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International audience; 1. Large river floodplains are dynamic environments, where alternating low and high flows are key ecological processes shaping aquatic biota. As a result of fluctuations in flow in floodplain channels, the diversity of benthic assemblages is assumed to result from the balance between surface flow connections, which are dominant during high flows, and groundwater inputs, which are dominant during low flows. However, the relative importance of these inputs in explaining aquatic invertebrate diversity has never been tested. 2. The response of aquatic invertebrates to hydrological changes of a river flood-plain was investigated in seven braided and six braided-anastomosed flood-plain channels of the French upper Rhône River that are fed by three different processes: groundwater supply (which controls the thermal inertia of the water bodies), surface slow flow connections (i.e. diffuse overbank flows; passive overflow), and surface shear stress-related connections (i.e. condensed flows; active overflow) during high flows. 3. Generalised dissimilarity models indicated that floodplain invertebrate composition had complex relationships with the three processes considered. The relative importance of the latter appeared dependent upon the morphology of the floodplain channels. In the braided channels, the effects of shear stress-related connections were more prominent than in the anastomosed ones, for which the effects of the three processes were more similar. 4. Overall, the diversity of flow connections, that is, lateral surface water connections (both shear stress-related and slow, as defined above) and vertical connection with groundwater (inferred through thermal inertia) enhanced the species turnover at the reach scale. Thermal inertia influenced invertebrate composition when, during low flow periods, surface flow connections had limited effect. 5. Our results highlighted that the role of hydrologic connectivity upon flood-plain diversity cannot be reduced to a single process. They also indicate the importance of vertical connectivity for maintaining biodiversity in floodplain habitats where surface flow connectivity is neither frequent nor constant.

International audience; Beaches are attractive areas that are subject to multiple pressures. Some of these beaches are located in large coastal cities with which they interact on a physical and social level. Facing this particularity, we propose a state of knowledge dedicated to the management of beaches in large coastal cities, here defined as cities with more than 500,000 inhabitants. Using the WoS and an analysis grid, 53 articles were identified and studied. This analysis shows that these beaches at the interface of a large coastal city are mainly the subject of sectorial studies and that the interactions between the city and the beach are relatively little studied. In this context, this article aims to highlight the need to develop integrated management model specific to beaches located in large cities.

International audience; Le LabEx DRIIHM est un réseau de recherche qui regroupe 13 Observatoires Hommes-Milieux (OHMs) centrés sur l’étude des socio-écosystèmes modifiés par l'homme, en France et à l’étranger. Dans le cadre de la Science Ouverte, une Infrastructure de Données de Recherche (IDR) a été mise en place pour décrire, visualiser et diffuser les jeux de données multidisciplinaires et hétérogènes produits par la communauté. Cette IDR contient des outils et des standards développés à l'échelle du DRIIHM, et des outils spécifiques pour répondre aux besoins de chaque observatoire. Cette présentation décrit les éléments constitutifs de l’IDR. Une analyse des forces du dispositif et des défis qu’il reste à relever est menée sur la base des retours d’expérience des administrateurs de données et d’enquêtes auprès des utilisateurs. Cette analyse aboutit à des recommandations pour améliorer l’IDR, mieux mesurer son efficacité et renforcer la sensibilisation à la Science Ouverte. Le projet ANR SO-DRIIHM (2020-2023) vise à mettre en application ces recommandations. Des approches interdisciplinaires utilisant des outils DataViz ont déjà vu le jour, ce qui enrichit la diffusion de l'information scientifique et pourrait faire émerger de nouvelles questions de recherche.

Le territoire du Ferlo est de plus en plus « occupé », humainement, environnementalement et institutionnellement. Une cartographie basée sur les perceptions des acteurs locaux a été réalisée pour recenser les facteurs qui, aux yeux de ces acteurs, structurent l’organisation spatiale de ce territoire et de ses alentours : usages, pratiques, « pays » ou tout autre facteur recensé. En fusionnant toutes les cartes obtenues, chacune correspondant à un entretien, via une intersection spatiale via QGIS et une combinaison sémantique programmée sur JAVA, nous obtenons une base de données spatialisée sur les déterminants structurant ce territoire. Si les éléments structurants, écologiques et socio-historiques demeurent et tendent même vers la spécialisation des territoires en « pays » de productions, le faible nombre de mois de présence des troupeaux dans le Ferlo (deux mois) ainsi que le recours généralisé à la supplémentation en période de soudure pastorale nous induit à penser à des réorientations de cet élevage vers le sud, mais aussi à identifier des espaces de tension possible là où axe de transhumance nord-sud et axe de colonisation agricole ouest-est se croisent. Cette méthode exploratoire permet une réflexion sur le rôle des observatoires sur l’environnement et celui du Ferlo en particulier., The Ferlo territory is increasingly "occupied", humanly, environmentally and institutionally. A mapping based on the perceptions of local stakeholders (ZADA in French, PBRM or Perception-Based Regional Mapping) was carried out to identify the factors that, from the point of view of these stakeholders, structure the spatial organization of this territory and its surroundings: uses, practices, localisms or any other factor identified. By GIS-merging together all the maps obtained, each corresponding to an interview, we obtain a spatialized database on the determinants structuring this territory. Although the structural, ecological and socio-historical elements remain and even tend towards the specialization of territories into production 'countries', the short 2-months period herds graze in the Ferlo and the generalized use of supplementation during the pastoral lean season suggests a reorientation of these herds towards the south. It induces areas of possible tension where the north-south axis of transhumance and the West-East axis of agricultural colonization intersect. This experimental method allows us to reflect on the role of environmental observatories and the Ferlo in particular.

International audience; Dans les dernières décennies du XXe siècle, en rupture avec leur passé industrialo-portuaire, certaines grandes villes littorales de Méditerranée nord-occidentale ont procédé à de lourds investissements afin d’offrir à leurs habitants des espaces récréatifs en bord de mer. Dans la continuité de ces opérations, ces villes ont élaboré des politiques publiques de gestion spécifiques à ces espaces, en particulier sur les plages. Simples règlementations ou plans d’action stratégiques, ces politiques révèlent les ambitions que ces villes projettent sur leur littoral et leurs plages. L’analyse de ces politiques à Marseille, Barcelone et Valence constitue la matière de cette communication, dont l’objectif est d’interroger le caractère intégré de la gestion des plages.

International audience; The high biotic diversity supported by floodplains is ruled by the interplay of geomorphic and hydrological processes at various time scales, from daily fluctuations to decennial successions. Because understanding such processes is a key question in river restoration, we attempted to model changes in taxonomic richness in an assemblage of 58 macroinvertebrate taxa (21 gastropoda and 37 ephemeroptera, plecoptera and trichoptera, EPT) along two successional sequences typical for former braided channels. Individual models relating the occurrence of taxa to overflow and backflow durations were developed from field measurements in 19 floodplain channels of the Rhône floodplain (France) monitored over 10 years. The models were combined to simulate diversity changes along a progressive alluviation and disconnection sequence after the reconnection with the main river of a previously isolated channel. Two scenarios were considered: (i) an upstream + downstream reconnection creating a lotic channel, (ii) a downstream reconnection creating a semi-lotic channel. Reconnection led to a direct increase in invertebrate richness (on average x2.5). However, taxonomical richness showed a constant decrease as isolation progressed and reached an average of 2 for EPT and 7 for gastropods at the end of the scenarios. With more than 80% of the taxonomic models with an AUC equal or higher than 0.7 and slopes of linear relations between observed and predicted richness of 0.75 (gastropods) and 1 (EPT), the Boosted Regression Trees (BRT) provided a good basis for prediction of species assemblages. These models can be used to quantify a priori the sustainability and ecological efficiency of restoration actions and help floodplain restoration planning and management.

International audience

Le prunier d’Afrique ou Sclerocarya birrea est un arbre fruitier de la famille des Anacardiaceae, qui fournit aux populations des fruits consommables pendant la periode de soudure. Bien que presente dans les regions a climat soudano-sahelien du Senegal, sa zone de predilection demeure le Ferlo. Elle y fait l’objet de rehabilitation dans la mise en place du programme de l’Union Africaine dite de la muraille verte. Malheureusement, peu d’etudes scientifiques n’ont encore fait mention de la composition nutritive des fruits issus de cette zone. Dans le cadre de la reconstitution du couvert vegetal des zones arides, la connaissance des relations entre l’homme et son milieu s’avere importante. Ainsi, la presente etude est entreprise dans le but de connaitre les usages de Sclerocarya birrea et les potentialites qu’offre son fruit. Des enquetes ethnobotaniques ont permis de recueillir les connaissances sur les usages de l’espece dans la zone du Ferlo (Senegal). Des echantillons de fruits murs recoltes ont ete analyses grâce a des techniques de dosages normalises et conventionnelles. Les resultats revelent que les populations du Ferlo connaissent bien S. birrea , dont l’usage medicinal est de loin le plus important (79%). En usage medicinal, les organes vegetaux les plus utilises sont les ecorces et les feuilles. Les resultats obtenus sur la pulpe du fruit montrent qu'elle constitue une bonne source en vitamine C, en sucres, en Calcium, Magnesium, Potassium, Sodium et en Polyphenols totaux. L'huile de l'amande presente des caracteristiques qui dans l'ensemble restent dans la norme admise pour les huiles alimentaires. Ces resultats sont marques par une forte variabilite de la composition physico-chimique qui semble etre liees aux variations des conditions edaphiques et climatiques. Il ressort de cette analyse que le fruit de S. birrea constitue une excellente source de nutriments et peut valablement combler certaines carences nutritionnelles des populations autochtones. Par ailleurs, le fruit presente aussi des potentialites de transformation et de conservation qui doivent etre explorees. Mots cles: Sclerocarya birrea , fruits, usages, valeurs nutritionnelles, polyphenols, vitamine C, variabilite, Ferlo English Abstract The present study was undertaken to know the uses and some nutritional potentials of Sclerocarya birrea . The African plum tree called Sclerocarya birrea is a fruit tree of the Anacardiaceae family, which provides populations some consumable fruits during the lean season. Although it is present in Sudano-Sahelian regions of Senegal, its favorite repartition zone is the Ferlo. Sclerocarya birrea is being rehabilitated in the framework of the implementation of the African Union program called the “Green Wall”. Unfortunately, no scientific studies have mentioned the nutritional content of fruits coming from this area. In the context of the reconstitution of the vegetation cover, knowledge of the relations between man and his environment is important. Thus, the present study is undertaken with the aim of knowing the uses of Sclerocarya birrea and its fruits attibutes. According to that, ethnobotanical surveys have gathered knowledge on the species' uses in the Ferlo area (Senegal). Samples of ripe fruits harvested were analyzed using standard and conventional assay techniques. The results revealed that the populations of the Ferlo are well acquainted with Sclerocarya birrea and that its medicinal use is by far the most important (79%). In medicinal use, the most commonly used plant organs are barks and leaves. The results obtained on the pulp of the fruit showed that it is a good source of vitamin C, sugars, Calcium, Magnesium, Potassium, Sodium and total polyphenols. The almond oil has characteristics that remain within the accepted food standards. These results are marked by a high variability in the physicochemical composition, which appears to be linked to variations in edaphic and climatic conditions. The analysis shows that the fruit of Sclerocarya birrea is an excellent source of nutrients and can validly fill certain nutritional deficiencies of indigenous peoples. The fruit also has potential for transformation that needs to be explored. Keywords: Sclerocarya birrea , fruits, uses, nutritional values, polyphenols, vitamin C, variability, Ferlo

The African fauna of the rare family of parasitoid wasps, Orussidae, is reviewed. Five genera with 24 valid species are recognized. Chalinus davidi Vilhelmsen n. sp. is described; the male of Chalinus albitibialis Vilhelmsen, 2005, the male of Leptorussus madagascarensis Vilhelmsen, 2007 and the female of Orussus smithi Blank et al., 2006 are described. A neotype is designated for Oryssus plumicornis Guerin-Meneville, [1849] to properly define the genus-group name Chalinus Konow, 1897. Chalinus braunsi (Enslin, 1911), C. orientalis Guiglia, 1937 and C. somalicus Guiglia, 1935 are regarded as new junior synonyms of C. plumicornis. Leptorussus kwazuluensis Vilhelmsen, 2003 is regarded as a new junior synonym of L. africanus Benson, 1955. Distribution records for specimens examined by us are listed. The Afrotropical component of the African orussid fauna shows a high degree of endemism, with two endemic genera and 13 endemic species; only Chalinus timnaensis Kraus, 1998 and Pseudoryssus niehuisorum...

[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARE; International audience; The restoration of side channels (also referred to as abandoned channels, former channels, floodplain channels, or side arms) is increasingly implemented to improve the ecological integrity of river-floodplain systems. However, the design of side channel restoration projects remains poorly informed by theory or empirical observations despite the increasing number of projects. Moreover, feedback regarding the hydromorphological adjustment of restored channels is rarely documented, making it difficult to predict channel persistence as aquatic habitats. In this study, we analyze the spatial and temporal patterns of fine sediment deposition (< 2 mm) in 16 side channels of the Rhône River, France, restored in 1999–2006 by a combination of dredging and/or partial to full reconnection of their extremities and as a by-product of an increase in minimum flow through the bypassed main channels. We develop prediction tools to assess the persistence of restored channels as aquatic habitats, using between five and seven monitoring surveys per channel (spanning 7–15 years after restoration). Observed channel-averaged sedimentation rates ranged from 0 to 40.3 cm·y−1 and reached 90.3 cm·y−1 locally. Some channels exhibited a significant decline of sedimentation rates through time, whereas others maintained rather constant rates. Scouring processes (i.e., self-rejuvenation capacity) were occasionally documented in 15 channels. Six of the 16 studied channels appeared to be self-sustaining. The 10 others accumulated more and more fine sediment deposits after restoration. Parametric modeling of sedimentation rates suggested that among these 10 channels, four have long life-durations (i.e., more than a century), three have intermediate life-durations (i.e., likely between three and nine decades), and three others have short life-durations (i.e., likely between two and five decades). Observed channel-averaged sedimentation rates can be predicted from the frequency and magnitude (i.e., maximum shear stress) of upstream overflow events and the maximum intensity of backflow events (i.e., maximum backflow capacity). These predictors reflect the dominant role of side channel geometry (i.e., morphology of the upstream alluvial plug, slope conditions) in controlling their flooding regime. These models applied successfully to a wide range of channel morphologies and can be used to quantify a priori the likely effects and the sustainability of side channel restoration.

Over the past 50 years, a large number of development initiatives have addressed the diverse social and ecological challenges in the Sahel, often focusing on a single entry point or action, resulting in only a limited degree of success. Within the last decade, the international development discourse has evolved to incorporate resilience thinking as a way to address more complex challenges. However, concrete examples as to how to operationalize resilience thinking are lacking. The Great Green Wall for the Sahara and the Sahel Initiative (GGW), a pan-African program with a strong reforestation focus, is the latest and most ambitious of these development programs to date. The GGW represents an ideal opportunity to apply resilience thinking at a large scale, but in order to do so, it must intelligently gather and centralize pre-existing interdisciplinary knowledge, generate new knowledge, and integrate knowledge systems to appropriately navigate future uncertainties of the diverse social-ecological systems along its path. Herein, after a brief description of large-scale reforestation history in the Sahara and Sahel and the conceptual evolution of the GGW, we propose a transdisciplinary research framework with resilience thinking at its core. It includes analysis of complex social-ecological systems, their temporal and spatial cross-scale interactions, and outcomes focused on the supply of abundant, diverse, equitable, and durable ecosystem services to support livelihoods in the region. If the research areas that comprise the framework were to be properly addressed, they could conceivably guide GGW actions in a way that would contribute to desirable future pathways.

International audience; Based on interviews with the population, we will show in this article what perceptions of air pollution have residents of two urban areas (the city of Yaoundé in Cameroon and the former coal mining basin of Provence, Department of Bouches du Rhône, France). Points of convergence on perceptions of air pollution appear in the speeches of people interviewed in both sites, including how to name pollution, relate it to the climate and defining an air quality. The association between dust and odor is found in the speeches of the residents of the two sites studied and it is the same for the issue of the proximity of sources of pollution which is a subject of complaints. On the other hand, there are differences in people's perception of the impact of pollution on their health. In Yaoundé, people make little reference to the impact of air pollution on health and consider factors contributing to the disease (cold, dust, wind ...) as real causes that they often associate with the seasons. This is much less the case for the populations of the former coal mining basin of Provence, although the impact of pollution on allergies is probably overestimated. This can be explained by the role played by the media in the dissemination of sometimes alarmist information on these subjects and, at the same time, by the increase in the general population of an awareness of environmental issues.; En nous appuyant sur des entretiens réalisés auprès de la population, nous montrerons dans cet article quelles perceptions de la pollution de l'air ont les résidents de deux zones urbaines (la ville de Yaoundé au Cameroun et l'ancien bassin minier de Provence dans le département des Bouches du Rhône, France) Des points de convergence en matière de perceptions de la pollution de l'air apparaissent dans les discours des personnes interrogées dans les deux sites, notamment dans la façon de nommer la pollution, de la mettre en relation avec le climat et de définir un air de qualité. L'association poussières/odeurs se retrouve dans les discours des riverains des deux sites étudiés et il en est de même pour la question de la proximité des sources de pollution qui est un sujet de plaintes. En revanche, des divergences se font jour dans la perception que les populations ont de l'impact de la pollution sur leur santé. A Yaoundé, les populations font peu référence à l'impact de la pollution de l'air sur la santé et considèrent les facteurs favorisants la maladie (froid, poussière, vent…) comme des causes réelles qu'elles associent très souvent aux saisons. C'est nettement moins le cas pour les populations de l'ancien bassin minier de Provence, bien que l'impact de la pollution sur les allergies soit probablement surestimé. Cela peut s'expliquer par le rôle que jouent les médias dans la diffusion d'informations parfois alarmistes sur ces sujets et, parallèlement, par la progression dans la population générale d'une prise de conscience des enjeux environnementaux.

What is the meaning and the relevance of the words of Changes and Transitions for the hugely anthropized ecosystems contexts ? This question is asked through the Human-environments observatories (OHM), a system built precisely to deal with them. It seems that the underlying concepts are quite not relevant. The related notions of State and Resilience directly associated with those two concepts are considered and the relevance of their substrate as well in those specific contexts. The question of the way to cope with those ecosystems and some of the questions induced are addressed., Quel est le sens et la pertinence des notions de changement et de transition pour les écosystèmes très anthropisés ? Cette question est posée au travers de l’expérience des Observatoires Hommes-Milieux, dispositifs conçus pour leur étude. Il apparaît que les notions qui les sous-tendent y sont peu opérationnelles. Celles, connexes, d’état et de résilience sont abordées, ainsi que les substrats sur lesquels elles reposent et interrogées pour leur pertinence dans ces contextes. La question des modalités de l’action sur ces écosystèmes est également considérée et les interrogations qu’elle soulève évoquées.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARE [ADD1_IRSTEA]Systèmes aquatiques soumis à des pressions multiples; International audience; Numerous projects of side channel restoration have been implemented during the last decades to improve the ecological functioning of highly regulated rivers. Feedbacks regarding the hydromorphological adjustment of restored channels are rare or not shared. Nevertheless, such information is crucial to improve the design of restoration measures and to assess their sustainability. In this paper, we report an overview of results derived from the monitoring of 18 restored side channels conducted over more than 15 years in the Rhône River. Firstly, hydromorphological adjustments of restored channels (bed material grain size longitudinal patterns, dynamics of fine sediment accumulation) are described. Then, an assessment of the potential persistence of channels as aquatic habitats is conducted using trend models. Our results suggest that side channel restoration can be a relevant and sustainable measure in the context of the Rhone River. We also demonstrate that grain size conditions and fine sediment accumulation rates can be successfully predicted using simple metrics reflecting the hydrodynamic functioning of side channels, that managers can target or modify: the frequency and magnitude (i.e. maximum shear stress) of upstream overflow events and the maximum intensity of backflow events (i.e. maximum backflow capacity). These empirical relationships are important operational tools for guiding future project design in the Rhone River and potentially elsewhere. They can be used to predict the effects and the sustainability of side channel restoration. They may reduce the uncertainty about the potential hydromorphological adjustments of side channels after restoration, and contribute to optimize the balance between local ecological gains and restoration costs.; Au cours des dernières décennies, de nombreux projets de restauration de chenaux latéraux ont été mis en œuvre, notamment pour améliorer le fonctionnement écologique de tronçons fluviaux de plaine fortement anthropisés. Néanmoins, les retours d'expérience concernant les ajustements morphologiques s'opérant après les travaux restent rares ou peu partagés, alors qu'ils semblent essentiels pour améliorer la conception technique de tels projets et évaluer leur durabilité. Cet article constitue une synthèse des résultats acquis depuis plus de 15 ans dans le cadre du suivi de 18 bras restaurés du Rhône. Les ajustements morphologiques enregistrés par les bras depuis leur restauration en termes de granulométrie et de sédimentation sont décrits. Puis, une estimation de leur durée de vie potentielle en tant qu'habitat aquatique est réalisée s'appuyant sur des modèles tendanciels. L'analyse de ces résultats suggère que la restauration des bras du Rhône constitue une solution à la fois pertinente et pérenne dans le contexte rhodanien. Nous démontrons également que les patrons granulométriques et les vitesses d'accumulation des fines peuvent être bien prédits à partir de descripteurs simples du fonctionnement hydrodynamique des bras. Ces modèles empiriques constituent des outils opérationnels pour guider la conception technique des futurs bras à restaurer du Rhône et potentiellement d'autres hydrosystèmes.

For more than 50 years, the treatment of bauxite residues from the Gardanne alumina plant is the subject of a conflict between the plant, the state administrations, local authorities, environmental associations and residents. A first dispute had occurred between 1965 and 1967 with the discharge of residues in Mediterranean Sea. After the Barcelona Convention (1992) and the creation of the” Parc National des Calanques”, the plant had been obliged to modify the residues treatment, with a liquid effluent, always discharged in the sea, and solid wastes which are stored in Mangegarri site. Then, a new dispute had started in 2014, always about the discharge in the sea but also about the storage on land. The dispute was very intense between 2015 and 2016 and is still relevant.To focus debates, Ministry of Environment had created, in 2016, a “Commission de Suivi de Site” (CSS), with representatives of state and local authorities, management and employees of the plant, environmental associations and residents. After one year of operation, the CSS had been divided in two subcommittee, one for the sea discharge and an other for the storage on land. These committees have no decision-making role, but are spaces of information, explanation and discussion. Formally, there are no scientific representatives in these committees, but, in some case, scientific can be invited to the meetings.An OHM (Human-Environment Observatory) is a study of socio-ecosystems manmade tool, designed to respond to their complexity by implementing a comprehensive approach by combining the study of environmental science and creating dynamic for the development instead of interdisciplinarity needed. For this, each OHM is organized around a focal object - which will be studied by all environmental sciences - a founder event came deeply upset (e.g. a mining area - object - and stopping the operation - founding event). The DRIIHM LabEx, Device for Interdisciplinary Research on human-environments Interactions, aggregates the 12 human-environments observatories in a network. The OHM Bassin Minier de Provence (OHM-BMP) had been the first OHM created in 2007 by the Environment Institute of CNRS. Located in the east of the department of Bouches-du-Rhône (SE of France), between Marseille and Aix-en-Provence, it concerns seventeen towns just over 100,000 inhabitants. For nearly two centuries, the unity of this space has been built around the lignite mining and industrialization induced by the mine. This area is typical of suburban and industrial dynamics in the Mediterranean area. These dynamic, often contradictory, have been particularly affected by the permanent cessation of mining in 2003.Long before the media coverage of the red mud dispute, OHM-BMP had launched interdisciplinary studies about the potential environmental and sanitary impacts of land storage. In this way, the OHM-BMP had provided scientific informations which had been recognized as independent by the different protagonists of the conflict. This is largely because these studies are financed with CNRS and Labex money and are not an order of one or another protagonist. The other side is that the financial resources are limited and not sufficient for a complete work. It’s also regrettable that the state authorities do not consider these studies which, in contrast, have the confidence of the civil society. With their interdisciplinary approach and their opening to society, the OHMs are able to participate to the increase of scientific transparency, arguments analysis and explanations of issues – all things which are necessary to the resolution of a conflict, in a participatory approach., Depuis plus de 50 ans, la gestion des résidus de traitement de bauxite de l’usine d’alumine de Gardanne est source de conflit entre industriel, état, collectivités locales, riverains et associations écologistes. Un premier conflit a eu lieu en 1965-1967, avec le rejet des résidus en mer. La convention de Barcelone (1992) et la création du Parc National des Calanques (2012) ont amené l’industriel à développer un nouveau mode de gestion de ses résidus, avec un effluent liquide, toujours rejeté en mer, et un résidus solide stocké à terre. Cela a relancé les débats sur les rejets en mer mais a également déclenché l’apparition d’un conflit autour du stockage à terre. Ce nouveau conflit, démarré en 2014, très intense en 2015-2016, est toujours d’actualité, avec des pics médiatiques notamment lors d’épisodes météorologiques particuliers.Pour essayer de « canaliser » ce débat, l’Etat a mis en place, en 2016, une Commission de Suivi de Site (CSS) à cinq collèges : Services de l’Etat, Collectivités locales, Industriel, Salariés, Riverains et Associations. Ultérieurement, vu l’ampleur des sujets à traiter, cette CSS a été divisée en deux sous-commissions (Terre et Mer) et, devant la violence de certains échanges, un Garant a été nommé par la Commission Nationale du Débat Public pour conserver une certaine sérénité aux débats. La CSS n’a pas de rôle décisionnaire (cela relève directement du Préfet), mais est un espace d’information, d’explication, de discussion et de suggestion d’actions à mener. Officiellement, la recherche scientifique n’est pas présente dans cette CSS mais, sous certaines conditions, des « experts » ou « sachants » peuvent être invités à la demande de l’un ou l’autre des collèges.Les Observatoires Hommes-Milieux (OHM) ont été créé par le CNRS en 2007, comme des outils de recherches interdisciplinaires, permettant la mise en œuvre, autour d’un objet partagé, de recherches disciplinaires et interdisciplinaires aptes à développer le champ de l’écologie globale, dans l’objectif de répondre à la demande sociétale et de documenter la décision politique. Les OHM sont construits autour d’un objet constitué d’un lieu caractérisé par un fait structurant qui est profondément modifié par un élément fondateur. Les 12 OHMs existant sont réunis dans le Labex DRIIHM (Dispositif de Recherches Interdisciplinaires sur les Interactions Hommes-Milieux). Dans le cas du premier OHM créé, l’OHM Bassin Minier de Provence (OHM-BMP), le territoire est celui du Bassin Minier (entre Marseille et Aix en Provence), le fait structurant l’exploitation minière et l’élément fondateur, l’arrêt assez brutal de l’exploitation minière en 2003. Avant même l’émergence médiatique du conflit, l’OHM-BMP avait lancé différentes études interdisciplinaires sur la question des impacts sanitaires et environnementaux potentiels du site de stockage. L’OHM a ainsi pu intervenir à certaines étapes du débat public, en apportant des informations nouvelles qui ont été reconnues comme indépendantes par tous les partis. Le fait que l’OHM mène ces études, financés par de l’argent publique, de sa propre initiative et non pas à la commande de tel ou tel acteur a contribué à cette confiance. L’envers de la médaille est que, de ce fait, les moyens sont limités et pas à la hauteur du travail à faire. Malgré ces réussites, on peut déplorer que l’OHM soit plus considéré par certains acteurs que d’autres, et qu’en particulier les services de l’Etat et l’industriel ne reconnaissent pas réellement cet interlocuteur qui inspire à l’inverse une certaine confiance dans la société civile. Du fait d’une forte interaction interne, grâce à laquelle se mettent en place des débats contradictoires et un affinement des dispositifs, l’OHM est à ce stade capable d’aider à l’augmentation de la transparence scientifique, l’explicitation des enjeux, l’analyse des argumentations - nécessaires à un règlement de conflit dans la perspective des approches participatives en politique, exigées de nos jours par les institutions européennes.

International audience; Les Observatoires Hommes-Milieux (OHM) ont été créé par le CNRS en 2007. Les OHM, outils de recherches interdisciplinaires, permettent la mise en oeuvre, autour d’un objet partagé, de recherches disciplinaires et interdisciplinaires aptes à développer le champ de l’écologie globale, dans l’objectif de répondre à la demande sociétale et de documenter la décision politique. Les OHM sont construits autour d’un objet constitué d’un lieu caractérisé par un fait structurant qui est profondément modifié par un élément fondateur. Dans le cas du premier OHM créé, l’OHM Bassin Minier de Provence (OHM-BMP), le territoire est celui du Bassin Minier (entre Marseille et Aix en Provence), le fait structurant l’exploitation minière et l’élément fondateur, l’arrêt assez brutal de l’exploitation minière en 2003. Associé à cette exploitation minière, existe depuis la fin du XIXème siècle, une usine de fabrication d’alumine à partir de bauxite. Depuis 1966, les résidus de traitement de bauxite connus sous l’appellation de « boues rouges », ont été rejetés en mer au large de Cassis, par 300 m de fond. La création du Parc National des Calanques et l’évolution de la réglementation ont entrainé l’arrêt du rejet en mer de la fraction solide de ces résidus, et la mise en place d’un stockage à terre. Cela a réveillé le débat concernant la gestion des résidus de traitement de bauxite, issus de l’usine d’alumine de Gardanne, avec l’apparition d’une polémique « terrestre » qui s’est ajoutée à la polémique « marine » existante depuis 50 ans, allant jusqu’à la mise en doute de la pérennité de cette entreprise.Dans le cadre de ce débat très conflictuel, l’OHM-BMP a lancé une étude interdisciplinaire sur la question des impacts sanitaires et environnementaux potentiels du site de stockage. Les premiers résultats sur les contaminations atmosphériques montrent que les flux de particules au voisinage du site sont très nettement inférieurs à ceux mesurés au centre-ville de Gardanne, à proximité de l’usine, signifiant que l’emprise de la pollution est différente de celle qui était intuitivement imaginable. L’OHM a pu intervenir à certaines étapes du débat public, en apportant des informations nouvelles qui ont été reconnues comme indépendantes par tous les partis. Il a ainsi pu présenter ces travaux devant la commission de suivi de site, en tant qu’invité à la demande des associations. Malgré ces réussites, on peut déplorer que l’OHM soit plus considéré par certains acteurs que d’autres, et qu’en particulier les services de l’Etat et l’industriel ne reconnaissent pas réellement cet interlocuteur qui inspire à l’inverse une certaine confiance dans la société civile. Du fait d’une forte interaction interne, grâce à laquelle se mettent en place des débats contradictoires et un affinement des dispositifs, l’OHM est à ce stade capable d’aider à l’augmentation de la transparence scientifique, l’explicitation des enjeux, l’analyse des argumentations - nécessaires à un règlement de conflit dans la perspective des approches participatives en politique, exigées de nos jours par les institutions européennes.

International audience; Mapping landscape visibility to reveal and measure the visual interactions between places within a territory is common practice today, especially in the context of visual impact studies. Maps of landscape visibility are also a powerful aid to considering development options and anticipating the future for territories that face a variety of challenges. On coasts, where landscape and views form part of the territorial resources, spatial planning particularly requires awareness of the visual properties of the space. Because of their attractiveness for residential and other types of development, coastal areas present management issues that often have a visual landscape dimension. This article proposes a method of characterizing the visual potential of coastal municipalities in the south of France, with a view to promoting consideration of landscape views in spatial planning. Developed in a GIS environment, this method defines the extent of the potentially visible landscape as well as the different landscape components of a municipality, which can then be compared to spatial planning data. Discussion of our results with stakeholders involved in local development revealed a positive perception and suggest that the approach could be extended to other coastal areas subject to urban pressure.

International audience

In African rural area, studies have shown under-utilization of rural health services. This situation occurs in a context of therapeutic pluralism that competes with access to the health service. The aim of this study is to analyze the place of the modern health care system at the heart of the search for childcare in a rural environment in Ferlo, Senegal. Methods: A cross-sectional study was carried out to examine the place modern health care in the stages of the therapeutic itinerary among children living in Senegal rural area in March 2017. Using Schwartz formula for sampling, we include in this study 173 children aged 6 to 59 months living in the area of Widou Thiengoly. Bivariate and multivariate analyses were made. Result: Most of children (82.3%) lived on more than 1 hour drive from health facility. For the first instance of therapeutic choice, most of mothers (61.2%) used self –medication in case of children disease, 35.3% of mothers used health facilities and 2.6% choosed traditional healers. For second instance, only 2.4 % of mothers were used self-medication. For third instance, there was no self-treatment. Therapy organizing group were led by mothers at 56.5 % and fathers in 45.6%. At 77.6% of cases, there were discussions to decide on the treatment of the child. In most cases, fathers were interviewed (90.9%) to give their opinion on the therapeutic choice. Fathers paid for children care in 87.6% of cases. 30.6% of mothers said that self-medication was cheaper compared to health facilities and traditional healers. 95.3% said that they believed that it was most efficiency to use a lot of type of therapeutic in same moment. Multilogistic regression found that the quality of the caring relationship impacted in using health services ajOR=0.19: IC=0.056-0.59. Conclusion: This study contributes to the knowledge of self-treatment choices regarding children disease management in Senegal rural area. The main finding of this study was that the quality of the caring relationship impacts attendance and utilization of health services. A professional and competent attitude on the part of health workers will thus be able to improve the use of health services in traditional rural areas in Senegal.

International audience

International audience

International audience; What is the meaning and the relevance of the words of Changes and Transitions for the hugely anthropized ecosystems contexts ? This question is asked through the Human-environments observatories (OHM), a system built precisely to deal with them. It seems that the underlying concepts are quite not relevant. The related notions of State and Resilience directly associated with those two concepts are considered and the relevance of their substrate as well in those specific contexts. The question of the way to cope with those ecosystems and some of the questions induced are addressed.; Quel est le sens et la pertinence des notions de changement et de transition pour les écosystèmes très anthropisés ? Cette question est posée au travers de l'expérience des Observatoires Hommes-Milieux, dispositifs conçus pour leur étude. Il apparaît que les notions qui les sous-tendent y sont peu opérationnelles. Celles, connexes, d'état et de résilience sont abordées, ainsi que les substrats sur lesquels elles reposent et interrogées pour leur pertinence dans ces contextes. La question des modalités de l'action sur ces écosystèmes est également considérée et les interrogations qu'elle soulève évoquées.

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International audience; Stocking is a worldwide activity on geographical and historical scales. The rate of non-native fish introductions have more than doubled over the last decades yet the effect on natural ecosystems, in the scope of biologically mediated transport and biomagnification of Hg and Hg-isotopes, is unknown. Using geochemistry (THg) and stable isotopes (N, Sr and Hg), we evaluate natal origin and trophic position of brown trout (Salmo trutta fario), as well as mercury biomagnification trends and potential pollution sources to three high-altitude lakes. Farmed trout show Hg-isotope signatures similar to marine biota whereas wild trout shows Hg-isotope signatures typical of fresh water lakes. Stocked trout initially show Hg-isotope signatures similar to marine biota. As the stocked trout age and shifts diet to a higher trophic level, THg concentrations increase and the marine Hg isotope signatures, induced via farm fish feed, shift to locally produced MeHg with lower δ 202 Hg and higher Δ 199 Hg. We conclude that stocking acts a humanly induced biovector that transfers marine Hg to freshwater ecosystems, which is seen in the Hg-isotopic signature up to five years after stocking events occurred. This points to the need of further investigations of the role of stocking in MeHg exposure to freshwater ecosystems.

International audience; In the second half of the 19th century, channelization of large multi-thread rivers such as the Rhine, the Danube, and the Rhône rivers induced artificial disconnection of most of their secondary channels. Compared to naturally abandoned channels, terrestrialization (i.e., the passage from the aquatic to the terrestrial stage, controlled by sediment deposits and/or lowering of the water level) patterns and rates of such artificially prematurely abandoned channels remain largely unknown. Moreover, factors controlling their evolutionary trajectories are complex owing to a set of pressures occurring throughout the 20th century within specific space-time windows. Through a case study of the Rhône River, this paper aims to assess and distinguish the effects of a set of potential controlling factors on abandoned channel terrestrialization dynamics and lifespan. We tested the influence of: (i) submersible embankments closing the entrance of abandoned channels, (ii) main channel degradation following its channelization or the water level lowering due to channel bypassing in the middle of the 20th century involving drastic water abstraction in these reaches, (iii) transverse dykes within the abandoned channels, (iv) the flooding regime of abandoned channels (i.e., frequency and magnitude of upstream connections producing lotic functioning), and (v) longitudinal variation in the suspended sediment concentration along the main channel. To this end, we studied 24 abandoned channels (16 artificially disconnected at their upstream end by submersible embankments and eight naturally disconnected by bar plug establishment) from the mid-19th to the beginning of the 20th century. Their terrestrialization rates were characterized through the reconstruction of their planimetric trajectories using historical maps and aerial photos.The results reveal a much longer lifespan of artificial abandoned channels compared to natural ones because of the truncation of the initial bedload infilling phase due to the artificial and imposed closing of their entrance. Moreover, terrestrialization occurred faster when water level lowering or channel degradation was greater. Surprisingly, terrestrialization rates were the highest in the most frequently connected artificial abandoned channels (i.e., channels with a high frequency of lotic functioning), probably in relation to the roughness induced by the presence of transversal dykes. Finally, it is difficult to rank all the factors tested because of their complex combinations, which can change in space and time.

Au Sahel, les ligneux jouent un role important dans l’alimentation du cheptel, en toute saison. La presente etude est une analyse de l’etat actuel et de l’usage de ces especes ligneuses dans six villages (Keur Momar Sarr, Syer, Mbar Toubab, Widou Thiengoly, Tessekere et Labgar) du Ferlo-Nord suivant un gradient de facteur ecologique est-ouest. Elle combine une approche ecologique et des enquetes ethnobotaniques aupres des populations locales. Les 120 releves dendrometriques menes sur le terrain et les 52 entretiens, ont permis de repertorier 42 especes reparties en 33 genres et 18 familles. Les Fabacees et les Combretacees sont les familles les plus representees. Certaines especes (Balanites aegyptiaca, Boscia senegalensis, Calotropis procera et Acacia tortilis var. raddiana) sont preponderantes dans la zone malgre l’interet porte par la population (fourrage, alimentation, medecine traditionnelle et energie domestique). La richesse floristique, le couvert aerien ainsi que la densite reelle sont plus importants a Widou Thiengoly, Tessekere et Labgar (situes a l’est dans la zone des six forages) compares aux autres sites situes a l’ouest dans la zone du lac de Guiers.

Highlights • A rapid, standardised and objective assessment of the biophysical impact of restoration interventions is proposed. • The intervention impact is evaluated by a before–after control-impact sampling design. • The method provides a statistical test of the no-change hypothesis and the estimation of the relative magnitude of the change. • The method is applicable to NDVI and other remote sensing-derived variables., Restoration interventions to combat land degradation are carried out in arid and semi-arid areas to improve vegetation cover and land productivity. Evaluating the success of an intervention over time is challenging due to various constraints (e.g. difficult-to-access areas, lack of long-term records) and the lack of standardised and affordable methodologies. We propose a semi-automatic methodology that uses remote sensing data to provide a rapid, standardised and objective assessment of the biophysical impact, in terms of vegetation cover, of restoration interventions. The Normalised Difference Vegetation Index (NDVI) is used as a proxy for vegetation cover. Recognising that changes in vegetation cover are naturally due to environmental factors such as seasonality and inter-annual climate variability, conclusions about the success of the intervention cannot be drawn by focussing on the intervention area only. We therefore use a comparative method that analyses the temporal variations (before and after the intervention) of the NDVI of the intervention area with respect to multiple control sites that are automatically and randomly selected from a set of candidates that are similar to the intervention area. Similarity is defined in terms of class composition as derived from an ISODATA classification of the imagery before the intervention. The method provides an estimate of the magnitude and significance of the difference in greenness change between the intervention area and control areas. As a case study, the methodology is applied to 15 restoration interventions carried out in Senegal. The impact of the interventions is analysed using 250-m MODIS and 30-m Landsat data. Results show that a significant improvement in vegetation cover was detectable only in one third of the analysed interventions, which is consistent with independent qualitative assessments based on field observations and visual analysis of high resolution imagery. Rural development agencies may potentially use the proposed method for a first screening of restoration interventions.

Objective: To assess the effect of vegetation cover on soil macrofauna, a study focused on the diversity of soil macrofauna inside and outside reforestation plots of the Great Green Wall in Senegal was carried out. Methodology: The sampling of macrofauna was performed according to the method recommended by the TSBF network (Tropical Soil Biology and Fertility). It involves isolating 10 ground plots along a transect of 50 meters chosen at random in each plot and outside of each plot. The macrofauna was sampled between February and July 2016 during the dry season Results: The results show, in order of importance Hymenoptera, Isoptera, Coleoptera, the Spiders, the isopods and springtails are the taxonomic groups of the study area. The density of each of these taxa is larger inside and outside of the plots. The vertical distribution of macrofauna shows that the 0-10 cm layer is more densely populated than the deeper layers. Conclusion: This study showed a low diversity of soil macrofauna in the area. It also shows that the vegetation cover affects the density of the macrofauna.

In education and educational activities, repeated photographs often make it possible to identify changes in landscape units and thus changes in the organisation of spatial systems. But repeated photographs of an area in which children live can also be a means for them to express what they know of it. This was studied as part of a collaborative research project conducted with pupils in primary and middle school in the town of Vicdessos (Ariège, France), in connection with research done by the Observatoire homme-milieux (OHM) Pyrénées Haut-Vicdessos (Pyrénées Haut-Vicdessos Human-Environment Observatory). The activities and their subsequent analysis reveal the importance of working on the chronological filing of the photographs as well as the role of the discussions between pupils concerning possible divergences in the way of arranging the photographs, Le paysage est de longue date très présent dans l'enseignement de la géographie, et dans une moindre mesure dans celui des sciences de la vie et de la terre (SVT), tant à l'école primaire que dans l'enseignement secondaire (Vergnolle Mainar 2011). Considéré comme la face visible d'un territoire ou d'un milieu, il a à la fois le statut d'objet d'étude et d'outil pédagogique. En effet, par sa dimension visuelle, le paysage est un support d'étude concret qui permet d'entrer relativement facilement dans la complexité du territoire ou du milieu étudié et d'aborder des notions abstraites liées à son organisation et à son fonctionnement. Dans cette perspective, le paysage est au service de l'acquisition de connaissances et deconcepts disciplinaires et pour cela les paysages mobilisés sont soigneusement sélectionnés. Il s'agit de paysages remarquables, en géographie souvent photographiés de façon panoramique, qui ont peu de points communs avec les paysages que les élèves voient dans leur quotidien. Pour cette raison, le lien entre les apprentissages scolaires à partir de ces paysages remarquables et les enjeux concernant les paysages ordinaires de proximité qui constituent leur cadre de vie est à construire.

International audience; An experiment was conducted over nine months in a field system in northern Senegal in order to determine the effects on soil nitrogen (N) cycling and the microbial biomass-C properties of five plant species proposed for the Senegalese Great Green Wall (GGW): Acacia senegal (L.) Willd., Acacia tortilis var. raddiana (Savi) Brenan, Balanites aegyptiaca (L.) Del., Boscia senegalensis (Pers.) Lam. ex Poir., and Sclerocarya birrea (A. Rich.) Hochst. Soil samples were collected to a depth of 0-10 cm, outside (control) and beneath tree canopies. Microbial biomass, inorganic N content and net mineralization of organic N were determined for the soil samples collected under trees, and compared to soils collected outside tree canopies. The results showed that concentrations of inorganic N and soil microbial biomass-C were generally higher under canopy cover and differed according to species. In May 2014 (end of the dry season), microbial biomass-C was higher under A. senegal (31.8 mg C/kg soil) and lower under B. senegalensis and in the control sample from outside the canopy (17 mg C/kg soil). A higher microbial biomass-C content was found under A. senegal (49 mg C/kg soil) and B. aegyptiaca (53.7 mg C/kg soil) in October 2014 (end of the rainy season) and in January 2015 (middle of the dry season). In May 2014, the concentration of ammonium was significantly higher under B. senegalensis (11.17 mu g/g soil), while the control sample (outside the canopy) had the lowest concentration (4.93 mu g/g soil). For nitrates, there was no significant difference between canopy species (P

Introduction: The complementary diet of young children breastfed constitutes one of the main determinants of their health in the developing world. The use of composite dietary indicators has long been used and described in the literature. In a context of food insecurity, these indicators could be used to improve the nutritional status of children. The main of this study is to study the use of a composite index of food, the Infant Child Feeding index (ICFI) comparing it with the food practices and modalities of anthropometric growth in children living in semi-arid Sahel rural country part in Senegal. Materials and methods: We made a transversal study with analytical aim in May 2017 in Widou Thiengholi. The sampling was carried out according to the Schwartz formula with the basis of calculation the malnutrition rate in Linguere (12.3% according to SMART 2012). Thus, 170 children were included in the study. Data analysis was done using R studio version 3.1.3. The anthropometric indicators were analysed using the WHO anthro software. ICFI was calculated using the following components: (1) breastfeeding, (2) dietary diversity, (3) consumption Foods rich in certain micronutrients and (4) frequency of meals. ICFI was compared with food practices and anthropometric indicators. Results: The prevalence of malnutrition, taking into account anthropometric indicators compared to international standards (WHO), is for acute malnutrition (Weight-for-Lenght) of 10%, for wasting (Weight-for-Age) 15.9%, for stunting (Length-for- Age) 15.3%. Regarding breastfeeding, 37% of the children had a delay in breastfeeding. The ICFI score mean in our study was 4.31 ± 1.15. Ninety-two percent (92.9%) of children had a low ICFI. A Low ICFI reflects dietary diversity of children aged 9-11 months (OR=55.71 [9.16-339.16]) and children aged 24-59 months (0.1 [0.02-0.39]). Some socio-economic determinants as (number of people living in the household is more than 15) was linked with low ICFI (4.58 [1.31-15.95]).ICFI was associated with underweight (WLZ) p=0.03.The specificity (ability for ICFI to recognize normal children were range from 31.2% to 71.2. However sensibility of ICFI is highest for WLZ, specificity is highest for WAZ. The findings of this study show that ICFI is better to predict children suffering of acute malnutrition i.e. underweight (WLZ) with a sensibility of 91.7%. Conclusion: This study shows that ICFI can address the issues of for child feeding practices in African rural area. The ICFI in food insecure area can be a good tool for predict acute malnutrition in a context of fighting against malnutrition.

Forest restoration is carried out with varying objectives in mind, one of which is biodiversity conservation. The present study examines the extent by which tree biodiversity could potentially be maximized in the context of the pan-African Great Green Wall for the Sahara and the Sahel Initiative (GGW). Towards this end, ten indigenous tree species were selected for study in the Ferlo region in Northern Senegal based on previous ethnobotanical studies in the zone. The species included Acacia senegal, Acacia nilotica, Acacia tortilis subsp. raddiana, Acacia seyal, Adansonia digitata, Balanites aegyptiaca, Dalbergia melanoxylon, Sclerocarya birrea, Tamarindus indica and Ziziphus mauritiana. Germination experiments were first performed in the laboratory on seed lots from Senegal, Burkina Faso, Kenya, and South Africa prior to in situ sapling production in the nursery in Northern Senegal situated along the GGW. A split plot field design was employed and the effects of seed provenance (two per species) and the addition of organic fertilizer at the timing of planting were determined. Over the course of the 2 year experimental period, the newly planted trees, in addition to the naturally regenerating woody vegetation and herbaceous grasses were monitored in the fenced-in experimental field plot. Of the ten species, only B. aegyptiaca, A. tortilis subsp. raddiana, and S. birrea exhibited moderate survival rates. The effects of provenance and fertilizer addition were sporadic and species-dependent. Natural regeneration of woody species was abundant albeit characterized by low biodiversity whereas herbaceous grass species showed extensive biodiversity, especially under tree canopies as compared to open areas.

International audience; Being a growing recreational activity on many coasts in the world, scuba diving is mainly known thanks to studies conducted in the frame of marine protected areas (MPAs). For management purposes indeed, it is necessary to know scuba diving practices and their ecological impact. But it is also important to report the socio-economic added value of this activity and thus the social utility of the environmental protection measures. Yet, as for many other recreational activities at sea, knowledge about scuba diving remain relatively incomplete and often unreliable. Furthermore, in the case of complex coastal zones, the geographical extent of the practices does not match systematically with the area of an MPA when it exists. It is therefore relevant to approach this activity at the level of the territorial system in which it occurs. This is the subject of this article which deals with the coast of Marseille (France), one of the world’s cradles of diving. Combining a large commercial port with various marine protected areas with distinct regulations, this coast is a prime but complex area for this activity. From a survey of key diving structures, a descriptive geography of scuba diving can then be revealed. It is then discussed with the management areas and the few efforts to organize the activity on the whole coast, from the integrated coastal area management perspective.; Activité récréative en pleine croissance sur de nombreux littoraux du monde, la plongée sous-marine est principalement connue grâce à des études conduites dans le cadre d’aires marines protégées (AMP). Les préoccupations de gestion imposent en effet de connaître les pratiques et leurs effets sur les milieux, mais aussi les retombées socio-économiques de l’activité et ainsi l’utilité sociale de la protection de l’environnement. Pourtant, comme pour de nombreuses autres activités récréatives en mer, les connaissances sur la plongée demeurent relativement lacunaires et sont souvent sujettes à caution. En outre, dans le cas de zones côtières complexes, l’espace des pratiques ne se confond pas systématiquement avec le périmètre d’une AMP lorsqu’elle existe. Il est alors pertinent d’appréhender cette activité au niveau du système territorial dans lequel elle s’insère. Tel est le propos de cet article qui s’intéresse au littoral de Marseille (France), l’un des berceaux mondiaux de la plongée. Juxtaposant un grand port de commerce avec divers périmètres de protection de l’espace marin littoral aux réglementations distinctes, ce littoral constitue une zone privilégiée pour cette activité. À partir d’une enquête auprès des principales structures d’encadrement de la plongée, une géographie des pratiques est alors révélée. Dans une perspective de démarche intégrée, elle est ensuite mise en discussion avec les périmètres de gestion et les quelques efforts d’organisation de l’activité sur l’ensemble du littoral.

International audience

International audience; The combined effects of climate change and human pressure have led to the progressive degradation of natural resources in semi-arid regions. Woody taxa in these regions play an important role in the functioning and services provided by semi-arid savannah by serving as forage for both domestic and non-domestic grazers. Maintaining the functioning of semi-arid savannas thus requires understanding the dynamics of these communities of woody taxa and their responses to exogenous forces, such as climate. To better understand the dynamics of woody taxa in semi-arid environments we collected dendrometric characteristics from five field sites along an environmental gradient in the Ferlo region of central Senegal. Density and basal area were found to be greater in the northern part of the zone, contrasted with the distance between individuals and crown cover, which is greater in the southern part of the zone. Stand structure estimated from the distribution according to height and diameter at breast height shows a preponderance of individuals in the shrub layer, although with a significant representation of the tree layer in southern Ferlo. Stand regeneration was better in the south and less effective in the north. There was a trend towards the rejuvenation of populations belonging to the dominant species. There were only three species for which degradation was not apparent (Balanites aegyptiaca, Acacia raddiana and Dalbergia me-lanoxylon), all of which have important ethnobotanical uses, suggesting that human use of taxa can play an important role in preventing degradation. Three distinct groups of woody taxa were found to correspond to gradients of precipitation, topography, and human land use pressure. Our results suggest an important role in the management and reintroduction of woody species in the Sahel and the regulation of pastoral techniques necessary for the rehabilitation of the agro-pastoral zone of Senegal.

International audience

Objectif. Pour une meilleur comprehension des interactions entre Termites et ligneux dans les parcelles de reboisement de la Grande Muraille Verts au Senegal, nous nous sommes interesse a l’attaques des Termites sur les ligneux. Methodologie et resultats. Dans chaque parcelle, une superficie d’un hectare a ete delimitee. Le nombre d’especes ligneuses, ainsi que le nombre d’individus de chaque essence attaques ont ete denombres. Les especes de Termites qui les attaquent ont ete inventoriees. Cette etude a permis de recenser 15 especes ligneuses attaquees par 14 especes de Termites. Les especes les plus attaquees sont Boscia senegalensis et Balanites aegyptiaca . Les especes du genre Acacia ne sont attaquees que sur les parties dont l’ecorce a ete enlevee. Les especes des genres Psammotermes , Microcerotermes et Odontotermes s’attaquent plus aux ligneux. Conclusion et application des resultats: Cette etude a permis de connaitre d’avantage la diversite des termites et des essences vegetales dans les parcelles de reboisement mais aussi les interactions qui existent entre les termites est les essences vegetales. Mots Cles: Termites, ligneux, attaques, zone semi-aride English Abstract Objective: To better understand interactions between Termites and ligneous in the plots of reafforestation in the Great Green Wall of Senegal, we are interested in Termites attacks on ligneous. Methodology and results: In each plot a surface of one hectare was delimited. The number of ligneous species as weel as the number of individual of each attacked spicy were counted. The termites species that attack them were made an inventory of this survey has allowed to make an inventory of fifteen ligneous species attacked by fourteen Termites species. The most attacked species are B oscia senegalensis and Balanites aegyptiaca . The species like Acacia are only attacked on the sides the bark of which was abstracted. The species like (such as) Psammotermes , Microcerotermes and Odontotermes attack most on ligneous. Conclusion and Application of results: The study to know the advantage of diversity of termites and plant species in reforestation plots but also the interactions between termites is the plant species Keywords: termites, ligneous, attacks, half dry area

Cette étude est consacrée aux pratiques alimentaires, à la croissance et à la santé d'enfants vivant dans une zone sahélienne aride avec des conditions de vie semi-nomade et dans le contexte d'un processus de changement du mode de vie lié à l'implantation de la Grande muraille verte, projet de restructuration écologique. Pour cette étude, on s'est focalisé sur les pratiques de diversification alimentaire et leur impact sur les mesures anthropométriques de l'enfant. Étaient inclus dans l'étude des enfants âgés de 0 à 59 mois résidant dans la zone de Widou Thiengoly. Les mesures anthropométriques ainsi que l'âge de l'enfant ont été relevés chez 150 enfants, dont 149 enfants sont d'origine peule. Dans cette population enfantine, nous avons trouvé une relation entre l'état de nutrition et la pratique alimentaire de diversification. De manière générale, la pratique de la diversification alimentaire telle que préconisée par les politiques et normes au Sénégal diffère de celle observée à Widou. Ainsi, on note que l'aliment de diversification le plus utilisé est le lait de vache (67,5 % des enfants en reçoivent précocement) avec un âge moyen d'introduction de 6,81 mois. Par ailleurs, on note une introduction tardive et une sous-consommation des protéines animales (viande, poisson) et des fruits et légumes. Les populations ont des comportements alimentaires qui répondent à des codes culturels bien établis et ne suivent pas les recommandations normatives émises par les politiques de santé publique, sauf lorsque ces dernières intègrent les codes culturels locaux, ce qui est très rarement le cas. Ainsi, bien que la croissance des enfants de Widou se fasse sur une tendance linéaire, on note une prévalence élevée de malnutrition chez ces enfants de 25 %, taux qui est légèrement plus élevé que celui de la population sénégalaise du même âge. Les courbes de croissance des enfants de Widou se distribuent en deçà des courbes de croissance de l'OMS à l'exception de celles du périmètre crânien. Par ailleurs, on note que l'état de malnutrition de la mère n'impacte pas sur celui de l'enfant, ce qui n'est pas le cas des maladies digestives telles que la diarrhée, dont la survenue est fortement corrélée à celle de l'insuffisance pondérale (p

The development of equations to predict tree height, crown diameter, crown depth from stem diameter of a tree species enables arborists, researchers, and urban forest managers to model costs and benefits, analyze alternative management scenarios, and determine the best management practices for sustainable forests. The objective of this study was to develop regression prediction models for tree age, tree height, crown diameter, crown ratio and crown depth for A. senegal growing in Ferlo, in the northern Senegal. Four plantations of different years old (ISRA, 10 years old plantations, Ndodj, 8 years old plantations, Boulal, 5 years old plantations and Deali, 4 years old plantations) were selected. The following dendometric variables: crown height, crown diameter, stem diameter at the breast height, stem basal diameter (at 0.30 m) and the height from the tree base to first branch were measured on a total of 489 trees. The results suggested that the ecological structure of the different year old A. Senegal plantation revealed a bell-shaped form with left dissymmetric distribution indicating a predominance of individuals with small diameter at breast height. Allometry study of A. Senegal showed highly significant positive correlations (p = 0.00) between stem diameter at breast height, stem basal diameter, tree height, crown diameter and crown depth. Positive correlations were also found between crown diameter, tree height and crown height. Prediction models derived from these relationships can be used to estimate the tree height, stem diameter at breast height and crown depth from crown diameter with greater precision. As for A. Senegal age estimation, the established model is not strong as it can explain only 49.1% of the age variation.

To support the ecosystem resilience in the sylvo-pastoral area, Senegal did pioneering work by initiating, since 2008,field activities in the framework of the pan-African project of the Great Green Wall (GGW). How have theSenegalese practices contributed to the pastoral resilience and development? What are the lessons that the PanAfrican Agency and the Sahelian countries involved can draw from the Senegalese experience? To answer thesequestions, this study proposes to identify the major characteristics of the GGW practices as well as the effects onpastoralism in a comprehensive and strategic perspective, following an inductive approach.The Great Green Wall looks like a sectorial project (forest) with diversification activities (horticulture). The wayfield workers perceive it is not homogeneous. Reforestation plots have impacts on the resilience of the courses andthe populations. They modify the grazing plans and encourage private fodder banks to the detriment of traditionalpasture reserves. Several actions (distribution of food, medical consultations, employment) of the Great Green Wallcontribute to the resilience of the pastoral populations (health, food security and income). The Great Green Wall alsohas effects on social transformation and pastoral development. There is a noticeable change of mindset, adevelopment of civic awareness, as well as a breakdown of their social isolation.To become a systemic project development, the GGW could integrate production sectors such as hydraulics andeducation. To accomplish this, the agency must hire a multidisciplinary staff with a corporate culture to break awaywith participative behaviors.

International audience; To assist spatial planning and environmental management policies in coastal areas, the monitoring of urban sprawl and the characterization of the evolution of built-up areas are essential prerequisites. In this perspective, the production of land use data sets on a large-scale is necessary and many governmental and research initiatives have been engaged for this purpose. Taking as a case study the coastal zone of the Côte bleue, in Provence, this paper reports on an experiment of land use mapping on a large-scale, based on a classification made of 44 urban classes compliant with Corine Land Cover. Available with four versions (1998, 2003, 2008 and 2011), the resulting database allows an accurate characterization of the recent evolution of the urbanization. Urban sprawl and urban densification can be studied using spatial analysis. Thus, the transformation of artificial areas appears much higher than urban sprawl. However, urban areas composed of single houses still prevail.; Pour assister les politiques publiques d’aménagement du territoire et de gestion de l’environnement sur le littoral, le suivi de l’étalement urbain et la caractérisation de l’évolution des tissus urbanisés constituent un préalable indispensable. Dans cette perspective, la production de données d’occupation du sol à grande échelle est une nécessité et de nombreuses initiatives de la recherche et des pouvoirs publics ont été engagées à cet effet. En prenant pour terrain d’application le littoral de la Côte bleue, en Provence, cet article rend compte d’une expérimentation de cartographie de l’occupation du sol à grande échelle, basée sur une nomenclature urbaine à 44 classes compatible Corine Land Cover. Produite avec quatre millésimes (1998, 2003, 2008 et 2011), la base de données résultante permet la caractérisation de l’évolution récente de l’urbanisation à une échelle fine. L’étalement urbain et la densification urbaine peuvent alors être analysés avec précision. La transformation des territoires artificialisés apparaît ainsi bien supérieure à la production de nouveaux tissus urbanisés par étalement. Mais malgré cette densification, l’urbanisation pavillonnaire demeure majoritaire.

International audience; Coastal landscape can be studied through social representations of individuals who live and/or participate in its management. In this perspective, this work proposes a methodological framework to reveal the ways of living on the French Mediterranean coast. It also proposes some results produced by the implementation of this methodology. Its heuristic potential is based on its interdisciplinary approach, the articulation of several conceptual frameworks (coast, way of living, landscape and social representations), and the analysis of several datasets.; Le paysage côtier peut être étudié par les représentations sociales des individus qui l’habitent et/ou participent à sa gestion. Dans cette perspective, ce travail propose un cadre méthodologique pour révéler les modes d’habiter le littoral sur les rivages méditerranéens de la France. Il offre également quelques résultats produits par la mise en œuvre de cette méthodologie. Son caractère heuristique repose sur des pratiques interdisciplinaires, le couplage de plusieurs référentiels conceptuels se faisant écho (littoral, mode d’habiter, paysage et représentations sociales), et l’exploitation de plusieurs corpus de données.

International audience; Les parcs nationaux du Québec, en plus de leurs mandats d’éducation et d’accessibilité, jouent un rôle essentiel pour la conservation : ils permettent de préserver un territoire représentatif d’une région naturelle. Dans les parcs nationaux du Nunavik, la conservation du patrimoine culturel prend tout son sens. En effet, le Nunavik englobe un vaste territoire où les peuples autochtones se rencontrent avec un bagage culturel inestimable. En 2009, un projet de recueil photographique a débuté dans la communauté d’Umiujaq pour être ensuite transposé dans les communautés de Kuujjuarapik et de Whapmagoostui, qui fréquentent aussi le territoire du parc national Tursujuq ( Figure 1 ). Les Inuits et les Cris de ces communautés ont été appelés à fournir des photographies de paysages dans le cadre d’un concours. Ces images ont été choisies par leurs auteurs pour leur beauté, les souvenirs qu’elles évoquaient ou le lieu qu’elles suggéraient. Chacune d’entre elles était commentée par son auteur.

International audience; ""Les paysages prennent leur valeur dans l’œil des hommes qui les regardent. Que ce soit chez les peuples autochtones de l'Arctique ou en Occident, la nature n'est sauvage que dans la mesure où elle est pensée comme telle"".F.Joliet

Objective: Millet is the staple food of millions of people living in the Sahelian zone and the tropical countries of West Africa. It occupies an important place in the Senegalese alimentation. The major damages to this cereal are caused by the beetle Tribolium castaneum Herbst (Tenebrionidae) whose adults give a repulsive smell of stored food and making them unusable. The objective of this study is to identify the different haplotypes of T. castaneum and their distribution in Senegal.Methodology and Results: To achieve this, a sampling was performed in seven (7) localities of Senegal belonging to four agro-ecological zones. The DNA of each individual was extracted and the cytochrome b was amplified with Qiagen protocol and then sequenced. The results showed the existence of nine (9) haplotypes in Senegal and the haplotype Hap_1 prevailed among them and was present in all sampled areas. Haplotypes Hap_4 of Mbam, Hap_3 of Diaroumé, Hap_5 of Koungheul and Hap_7, Hap_8 and Hap_9 of Sandiara were individuals. Sandiara had a market for cereals, which may be a plausible reason for getting the largest number of haplotypes. The Hap_5 comes in all networks as the central Haplotype. Changes of nucleotide composition did not affect the amino acid composition of the haplotypes. Thus, all the mutations were synonymous.Conclusion and application of results: From 2012 to 2015, 9 haplotypes on 12 of Tribolium castaneum imposed themselves in these localities. 9 haplotypes were identified in Senegal including 6 (six) of them are individual. The locality of Sandiara has the largest number of haplotype of T. castaneum because of the very strong marketing of cereals and vegetables in that area. The mutations are synonymous; Haplotypes therefore would have the same behaviour towards biopesticides.Keywords: Tribolium castaneum, Cytochrome b, haplotype, Senegal, identification, distribution

International audience

Oral diseases belong to non-communicable diseases. They are characterized by their importance especially in disadvantaged areas. The objective of this study was to measure the extent and severity of caries among rural populations of Widou, an area located in central Ferlo. It was a descriptive and cross-sectional study which involved 300 individuals selected using simple random sampling. The socio-demographic characteristics collected were sex, age, educational level and occupation. The dental status was rated by the prevalence of dental caries and DMF and its components. The data were analyzed with the software Epi info 3.4.5 with 5% of threshold statistical significance. The prevalence of dental caries was 89%. The mean DMF was 5.4 ± 5.6 with a maximum of 26. The mean of component “D” was 3.8 with a maximum of 24. Variables significantly associated with dental caries were sex (p = 0.012) and occupation (p = 0.03). The extent and severity of caries in rural areas of the Ferlo evoke a relatively low support or management and require efforts in prevention, directed on oral hygiene and dietary habits.

International audience; Coastal landscape can be studied through social representations of individuals who live and/or participate in its management. In this perspective, this work proposes a methodological framework to reveal the ways of living on the French Mediterranean coast. It also proposes some results produced by the implementation of this methodology. Its heuristic potential is based on its interdisciplinary approach, the articulation of several conceptual frameworks (coast, way of living, landscape and social representations), and the analysis of several datasets.; Le paysage côtier peut être étudié par les représentations sociales des individus qui l’habitent et/ou participent à sa gestion. Dans cette perspective, ce travail propose un cadre méthodologique pour révéler les modes d’habiter le littoral sur les rivages méditerranéens de la France. Il offre également quelques résultats produits par la mise en œuvre de cette méthodologie. Son caractère heuristique repose sur des pratiques interdisciplinaires, le couplage de plusieurs référentiels conceptuels se faisant écho (littoral, mode d’habiter, paysage et représentations sociales), et l’exploitation de plusieurs corpus de données.

International audience; L'objectif de cette étude est de suivre la chute et la décomposition de la litière de cinq espèces ligneuses, Acacia senegal (L.) Willd, Acacia tortilis var. raddiana (Savi) Brenan, Balanites aegyptiaca (L.) Del., Boscia senegalensis (Pers.) Lam. ex Poir., et Sclerocarya birrea (A. Rich.) Hochst., et leur influence sur la biomasse herbacée dans le Nord Ferlo, Sénégal. Les cinq espèces ligneuses ont été choisies parmi les essences retenues pour la restauration des écosystèmes sahéliens dans le cadre du projet de reforestation panafricaine de la Grande Muraille Verte. Le suivi de la chute des litières a été effectué pendant un an entre mars 2015 et mars 2016 sous-couvert des arbres. L'étude de la décomposition des litières a été suivie durant 16 mois entre juin 2014 et octobre 2015. Enfin, les mesures de la biomasse herbacée et l'analyse floristique qualitative ont été déterminées à la fin de la saison pluvieuse, en octobre 2015. Les résultats ont montré que la chute de litière varie selon les traitements et qu'elle s'étale le long de l'année. Les quantités de litières sous B. senegalensis (39,3 t ha-1) étaient significativement plus élevées que celles des autres espèces ligneuses (P≤0,05). Les quantités les plus faibles ont été enregistrées sous A. tortilis var. raddiana (7,89 t ha-1) et A. senegal (4,73 t ha-1). Le pourcentage de perte de masse des litières évolue de manière exponentielle et varie en fonction des espèces ligneuses. Le pourcentage le plus élevé a été noté chez l'A. tortilis var. raddiana (70%), suivi de l'A. senegal (65%) et de B. senegalensis (61%). Le pourcentage le plus faible a été enregistré chez S. birrea (44%) et B. aegyptiaca (52%). Les résultats de l'évaluation de la biomasse herbacée ont montré une quantité de phytomasse significativement plus élevée sous-couvert que hors-couvert (P≤0,05). L'inventaire floristique sous et hors-couvert a permis de recenser 35 espèces herbacées qui se répartissent en 31 genres et 17 familles. ABSTRACT Litter fall and decomposition of five woody species and their influence on the herbaceous biomass in North Ferlo, Senegal This study aims to follow the fall and decomposition of litter from five woody species, Acacia senegal (L.) Willd, Acacia tortilis var. raddiana (Savi) Brenan, Balanites aegyptiaca (L.) Del., Boscia senegalensis (Pers.) Lam. ex Poir., and Sclerocarya birrea (A. Rich.) Hochst., and their influence on the herbaceous biomass in North Ferlo, Senegal. The five species were chosen from the species selected for the pan-African reforestation project, " the Great Green Wall. " Litter fall was followed for one year between March 2015 and March 2016 under tree canopy. The decomposition of litter was followed for 16 months between June 2014 and October 2015. Finally, measures of herbaceous biomass and floristic qualitative analysis were determined at the end of the rainy season in October 2015. The results show that litter fall varies according to the treatment and that it spreads along the year. Litter quantities under B. senegalensis (39.3 t ha-1) were significantly higher than that of the other woody species (P≤0.05). Lower quantities were recovered under A. tortilis var. raddiana (7.89 t ha-1) and A. senegal (4.73 t ha-1). Percent litter loss was exponential and varied by tree species. The highest percent loss was observed for A. tortilis var. raddiana (70%), followed by A. senegal (65%) and B. senegalensis (61%). The lowest percent loss was for S. birrea (44%) and B. aegyptiaca (52%). The results of the evaluation of herbaceous biomass showed an amount of phytomass significantly higher under-than away from canopy (P≤0.05). The floristic inventory under-and away from canopy identified 35 herbaceous species from 31 genera and 17 families.

International audience; Un collège expérimente un Enseignement intégré de sciences et de technologie, à partir d'un projet multi-partenarial sur la ressource eau en montagne, à partir du contexte local. Ce projet s'appuyant sur l'intervention de chercheurs de l'OHM Haut Vicdessos en classe a permis de travailler sur des scénarii du futur. La recherche conduite s'est focalisée sur le degré et le type de contributions du monde de la recherche à la construction chez les élèves de capacités à se projeter vers le(s) futur(s). Les notions de transposition didactique et de pratiques sociales de référence ont été mobilisées pour positionner le travail et ana-lyser les productions des élèves. Cette collaboration particulière semble favoriser la prise en compte par les élèves d'une grande diversité de données, de séquences temporelles et de sites clefs au sujet de la dynamique de la ressource eau en montagne.