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The relationship between species' niche breadth (i.e. the range of environmental conditions under which a species can persist) and range size (i.e. the extent of its spatial distribution) has mostly been tested within geographically restricted areas but rarely at the global extent.[br/] Here, we not only tested the relationship between range size (derived from species' distribution data) and niche breadth (derived from species' distribution and co-occurrence data) of 1255 plant species at the regional extent of the European Alps, but also at the global extent and across both spatial scales for a subset of 180 species.[br/] Using correlation analyses, linear models and variation partitioning, we found that species' realized niche breadth estimated at the regional level is a weak predictor of species' global niche breadth and range size.[br/] Against our expectations, distribution-derived niche breadth was a better predictor for species' range size than the co-occurrence-based estimate, which should, theoretically, account for more than the climatically determined niche dimensions.[br/] Our findings highlight that studies focusing on the niche breadth vs range size relationship must explicitly consider spatial mismatches that might have confounded and diminished previously reported relationships.

La préoccupation liée à la préservation, la sauvegarde et la valorisation du village kabyle traditionnel en Algérie, comme témoignage de notre histoire et symbole de notre identité, se chevauche inévitablement avec celle du développement local des régions de la zone de montagne, notamment du Djurdjura. Actuellement, ses villages se dépeuplent vue l’absence d’alternative de développement, ce qui les faits sombrer dans l’oubli et la désuétude, « cas du village traditionnel d’Ath El Kaid, situé au coeur de la montagne du Djurdjura, malgré qu’il soit érigé en secteurs sauvegardés après son classement comme patrimoine culturel national année 2009». En vue d’une valorisation du village traditionnel, il est crucial d’opter pour sa redynamisation, et d’en faire un élément actif dans son territoire. Ainsi, l’intégration d’une activité touristique mobilisant ses potentialités naturelles et culturelles s’imposent, pour un développement local certain. Le tourisme culturel-patrimonial est une forme de tourisme qui a pour but de découvrir le patrimoine culturel et architectural d’une région. Il doit être réfléchi comme un agent de développement durable, et s’appliquer aux valeurs fondamentales à savoir l’authenticité des projets et la protection du patrimoine. Le tourisme culturel-patrimonial, peut contribuer de façon significative à la prospérité économique de la région de la Kabylie du Djurdjura, comme il peut générer des retombées sociales à savoir la reconnaissance de son patrimoine culturel et architectural comme composante du territoire. Et par conséquent la promotion de sa culture locale vivante, la découverte des différentes activités et traditions de la population locale. Ainsi les apports de ce type de tourisme, contribuent à améliorer la qualité de vie des habitants et leur procurent un sentiment de fierté renouvelé à l’égard de leur culture et leur patrimoine et deviennent soucieux de leur préservation à travers le temps.

[Departement_IRSTEA]Eaux [ADD1_IRSTEA]Adaptation des territoires au changement global; Taking into account the uncertainties associated with climate projections is essential but often overlooked. One main reason for that is the multiplicity of climate projections representing possible future climates as a consequence of uncertainties surrounding developments for greenhouse gases, uncertainties arising from the climate models and the impact models (hydrology, biodiversity etc.), as well as the natural variability of the climate. To describe these different sources of uncertainty, and take them into account is not easy for engineers and managers who are more accustomed to reasoning in a determinist framework. This article aims to demonstrate that statistics offers a number of approaches which make it possible to use a given multi-scenario, multimodel climate projection. The simplest propose a descriptive summary of the information, while the more complex approaches can test the significance of the expected changes, to separate the different causes of uncertainty and measure each one's contribution to the overall variability. The approach is illustrated by a set of projections for temperature, precipitation and mean snow depth for a mountainous region of the French Alps. It can be easily applied to any variable whose projections have been generated through an impact model which simulates the consequences of a set of climate projections for a given sector defined in social and ecosystem terms.; La prise en compte des incertitudes est devenue un impératif affiché, mais reste souvent un voeu pieu dans la pratique. Le cas des projections climatiques et de leur déclinaison sectorielle constitue un exemple emblématique de cette dichotomie. La communauté scientifique génère un nombre croissant de trajectoires représentant des futurs possibles. Cette multiplicité résulte d'un ensemble de scénarios d'évolution des gaz à effet de serre, d'un nombre croissant de modèles climatiques globaux et régionaux et de modèles d'impact (hydrologie, biodiversité, etc.) comportant tous leur lot d'hypothèses. À cette incertitude se conjugue la variabilité naturelle du climat. Gérer rigoureusement ces différentes sources jusqu'aux impacts sectoriels est nécessaire, mais l'ingénieur et le décideur, plus habitués à raisonner dans un monde déterministe, s'en affranchissent fréquemment du fait d'un manque d'appropriation des outils et des méthodes disponibles. Comme illustré dans cet article, la statistique propose une boite à outils complète allant de simples résumés descriptifs de l'information à des modèles explicites permettant l'évaluation des contributions respectives à la variabilité totale des projections. Les méthodes introduites sont illustrées à partir d'un ensemble de projections pour un massif des Alpes françaises, la Chartreuse, et pour trois variables (température, précipitation, hauteur de neige moyenne en hiver). L'approche se généralise aisément à toute transformation des projections climatiques par un modèle d'impact.

International audience; This paper examines social changes currently underway in a Tày commune in the Lào Cai province through the lens of the balance between State interventions in social practices and the responses of the local population. The author compares empirical facts with the three interpretations of State-Society relationships conceptualized by Benedict Kerkvliet. This study focuses on the way the national policies of “establishing a civilized way of life” are implemented by the local authorities and then adopted, assimilated and changed by the local population. The first part introduces the principles, objectives and rationale behind these policies from a historical perspective, beginning at the national level and ending at the local one. The second part gives details on the content of the reform with respect to weddings, funerals and festivals, as implemented in the commune studied. The last part aims to illustrate, through a specific case study of a wedding, how these policies are implemented, focusing particularly on the responses of the local population. This case study cross-checked with others allows the identification of three main ways of receiving external influences : passive resistance by maintaining prohibited practices and norms ; a combination of endogenous and exogenous elements ; a pragmatic assimilation. Finally, this study shows that the social change operates through a dialectic between State interventions, which entail assimilation, and local cultural reinventions.; Cet article vise à comprendre certaines modalités du changement social actuel dans une commune tày de la province de Lào Cai à travers la tension entre les interventions de l'État sur les pratiques de sociabilité collectives et les réactions des populations locales face à ces interventions. L'auteur opère par ce biais une mise en perspective des faits empiriques avec les trois interprétations des rapports État-société conceptualisées par Benedict Kerkvliet. L'étude se concentre sur la manière dont les politiques nationales « d'édification d'un mode de vie civilisé » sont mises en place par les autorités locales puis adoptées, assimilées et transformées par les populations. La première partie présente les principes, les objectifs et les logiques de ces politiques dans une perspective historique, en partant du point de vue national pour aboutir sur une échelle locale. La seconde partie détaille le contenu des réformes mises en oeuvre dans la commune étudiée. La troisième et dernière partie vise à illustrer par un cas de mariage la mise en oeuvre de ces politiques, en axant la réflexion sur les réactions locales. Ce cas recoupé à d'autres permet d'identifier trois modalités de réception d'éléments extérieurs : une résistance passive par contournement des règles officielles ; une combinaison des éléments endogènes et exogènes; et une assimilation pragmatique. Cette étude montre en définitive que le changement social s'opère à travers une dialectique entre des interventions étatiques assimilatrices et des réinventions culturelles.

LA DIVERSITÉ DES CONDITIONS DE VIE : ALIMENTATION ET BUDGETS Au fil de ce parcours des monts Mandara est apparue la grande diversité des systèmes agraires en présence, celle aussi des conditions de vie qui en résultent. Ce sont ces dernières dont nous tenterons d’abord de préciser les différences à l’aide de deux enquêtes, l’une sur l’alimentation, l’autre sur les budgets. L’alimentation Bien que déjà ancienne, une enquête alimentaire réalisée en 1960-61 par la Misoencam (Mission socio-économ...

Les habitants des monts Mandara sont des paysans enracinés, qui savent tirer parti d'un milieu naturel difficile. Au nord de Mokolo, où les densités humaines sont très élevées, ils parviennent à subsister et à conserver la fertilité de leurs sols, grâce à des techniques culturales intensives (terrasses, adaptation des semences, engrais). Au sud de Mokolo, les systèmes agraires, d'une étonnante diversité, peuvent se montrer remarquablement performants chez certains groupes ethniques. Progressivement, ces populations sont entrées dans une économie monétaire en développant certaines cultures pour la vente. Depuis 1960, elles sont confrontées à des changements plus radicaux. Les pressions exercées pour qu'elles abandonnent les parties les plus accidentées de leur terroir et s'installent en piémont, la possibilité d'émigrer en plaine, la scolarisation, l'islamisation – qui touche une bonne partie des ethnies du sud –, et enfin les actions menées au plan agricole, ébranlent les structures agraires et sociales traditionnelles. Comment ces sociétés, jusqu'alors très préservées, et chez qui le social, l'agraire et le religieux sont étroitement liés, vivent-elles ces changements ? Quels sont leurs perspectives de développement, mais aussi les risques que représente l'abandon de certaines pratiques agricoles parfaitement adaptées au milieu ?

LE MILIEU NATUREL C’est le milieu naturel qui donne son unité à la région. Sont présentés ici les grands traits du relief, les caractéristiques du climat et les problèmes liés à l’eau. Les sols et la végétation ont également leur spécificité, mais ils seront examinés dans les chapitres consacrés aux structures agraires avec lesquelles ils sont intimement liés. Les trois grands types de relief Les monts Mandara forment une longue chaîne orientée NNE-SSO. Mo...

L’HOMME ET LE MILIEU PHYSIQUE La partie nord des monts Mandara constitue une région différente du reste, fortement typée, marquée par les fortes densités et par son unité sur le plan agraire. Elle s’étend entre la plaine de Mora au nord, celle de Diamaré à l’est, le plateau de Mokolo et la plaine de Gawar au sud. Elle relève de cinq arrondissements : ceux de Koza et de Mokolo (département du Mayo-Tsanaga)), de Mora et de Tokombéré (département du Mayo-Sava), et de Méri...

Cet ouvrage est consacré aux paysans des monts Mandara, à leurs conditions de travail et de vie. Habitant une région montagneuse située au nord du Cameroun en bordure du Nigeria, ils forment un ensemble important — environ 400 000 personnes —, et bien typé. Fortement marqués par le milieu accidenté auquel ils ont dû s’adapter, plus ou moins coupés dans le passé des plaines voisines du fait du contexte historique, ils se distinguent à maints égards des populations qui les entourent. La caracté...

Le sud des monts Mandara, de Mokolo à Mayo-Oulo, tranche nettement sur le plan agraire par rapport au nord. Nous lui consacrons deux parties, l’une à la zone centrale des plateaux, l’autre à l’extrémité sud, mais il convient au préalable d’en faire ressortir les caractéristiques communes. Avec 120 000 habitants, soit 30 % de la population, occupant près des deux tiers de la superficie totale, l’effondrement des densités est le facteur déterminant du clivage nord/sud. En outre, le milieu physi...

DES MONTAGNARDS À LA CONQUÊTE DU PLATEAU De Mokolo à Tchévi, la partie centrale des monts Mandara s’articule autour des plateaux intérieurs, qui se succèdent sur environ 70 km de longueur, séparés les uns des autres et entourés par de hauts reliefs montagneux. Ils dépendent de deux grands ensembles de population. Au nord, les Mafa, les Kapsiki, et les petits groupes qui leur sont apparentés, sont d’authentiques montagnards. Ils avaient choisi de vivre en milieu acciden...

River Flow 2018: 9th International Conference on Fluvial Hydraulics, Lyon, FRA, 05-/09/2018 - 08/09/2018; International audience; In this paper, we present some first attempt to measure graded sus-pension of sands in an alpine river. It is a real challenge to measure graded-suspensions of sands in such dynamic rivers. Specific measurements of the graded suspension in the middle of a secondary channel were attempted using a sampler that allows simultaneous sampling at three different elevations (5 cm, 10 cm, and 20 cm) above the bed. Very large concentrations (up to C = 40 g/l) of fine sediments in suspension were measured during a dam reservoir flush-ing event. It included large amounts of sand (from 10 to 60% of the measured concentration). A substantial graded suspension of sand was measured even for relatively low velocities. Sand fluxes estimates for varying bed shear stresses during the event are discussed. In particular, based on the measured bed shear stress, a semi-empirical formula developed for sand suspension is applied to test its ability to predict sand flux in alpine rivers. The sensibility of such formula to the grain size is very high whereas large uncertainties exist in the measure-ment (d50 varies from 0.1 to 0.3 mm depending on the sample), which makes its application difficult at the moment.

National audience

International audience; Mots-clés résilience, agriculture familiale, filière laitière, observatoire, Madagascar RésuMé À Madagascar, la production de lait destinée à la commercialisation a été développée depuis plusieurs décennies dans le cadre d'une petite agriculture familiale diversifiée sur des plateaux d'altitude. En 2009, suite à des événements politiques ayant entraîné la disparition d'un acteur majeur de la collecte et de la transformation, la « crise du lait » a affecté l'ensemble de la filière et entraîné d'importantes recompositions dans son organisation. À partir des données pluriannuelles d'un observatoire rural, nous avons reconstitué les trajectoires d'adaptation ou de résilience des petits produc-teurs laitiers, que nous avons replacées dans une perspective systémique qui interroge les politiques publiques agricoles conduites dans le pays.

Espèce américaine, l’arachide (Arachis hypogaea) fut introduite sur la côte de Guinée vers 1550 et connut une diffusion relativement rapide. Il s’agissait de types Virginia rampants, avec des tiges secondaires alternes et une tige principale sans inflorescence. Elle fut cultivée en concurrence avec le pois voandzou (Vigna subterranea), dont elle a souvent pris le nom, ce dernier se démarquant par un qualificatif. Les types Virginia furent par la suite supplantées par les types érigés de la pé...

National audience

International audience; Mountain soils store huge amounts of carbon which may be highly vulnerable to the strong land use and climate changes that mountain areas currently experience worldwide. Here, we tested the Rock-Eval (RE) pyrolysis as a proxy technique to (i) quantify soil organic carbon (SOC) stocks, (ii) bring insights into SOC bulk chemistry and (iii) investigate biogeochemical stability at the landscape scale in a mountain area of the French calcareous Prealps. A total of 109 soils from 11 eco-units representing the variety of ecosystems of the study area were analyzed with RE pyrolysis. RE pyrolysis showed an excellent predictive performance (R2 = 0.99) for SOC content even in calcareous soils. The technique revealed specific chemical fingerprints for some eco-units and soil types, with decreasing hydrogen index values from Anthroposols (425 ± 62 mg HC/g SOC) to Umbrisols, Leptosols (311 ± 49 mg HC/g SOC) and to Cambisols (278 ± 35 mg HC/g SOC), associated with an increase in SOC maturation. Newly developed RE pyrolysis indices revealed the high stability of SOC in most eco-units developed on Cambisols (acidic grasslands, alpine meadows, bushy facies) and a significantly lower stability of SOC in mountain ridges, sheepfold areas and coniferous forest soils. The persistence of SOC in this mosaic of ecosystems may depend not only on its chemistry or thermal stability, but also on local environmental factors such as climatic conditions or pH, especially for high altitude soils. Overall, RE pyrolysis appears as an appropriate tool for landscape scale carbon inventories and could become a standardized proxy for assessing the vulnerability of SOC stocks.

« Les forêts précèdent les peuples, les déserts les suivent »François René de Chateaubriand Pluie et forêt ! ces éléments sont sans conteste liés puisque plus il pleut et plus la végétation naturelle est dense. Et les zones de forêts sont souvent associées aux montagnes ; les unes et les autres sont souvent liées, et ont pu paraître répulsives ou effrayantes même à diverses époques (Corbin, 2001). Aujourd'hui où l'on cherche des endroits « sauvages », ce qu'il reste de milieux « moins anthrop...

On entend souvent dire que les montagnes sont les châteaux d'eau de la planete. C'est globalement vrai, etant donne que les regions montagneuses sont en general les mieux arrosees et que c'est la que prennent naissance la plupart des grands cours d'eau. Le role reel ou percu des montagnes dans l'espace ainsi que dans l'amenagement de l'espace, est tres different d'une region du globe a l'autre. la montagne peut etre repulsive dans les regions froides, ou seche dans les regions sous le vent (versant oriental des Rocheuses canadiennes et americaines; plateau tibetain au-dela de la barriere himalayenne) ; ou au contraire etre des plus recherchees dans les regions chaudes du fait d'un climat plus agreable ou d'une meilleure pluviometrie (plateau ethiopien, par exemple) ; dans le cas de chaines volcaniques recentes, les montagnes peuvent de surcroit offrir l'avantage de meilleurs sols

Alors que l'ensemble du territoire mexicain appartient au domaine tropical, caractérisé par l'alternance d'une saison des pluies correspondant aux mois les plus chauds et d'une saison sèche ou relativement sèche, marquée par les mois les plus froids, la majeure partie de la moitié septentrionale, plus précisément 60 % du pays, correspond à des zones arides ou semi-arides, qui reçoivent, en moyenne, moins de 500 mm de pluie par an. Cette vaste région, située entre le tropique du Cancer et le 3...

Essentiellement masculine, l’émigration internationale de travail constitue au Népal, un phénomène ancien et de grande ampleur. Dans les régions où il est le plus actif, il se traduit par une nette féminisation des sociétés locales, qui ne s’accompagne pas partout d’un gain en autonomie et en indépendance pour les femmes qui restent. A partir d’une étude de cas en versant sud du massif des Annapurna où l’absence des hommes est particulièrement marquée, cet article tente de préciser la manière dont le développement touristique, en tant que secteur d’activité, offre des opportunités de travail, et au-delà d’émancipation, aux femmes qui sont en mesure de s’en saisir. Predominantly male, the labor out-migration is in Nepal a large-scale phenomenon which has a long history. In the areas where it is the most important, this process leads to a clear feminization of the local societies. But it don’t mean in every case that the womens who stay behind have win something regarding to their autonomy and independance. This paper is based on a case study on the southern slope of the massif of Annapurna, in a tourist area where the absence of the men is particularly marked. Its pupose is to analyze in what extend the development of the tourist sector offers working opportunities – and at the same time opportunities of empowerment – to the womens who are in capacity to seize them.

National audience

Glacier retreat is a worldwide phenomenon with important consequences for the hydrological cycle and downstream ecosystem structure and functioning. To determine the effects of glacier retreat on aquatic communities, we conducted a 4-year flow manipulation in a tropical glacier-fed stream. Compared with an adjacent reference stream, meltwater flow reduction induces significant changes in benthic fauna community composition in less than 2 weeks. Also, both algal and herbivore biomass significantly increase in the manipulated stream as a response to flow reduction. After the flow reduction ceased, the system requires 14–16 months to return to its pre-perturbation state. These results are supported by a multi-stream survey of sites varying in glacial influence, showing an abrupt increase in algal and herbivore biomass below 11% glacier cover in the catchment. This study shows that flow reduction strongly affects glacier-fed stream biota, prefiguring profound ecological effects of ongoing glacier retreat on aquatic systems., Glacier retreat due to climate change can affect the biodiversity and ecosystem function. Here, Cauvy-Fraunié and colleagues manipulated the flow of tropical glacier-fed stream in the Ecuadorian Andes, and show that benthic fauna community composition requires several months before it can recover to the pre-blockade conditions.

International audience; This paper examines social changes currently underway in a Tày commune in the Lào Cai province through the lens of the balance between State interventions in social practices and the responses of the local population. The author compares empirical facts with the three interpretations of State-Society relationships conceptualized by Benedict Kerkvliet. This study focuses on the way the national policies of “establishing a civilized way of life” are implemented by the local authorities and then adopted, assimilated and changed by the local population. The first part introduces the principles, objectives and rationale behind these policies from a historical perspective, beginning at the national level and ending at the local one. The second part gives details on the content of the reform with respect to weddings, funerals and festivals, as implemented in the commune studied. The last part aims to illustrate, through a specific case study of a wedding, how these policies are implemented, focusing particularly on the responses of the local population. This case study cross-checked with others allows the identification of three main ways of receiving external influences : passive resistance by maintaining prohibited practices and norms ; a combination of endogenous and exogenous elements ; a pragmatic assimilation. Finally, this study shows that the social change operates through a dialectic between State interventions, which entail assimilation, and local cultural reinventions.; Cet article vise à comprendre certaines modalités du changement social actuel dans une commune tày de la province de Lào Cai à travers la tension entre les interventions de l'État sur les pratiques de sociabilité collectives et les réactions des populations locales face à ces interventions. L'auteur opère par ce biais une mise en perspective des faits empiriques avec les trois interprétations des rapports État-société conceptualisées par Benedict Kerkvliet. L'étude se concentre sur la manière dont les politiques nationales « d'édification d'un mode de vie civilisé » sont mises en place par les autorités locales puis adoptées, assimilées et transformées par les populations. La première partie présente les principes, les objectifs et les logiques de ces politiques dans une perspective historique, en partant du point de vue national pour aboutir sur une échelle locale. La seconde partie détaille le contenu des réformes mises en oeuvre dans la commune étudiée. La troisième et dernière partie vise à illustrer par un cas de mariage la mise en oeuvre de ces politiques, en axant la réflexion sur les réactions locales. Ce cas recoupé à d'autres permet d'identifier trois modalités de réception d'éléments extérieurs : une résistance passive par contournement des règles officielles ; une combinaison des éléments endogènes et exogènes; et une assimilation pragmatique. Cette étude montre en définitive que le changement social s'opère à travers une dialectique entre des interventions étatiques assimilatrices et des réinventions culturelles.

International audience; Glacier retreat is a worldwide phenomenon with important consequences for the hydrological cycle and downstream ecosystem structure and functioning. To determine the effects of glacier retreat on aquatic communities, we conducted a 4-year flow manipulation in a tropical glacier-fed stream. Compared with an adjacent reference stream, meltwater flow reduction induces significant changes in benthic fauna community composition in less than 2 weeks. Also, both algal and herbivore biomass significantly increase in the manipulated stream as a response to flow reduction. After the flow reduction ceased, the system requires 14-16 months to return to its pre-perturbation state. These results are supported by a multi-stream survey of sites varying in glacial influence, showing an abrupt increase in algal and herbivore biomass below 11% glacier cover in the catchment. This study shows that flow reduction strongly affects glacier-fed stream biota, prefiguring profound ecological effects of ongoing glacier retreat on aquatic systems.

International audience; Alpine gravel-bed rivers are characterized by very poorly sorted sediments and significant grain sorting is generally observed on gravel bars. The purpose of this paper is to present some field measurements achieved on the Arc en Maurienne River, France. The main objective is to characterize the dynamics of fine sediments, mainly infiltration, for conditions close to the incipient motion of gravels. The field campaign was carried out on a gravel bar located 10 km downstream of St Jean de Maurienne during the dam flushing event on June 17th, 2014. Patches made of gravels and pebbles were settled on the gravel and infiltration of fine sediment was measured after the event. During the flushing event, surface velocities over the gravel bar were measured thanks to video analysis (LSPIV). Water levels and mean slope in the secondary channel were measured thanks to pressure gauges positioned on the side of the secondary channel. An estimation of the bed shear stresses over the patches was thus possible all along the event. Intense water sampling was also carried out both upstream and downstream the secondary channel. Grain size analysis showed that deposited sediments were much coarser than sediments in suspension. An estimation of the fine sediment deposition rate and a discussion on the sediment dynamics is proposed from these measurements.

International audience; Alpine gravel-bed rivers are characterized by very poorly sorted sediments and significant grain sorting is generally observed on gravel bars. The purpose of this paper is to present some field measurements achieved on the Arc en Maurienne River, France. The main objective is to characterize the dynamics of fine sediments, mainly infiltration, for conditions close to the incipient motion of gravels. The field campaign was carried out on a gravel bar located 10 km downstream of St Jean de Maurienne during the dam flushing event on June 17th, 2014. Patches made of gravels and pebbles were settled on the gravel and infiltration of fine sediment was measured after the event. During the flushing event, surface velocities over the gravel bar were measured thanks to video analysis (LSPIV). Water levels and mean slope in the secondary channel were measured thanks to pressure gauges positioned on the side of the secondary channel. An estimation of the bed shear stresses over the patches was thus possible all along the event. Intense water sampling was also carried out both upstream and downstream the secondary channel. Grain size analysis showed that deposited sediments were much coarser than sediments in suspension. An estimation of the fine sediment deposition rate and a discussion on the sediment dynamics is proposed from these measurements.

36th IAHR world congress, La Haye, NLD, 28-/06/2015 - 03/07/2015; International audience; Alpine gravel-bed rivers are characterized by very poorly sorted sediments and significant grain sorting is generally observed on gravel bars. The grain size variability may significantly influence the inception of movement for each of the classes represented over a gravel bar. The purpose of this paper is to present some field measurements achieved on the Arc en Maurienne River, France. The main objective is to characterize the dynamics of fine and coarse sediments for conditions close to the incipient motion of gravels and for different degrees of clogging of the river bed. The field campaign was carried out on a gravel bar located 10 km downstream of St Jean de Maurienne during the dam flushing event on June 17th, 2014. Six patches including tagged pebbles (using PIT-tag) were built up with three different characteristics: clean patches formed with gravels and pebbles only, patches with a natural mixture where tagged pebbles were substituted to naturally arranged ones, and patches artificially clogged with fine sediments. These patches were located on the side of a secondary channel on the gravel bar. Surface grain size analyses of the gravel (using the Woolman method and photo analyses using BaseGrain) as well as topographic measurements were achieved the day before the event. During the flushing event, surface velocities over the gravel bar were measured thanks to video analysis (LSPIV). Water levels and mean slope in the secondary channel were measured thanks to pressure gauges positioned on the side of the secondary channel. An estimation of the bed shear stresses over the patches was thus possible all along the event. Intense water sampling was also carried out both upstream and downstream the secondary channel. During the postevent survey the day after, the PIT-tag search showed that the coarse particles did not move. On the other hand, a significant amount of fine sediments were deposited on the patches and infiltrated on the clean patches. Grain size analysis showed that deposited sediments were much coarser than sediments in suspension. An estimation of the fine sediment deposition rate and a discussion on the sediment dynamics is proposed from these measurements.

The French version of vertical-flow constructed wetlands (VFCWs) is characterized by treating directly raw wastewater on a first-stage filter. VFCW is a well developed technology with more than 3,500 plants in operation in France. However, VFCW performance may be affected under the low temperatures reached in mountain areas during winter. The effect of cold conditions over 12 plants, ranging from 75 to 1,900 person equivalent and from 680 to 1,500 m above sea level, was studied over 2 years. The plant hydraulic loads, and air and filter temperatures were continuously measured. In addition, 24-h flow proportional sampling, at each stage of treatment, was conducted in summer (as a reference) and winter. Online measurements of ammonium and nitrates were also analyzed to describe the nitrogen removal dynamics. Since no impact on chemical oxygen demand (COD), biochemical oxygen demand (BOD) and suspended solids removal was observed, the effect of cold temperatures on nitrification was further analyzed. Nitrogen removal was relatively unaffected during winter season. Significant effects were confirmed only for the second stage for loads above 10 gTKN/m2/d (TKN: total Kjeldahl nitrogen). Temperature profiles allowed analysis of the filter buffer capacity in terms of freezing. Under minimal air temperature of −19 °C, no critical operation was observed, although design and operation recommendations can be provided to ensure suitable plant performances.

Colloque de la Société Française d'Économie Rurale : « Structures d'exploitation et exercice de l'activité agricole : Continuités, changements ou ruptures? », Rennes, FRA, 12-/02/2015 - 13/02/2015; National audience; Le maintien de l'élevage laitier constitue un enjeu majeur dans les zones de montagne, sur les plans économique, social et environnemental. Or les exploitations laitières de ces zones doivent faire face à des contraintes structurelles qui leur confèrent une moindre compétitivité que les exploitations de plaine sur le marché du lait. L'abandon des quotas laitiers pourrait accroître leur fragilité et précipiter leur disparition. Cet article interroge le rôle des coopératives laitières sur le maintien des élevages laitier dans les zones de montagne. En nous appuyant sur l'étude d'un bassin laitier des Alpes du Nord françaises, et notamment sur des enquêtes auprès des éleveurs du bassin laitier et de responsables des coopératives impliquées, nous analysons le rôle des coopératives dans le fonctionnement du bassin laitier. Nous décryptons les interrelations entre les coopératives laitières et leurs adhérents, ainsi que les coordinations entre coopératives. Le travail met ainsi en évidence les engagements réciproques entre les coopératives et leurs adhérents ainsi que l'importance de l'ancrage territorial des coopératives et les formes qu'il peut prendre. Nous dégageons certains impacts favorables des coopératives sur la pérennisation des exploitations laitières.

Smallholder farmers in the Taita hills and Mount Kilimanjaro recognize the need to conserve soil nutrients of fields and farms located in the upper, middle and lower zones of mountainous areas. These mountain communities depend on rain-fed subsistence agriculture which means that for sustainable subsistence crop production, they also depend on nutrient availability and use efficiency in farming households. A study under way in the area has looked at loss of land cover and infestations of plant pests and diseases and is using this information to raise farmers’ awareness of soil fertility and to introduce best cropping practices.

Globally, the number of protected areas (PAs) has increased exponentially during the last 25 years, particularly in biodiversity-rich developing countries. Many recent initiatives have integrated local-scale socioeconomic development into both design and management. Because the rates of deforestation and species extinction are increasing in most parts of the world, substantial efforts have been made to build and strengthen local environmental organizations, to establish new protected areas (NPAs), and to improve natural resource management. An NPA was recently established at Ibity Massif in central Madagascar, where a community-based conservation project is being coordinated by the Missouri Botanical Garden (MBG). In December 2008, a temporary protection order was issued, and definitive establishment of the NPA, which falls under Category V of the IUCN PA system, is expected before the end of 2015. This initiative has involved significant outreach and community education programs to raise awareness of Ibity's conservation and economic importance and the threats to its biodiversity, along with ongoing efforts to reduce fire frequency and implement ecological restoration projects with significant local community participation. In order to ensure the sustainability of this NPA, a co-management plan has been implemented involving MBG, local authorities, and the local population. This study describes the diagnostic process undertaken at Ibity in order to: 1) disseminate the data gathered to inform establishment of the NPA; and 2) summarize the initial state of the environment on the massif prior to the implementation of a management plan, as a baseline for assessing the NPA's effectiveness., Globalement, le nombre d'aires protégées (AP) a augmenté de façon exponentielle au cours des 25 dernières années, en particulier dans les pays en développement plus riches en biodiversité. De nombreuses initiatives récentes ont intégré le développement socio-économique à l'échelle locale dans sa conception et gestion. Etant donné que les taux de déforestation et d'extinction des espèces sont en augmentation dans la plupart des régions du monde, des efforts considérables ont été faits pour construire et renforcer les organisations locales de l'environnement, pour créer de nouvelles aires protégées, et pour améliorer la gestion des ressources naturelles. Une nouvelle AP est actuellement mise en place dans le massif d'Ibity, dans les haut-plateaux au centre de Madagascar, où un projet de conservation basé dans la participation communautaire est coordonné par le Missouri Botanical Garden (MBG). En Décembre 2008, un arrêté temporaire de protection a été délivré et la mise en place définitive de la nouvelle AP qui est classé dans la catégorie V selon le système des aires protégées de l'UICN est attendue avant la fin de 2015. Cette initiative a impliqué un programme de vulgarisation et d'éducation à la communauté centré sur la sensibilisation de la conservation de la diversité d'Ibity et de l'importance économique, les menaces qui pèsent sur la biodiversité, et les efforts en cours pour réduire la fréquence des feux et la mise en oeuvre des projets de restauration écologique avec une importante participation de la communauté locale. Afin d'assurer la durabilité de cet AP, un plan de co-gestion a été mis en place impliquant MBG, les autorités locales et la population locale. Cette étude documente et synthétise le processus de diagnostic entrepris à Ibity afin de: 1) faciliter la diffusion des données recueillies afin d'informer l'établissement de la nouvelle AP; 2) résumer l'état initial de l'environnement sur le massif avant la mise en oeuvre d'un plan de gestion et d'établir ainsi une base de référence qui peut être utilisée pour évaluer l'efficacité des nouvelles AP.

A volcanic tuff rock known as cangahua (Ecuador) or tepetate (Mexico) is found throughout the Andes. Problems have arisen as the layers of light but fragile soil that once covered the tuff have been lost for both natural (environmental) reasons and because of over-cultivation. When the soil is gone, the tuff is impermeable and sterile. Now, a project in Ecuador has determined that the tuff itself can be reclaimed and is supporting a programme that sends bulldozers to the tuff regions to break up the rock and create a new fertile soil.

International audience; In the highlands of southern Colombia and northern Ecuador, soils developed on volcanic ash deposits have specific properties: high water retention, high hydraulic conductivity and high carbon (C) contents. The main role of the soils is to regulate the water available for the dense population living in the valleys. Soil properties and land use depend on their altitudes. Any important modification of land-use change has a serious effect on soil properties and consequently the ecosystem properties such as water regulation and flood control. This can be a threat for a city that relies on the ecosystem for its water supply, as is the case in Ecuador's capital, Quito.

The authors propose to exploit the similitude and complementarity between simulation-gaming and multi-agent modeling through the development of a new methodology called SAMBA-Week, which is used for agricultural research and development. The need for such a new methodology came from the context of mountainous areas of Northern Vietnam characterized by a high social and natural diversity. As actions of research and development typically involve multiple actors, a precondition for communication is a mutual understanding of each other's point of view. The authors thus used simulation-gaming, individual interviews, and multiagent modeling to enhance communication by constructing with the stakeholders a shared representation of their system as a basis for discussion.

International audience

International audience; While there is a large consensus that plant-plant interactions are a crucial component of the response of plant communities to the effects of climate change, available data remain scarce, particularly in alpine systems. This represents an important obstacle to making consistent predictions about the future of plant communities. Here, we review current knowledge on the effects of climate change on facilitation among alpine plant communities and propose directions for future research. In established alpine communities, while warming seemingly generates a net facilitation release, earlier snowmelt may increase facilitation. Some nurse plants are able to buffer microenvironmental changes in the long term and may ensure the persistence of other alpine plants through local migration events. For communities migrating to higher elevations, facilitation should play an important role in their reorganization because of the harsher environmental conditions. In particular, the absence of efficient nurse plants might slow down upward migration, possibly generating chains of extinction. Facilitation-climate change relationships are expected to shift along latitudinal gradients because (1) the magnitude of warming is predicted to vary along these gradients, and (2) alpine environments are significantly different at low vs. high latitudes. Data on these expected patterns are preliminary and thus need to be tested with further studies on facilitation among plants in alpine environments that have thus far not been considered. From a methodological standpoint, future studies will benefit from the spatial representation of the microclimatic environment of plants to predict their response to climate change. Moreover, the acquisition of long-term data on the dynamics of plant-plant interactions, either through permanent plots or chronosequences of glacial recession, may represent powerful approaches to clarify the relationship between plant interactions and climate change.

National audience; In a few years the new specifications of the Saint-Nectaire PDO cheese will prohibit the use of wet forage like grass silage, forcing number of producers to change their winter feeding. Therefore, Inra and the Saint-Nectaire inter-profession implemented an experiment to optimize milk production during a complete lactation with an 'all hay' winter diet, in comparison with a silage diet, associated with the maximum amount of concentrate permitted (30% over the year). Two groups of 15 autumn calving cows were compared for 305 days of lactation: a Silage group fed during winter with a '50% grass silage–hay–concentrate' diet; a Hay group fed with a 'hay–concentrate' diet. At pasture, the 30 cows were kept together on a rotational grazing system. During the first 14 weeks of lactation, Silage cows ingested more forage than Hay cows (12.3 vs. 10.9 kg/d on total winter period). The lowest milk production of Hay cows (-343 on 7740 kg/y, ns) took place essentially during winter. The difference is less pronounced for multiparous than for primiparous (-113 vs. -801 kg/y), penalized by the lower energy density of the hay diet, their limited intake capacity and their growth needs. Finally, the experiment was enriched by simulations with the Dynamilk model, which allowed extrapolating the results to other harvesting or grazing conditions.; Le futur cahier des charges du fromage AOP Saint-Nectaire, sans fourrage humide, va obliger de nombreux producteurs à modifier leur alimentation hivernale. L’Inra et l’interprofession du Saint-Nectaire ont donc mis en place une expérimentation visant à optimiser la production laitière sur une lactation complète (305 jours) d’animaux recevant une alimentation hivernale "tout foin", associée à la quantité maximale de concentré autorisé (30 % sur un an). Deux lots de 15 vaches vêlant en automne ont été comparés : un lot témoin Ensilage recevant un régime hivernal "50 % ensilage d'herbe–foin–concentré" ; un lot Foin recevant un régime "foin–concentré". L’été, les 30 vaches ont été conduites ensemble en pâturage tournant. Pendant les 14 premières semaines de lactation, les vaches Ensilage ont ingéré plus de fourrage que les vaches Foin (12,3 vs 10,9 kg/j sur l’ensemble de la période hivernale). La plus faible production laitière des vaches Foin (-343 kg/an, ns) a eu lieu essentiellement l’hiver. La différence est moins marquée chez les multipares que chez les primipares (-113 vs -801 kg/an), pénalisées par la densité énergétique plus faible de la ration foin, par leur capacité d'ingestion limitée et par leur besoin de croissance. Enfin, l'expérimentation a été enrichie par des simulations effectuées avec le logiciel Dynamilk, qui ont permis l'extrapolation des résultats à d'autres conditions de récolte ou de pâturage.

11th European IFSA Symposium , Berlin, DEU, 01-/04/2014 - 04/04/2014; International audience; The maintenance of dairy production in mountain areas pose a real challenge in a context of globalization, particularly in France where milk quotas are about to be dismantled. Although acknowledged and sustained for its multifunctionality, European mountain agriculture has significant natural constraints to contend with and cannot follow the same paths of development as in the plains (specialization, enlargement, industrial organization of labour). Mountain dairy farms have thus had to develop their own specific responses. The goals of this study are: (i) to analyze the recent changes in mountain dairy farming in the Vercors (Alpine uplands under residential and tourist dynamics); (ii) to characterize the diversity of farming system development trajectories; and (iii) to discuss the different responses adopted by dairy farmers to last over time, which are not based on the same adaptive resources. We thus developed an analytical framework that allows us to link evolutions in livestock farming systems and family-farm organizations, via a multi-phase process where each phase of investigation provides more finely grained detail. The process consists in analyzing individual data from: i) national census of agriculture (1988, 2000, 2010) to capture general trends and analyze family-farm trajectories between 2000 and 2010 on 68 dairy farms; ii) semi-directive on-farm interviews (n = 33), to analyze the long term processes of change beyond the family-farm trajectories.

International audience; The export of dissolved organic carbon (DOC) from agricultural soils can represent an important pathway of soil organic carbon loss. However, despite its importance in terrestrial and downstream aquatic ecosystems, most work has focused on temperate agrosystems with tropical and sub-tropical ecosystems being ignored. Here we present the results of a series of rain simulation experiments aimed at examining DOC export from sloping lands in North Vietnam. Three regularly used agricultural practices were tested and compared with Bare soils. We also compared the impact of leaf litter in two planted forest sites. We found high rates of DOC export (0.03-0.25 g C m(-2)) during a 40 min rain episode with the lowest rates observed in the Bare soils and the highest in the planted Forest without leaf litter. This is equivalent to a loss of between 0.001 and 0.008% of the total soil organic carbon in the upper 10 cm during a single, intense rain event. This work highlights the impact of different agricultural practices (Bare soil, hoeing, mulching and fallow) and land use (planted Forest with or without leaf litter) on the export of DOC from upland, tropical soils and further underlines the importance of studying DOC fluxes from agricultural land as it represents an important and highly mobile component of ecosystem carbon fluxes.

10 páginas.-- 5 figuras.-- 1 tabla.-- 45 referencias.-- Supporting Information Additional Supporting Information may be found in the online versionof this article. Fig. S1. Performance of palm seedlings in each treatment. Fig. S2. Influence of light intensity on VPD. http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12311/suppinfo, © 2014 British Ecological Society. The degradation of the Andean cloud forest raises strong biological conservation issues and threatens the sustainability of a crucial water resource. The idea that nurse-based restoration can accelerate the recovery of these forests is underexplored, despite its promise as a restoration technique. Recent conceptual models predict that facilitation among plants may be an important mechanism, but there is a lack of strong empirical support. We gathered experimental data to test this prediction and explore the relevance of using nurse-based forest restoration in these environments. A 20-month factorial experimental design in the Andean tropical cloud forest was established. We measured the survival and estimated the biomass production of transplanted seedlings of a keystone canopy forest species, Ceroxylon echinulatum (Arecaceae), in a deforested area in the presence/absence of herbivory, a potential nurse plant (the tussock grass Setaria sphacelata, Poaceae) and artificial shade. The joint effects of deforestation and herbivory led to the death of all seedlings, whereas most seedlings survived in the adjacent forest, which was used as the control. The presence of nurse plants led to significantly higher survival and growth of Ceroxylon seedlings throughout the experiment, regardless of herbivore presence. The nurse effects were explained by a reduction of the relative abiotic stress experienced by the seedlings outside the forest, that is, the consistently decreasing maximum vapour pressure deficit. Furthermore, nurse tussocks delayed and reduced the effects of herbivory by offering physical protection and a refuge for seedlings against detection by herbivores. However, the effects of herbivory and abiotic stress on facilitation were not additive. Synthesis and applications. Facilitation in degraded cloud forest can be intense as soon as the beneficiary plants are driven away from their physiological optimum (relative abiotic stress) and/or are confronted by herbivory. Using pre-established exotic tussock grasses as a nurse-based restoration technique in degraded cloud forest is a low-cost, non-detrimental (to biodiversity) option, especially in the absence of nurse trees and shrubs. The success of this method requires transplanting seedlings at the base of tussocks. Facilitation in degraded cloud forest can be intense as soon as the beneficiary plants are driven away from their physiological optimum (relative abiotic stress) and/or are confronted by herbivory. Using pre-established exotic tussock grasses as a nurse-based restoration technique in degraded cloud forest is a low-cost, non-detrimental (to biodiversity) option, especially in the absence of nurse trees and shrubs. The success of this method requires transplanting seedlings at the base of tussocks., We thank the people of the Inti-Llacta Reserve for their kind reception and J. Lincango, S. Cauvy-Fraunie, and C. Gully for their help with data collection. We are also grateful to P. Liancourt and two anonymous reviewers for extensive comments on the manuscript and to the LucidPapers team for English revision. This research was funded by the Ecuadorian government (ECOFONDO grant no. 019-ECO7-Inv1) and the project PALMS FP7-ENV-2007-I (www.fp7-palms.org).