175 research outputs found

    A project for the restoration plan of Pyrenean Aster (Aster pyrenaeus DC.)

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    L’Aster des PyrĂ©nĂ©es (Aster pyrenaeus DC.) est une trĂšs belle AstĂ©racĂ©e vivace, endĂ©mique rare des PyrĂ©nĂ©es françaises et des Monts Cantabriques. Dix populations sont actuellement connues, dont 7 ont Ă©tĂ© dĂ©couvertes ou redĂ©couvertes ces 7 derniĂšres annĂ©es. ProtĂ©gĂ©e en France, elle fait Ă©galement partie des espĂšces prioritaires pour la Directive europĂ©enne « Habitats, faune, flore ». Sa situation, jugĂ©e critique depuis bien longtemps, nous a conduit Ă  initier un projet de plan de restauration, aprĂšs une premiĂšre phase de prospection sur le terrain et d’études prĂ©liminaires (voir aussi GUZMAN & al. 2003). Nous prĂ©sentons ce projet qui a pour objectifs : – de terminer le recensement des donnĂ©es sur les stations anciennes, de poursuivre les prospections de terrain et de dĂ©crire l’ensemble des populations connues, – d’approfondir les connaissances sur la biologie, la gĂ©nĂ©tique, l’écologie de l’espĂšce et la dynamique de ses populations afin de dĂ©terminer les causes naturelles ou anthropiques de raretĂ© ou de rarĂ©faction de l’espĂšce, – d’élaborer un plan de restauration intĂ©grĂ© comprenant pour chacune des stations/populations la proposition de modalitĂ©s de gestion et de protocoles de suivi (conservation in situ) ainsi que leur conservation ex situ. La durĂ©e de cette phase est fixĂ©e Ă  4 ans (2000-2003). Le plan de restauration qui sera rĂ©digĂ© Ă  l’issue sera validĂ© en concertation avec les acteurs locaux.Aster pyrenaeus is an attractive perennial restricted in distribution to the French Pyrenees and the Cantabric Mountains. Only 10 populations are known to exist. 7 of them were discovered or found again during the last 10 years. Aster pyrenaeus is protected in France and listed as endangered. Its situation has been considered as critical for a long time and led us to initiate a restoration plan after a phase step of field investigations and preliminary studies (see also Guzman et al. in this issue). The purposes of this project are: – To make a survey of old data from literature and herbaria – To look for new sites, exploring suitable habitats – To get more information regarding the biology, ecology and population genetics and biological and/or human factors controlling the establishment, growth and maintenance or demise of colonies – To implement a conservation strategy including monitoring populations and elaborating proposals for land management and ex situ conservation. This study phase will last for 3 years (2000-2002). The restoration plan will be written then, and validated with local actors

    Reclaiming in another way in the Pyrenees

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    Le dĂ©veloppement des activitĂ©s humaines en montagne (amĂ©nagement des stations de sport d’hiver, gĂ©nie routier ou forestier) s’accompagne souvent de travaux de terrassement ou de remaniement des terrains. En altitude, les dĂ©lais de recolonisation naturelle par les formations vĂ©gĂ©tales Ă©tant trĂšs importants, les sites remaniĂ©s sont gĂ©nĂ©ralement revĂ©gĂ©talisĂ©s afin de limiter l’érosion et d’accĂ©lĂ©rer leur intĂ©gration paysagĂšre. Les opĂ©rations de revĂ©gĂ©talisation constituent une cause d’introduction d’espĂšces allochtones ou de matĂ©riel vĂ©gĂ©tal d’origine non pyrĂ©nĂ©enne. AprĂšs une phase prĂ©liminaire d’analyse du marchĂ© et d’études Ă©cologiques, le Conservatoire botanique pyrĂ©nĂ©en intervient pour sensibiliser les acteurs des opĂ©rations de revĂ©gĂ©talisation et promouvoir l’utilisation de matĂ©riel vĂ©gĂ©tal d’origine locale. Nous prĂ©sentons notre programme d’action qui vise Ă  faire prendre en compte des objectifs de conservation de la diversitĂ© biologique, notamment au niveau gĂ©nĂ©tique, dans la restauration des Ă©cosystĂšmes herbacĂ©s dans les espaces pyrĂ©nĂ©ens d’altitude. Ce programme intĂšgre des actions d’information et d’appui technique, des recherches en Ă©cologie et en gĂ©nĂ©tique des populations, des expĂ©rimentations de terrain. Il pourrait contribuer Ă  l’émergence d’une filiĂšre de production des semences pyrĂ©nĂ©ennes.The development of human activities in the mountains (ski resorts, road of forest engineering
) is often combined with excavation works and soil perturbations. At high altitude the time for natural revegetation is very long. So the disturbed sites are usually sown in order to limit erosion and to speed up their integration in the landscape. These revegetation operations introduce non native species or non local plant material in the Pyrenees. Conservatoire botanique pyrĂ©nĂ©en first ran a market analysis and some ecological studies. Our purpose now is to make the actors involved in revegetation more aware of ecological issues (especially the conservation of genetic diversity) and to promote the use of native plant material for high altitude reclamation programmes. This project includes information and technical support, investigations in ecology and population genetics and preliminar experiments of revegetation with local plant material

    Juniperus thurifera in the Pyrenees: conservation status and stands management

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    Le GenĂ©vrier thurifĂšre (Juniperus thurifera L.), arbre ou arbuste dioĂŻque de la famille des CupressacĂ©es, joue un rĂŽle particulier dans le bassin occidental de la MĂ©diterranĂ©e. PrĂ©sent au Sud de la MĂ©diterranĂ©e dans les Atlas marocains et les AurĂšs d’AlgĂ©rie, au Nord de la MĂ©diterranĂ©e en Espagne, France et Italie, ce GenĂ©vrier n’existe dans les PyrĂ©nĂ©es que dans deux stations d’importance: Le QuiĂ© de Lujat en AriĂšge et La Montagne de RiĂ© en Haute-Garonne. Il y constitue un Ă©lĂ©ment de biodiversitĂ© remarquable. Les auteurs prĂ©sentent une description et un Ă©tat des lieux des deux stations principales entourĂ©es elles-mĂȘmes de petites populations satellites. Il s’intĂ©ressent aussi, dans le contexte gĂ©nĂ©ral de dĂ©prise agricole qui caractĂ©rise les espaces pyrĂ©nĂ©ens, Ă  la question de la conservation ou de la rĂ©habilitation de ces Ă©cosystĂšmes particuliĂšrement originaux.Thuriferous juniper (Juniperus thurifera L.) , a dioecious bush or tree, is only found in isolated parts of the Western Mediterranean : France, Spain, Algeria and Morocco. As a botanical rarity in France, thuriferous juniper is only found in three specific areas: the Corsican highlands, the Alps, and the Pyrenees, where only two extensive locations have so far been identified : Montagne de Rie and QuiĂ© de Lujat. In these two locations, this heliophilous and xerothermic species colonizes limestone, rocky south facing slopes, but also former pastures or terraces. The decline in human and livestock activities over recent decades has led to a recolonisation of some of these stands by oaks (Quercus pubescens in RiĂ© and Quercus ilex in QuiĂ© de Lujat); their competition with juniper trees are responsible for the regression of J. thurifera, outside rocky stands where it is not under threat, since it is the only tree species able to grow on such biotopes. Long-term management, including subsidized grazing and/or periodic manual clearing of the meadows, must be considered if we want ensure its survival not only in the rocky stands

    Agent-based simulation of pedestrians' earthquake evacuation; application to Beirut, Lebanon

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    Most seismic risk assessment methods focus on estimating the damages to the built environment and the consequent socioeconomic losses without fully taking into account the social aspect of risk. Yet, human behaviour is a key element in predicting the human impact of an earthquake, therefore, it is important to include it in quantitative risk assessment studies. In this study, an interdisciplinary approach simulating pedestrians' evacuation during earthquakes at the city scale is developed using an agent-based model. The model integrates the seismic hazard, the physical vulnerability as well as individuals' behaviours and mobility. The simulator is applied to the case of Beirut, Lebanon. Lebanon is at the heart of the Levant fault system that has generated several Mw>7 earthquakes, the latest being in 1759. It is one of the countries with the highest seismic risk in the Mediterranean region. This is due to the high seismic vulnerability of the buildings due to the absence of mandatory seismic regulation until 2012, the high level of urbanization, and the lack of adequate spatial planning and risk prevention policies. Beirut as the main residential, economic and institutional hub of Lebanon is densely populated. To accommodate the growing need for urban development, constructions have almost taken over all of the green areas of the city; squares and gardens are disappearing to give place to skyscrapers. However, open spaces are safe places to shelter, away from debris, and therefore play an essential role in earthquake evacuation. Despite the massive urbanization, there are a few open spaces but locked gates and other types of anthropogenic barriers often limit their access. To simulate this complex context, pedestrians' evacuation simulations are run in a highly realistic spatial environment implemented in GAMA [1]. Previous data concerning soil and buildings in Beirut [2, 3] are complemented by new geographic data extracted from high-resolution Pleiades satellite images. The seismic loading is defined as a peak ground acceleration of 0.3g, as stated in Lebanese seismic regulations. Building damages are estimated using an artificial neural network trained to predict the mean damage [4] based on the seismic loading as well as the soil and building vibrational properties [5]. Moreover, the quantity and the footprint of the generated debris around each building are also estimated and included in the model. We simulate how topography, buildings, debris, and access to open spaces, affect individuals' mobility. Two city configurations are implemented: 1. Open spaces are accessible without any barriers; 2. Access to some open spaces is blocked. The first simulation results show that while 52% of the population is able to arrive to an open space within 5 minutes after an earthquake, this number is reduced to 39% when one of the open spaces is locked. These results show that the presence of accessible open spaces in a city and their proximity to the residential buildings is a crucial factor for ensuring people's safety when an earthquake occurs

    Apprendre à gérer des collections patrimoniales en bibliothÚque

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    Vous venez d'ĂȘtre nommĂ©-e responsable de la collection patrimoniale d'une bibliothĂšque mais vous n'ĂȘtes pas spĂ©cialiste ou vos connaissances sont lointaines. D'oĂč viennent ces vieux livres qui dorment dans la rĂ©serve ? Qu'en faire ? A-t-on le droit de s'en dĂ©barrasser s'ils paraissent ne servir Ă  personne ? Y en a-t-il qui sont rares et qu'il faudrait mettre en valeur ? Quelques-uns sont cataloguĂ©s mais c'est loin d'ĂȘtre le cas de tous, comment faire ? Et puis il y a des gravures dans des portefeuilles, des photographies anciennes ici et lĂ . Comment savoir si elles ont quelque intĂ©rĂȘt ? Dans un coin des magasins, des moisissures sont brusquement apparues et semblent contaminer peu Ă  peu les ouvrages. Comment s'en dĂ©barrasser ? Qui prĂ©venir ? Si vous vous posez parfois ces dĂ©licates questions, ce manuel est pour vous. (Dominique Coq, responsable scientifique du volume) ÉclairĂ© par des retours d'expĂ©riences de spĂ©cialistes, ce manuel rĂ©unit un ensemble raisonnĂ© d'informations de base, qui prĂ©sente la marche Ă  suivre pour apprĂ©hender, traiter, signaler et valoriser ces fonds patrimoniaux ; il permet d'en comprendre l'environnement juridique, administratif et documentaire. Un document indispensable pour les professionnels peu formĂ©s dans le domaine, confrontĂ©s pour la premiĂšre fois Ă  une collection patrimoniale, ou qui s'y destinent, et dĂ©sireux d'acquĂ©rir les rudiments nĂ©cessaires pour la gĂ©rer

    The use of passive seismological imaging in speleogenetic studies: an example from Kanaan Cave, Lebanon

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    Among many parameters that control the evolution of caves stands the volume of unconsolidated clay sediments generally produced by the alteration of the calcareous rocks. Here we introduce the use of a passive seismological imaging technique to investigate the clay deposits and estimate its total volume in a cave. Applied for the first time for speleogenesis studies, the HVSR (Horizontal / Vertical Spectral Ration) is a geophysical technique that can help better interpret cave geomorphology. We apply seismological spectral techniques (H/V ratio) on ambient noise vibrations to derive the clay volume, as well as its shape. This technique applied on the clay volume reveals some internal details, such as fallen blocks prior to the deposit accumulation and helps to understand deposit evacuation dynamics. The study focuses on the Kanaan Cave, located in Metn District, Lebanon, and reveals new stages related to the cave speleogenesis. This technique could be applied on ‘paragenetic’ caves where clay volume is frequently present in order to constrain the clay volume and reconstruct the buried floor shape of the cave, underneath the clay deposit

    Erratum to: Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B3: Area 5)

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