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1. State of trace element contamination of sediments from the Nangbéto hydroelectric dam lake (Togo)

Author

Koudjo Adje, Tchaa Esso-Essinam Badassan, Kissao Gnandi, Housséni Ahoudi, Gnon Tanouayi, Kamilou Ouro-Sama, Sadikou Agbere, Hodabalo Dheoulaba Solitoke, Université de Lomé, Faculté Des Sciences, Laboratoire de Gestion, Traitement et Valorisation des Déchets, Département de Géologie et Environnement, BP : 1515, Lomé-TOGO, Ecole Normale Supérieure d’Atakpamé, Département Sciences de la Vie et de la Terre, BP : 07, Atakpamé-Togo, and Université de Lomé [Togo]

Subjects
Hydrology, Trace elements, Lac, Togo, [SDE.IE]Environmental Sciences/Environmental Engineering, Trace element, Contamination, Lake, Nangbéto, Sediments, Sédiments, 13. Climate action, Hydroelectricity, Environmental science, Eléments traces
Abstract

The Nangbéto hydroelectric dam lake, which is a spillway for agricultural input residues, urban and industrial effluents present in the Mono basin, is exposed to all forms of pollution. The aim of this work is to estimate the content of seven trace elements present in the sediments of the aforementioned lake in order to assess the ecological risk incurred by the aquatic biocenosis and therefore by man. Forty-two sediment samples (21 per season) are realized in different areas of the Lake. Cd, Pb, Ni, Cu, Cr, As and Hg are measured out in the sediments by the flame atomic absorption spectrophotometer in these pre-mineralized samples. The results show average contents varying from the lowest level 0.04 mg / kg for Hg to the highest 12.15 mg / kg for Cu in the rainy season and from 0.03 mg / kg for Hg and for As to 9.14 mg/kg for Cu in the dry season. All of these values are below Canadian sediment quality standards. The strongest average geoaccumulation indices (Igeo) are obtained for Pb with values less than 2. The mean values of the contamination factor (FC) are less than 1. The mean indices of contamination (Im) are less than 2, threshold d 'an onset of polymetallic contamination. The ecological risk (Ri) in relation to the contamination of the sediments of the Lake with trace elements is low in any season (Ri Le Lac du barrage hydroélectrique de Nangbéto qui constitue un déversoir des résidus des intrants agricoles, des effluents urbains et industriels présent dans le bassin du Mono est exposé à toutes formes de pollution. Le but de ce travail est de quantifier les teneurs de sept (7) éléments traces dans les sédiments dudit Lac afin d’évaluer le risque écologique encouru par la biocénose aquatique et partant par l’homme.Quarante-deux (42) échantillons de sédiments (21 par saison) sont échantillonnés dans différentes zones du Lac. Le Cd, Pb, Ni, Cu, Cr, As et Hg sont dosés dans les sédiments par le spectrophotomètre d’absorption atomique à flamme dans ces échantillons minéralisés. Les résultats montrent des teneurs moyennes variant de la plus faible teneur 0,04mg/kg pour le Hg à la plus forte (12,15mg/kg) pour le Cu en saison pluvieuse et de 0,03 mg/kg pour le Hg et pour l’As à la plus forte (9,14 mg/kg) pour le Cu en saison sèche. Toutes ces valeurs sont inférieures aux normes canadiennes de qualité des sédiments. Les plus forts indices de géoaccumulation (Igeo) moyens sont obtenus chez le Pb avec des valeurs inférieures à 2. Les valeurs moyennes de facteur de contamination (FC) sont inférieures à 1. Les indices moyens de contamination (Im) sont inférieurs à 2, seuil d’un début de contamination polymétallique. Le risque écologique (Ri) par rapport à la contamination des sédiments du Lac en éléments traces est faible en toute saison (Ri < 40) et cela implique un faible risque de contamination de la biocénose. La présente étude ne porte toutefois que sur les éléments traces métalliques. Elle ne tient compte ni des autres polluants, ni des effets "cocktail" potentiels entre eux. Un travail complémentaire devra donc être poursuivi dans ce sens pour consolider le faible risque enregistré pour la biocénose.

Published
2021
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2. Mediterranean land surfaces under global change : towards a roadmap for sustainable land use in Europe

Author

Didier Genin, Mohamed Alifriqui, Robin Duponnois, Richard Joffre, Thierry Gauquelin, Wadi Badri, Bruno Fady, Mohamed Aderghal, Magda Bou Dagher-Kharrat, Geneviève Michon, Hervé Sanguin, Arezki Derridj, Romain Simenel, Virginie Baldy, Laurent Auclair, Said Slimani, Ezékiel Baudoin, Yves Prin, Catherine Fernandez, Antoine Galiana, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Laboratoire Mixte International MEDITER ‘‘Terroirs Méditerranéens’’, Institut de Recherche pour le Développement (IRD [France-Ouest]), Gouvernance, Risque, Environnement, Développement (GRED), Université Paul-Valéry - Montpellier 3 (UM3)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut de Recherche pour le Développement (IRD), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université Paul-Valéry - Montpellier 3 (UM3), Laboratoire des symbioses tropicales et méditerranéennes (UMR LSTM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université Montpellier 1 (UM1)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Laboratoire Population-Environnement-Développement (LPED), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU), Ecologie des Forêts Méditerranéennes [Avignon] (URFM 629), Institut National de la Recherche Agronomique (INRA), Département Sciences de la Vie et de la Terre, Saint Joseph University, Faculté des Sciences Biologiques et des Sciences Agronomiques, Université Mouloud Mammeri [Tizi Ouzou] (UMMTO), Faculté des Sciences Ben M’sik, Département de Biologie, Laboratoire Ecologie et Environnement, Université Hassan II [Casablanca] (UH2MC), Faculté des Sciences Semlalia, Département de Biologie, Laboratoire Ecologie et Environnement Unité associée au CNRST - URAC 32, Université Cadi Ayyad [Marrakech] (UCA), E3R – Equipe de Recherche sur la Région et la Régionalisation – CERGéo, Laboratoire Mixte International MEDITER ‘‘Terroirs Méditerranéens’’ UM5A, Université Mohammed V de Rabat [Agdal], Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU), Université Paul-Valéry - Montpellier 3 (UPVM)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut de Recherche pour le Développement (IRD [France-Sud]), Ecologie des Forêts Méditerranéennes (URFM), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Voltz M. (ed.), Ludwig W. (ed.), Leduc Christian (ed.), Bouarfa S. (ed.), Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Université Mohammed V de Rabat [Agdal] (UM5)

Subjects
0106 biological sciences, Mediterranean climate, 010504 meteorology & atmospheric sciences, Socio-ecological systems, Biodiversity, Arecaceae, 01 natural sciences, Mediterranean Basin, forest, Quercus, K01 - Foresterie - Considérations générales, Abies pinsapo, Photosynthèse, biodiversity, Global and Planetary Change, changement climatique, Ecology, forêt méditerranéenne, sustainability, Communauté rurale, Deciduous, Sustainability, Pistacia, Écosystème forestier, P01 - Conservation de la nature et ressources foncières, Biodiversité, Abies, forêt tempérée, Argania spinosa, P40 - Météorologie et climatologie, mediterranean basin, gestion des ressources naturelles, 010603 evolutionary biology, bassin méditerranéen, socio-ecological systems, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Quercus suber, Corylus, E50 - Sociologie rurale, Forest, Functioning, Propriété physicochimique du sol, global change, 0105 earth and related environmental sciences, Land use, Composition botanique, Climat, Mediterranean basin, Global change, 15. Life on land, Evergreen, Zone méditerranéenne, Pinus, biodiversité forestière, Tetraclinis articulata, 13. Climate action, Juniperus, Threatened species, Peganum, fonctionnement socio écologique, Pinus halepensis, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, écosystème forestier méditerranéen
Abstract

Mediterranean forests are found in the Mediterranean basin, California, the South African Cape Province, South and southwestern Australia and parts of Central Chile. They represent 1.8 % of the world forest areas of which the vast majority is found in the Mediterranean basin, where historical and paleogeographic episodes, long-term human influence and geographical and climatic contrasts have created ecosystemic diversity and heterogeneity. Even if evergreen is dominant, deciduous trees are also represented, with different forest types including dense stands with a closed canopy (forests sensu stricto) and pre-forestal or pre-steppic structures with lower trees density and height. The Mediterranean basin is also a hot spot of forest species and genetic diversity, with 290 woody species versus only 135 for non-Mediterranean Europe. However, the characteristics of the Mediterranean area (long-standing anthropogenic pressure, significant current human activity and broad biodiversity) make it one of the world’s regions most threatened by current changes. Four examples of Mediterranean forest types, present in south and north of the Mediterranean basin and more or less threatened, are developed in order to show that linking “hard sciences” and humanities and social sciences is necessary to understand these complex ecosystems. We show also that these forests, in spite of specific climatic constraints, can also be healthy and productive and play a major ecological and social role. Furthermore, even if the current human activity and global change constitute a risk for these exceptional ecosystems, Mediterranean forests represent a great asset and opportunities for the future of the Mediterranean basin.

Published
2018
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3. Does nitrogen fertilization history affects short-term microbial responses and chemical properties of soils submitted to different glyphosate concentrations?

Author

Nivelle E, Verzeaux J, Chabot A, Roger D, Spicher F, Lacoux J, Nava-Saucedo JE, Catterou M, and Tétu T

Subjects
Glycine administration & dosage, Glycine analysis, Glyphosate, Fertilizers, Glycine analogs & derivatives, Nitrogen analysis, Soil Microbiology
Abstract

The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\100FR and N+\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate.

Published
2017
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4. Mapping Post-Glacial expansions: The Peopling of Southwest Asia.

Author

Platt DE, Haber M, Dagher-Kharrat MB, Douaihy B, Khazen G, Ashrafian Bonab M, Salloum A, Mouzaya F, Luiselli D, Tyler-Smith C, Renfrew C, Matisoo-Smith E, and Zalloua PA

Abstract

Archaeological, palaeontological and geological evidence shows that post-glacial warming released human populations from their various climate-bound refugia. Yet specific connections between these refugia and the timing and routes of post-glacial migrations that ultimately established modern patterns of genetic variation remain elusive. Here, we use Y-chromosome markers combined with autosomal data to reconstruct population expansions from regional refugia in Southwest Asia. Populations from three regions in particular possess distinctive autosomal genetic signatures indicative of likely refugia: one, in the north, centered around the eastern coast of the Black Sea, the second, with a more Levantine focus, and the third in the southern Arabian Peninsula. Modern populations from these three regions carry the widest diversity and may indeed represent the most likely descendants of the populations responsible for the Neolithic cultures of Southwest Asia. We reveal the distinct and datable expansion routes of populations from these three refugia throughout Southwest Asia and into Europe and North Africa and discuss the possible correlations of these migrations to various cultural and climatic events evident in the archaeological record of the past 15,000 years.

Published
2017
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5. Unlocking the Karyological and Cytogenetic Diversity of Iris from Lebanon: Oncocyclus Section Shows a Distinctive Profile and Relative Stasis during Its Continental Radiation.

Author

Abdel Samad N, Bou Dagher-Kharrat M, Hidalgo O, El Zein R, Douaihy B, and Siljak-Yakovlev S

Subjects
Chromosomes, Plant genetics, Flowers classification, Flowers genetics, Heterochromatin genetics, Iris Plant cytology, Lebanon, Phylogeny, Ribosomes genetics, Cytogenetics, Genetic Variation, Iris Plant genetics, Karyotype
Abstract

Despite being an important target of conservation concern and horticultural interest, Lebanese irises yet have a confusing taxonomic history and species' delimitation is often considered problematic, more especially among royal irises (Iris section Oncocyclus). Indeed, these irises of exceptionally large and spectacular flowers have radiated across Caucasus and eastern Mediterranean giving rise to a number of strict endemic taxa, many of them being considered under threat. Whilst efforts have mostly focused on clarifying the evolutionary relationships in the group based on morphological and molecular data, karyological and cytogenetic characters have been comparatively overlooked. In this study, we established for the first time the physical mapping of 35S rDNA loci and heterochromatin, and obtained karyo-morphological data for ten Lebanese Iris species belonging to four sections (Iris, Limniris, Oncocyclus and Scorpiris). Our results evidenced distinctive genomic profiles for each one of the sections, where Oncocyclus irises, while having the lowest chromosome numbers, exhibit both the highest number of 35S loci and CMA3+ sites. The continental radiation of royal irises has been accompanied by a relative karyological and cytogenetic stasis, even though some changes were observed regarding karyotype formula and asymmetry indexes. In addition to that, our results enabled taxonomic differentiation between I. germanica and I. mesopotamica-two taxa currently considered as synonyms-and highlighted the need for further studies on populations of I. persica and I. wallasiae in the Eastern Mediterranean Region.

Published
2016
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