisation occurred at pH < 4.8, while acidification occurred at greater pH. This explained the changes of CaCl2–Cu in the rhizosphere at low pH and the absence of pH dependency of Cu bioavailability to rape. In addition, apoplastic Cu in roots increased with increasing soil pH, most probably as a result of increased dissociation and affinity of cell wall compounds for Cu. Root-induced increase in pH reduces Cu availability in the rhizosphere and Cu bioavailability to rape.

Chlordecone was applied between 1972 and 1993 in banana fields of the French West Indies. This resulted in long-term pollution of soils and contamination of waters, aquatic biota, and crops. To assess pollution level and duration according to soil type, WISORCH, a leaching model based on first-order desorption kinetics, was developed and run. Its input parameters are soil organic carbon content (SOC) and SOC/water partitioning coefficient (Koc). It accounts for current chlordecone soil contents and drainage water concentrations. The model was valid for andosol, which indicates that neither physico-chemical nor microbial degradation occurred. Dilution by previous deep tillages makes soil scrapping unrealistic. Lixiviation appeared the main way to reduce pollution. Besides the SOC and rainfall increases, Koc increased from nitisol to ferralsol and then andosol while lixiviation efficiency decreased. Consequently, pollution is bound to last for several decades for nitisol, centuries for ferralsol, and half a millennium for andosol. Soil and water contamination by chlordecone will persist for several centuries in the French West Indies, because the only decontamination is through leaching by drainage water.

The relationships between total mercury (Hg) concentration and stable nitrogen isotope ratio (delta N-15) were evaluated in Mullus barbatus barbatus and M. surmuletus from the Mediterranean Sea and M. barbatus ponticus from the Black Sea. Mercury concentration in fish muscle was six times higher in the two Mediterranean species than in the Black Sea one for similar sized animals. A positive correlation between Hg concentration and delta N-15 occurred in all species. Increase in Hg concentration with delta N-15 was high and similar in the two Mediterranean fishes and much lower in the Black Sea species. Since this was neither related to trophic level difference between species nor to methylmercury (MeHg) concentration differences between the north-western Mediterranean and the Black Sea waters, we suggested that the higher primary production of the Black Sea induced a dilution of MeHg concentration at the base of the food webs. (c) 2009 Elsevier Ltd. All rights reserved.

This paper describes the PREI (Posidonia oceanica Rapid Easy Index), a method used to assess the ecological status of seawater along Mediterranean French coasts. The PREI was drawn up according to the requirements of the Water Framework Directive (WFD 2000/60/EC) and was tested on 24 and 18 stations in PACA (Provence-Alpes-Cotes d'Azur) and Corsica, respectively. The PREI is based on five metrics: shoot density, shoot leaf surface area, E/L ratio (epiphytic biomass/leaf biomass), depth of lower limit, and type of this lower limit. The 42 studied stations were classified in the first four levels of status: high, good, moderate and poor. The PREI values ranged between 0.280 and 0.847; this classification is in accordance with our field knowledge and with our knowledge of the literature. The PREI was validated regarding human pressure levels (r(2)=0.74). (http://eurex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2000: 327:0001:0072:EN:PDF). (C) 2009 Elsevier Ltd. All rights reserved.

This study was carried out in shrimp ponds from New Caledonia, in order to determine the cause of the exceptional proportion of abnormal tests (FAI) (often >50%, sometimes >80%). FAI was positively correlated to the quantity of easily oxidized material (EOM) deposited on the bottom of the ponds and to the sediment oxygen demand, and negatively correlated to redox. These results suggest that a very high FAI is a potential indicator for great accumulations of native organic matter, leading to a high sediment oxygen demand. When studying ancient sediments in core samples, exceptional abundances of abnormal tests may indicate periods of high accumulation of EOM, and therefore of oxygen depletion. This finding should help in better management of aquaculture ponds, but should also allow new insight into the interpretation of sedimentary records, providing a useful proxy for paleoenvironmental reconstructions.

[Departement_IRSTEA]Territoires [TR1_IRSTEA]SYNERGIE | International audience | The strategy of CLIMB is aiming to employ and integrate advan¬ced field monitoring techniques, remote sensing ana-lyses and retrievals, climate models auditing and integra¬ted hydrologic modeling and socioeconomic factor assess¬ment in a new conceptual framework to significantly reduce exist-ing uncertainties in climate change impact analysis. It will create an integrated risk assessment tool for adaptive water resources management and best agricultural practice under climate change conditions. The risk and vulnerability analysis tool will also enable the assess¬ment of risks for conflict-inducing actions. The impro¬ved models, new assessment tools, and their results will be evaluated against current methodologies. Improvements will be communicated to stakeholders and decision makers in a transparent, easy-to-understand form, enabling them to utilize the new findings in regional water resource and agricultural management initiatives as well as in the design of mechanisms to reduce potential for conflict CLIMB is embedded in a cluster of independent EU- projects with WASSERMed and CLICO, focused on climate induced changes in water resources as a threat to security. | L'objectif de la stratégie du projet CLIMB est d'utiliser et d'intégrer des techniques de suivi avancées sur le terrain, des analyses et des recherches de données faisant appel à la télédétection, de vérification de modèles d'évolution climatique et de modélisation par l'intégration hydrologique, et d'évaluation des facteurs socio-économiques dans un cadre conceptuel nouveau afin de réduire de façon significative les incertitudes existantes au sein des analyses des impacts du changement climatique. Ce projet créera un outil intégré d'évaluation du risque qui servira à gérer d'une façon adaptée les ressources en eau et à mettre en ½uvre les meilleures pratiques agricoles possibles dans les conditions du changement climatique. Cet outil d'analyse du risque et de la vulnérabilité permettra aussi l'évaluation des risques dans le cas d'actions conflictuelles. On comparera les modèles améliorés, les nouveaux outils d'évaluation, et leurs résultats aux méthodologies couramment utilisées. On diffusera les progrès obtenus aux parties prenantes et aux décideurs sous une forme transparente et facile à comprendre, leur permettant d'une part d'utiliser les résultats fraichement produits, tant dans les initiatives relatives à la ressource régionale en eau et à la gestion de l'agriculture, et d'autre part de réduire la source de conflit potentiel.

[Departement_IRSTEA]Territoires [TR1_IRSTEA]SYNERGIE | International audience | The strategy of CLIMB is aiming to employ and integrate advan¬ced field monitoring techniques, remote sensing ana-lyses and retrievals, climate models auditing and integra¬ted hydrologic modeling and socioeconomic factor assess¬ment in a new conceptual framework to significantly reduce exist-ing uncertainties in climate change impact analysis. It will create an integrated risk assessment tool for adaptive water resources management and best agricultural practice under climate change conditions. The risk and vulnerability analysis tool will also enable the assess¬ment of risks for conflict-inducing actions. The impro¬ved models, new assessment tools, and their results will be evaluated against current methodologies. Improvements will be communicated to stakeholders and decision makers in a transparent, easy-to-understand form, enabling them to utilize the new findings in regional water resource and agricultural management initiatives as well as in the design of mechanisms to reduce potential for conflict CLIMB is embedded in a cluster of independent EU- projects with WASSERMed and CLICO, focused on climate induced changes in water resources as a threat to security. | L'objectif de la stratégie du projet CLIMB est d'utiliser et d'intégrer des techniques de suivi avancées sur le terrain, des analyses et des recherches de données faisant appel à la télédétection, de vérification de modèles d'évolution climatique et de modélisation par l'intégration hydrologique, et d'évaluation des facteurs socio-économiques dans un cadre conceptuel nouveau afin de réduire de façon significative les incertitudes existantes au sein des analyses des impacts du changement climatique. Ce projet créera un outil intégré d'évaluation du risque qui servira à gérer d'une façon adaptée les ressources en eau et à mettre en ½uvre les meilleures pratiques agricoles possibles dans les conditions du changement climatique. Cet outil d'analyse du risque et de la vulnérabilité permettra aussi l'évaluation des risques dans le cas d'actions conflictuelles. On comparera les modèles améliorés, les nouveaux outils d'évaluation, et leurs résultats aux méthodologies couramment utilisées. On diffusera les progrès obtenus aux parties prenantes et aux décideurs sous une forme transparente et facile à comprendre, leur permettant d'une part d'utiliser les résultats fraichement produits, tant dans les initiatives relatives à la ressource régionale en eau et à la gestion de l'agriculture, et d'autre part de réduire la source de conflit potentiel.

Protecting geotextiles are used in the design of watertight bottom liners at landfill sites, above the géomembrane, to protect it against puncture during the installation of the drainage layer and, during the service life, to the weight of the waste to be put in place. To date, the results of the 2 standard tests (static and dynamic tests) given by the technical sheets for the protecting geotextiles are not sufficient to choose the good geotextile. The development of an experimental procedure to simulate in the lab the waste loading conditions is presented here; this procedure uses large size static damage tests and follows a previous study concerning the implementation dynamic conditions (Budka & al., 2006). | Les géotextiles sont utilisés dans la constitution des étanchéités des installations de stockage de déchets (ISD) pour protéger la géomembrane contre les effets du poinçonnement liés à la mise en oeuvre de la couche de drainage puis, en service, au poids des déchets sus jacents. À ce jour, les deux essais normalisés de poinçonnement, statique et dynamique, figurant sur les fiches techniques des géotextiles de protection ne permettent pas directement le choix du produit adapté. La mise au point d'une procédure d'étude des effets des sollicitations en service est présentée ici ; elle s'appuie sur des essais d'endommagement de grandes dimensions et fait suite à une étude déjà publiée sur l'effet des sollicitations de mise en oeuvre (Budka et al., 2006).

The paper presents parts of the recent guide of recommendations "Mountain reservoirs". It makes a synthesis of a feedback on the behaviour and the pathology of geomembrane lining systems and gives the strong recommendations of the guide relative to these systems, in particular onto the structure support, the drainage inherent to the DEG and the covering structure. A general description of the guide ends the article. | L'article présente, à travers le récent guide de recommandations «&nbsp;Retenues d'altitude&nbsp;», la synthèse d'un retour d'expérience sur le comportement et la pathologie des dispositifs d'étanchéité par géomembrane (DEG) en altitude. Il donne les recommandations fortes du guide relatives à ces dispositifs, en particulier sur la structure support, le drainage inhérent au DEG et la structure de recouvrement. Un descriptif général du guide termine l'article.