Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Le bassin du fleuve Sixaola est un bassin transfrontalier partagé entre le Costa Rica et le Panama. Localisé sur la façade caraïbe de l’isthme centraméricain, il est depuis une vingtaine d’années considérées par les organismes de coopération et les organisations non gouvernementales comme un espace privilégié pour la coopération en matière environnementale. Ce bassin concentre en effet d’importantes richesses naturelles et culturelles propres à cette façade caraïbe. Dans le même temps, on y constate une importante vulnérabilité sociale et des dégradations environnementales croissantes, d’autant plus qu’on trouve autour de ce bassin des activités productives polluantes (monocultures, tourisme, etc.), ainsi que les villages les plus pauvres des deux pays.Cet article cherche à analyser comment, à côté des mécanismes d’intégration et des initiatives appuyées par les États, cet espace connaît aussi de nombreux projets et programmes de coopération menés par des organismes internationaux et des organisations non gouvernementales (ONG). Ces projets visent principalement à accroître la coopération transfrontalière pour la conservation et la gestion environnementale.En revanche, leur rôle est de plus en plus remis en cause par des acteurs locaux qui affirment que ces organismes « transnationaux » déplacent les États et imposent des projets qui ne prennent pas en compte les réalités et les besoins locaux tout en développant des discours « hégémoniques » sur la gestion intégrée des bassins transfrontaliers, le changement climatique, entre autres.
The Sixaola River basin is shared by Costa Rica and Panama. On the Caribbean side of the Central American Isthmus, it has been considered by cooperation organisms and non-governmental organizations as a privileged space for environmental cooperation for the past 20 years. This basin in fact concentrates an important amount of natural and cultural heritage that is endemic to this side of the Caribbean. At the same time, one can observe increasing social vulnerability and environmental degradation related to the presence of the poorest communities of both Panama and Costa Rica within the basin, and to polluting activities (monoculture, tourism, etc.) carried out around it.This article analyzes how this space is the locus of State integration mechanisms and other initiatives, at the same time that it harbors international organism and non-governmental cooperation programs. These latter projects claim to increase trans-border cooperation for conservation and environmental management.But their role is increasingly being contested by local stakeholders, who more and more claim that these “transnational” organisms displace States and impose projects that do not take into account local realities and needs, while developing “hegemonic” discourses on integrated management of trans-border basins and climate change, among other issues.
Amérique centrale
Costa Rica
Panama

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5747
http://journals.openedition.org/etudescaribeennes/5747

Éditeur(s) : HAL CCSD European Geosciences Union (EGU)
Résumé : International audience
Climate models project that rising atmospheric carbon dioxide concentrations will increase the frequency and the severity of some extreme weather events. The flood events represent a major risk for populations and infrastructures settled on coastal lowlands. Recent studies of lagoon sediments have enhanced our knowledge on extreme hydrological events such as palaeo-storms and on their relation with climate change over the last millennium. However, few studies have been undertaken to reconstruct past flood events from lagoon sediments. Here, the past flood activity was investigated using a multi-proxy approach combining sedimentological and geochemical analysis of surfaces sediments from a southeastern Tunisian catchment in order to trace the origin of sediment deposits in the El Bibane Lagoon. Three sediment sources were identified: marine, fluvial and aeolian. When applying this multi-proxy approach on core BL12-10, recovered from the El Bibane Lagoon, we can see that finer material, a high content of the clay and silt, and a high content of the elemental ratios (Fe ∕ Ca and Ti ∕ Ca) characterise the sedimentological signature of the palaeo-flood levels identified in the lagoonal sequence. For the last century, which is the period covered by the BL12-10 short core, three palaeo-flood events were identified. The age of these flood events have been determined by 210Pb and 137Cs chronology and give ages of AD 1995 ± 6, 1970 ± 9 and 1945 ± 9. These results show a good temporal correlation with historical flood events recorded in southern Tunisia in the last century (AD 1932, 1969, 1979 and 1995). Our finding suggests that reconstruction of the history of the hydrological extreme events during the upper Holocene is possible in this location through the use of the sedimentary archives.
ISSN: 1814-9324

hal-01571962
https://hal.archives-ouvertes.fr/hal-01571962
https://hal.archives-ouvertes.fr/hal-01571962/document
https://hal.archives-ouvertes.fr/hal-01571962/file/affouri2017.pdf
DOI : 10.5194/cp-13-711-2017

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Comme dans d’autres régions du monde, la croissance démographique et l’aménagement côtier sur le littoral acadien au Nouveau-Brunswick contribuent à une plus grande vulnérabilité et à la détérioration des espaces côtiers et environnements littoraux. L’élévation du niveau marin et les effets des changements climatiques rendent les côtes du Nouveau-Brunswick extrêmement sensibles et entrainent des impacts de plus en plus importants. Ainsi, l’adaptation aux changements climatiques constitue un enjeu de taille pour la province.Nous décrivons ici les résultats d’une étude comparative sur les expériences et les stratégies d’adaptation de deux communautés côtières, les communautés de Cocagne - Grande Digue et de Beaubassin-Est - Cap Pelé. Les deux territoires ont en commun d’avoir des littoraux convoités par le tourisme et le secteur immobilier. Des entretiens semi-dirigés et des groupes de discussion (focus groups) ont permis d’obtenir des informations sur les thématiques suivantes : l’expérience des modifications environnementales, les mesures d’adaptation initiées individuellement ou collectivement, les réactions et les besoins futurs. Les résultats de l’étude mettent en évidence l’enchâssement des aspects économiques et sociétaux dans les enjeux environnementaux et le rôle des représentations et des acteurs qui déterminent le niveau de mobilisation. Enfin, le projet souligne l’importance d’une coordination entre les différentes échelles de gouvernance.
As in other parts of the world, population growth and coastal planning on New Brunswick’s Acadian coastline are contributing to greater vulnerability and deterioration of the natural environment. The rise in sea level and the effects of climate change make the coasts of New Brunswick extremely sensitive, leading to impacts that are increasingly larger. Thus, adaptation to climate change is a major challenge for the province.Here, we describe the results of a comparative study of the experiences and coping strategies of two coastal communities: Cocagne – Grande-Digue and Beaubassin East – Cap-Pelé. Both these territories attract tourism and real estate investors. Semi-structured interviews and focus groups were used to obtain information on the following topics: the experience of environmental change, adaptation measures initiated individually or collectively, reactions and future needs. Results of the study highlight the entrenchment of economic and societal aspects of environmental issues and the role of representations and stakeholders that determine the level of mobilization. Finally, the project emphasizes the importance of coordination between the different levels of governance.
Acadie
Nouveau-Brunswick

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6663
http://journals.openedition.org/etudescaribeennes/6663

Éditeur(s) : HAL CCSD
Résumé : Report
This activity combines tide gauge and geodetic data to determine the 20th century trends and patterns of relative and absolute sea level changes along the coastline of British Columbia. This information is then used to derive scenarios of relative sea-level rise in coastalcommunities for the 21st century. Particular emphasis is put on the Fraser River Delta and Greater Vancouver region. The projections of 21 st century sea-level rise are provided to provincial and municipal partners to inform local and regional land-use and planning policies.
https://hal.archives-ouvertes.fr/hal-00856631

hal-00856631
https://hal.archives-ouvertes.fr/hal-00856631

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : This paper addresses the challenge of transforming Mediterranean islands into sustainable tourism areas, through the direct (or indirect) use of renewable energy projects and technologies. Through demonstration and a discussion of cases studies from studied islands, which takes into account island-specific characteristics and particularities, we assess the compatibility of renewable energy technologies (RETs) with sustainable tourism development. Conclusions emerge from this analysis which highlight prerequisites for RET-tourism compatibility; this has potential transferability to other insular territories. Developing an appreciation of the factors that can lead to sustainable tourism in islands through the use of renewable energy is a priority issue for two main reasons. Firstly, because until now scientific literature has only discussed the question of photovoltaics’ integration into tourism buildings, and secondly, because of the relatively high vulnerability to climate change impacts of islands compared to many mainland areas, according to predictions made by the United Nations and the European Union. Whilst international politics deal with the mass reduction of gaseous emissions into the atmosphere, reducing the adverse effects of climate change in the islands has become a significant component of national priorities.

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.3487
http://journals.openedition.org/etudescaribeennes/3487

Éditeur(s) : HAL CCSD Royal Society, The
Résumé : International audience
To forecast marine disease outbreaks as oceans warm requires new environmental surveillance tools. We describe an iterative process for developing these tools that combines research, development and deployment for suitable systems. The first step is to identify candidate host–pathogen systems. The 24 candidate systems we identified include sponges, corals, oysters, crustaceans, sea stars, fishes and sea grasses (among others). To illustrate the other steps, we present a case study of epizootic shell disease (ESD) in the American lobster. Increasing prevalence of ESD is a contributing factor to lobster fishery collapse in southern New England (SNE), raising concerns that disease prevalence will increase in the northern Gulf of Maine under climate change. The lowest maximum bottom temperature associated with ESD prevalence in SNE is 128C. Our seasonal outlook for 2015 and long-term projections show bottom temperatures greater than or equal to 128C may occur in this and coming years in the coastal bays of Maine. The tools presented will allow managers to target efforts to monitor the effects of ESD on fishery sustainability and will be iteratively refined. The approach and case example highlight that temperature-based surveillance tools can inform research, monitoring and management of emerging and continuing marine disease threats.
ISSN: 0080-4622

Droits : http://creativecommons.org/licenses/by/
hal-01282834
https://hal-univ-perp.archives-ouvertes.fr/hal-01282834
https://hal-univ-perp.archives-ouvertes.fr/hal-01282834/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01282834/file/20150208.full.pdf
DOI : 10.1098/rstb.2015.0208

Résumé : Cette thèse explore les relations entre histoire et archéologie sous-marine pour étudier le risque de perte en mer aux Petites Antilles à travers l' exemple de la Guadeloupe. Le phénomène du naufrage est envisagé comme un prisme pour aborder les aspects maritimes de l'histoire de la Guadeloupe à l' époque de la marine à voile, entre la fin du XVIIe siècle et la première moitié du XIXe siècle. L' étude repose sur un dépouillement exhaustif de la correspondance administrative et des sondages ciblés dans les archives de la Marine et de quelques-uns des principaux ports du royaume de France liés aux Antilles (Nantes, Bordeaux, Le Havre, Marseille). Le naufrage est défini à travers une étude quantitative des pertes en mer : nombre, fréquence, localisation, répartition chronologique. Cette perspective conduit à qualifier le phénomène de sériel mais marginal en comparaison avec la fréquentation maritime, ce qui n' ôte pas de son intérêt en tant que clé de lecture d'une colonie française d' Amérique et de son économie et de sa société si part iculières , entre cultures d'exportation et esclavage. Environ 550 naufrages son répertoriés en archives entre la fin du XVIIe siècle et le début du XIXe siècle, ce qui représente moins de 1 % de la fréquentation maritime de la colonie. Il s' agit d'un phénomène essentiellement côtier et portuaire lié à la survenue d'événements climatiques exceptionnels (coups de vent et ouragans). Mais, ponctuellement, d'autres causes sont mises en évidence. L'objectif est de dresser une typologie des pertes en mer s'intéressant aussi bien aux différents types de navires perdus qu'à leur fonction , leur cargaison et leur équipage. La question de la perception des risques de pertes (conditions de navigation, dangers d'échouage, aléas climatiques) est envisagée pour analyser les relations entre risques et les moyens mis en oeuvre pour en réduire l'impact. Les différentes pistes allant des premières missions à caractère hydrographique au XVIIIe siècle, aux premiers aménagements portuaires au XIXe siècle, sont étudiées pour voir si elles répondent aux risques de pertes en mer. L'étude des documents d'archives trouve une application dans l'évaluation du potentiel archéologique sous-marin de la Guadeloupe. Celui-ci est évalué à une fourchette entre 50 et 120 sites d'épaves. La lecture critique des sources propose par ailleurs des hypothèses d'identification de 5 sites sur les 15 sites d' épaves anciennes connus, permettant ainsi une vision différente de la question des risques maritimes.
This Ph D explores relationships between history and underwater archaeology in order to study the martime risks in West Indies through the example of Guadeloupe. Shipwreck phenomenon is presented as a prism to analyze maritime aspect of Guadeloupe history during the time of sailing, from the end of 17th to first half of 19th century. The study is based on a archivaI analysis of administrative correspondence and surveys in marine archives and French kingdom main ports linked with West Indies. Shipwreck is defined through an quantitative study of losses : quantity, frequency, localization, chronological spread. This point of view permits to qualify the this phenomenon as serial but low regarding to the maritime activity, This fact is not a lack in order to use this event as a reading key of an American French colony, its economy and society. About 550 shipwrecks have been recorded from the end of 17th to first half of 19th century, thi represents less than 1% of maritime activity of the colony .. This phenomenon is mainly a coastal and a port event, linked with climatic hazard as hurricanes, but the study focused also on others causes . The objective is to set up a losses' typology dealing with ships types, functions, cargos, and crews. The perception of losses risks (seafaring conditions, wrecks dangers and climatic hazards) is presented in order to analyze relationships between risks and means in order to prevent them or reduce their consequences. Different projects from first hydrographical missions during 18th century to first ports building projects at the beginning of 19th century have been studied in order to establish if they answer the losses risks.

http://www.theses.fr/2013AGUY0607

Éditeur(s) : HAL CCSD
Résumé : 1 p.
For groundwater issues (potential leakages in waste repository, aquifer management ...), the development of modeling techniques is far ahead of the actual knowledge of aquifers. This raises two fundamental issues: 1) which and how much data are necessary to make predictions accurate enough for aquifer management issues; 2) which models remain relevant to describe the heterogeneity and complexity of geological systems. The French observatory H+ was created in 2002 with the twofold motivation of acquiring a large database for validating models of heterogeneous aquifers, and of surveying groundwater quality evolution in the context of environmental changes. H+ is a network of 4 sites (Ploemeur, Brittany, France; HES Poitiers, France; Cadarache, France; Campos, Mallorca, Spain) with different geological, climatic, and economic contexts. All of them are characterized by a highly heterogeneous structure (fractured crystalline basement for Ploemeur, karstified and fractured limestone for Poitiers, Cadarache and Mallorca), which is far to be taken into account by basic models. Ploemeur is exploited as a tap-water plant for a medium-size coastal city (15,000 inhabitants) for 20 years. Each site is developed for long term investigation and monitoring. They involves a dense network of boreholes, detailed geological and geophysical surveys, periodic campaigns and/or permanent measurements of groundwater flow, water chemistry, geophysical signals (including ground motions), climatic parameter, etc. Several large-scale flow experiments are scheduled per year to investigate the aquifer structure with combined geophysical, hydrogeological, and geochemical instruments. All this information is recorded in a database that has been developed to improve the sustainability and quality of data, and to be used as a collaborative tool for both site researchers and modelers. This project lasts now for 5 years. It is a short time to collect the amount of information necessary to apprehend the complexity of aquifers; but it is already enough to obtain a few important scientific results about the very nature of the flow heterogeneity, the origin and residence time of water elements, the kinetic of geochemical processes, etc. We have also developed new methods to investigate aquifers (in-situ flow measurements, flow experiment designs, groundwater dating, versatile in-situ probes, etc.). This experience aiming at building up long term knowledge appears extremely useful to address critical issues related to groundwater aquifers: the structure and occurrence of productive aquifer in crystalline basement, the assessment of aquifer protection area in the context of highly heterogeneous flow, the biochemical reactivity processes, the long term evolution of both water quantity and quality in the context of significant environmental changes, for instance.
AGU, Fall Meeting 2008
San Francisco, United States

insu-00375980
https://hal-insu.archives-ouvertes.fr/insu-00375980

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
The impact of stratospheric ozone on the tropospheric general circulation of theSouthern Hemisphere (SH) is examined with a set of chemistry‐climate models participatingin the Stratospheric Processes and their Role in Climate (SPARC)/Chemistry‐ClimateModel Validation project phase 2 (CCMVal‐2). Model integrations of both the past andfuture climates reveal the crucial role of stratospheric ozone in driving SH circulationchange: stronger ozone depletion in late spring generally leads to greater polewarddisplacement and intensification of the tropospheric midlatitude jet, and greater expansion ofthe SH Hadley cell in the summer. These circulation changes are systematic as polewarddisplacement of the jet is typically accompanied by intensification of the jet and expansion ofthe Hadley cell. Overall results are compared with coupled models participating in theIntergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), andpossible mechanisms are discussed. While the tropospheric circulation response appearsquasi‐linearly related to stratospheric ozone changes, the quantitative response to a givenforcing varies considerably from one model to another. This scatter partly results fromdifferences in model climatology. It is shown that poleward intensification of the westerly jetis generally stronger in models whose climatological jet is biased toward lower latitudes.This result is discussed in the context of quasi‐geostrophic zonal mean dynamics.
ISSN: 2169-897X

hal-00337060
https://hal.archives-ouvertes.fr/hal-00337060
https://hal.archives-ouvertes.fr/hal-00337060/document
https://hal.archives-ouvertes.fr/hal-00337060/file/Bock_et_al-2008-Journalsur Geophysical_Research__Solid_Earth_%281978-2012%29.pdf
DOI : 10.1029/2008JD010327

Éditeur(s) : HAL CCSD
Résumé : Report
From 2003 to 2006, the Earth Sciences Sector of Natural Resources Canada conducted a study of the sensitivity of the Roberts Bank tidal flats and marsh to rising sea level, under the Climate Change Impacts and Adaptation Program (Project A600). The study was a multi-disciplinary effort involving geologists, biologists and social scientists comprising a scientific study of the tidal flat environment and a stakeholder engagement process. The results of the work were presented at a Final Stakeholder Workshop on 24 March 2006 and compiled into a preliminary report distributed to the major stakeholders.
https://hal.archives-ouvertes.fr/hal-00856757

hal-00856757
https://hal.archives-ouvertes.fr/hal-00856757
DOI : 10.4095/292672

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Cyanobacteria and cyanotoxins have been more and more studied during the last decades with regard to environment and health issues. More recently the consequences of climate change reinforced the need for research in view of a better management of cyanobacteria blooms. In this context the exploitation of the water quality survey of 26 recreational lakes in Brittany (north western France) between 2004 and 2011 is reported in this paper in order to encompass spatial and interannual patterns of cyanobacteria development at a regional scale. Starting from weekly data principally acquired during summertime, the links between cyanobacteria cell densities, toxin occurrences and interannual meteorological factors can give insights on the potential evolution of cyanobacterial crisis in the future. This study is part of a project aiming at a better understanding of potentially toxic cyanobacteria crisis occurrences in recreational waters, in order to improve predictive monitoring routines.
Environment International

hal-00877892
https://hal.archives-ouvertes.fr/hal-00877892
https://hal.archives-ouvertes.fr/hal-00877892/document
DOI : 10.1016/j.envint.2013.09.018

Résumé : Les forêts côtières inondables (FCI) des régions tropicales et subtropicales remplissent des fonctions écologiques nécessaires aux écosystèmes marins côtiers situés en aval et aux populations humaines vivant à proximité Aux Antilles, les mangroves et les forêts marécageuses à Pterocarpus officinalis sont structurés par des espèces ligneuses qui ont développé des adaptations particulières à la salinité, à l’inondation et aux substrats meubles sur lesquels elles reposent. Dans des contextes climatiques à forte saisonnalité, les saisons sèches prolongées entraînent de fortes variations de la salinité et du niveau de la nappe, que le changement climatique devrait amplifier. Les modèles climatiques de la région Caraïbe prévoient des saisons sèches plus sèches liées à une baisse des précipitations de 20 à 50 %. Or, la question des capacités de résistance et d’acclimatation des espèces ligneuses des FCI à des variations saisonnières marquées de leur environnement édaphique a été peu traitée dans la littérature scientifique.L’objectif de ce travail de thèse a été double. Il s’est agi, d'une part, de caractériser la structure et la croissance de faciès de végétation représentatifs des FCI antillaises et de mettre en évidence leurs déterminants. A cet effet, des individus adultes, des espèces ligneuses dominantes des FCI, (Avicennia germinans, Laguncularia racemosa, Pterocarpus officinalis, Rhizophora mangle), dans cinq faciès de végétation sur le gradient terre-mer, ont été suivis sur l'île de Grande-Terre (Guadeloupe). D’autre part, les effets de variations salines extrêmes sur la croissance et l’écophysiologie de ces quatre espèces ont été évalués au stade plantule par une expérience en conditions contrôlées.A travers cette étude, il a été montré que les différences de salinité et de fertilité entre les stationspermettent d’expliquer la composition et la structure des peuplements de FCI. Cette étude a égalementmontré que P. officinalis peut se maintenir dans une gamme de salinité plus large que ne l'indiquait lalittérature.Dans le contexte des Antilles où les marnages sont faibles, la saisonnalité du climat entraine des variations saisonnières importantes d’un ensemble de descripteurs édaphiques tels que le niveau de la nappe, la salinité du sol, le pH et le potentiel RedOx. L’inondation et la salinité des sols sont fortement corrélées aux variations mensuelles des précipitations. Les périodes sèches sont accompagnées de salinités élevées et d’une baisse du niveau de la nappe allant jusqu’à l’exondation des sols dans toutes les stations suivies. Les stress environnementaux liés à la saisonnalité entrainent une baisse de la production primaire. L’accroissement cambial mensuel des individus est fortement corrélé avec les précipitations et l’intensité du vent. Dans les stations de mangrove, la sècheresse édaphique régule la production primaire des palétuviers. En forêt marécageuse, la part de la sècheresse atmosphérique semble plus importante pour expliquer la production de P. officinalis. Aussi, les sècheresses édaphique et atmosphérique doivent être prises en compte toutes deux pour modéliser efficacement la croissance des peuplements des FCI.Lors de la saison sèche, le stress le plus important est le stress hydrique, lié à la diminution de la teneur en eau du sol et à l’augmentation de la salinité, qui entraine des contraintes physiologiques sur les palétuviers (ajustements stomatiques, pertes de surface foliaire et de conductivité hydraulique). Le stress ionique, lié à la toxicité des ions Na+ et Cl-, permet aussi d’expliquer une partie de la contrainte sur l’assimilation en carbone. En saison sèche, l’aération des sols ne se traduit pas par une amélioration des performances de croissance chez toutes les espèces. Aussi, la croissance cambiale maximale de toutes les espèces de FCI est réalisée en saison des pluies lorsque la salinité est faible et les niveaux d’inondation élevés.
In tropical and subtropical regions, flooded coastal forests provide essentials goods and services to local communities. In the Antilles, mangrove forests and the Pterocarpus officinalis swamp forest host tree species that are adapted to salinity, flooding and loose substrates. In areas were climatic seasonality is strong, dry seasons lead to strong fluctuations of soil salinity and water table level ; that climate change is likely to make stronger again. Climate model for the Caribbean project drier dry seasons with a decease of 20 to 50 % in annual rainfall amounts. However, resistance and acclimation ability of flooded coastal forest’s species to strong environmental fluctuations still remain poorly studied.This thesis aims two objectives. On the one hand, it aims to characterize the forest structure and monthly growth of vegetation structures representative of the Antillean flooded coastal forests and to highlight their determinants. In this respect, adult trees of the four dominant species of local flooded coastal forest (Avicennia germinans, Laguncularia racemosa, Pterocarpus officinalis, Rhizophora mangle), in five stations along a sea – land gradient were monitored on the Grande-Terre island (Guadeloupe). On the other hand, the effects of salinity variation patterns and salinity levels on growth performances and physiology of seedlings from the four same species were investigated through a greenhouse experiment.This study shows that differences among average salinity and soil fertility explain the vegetation structure of flooded coastal forest. It also extents, in the literature, the range of salinity in which P. officinalis can stand at the tree stage.In the Antilles were tidal range is small, climate seasonality lead to strong edaphic seasonal variations in water table level, soil salinity, pH and RedOx potential. Flooding and soil salinity are strongly correlated to monthly rainfall amounts: dry periods lead to high salinity and to a decrease in water table level under the soil surface. Seasonal environmental stresses lead to a decrease of primary production. Cambial growth was strongly correlated to monthly precipitation and average wind speed. In mangrove stations, edaphic drought determines primary production of mangrove trees, when, in swamp forest stations, atmospheric drought determines an important part of P. officinalis’ primary production.During the dry season, water stress is the more important environmental stress, both by the decrease in soil humidity and the increase in soil salinity, and leads to physiological strains (stomatal adjustment, loss of leaf area and hydraulic conductivity) for mangrove trees. Ionic toxicity of ions Na+ and Cl- also explains a part of the strain on carbon assimilation. During the dry season, re oxygenation of soils via low water table level does not lead to an increase of physiological traits. Thus, maximum cambial growth of all species is observed during the rainy season, when salinity is low and water table level is high.Flooded coastal forest’s species do not have the same ability to recover after a dry episode. In all the studied stations, A. germinans’ cambial growth rises back as soon as the rainy season starts, when, for one station, cambial growth of L. racemosa and R. mangle stay null during the three first month of the rainy season. This low ability to recover after a dry episode is correlated to a stronger impact of the dry season on the physiological traits of these two species.The greenhouse experiment shows that salinity variation patterns are to be taken into consideration for explaining seedlings’ growth and salinity tolerance. A stronger salinity increase impacts the growth of all the studied species; a punctual drop of salinity highlights that flooded coastal forest’s species differ in ability to take advantage of a low salinity episode. These results are coherent with field observations as cambial growth was fairly explained by monthly precipitation.

http://www.theses.fr/2013AGUY0674/document

Éditeur(s) : American Geophysical Union
Résumé : [1] A multiproxy integrated chronological framework, based on oxygen and carbon stable isotope stratigraphy, biostratigraphy (foraminifera and nannoplankton bioevents and foraminifer assemblage-based climate cyclicity), magnetostratigraphy, sapropel stratigraphy, and C-14 AMS radiometric dates, has been achieved for borehole PRAD1-2, collected in 185.5 m water depth in the central Adriatic. This work was carried out within the European Community project Profiles across Mediterranean Sedimentary Systems (PROMESS1). The 71.2 m long borehole spans a time interval between late MIS 11 and MIS 1 (the last 370 ka), showing a chronological resolution of 500 and 250 years per cm during interglacial and glacial intervals, respectively. At present, this record is the most expanded and continuous marine record available for the Adriatic Basin. Several orbital cycles can be recognized in the PRAD1-2 record: the 100 ka glacial-interglacial fluctuations and the 23 ka precession-related cycles, which in turn control the deposition of sapropel layers. An integrated analysis of short-term oscillations within the Last Glaciation interval (MIS 4-MIS 2) allowed the identification of the Adriatic signature of Dansgaard-Oeschger events, showing the potential to achieve a more refined chronostratigraphic framework for the top part of the PRAD1-2 record. Finally, the age model obtained by this study allowed the chronological integration of the main foraminifera bioevents detected in the borehole as well as of the volcanoclastic layers present in the upper part of the record. Despite its proximal location, PRAD1-2 presents a continuous record and shows the potential to be consistently correlated both with deep-sea and continental records in the Mediterranean region and beyond.
Geochemistry Geophysics Geosystems (1525-2027) (American Geophysical Union), 2008 , Vol. 9 , P. NIL_107-NIL_127

Droits : 2008 American Geophysical Union
http://archimer.ifremer.fr/doc/2008/publication-3605.pdf
DOI:10.1029/2007GC001713
http://archimer.ifremer.fr/doc/00000/3605/

Résumé : This report makes the synthesis of the works and the results acquired thanks to the development of the project Pace-Net (2010-2013) registered in the 7th framework program of the European Commission aiming to create a scientific and technological network between Europe and the Pacific in front of main common stakes. These concern the biodiversity and the environmental management, the climate change, the energy, the water, the agriculture and the forest, the natural risks, the fisheries and aquaculture and the trans-cutting approaches
Ce rapport effectue la synthèse des travaux et des résultats acquis à la faveur du développement du projet Pace-Net (2010-2013) inscrit dans le 7 ème programme cadre de la Commission Européenne et visant à faire naître un réseau scientifique et technologique entre l'Europe et le Pacifique face aux grands enjeux posés. Ceux-ci concernent la biodiversité et la gestion environnementale, le changement climatique, l’énergie, l’eau, l’agriculture et la forêt, les risques naturels, la pêche et de l’aquaculture et les approches intégratrices.

Droits : Pace-Net Network - All rights reserved
http://archimer.ifremer.fr/doc/00204/31488/29898.pdf
http://archimer.ifremer.fr/doc/00204/31488/

Résumé : This synthesis report assesses the current state of the marine hydrobiological knowledge acquired in the surroundings of the Flamanville electronuclear site (north-west of Cotentin), in the framework of the various project and monitoring programs in the pelagic, benthic and halieutic domains carried out on this site since 1976. Each domain is divided, as much as necessary, into different study areas such as hydrobiology, phytoplankton, microbiology, crustacean larvae or macrophyte algae. For each area, a series of parameters, considered as representative of the evolution of this area, is studied. In this way, for the hydrological area, the sea water temperature and salinity, the mineral nutriment concentrations, the holagen compounds and the boron are monitored. The evolution of each of these parameters enabled us to draw the following conclusions. The vegetal and animal species' physiology is conditioned by climate changes. The study of the pluviometry and air temperature parameters shows that the 1986/2005 period is slightly less humid and warmer than the 1949/2005 period. This reflects also on the sea water temperature whose average values increase on a regular basis.
Ce rapport de synthèse fait le point sur l'état des connaissances hydrobiologiques marines acquises aux abords du site électronucléaire de Flamanville (nord-ouest Cotentin), dans le cadre des différents programmes de projet et de surveillance des domaines pélagique, benthique et halieutique, menés sur ce site depuis 1976. Chaque domaine est divisé, autant que nécessaire, en compartiments d'étude, tels que l'hydrologie, le phytoplancton, la microbiologie, les larves de crustacés ou les algues macrophytes. Pour chaque compartiment, une série de paramètres, jugés représentatifs de l'évolution de ce compartiment, est étudié. Ainsi, pour le compartiment hydrologique, sont suivis la température et la salinité de l'eau de mer, les concentrations en nutriments minéraux, les composés halogénés et le bore. Les évolutions de ces différents paramètres ont permis d'élaborer les conclusions suivantes. La physiologie des espèces animales et végétales est conditionnée par les changements climatiques. L'examen des paramètres pluviométrie et température de l'air montre que la période 1986/2005 est sensiblement plus humide et plus chaude que la période 1949/2005. Cela se répercute également sur la température de l'eau de mer dont les valeurs moyennes croissent régulièrement.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2006/rapport-6405.pdf
http://archimer.ifremer.fr/doc/00000/6405/

Éditeur(s) : HAL CCSD Association Internationale de Climatologie
Résumé : 6 pages
International audience
This work presents an overview of spatio-temporal quality andspatial density of rainfall networks of Cameroon, Gabon, Congo, CAP and DRC, particularly in the recentperiod (1973-2014) through the GSOD international database. Faced with enormous gaps observed, theseresults will help to select metrological and analytical orientations in FORGREENE project (Tropical forestsgreeness and cloudiness in Central Africa: present conditions and future evolution). A comparison with rainfallsatellite estimates (RFE type) also indicates their great potential, provided they are based on in situ validations.
Ce travail fait un état des lieux de la qualité temporelle et de la densité spatiale des sériespluviométriques du Cameroun, Gabon, Congo, RCA et RDC, en particulier sur la période récente (1973-2014)grâce à la base de données internationale GSOD. Face aux énormes lacunes observées, ces résultats vontpermettre d’orienter les choix métrologiques et analytiques in situ du programme FORGREENE (Tropicalforests greeness and cloudiness in Central Africa: present conditions and future evolution). Une comparaisonavec des estimations satellitaires (de type RFE) indique aussi leur potentiel intéressant, à condition qu’elless’appuient sur des validations in situ.
Climat et pollution de l'air
Besançon, France

hal-01360178
https://hal.archives-ouvertes.fr/hal-01360178

Éditeur(s) : HAL CCSD
Résumé : Report
This activity uses available information on vertical land motion and on global glacier and ice sheet mass balance to make projections of sea-level change (to the year 2100) for Arctic communities and vital infrastructure.
https://hal.archives-ouvertes.fr/hal-00856635

hal-00856635
https://hal.archives-ouvertes.fr/hal-00856635