Éditeur(s) : ACH : Association of Caribbean Historians
Extrait de : 46e colloque de l'Association des historiens de la Caraïbe, du 11 au 15 mai 2014.
Description : En pleine Première Guerre mondiale, les marines envahissent Haïti. Inaugurée en juillet 1915, cette occupation durera 19 ans. La veille de cette invasion, à Port-au-Prince, la légation de France a été prise d'assaut par une foule en colère souhaitant lyncher le chef d'Etat en exercice qui venait de s'y réfugier.
Siècle(s) traité(s) : 20
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V14353
V14353

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Coral bleaching events threaten coral reef habitats globally and cause severe declines of local biodiversity and productivity.Related to high sea surface temperatures (SST), bleaching events are expected to increase as a consequenceof future global warming. However, response to climate change is still uncertain as future low-latitude climatic conditionshave no present-day analogue. Sea surface temperatures during the Eocene epoch were warmer than forecastedchanges for the coming century, and distributions of corals during the Eocene may help to inform models forecastingthe future of coral reefs. We coupled contemporary and Eocene coral occurrences with information on their respectiveclimatic conditions to model the thermal niche of coral reefs and its potential response to projected climate change.We found that under the RCP8.5 climate change scenario, the global suitability for coral reefs may increase up to 16%by 2100, mostly due to improved suitability of higher latitudes. In contrast, in its current range, coral reef suitabilitymay decrease up to 46% by 2100. Reduction in thermal suitability will be most severe in biodiversity hotspots, especiallyin the Indo-Australian Archipelago. Our results suggest that many contemporary hotspots for coral reefs,including those that have been refugia in the past, spatially mismatch with future suitable areas for coral reefs posingchallenges to conservation actions under climate change.
ISSN: 1354-1013

hal-01145464
https://hal.archives-ouvertes.fr/hal-01145464
DOI : 10.1111/gcb.12868

Éditeur(s) : HAL CCSD Wiley
Résumé :  
Aims: Astrocaryum sciophilum (Miq.) Pulle (Arecaceae) is an understorey palm, endemic to north-eastern South America with a patchy distribution. We tested the hypothesis that the spatial distribution of this palm species is not in equilibrium but is slowly colonizing the forest understorey. Location: Inventories and seed dispersal studies were conducted in the undisturbed tropical forest close to the Nouragues research station, French Guiana. Additional data were collected in the entire territory of French Guiana. Methods: We studied the demography of A. sciophilum on a 20-ha plot located at the edge of its distribution. The age of the palms was estimated by postulating an exponentially decreasing abundance by age class. Direct seed dispersal experiments were also conducted, to estimate dispersal parameters. The seeds of A. sciophilum were dispersed only by rodents. This information was used to parameterize a forest growth simulator, to study the spatial spread of this species. Results: Within the sampling plot, the density of A. sciophilum dropped sharply from about 500 individuals per hectare to zero. The maturation age was estimated to be 170 ± 70 years, and over 55 years with 95% confidence. Seed-dispersal experiments yielded an average seed dispersal distance of 11 m and a maximum estimated dispersal distance of 125 m across a generational span of 55 years to maturity. Therefore, the maximal estimated colonization speed is 2.3 m/y. Conclusions: Empirical results and numerical simulations suggest that the boundary of the A. sciophilum population is a colonization front, and that the range of this species is slowly expanding. The implications of this result in respect of palaeoenvironmental changes in this region are discussed.
ISSN: 1466-822X

hal-01032154
https://hal.archives-ouvertes.fr/hal-01032154
DOI : 10.1046/j.1466-822X.2003.00020.x

Éditeur(s) : ECMEA : Etudes Croisées des Mondes Européens et Américains CRILLASH : Centre de Recherches Interdisciplinaires en Lettres, Langues, Arts et Sciences Humaines
Extrait de : "Terres promises, représentations et imaginaires" : colloque, du 25 au 27 novembre 2015. Université des Antilles
Description : La relation entre terre promise et engagisme est une donnée importante dans le cadre de la colonisation française. Notre approche permet de comprendre l'importance de la volonté d'appropriation foncière et les expériences esclavagistes vécue par les engagés dans les petites Antilles Française entre 1626 et 1715, de la Compagnie de Sainte-Christophe à la mort de Louis XIV. À ses débuts, la colonisation française dans les Antilles se fit avec des vagues de migrants européens issus en majorité de l'allouage et connus sous le terme d'engagés. Pourquoi parler d'une terre promise pour des hommes sous contrat ? La Thématique de la terre promise présente des aspects particuliers : l'un se basait sur la puissance de l'Église catholique à travers une littérature missionnaire décrivant une forme d'âge d'or ; l'autre sur l'idée d'une terre de rédemption pour les « inadaptés » de la société française de l'époque. Ces aspects étayèrent les approches d'un renouveau spirituel, social, économique, moral et matériel sous la conduite des autorités publiques et religieuses. Une autre perception est celle de la vision des réformés français persécutés. Afin de rejoindre les refuges américains, il fallait passer par l'exil pour atteindre ces terres synonymes de liberté puis utiliser les interlopes.
Siècle(s) traité(s) : 17
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V16219
V16219

Éditeur(s) : Vertigo
Résumé : Submersible exploration of the deep-sea floor during the last decades revealed new insights in this part of our planet with the discovery of an unsuspected diversity of ecosystems. Coral reefs, confined in our mind to warm and shallow tropical waters, have been observed at several hundreds meter depth along continental margins. Like their tropical counterparts, cold water corals are home for several invertebrate and fish species. The diversity and complexity of this rich ecosystem has just started to be studied. Documented and potential treats by human activities including bottom fishing and petroleum industry activities have to be considered and there is an urgent need to prevent further degradation of these vulnerable reefs. The objective of the CARACOLE cruise, lead by Ifremer and gathering geologists and biologists of several European countries, was to explore by robotic submersible several coral mounds off Ireland. This new approach revealed the real extent of the coral colonies, the diversity of the associated fauna and helped to test hypotheses to understand the mound formation.
L'exploration des fonds océaniques, notamment à l'aide des submersibles, a apporté ces dernières décennies un nouvel éclairage sur cette partie du globe, avec la découverte d'une diversité d'écosystèmes jusque là insoupçonnée. Des massifs de coraux, surtout connus des eaux chaudes et peu profondes des régions tropicales se développent à plusieurs centaines de mètres de profondeur le long des marges continentales. Ils servent de substrat, de refuge et de nourriture à de nombreux invertébrés et poissons, et sont à l'origine d'un écosystème riche dont la diversité et la complexité commencent tout juste à être étudiées. Malgré leur profondeur, ils sont soumis à l'impact des activités humaines, notamment la pêche par chalut qui a déjà détruit certains de ces "récifs" mais aussi la menace potentielle de l'exploration pétrolière. La campagne CARACOLE, menée par l'Ifremer et regroupant des géologues et biologistes européens spécialistes de ces milieux, avait pour objectif la prospection par submersible filoguidé de plusieurs monts de coraux au large de l'Irlande. Elle a permis d'évaluer l'étendue des colonies de coraux, de caractériser la faune associée et de tester différentes hypothèses pour expliquer leur formation.
Vertigo (Vertigo), 2004-12 , Vol. 5 , N. 3

Droits : 2004 Vertigo
http://archimer.ifremer.fr/doc/2004/publication-2364.pdf
http://archimer.ifremer.fr/doc/00000/2364/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Le territoire d’Aysen, au sud du Chili, officiellement dénommé « Région XI », possède le charme discret d’une Patagonie oubliée. Cette région mythique n’a cessé de hanter l’imaginaire fécond des découvreurs et voyageurs en tout genre. Aujourd’hui, ces derniers sont autant des pêcheurs à la mouche fortunés que des routards européens ou israéliens, et de plus en plus des Chiliens venus des classes moyennes et du nord du pays. La Patagonie est un formidable terrain de jeu, et plus encore un vaste espace d’utopie, hier comme aujourd’hui, pour nombre de voyageurs et rêveurs.Le « charme » est indéniable, il suffit de contempler la nature qui domine ici la culture, et la région n’est pas un paradis pour les photographes par hasard ; quant au caractère « discret », il est également évident, comme en témoignent de nombreux touristes en quête de leur propre expérience “into the wild” et qui s’émerveillent en foulant ces sentiers non battus de la Patagonie. Terre de jeu pour aventuriers, lieu de science pour les chercheurs, espace de refuge pour de riches expatriés, territoire d’expérimentation sinon de rite de passage pour quelques jeunes et sportifs, marcheurs, cyclistes ou flâneurs, la Patagonie chilienne est désormais surtout devenue un enjeu, économique et donc politique, essentiel pour le pays.Cet article, fruit d’un travail en cours, apporte quelques éléments pour tenter de comprendre comment se fabrique et s’établit, dans le temps et dans l’espace, « une destination non touristique » qui, depuis ces dernières années, à la faveur des médias, mais pas seulement, a le vent en poupe. Avec ou sans le consentement des Patagons/Patagoniens ? C’est tout le véritable défi à venir.
The territory of Aysen in southern Chile, officially called "Region XI" has the discreet charm of a forgotten Patagonia. This legendary region has haunted the fertile imagination of explorers and travelers of all kinds. Today, they are so many rich fly fishermen that European or Israeli backpackers, and always more Chileans coming from the middle class and from the north of the country. Patagonia is a wonderful playground, and even more a vast space of utopia, then as now, for many travelers and dreamers.The "charm" is undeniable, simply contemplate the fabulous nature clearly dominating culture here, and the area is not a paradise for photographers by chance. As to the character "discrete", it is also clear, as evidenced by many tourists in search of their own experience "into the wild" and marvel treading the beaten path not of Patagonia. Playground for adventurers, place of science for researchers, refuge area for fortunate expatriates testing ground if not some rite of passage for young athletes, walkers, cyclists or loafers, Chilean Patagonia is now mostly become an issue, and therefore economic policy, rather essential for the country.This article, the first result of a work in progress, brings some elements to try to understand how to manufacture and settled in time and space, "a non-tourist destination", which, in recent years, the for the media but not only has the wind in its sails. With or without the consent of all the habitants of Patagonia? This is the real challenge ahead.
Chili

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.7402
http://journals.openedition.org/etudescaribeennes/7402

Résumé : Ce travail fait suite à la publication du premier volume « Etude de la crise de la pêche de la crevette en Guyane » (Lampert, 2011). Dans ce premier volume nous avons répondu à la première question qui se posait : « la crise de la crevette est-elle due à la pêche elle-même ? ». Nous avons pu répondre par la négative, laissant la porte ouverte à des hypothèses environnementales et trophiques. Facteurs environnementaux La piste des facteurs environnementaux est liée aux changements climatiques, pérennes ou cycliques. L’augmentation de la température de surface de la mer, les changements dans le régime des vents, de la houle et la salinité, la relation qu’il peut y avoir entre le recrutement et les précipitations locales, les débits des fleuves guyanais ou de l’Amazone. Sans oublier les indicateurs climatiques à grande échelle tels que la Southern Ocillation Index (SOI) et la Northern Oscillation Index (NOI) (Santamaría-del-Ángel et al. 2011 ; Aragon-Noriega et Alcántara-Razo 2005 ; Parsons et Lear 2001 ; Serge Garcia et Le Reste 1981 ; S. Garcia 1988 ; Saoud et Davis 2003 ; Rivierre 2007 ; Leal-Gaxiola et al. 2001 ; Li et Clarke 2005 ; Lee 2004 ; Ouellet, Savard, et Larouche 2007). Facteurs trophiques La crevette étant l’une des proies préférées des poissons de Guyane, nous avons avancé dans le premier volume l’hypothèse d’un impact trophique suite à la pression de la pêche au vivaneau. De l’autre coté du réseau trophique, il reste à explorer la piste des changements dans l’abondance phytoplanctonique, qui constitue l’essentiel de l’alimentation des larves de crevette. Un changement significatif dans leur source de nourriture pourrait avoir des conséquences dans leur recrutement. Il en va de même pour l’évolution de la mangrove en biomasse, qui fournit matière organique et refuge pour les larves (Anderson 2000 ; Fuentes-Yaco et al. 2007 ; D. G. Parsons et Colburne 2000 ; Santamaría-Miranda et al. 2005). Les données collectées sont présentées dans la première partie de ce document avec une étude de chaque paramètre et le choix du meilleur indicateur. Dans la deuxième partie nous abordons un premier traitement de ces données afin d’évaluer leur pertinence dans les relations qui peuvent exister avec les valeurs des recrutements de crevettes. Une étude plus exhaustive sera menée dans un prochain volume où seront ajoutés des paramètres tels que les concentrations en chlorophylle, en matières en suspension ou des matières organiques dissoutes. Ce deuxième volume est réalisé dans le cadre du marché ouvert par la Direction des Pêches Maritimes et de l’Agriculture (DPMA) « Marché DPMA 2012-021 », intitulé : Etude portant sur l’effet du changement climatique et/ou du réseau trophique sur le stock guyanais des crevettes pénéïdes. Il constitue le rapport intermédiaire du marché. Dans le troisième volume pourra être abordé l’étude liée au réseau trophique par les analyses des contenus stomacaux des vivaneaux, par les séries de données de biomasse phytoplanctonique (images satellite) et de son paramètre « chlorophylle » et par l’évolution temporelle de la biomasse de la mangrove. La piste de la dérive des oeufs et larves de crevettes depuis les côtes brésiliennes pourra également être explorée si le modèle de courants de surface venait à être opérationnel en 2013. Il permettrait d’avoir des cartes de courants et vitesses de surface permettant de valider l’hypothèse émise dans le volume 1.

Droits : 2013 Ifremer
http://archimer.ifremer.fr/doc/00137/24844/22928.pdf
http://archimer.ifremer.fr/doc/00137/24844/

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
AimThe global biodiversity crisis requires the identification of regions with high evolutionary potential, i.e. evolutionary hotspots (evospots). We created an analytical framework based on comparative phylogeography and coalescent methods to assess the dynamics of diversification and population persistence in the reef ecosystem of a little-studied region: the Southwestern Indian Ocean (SWIO).LocationCoral reefs of the SWIO, with comparative data from the Pacific Ocean.MethodsWe generated sequences of mitochondrial DNA (COI and 16S) for 10 widespread brittle-stars (345 specimens) from 21 localities (8 in the SWIO). We analysed them by combining comparative phylogeography approaches, coalescent-based methods, molecular clocks and the concept of evolutionarily significant units (ESUs) to draw conclusions about the drivers of biodiversity in the region.ResultsCryptic diversity was prevalent, increasing lineage diversity within the 10 nominal species by 70% within the SWIO and by 200% across the Indo-West Pacific. All seven new SWIO lineages meet the criteria for ESUs and at least six are biological species. We detected likely intraregional diversifications dating to the Plio-Pleistocene, supporting the SWIO as a generator of biodiversity. Geographical restriction of ESUs, long coalescent times (> 80 ka) and old in situ diversification (> 1 Ma) point to the persistence of populations over multiple glacio-eustatic cycles. We provide data suggesting demographic expansion during sea-level high stands. Regional connectivity was lower, and cryptic differentiation higher in lecithotrophs than in planktotrophs.Main conclusionsThe analytical framework based on a biodiversity survey makes it possible to identify evospots by assessing the potential of a region to maintain and generate biodiversity and by evaluating the evolutionary processes and potential drivers at play.
ISSN: 0305-0270

hal-01369697
http://hal.univ-reunion.fr/hal-01369697
DOI : 10.1111/jbi.12155

Éditeur(s) : HAL CCSD PeerJ
Résumé : International audience
Acoustic recording has been recognized as a valuable tool for non-intrusive monitoring of the marine environment, complementing traditional visual surveys. Acoustic surveys conducted on coral ecosystems have so far been restricted to barrier reefs and to shallow depths (10–30 m). Since they may provide refuge for coral reef organisms, the monitoring of outer reef slopes and describing of the soundscapes of deeper environment could provide insights into the characteristics of different biotopes of coral ecosystems. In this study, the acoustic features of four different habitats, with different topographies and substrates, located at different depths from 10 to 100 m, were recorded during daytime on the outer reef slope of the north Coast of Moorea Island (French Polynesia). Barrier reefs appeared to be the noisiest habitats whereas the average sound levels at other habitats decreased with their distance from the reef and with increasing depth. However, sound levels were higher than expected by propagation models, supporting that these habitats possess their own sound sources. While reef sounds are known to attract marine larvae, sounds from deeper habitats may then also have a non-negligible attractive potential, coming into play before the reef itself.
ISSN: 2167-8359

Droits : http://creativecommons.org/licenses/by/
hal-01654685
http://hal.upmc.fr/hal-01654685
http://hal.upmc.fr/hal-01654685/document
http://hal.upmc.fr/hal-01654685/file/peerj-4019.pdf
DOI : 10.7717/peerj.4019

Résumé : En Août 2005, l'ouragan Katrina s'est abattu sur la ville de la Nouvelle-Orléans, en Louisiane causant mort, désespoir, angoisse mais aussi destruction massive. Katrina a forcé une partie de la population affectée à déménager, et à chercher refuge dans les états voisins. Face aux premières images de l'une des pires catastrophes des Etats-Unis, la prépondérance des AfricainsAméricains parmi les victimes a été choquante. Katrina a révélé au monde entier et a mis sous les projecteurs la persistance de l'esclavage, du racisme et des inégalités raciales. Les AfricainsAméricains ont dû s'organiser seuls au Superdome et au Convention Center pour sur/vivre. Ce travail de recherche analyse le lien étroit qui existe entre les notions de «race» de classe et la géographie. Nous examinerons les concepts hautement controversés de « refugiés » et de « pilleurs» dans le contexte américain. Nous chercherons à comprendre comment l'histoire et le racisme peuvent influencer les comportements et les décisions politiques. Etait-ce une catastrophe naturelle, un désastre créé par l'humain ou une crise héritée de legs culturels? La culture et la race ont été les facteurs principaux de cette tragédie. Nous traiterons de cette catastrophe non pas comme un simple phénomène cyclonique mais comme un évènement culturel. La culture a successivement condamné et sauvé les Africains-Américains en 2005. Le jazz, le blues et le hip-hop ont été de véritables atouts suite à Katrina. Les Africains-Américains ont utilisé ces genres musicaux afin d'exprimer leur chagrin et colère. L'écriture est devenue une véritable thérapie assimilée à une catharsis. Grâce à cela, ils ont pu dire non à une annihilation programmée
In August 2005, hurricane Katrina made landfall on the city of New-Orleans, Louisiana causing not only death, despair, anguish but also massive destruction and subsequent relocation. As the catastrophe made headlines worldwide, people were shocked by the overwhelming preponderance of the African American poor among those stranded within the city. Many explained the disproportion as a result of continual neglect. The devastation left by Katrina brought to light the enduring legacy of slavery, racism and racial inequality. African Americans were left alone to fend for themselves at the Superdome and at the Convention Center. This doctoral research provides an insight into the correlation between race, class and geography. We will explore the highly controversial concepts of "the refuge(s)" and "looters" in the US context. We will try to figure out how history and cultural racism influence behaviors and political decisions. Was Katrina a natural catastrophe, a man-made disaster or a cultural crisis? Besides race, culture seems to be a major component in this tragedy. We delve into this analysis from the framework of cultural studies. On the one hand, culture condemned African-Americans in 2005, but on the other hand, it put them out of harm's way. Jazz, blues and hip-hop became serious assets in the aftermath of hurricane Katrina. African-Americans used these musical genres to express grief and anger. They used writing as a powerful tool to recover from Katrina. Jazz, blues and hip-hop proved to be synonymous with catharsis

http://www.theses.fr/2013AGUY0667

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
Understanding the distribution of genetic diversity in the light of past demographic events linked with climatic shifts will help to forecast evolutionary trajectories of ecosystems within the current context of climate change. In this study, mitochondrial sequences and microsatellite loci were analysed using traditional population genetic approaches together with Bayesian dating and the more recent approximate Bayesian computation scenario testing. The genetic structure and demographic history of a commercial fish, the black scorpionfish, Scorpaena porcus, was investigated throughout the Mediterranean and Black Seas. The results suggest that the species recently underwent population expansions, in both seas, likely concomitant with the warming period following the Last Glacial Maximum, 20 000 years ago. A weak contemporaneous genetic differentiation was identified between the Black Sea and the Mediterranean Sea. However, the genetic diversity was similar for populations of the two seas, suggesting a high number of colonizers entered the Black Sea during the interglacial period and/or the presence of a refugial population in the Black Sea during the glacial period. Finally, within seas, an east/west genetic differentiation in the Adriatic seems to prevail, whereas the Black Sea does not show any structured spatial genetic pattern of its population. Overall, these results suggest that the Black Sea is not that isolated from the Mediterranean, and both seas revealed similar evolutionary patterns related to climate change and changes in sea level.
ISSN: 1471-8278

hal-01330323
https://hal-univ-perp.archives-ouvertes.fr/hal-01330323
DOI : 10.1111/mec.13616

Éditeur(s) : HAL CCSD
Résumé : Les populations envahissantes sont généralement confrontées à un monde hétérogène où les conditions abiotiques, la distribution et la disponibilité en ressource et les densités d’espèces natives varient à la fois dans le temps et dans l’espace. Une telle hétérogénéité environmentale peut jouer un rôle décisif dans le succès d’établissement et sur la vitesse d’expansion d’une invasion. Des capacités de dispersion dans le temps et dans l’espace sont attendues pour permettre aux populations envahissantes de faire face à ces contraintes. Les Hyménoptères spécialistes des graines du genre Megastigmus (Torymidae) sont des modèles invasifs intéressants parce-qu’ils exploitent des populations d’arbres qui sont réparties en patchs discontinus dans le paysage et qui montrent des variations inter-annuelles synchronisées et de forte amplitude dans la production de graines (masting). Nous nous sommes intéressés à l’invasion récente des forêts de cèdre de l’Atlas du sud-est de la France par M. schimitscheki, qui montre de fortes propensions à : (i) la dispersion passive par le vent (dispersion spatiale), et (ii) la diapause prolongée, une forme de dormance larvaire pouvant durer de 3 à 5 années consécutives (dispersion temporelle). Dans un premier temps, nous montrons que, malgré une distribution très fragmentée de son hôte obligatoire à l’échelle du paysage, M. schimitscheki a pu envahir la quasi-totalité des cédraies de la région PACA par des évènements de dispersion à longue distance depuis sa zone d’introduction, à la faveur d’un vent régional dominant (le Mistral). Dans un second temps, nous montrons que, à l’échelle d’une population, la diapause prolongée peut constituer un refuge temporel démographique et génétique pour des cohortes soumises aux variations extrêmes de disponibilité en ressources, qui résultent du masting de leur hôte obligatoire.
Colloque de lancement du GdR ‘Invasions Biologiques’
Rennes, France

hal-01601706
https://hal.archives-ouvertes.fr/hal-01601706
PRODINRA : 404855

Éditeur(s) : HAL CCSD Wiley
Résumé :  
The chloroplast genome has been widely used to describe genetic diversity in plant species. Its maternal inheritance in numerous angiosperm species and low mutation rate are suitable characters when inferring historical events such as possible recolonization routes. Here we have studied chloroplast DNA variation using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) with seven pairs of primers and four restriction enzymes in 14 populations of Vouacapoua americana (Caesalpiniaceae) a neotropical tree sampled throughout French Guiana. Population diversity (Hs), total gene diversity (Ht) and differentiation among populations (GST) were estimated using Nei's method as 0.09, 0.87 and 0.89, respectively. This is consistent with the limited gene flow associated with synzoochory in this species. The genetic structure observed in the north of French Guiana suggests that historical events such as contractions and recent recolonizations have had a large impact on the distribution of genetic diversity in this species.
ISSN: 0962-1083

hal-01032176
https://hal.archives-ouvertes.fr/hal-01032176
DOI : 10.1046/j.1365-294x.2000.01027.x

Éditeur(s) : HAL CCSD Thai Society of Higher Education Institutes on Environment
Résumé : International audience
Due to the high level of endemic species that they support and the high threats they are facing, such as unsustainable limestone quarrying, hunting and urbanization, limestone karsts are recognized as biodiversity hotspots needing urgent protection. The first aim of our study was to investigate the mammal rodent diversity of Thai limestone karsts. Our second aim was to examine the diversity at a finer scale than the species level (intraspecific biodiversity) using phylogeographic approaches. Therefore, we studied the phylogeographic structure of a threatened rodent, endemic to limestone karsts of Thailand, the Murinae Leopoldamys neilli. We sampled 76 limestone karsts in whole Thailand and live-trapped 444 rodents including 115 Leopoldamys neilli. Our study revealed an important rodent diversity in Thai limestone karsts. Besides endemic rodent species, karsts also host typical forest species to which they provide forest refugia in deforested regions. At the intraspecific level, our study revealed an unexpected high level of genetic differentiation within the rodent species L. neilli. As each limestone area of Thailand is characterized by a particular genetic lineage of L. neilli, the destruction of these karsts would lead to the disappearance of unique intraspecific strains not found elsewhere. Our results highlight the importance of protecting limestone habitats to preserve not only their interspecific but also intraspecific rodent diversity that is highly threatened as more than 20% of limestone karsts in Thailand have already been quarried. Management plans of limestone, a non-renewable resource, should urgently take into account this high biological importance of karsts.
The 1st EnvironmentAsia International Conference on "Environmental Supporting in Food and Energy Security: Crisis and Opportunity"
Bangkok, Thailand

ird-00714455
http://hal.ird.fr/ird-00714455
http://hal.ird.fr/ird-00714455/document
IRD : fdi:010056152

Éditeur(s) : HAL CCSD Wiley
Résumé : The routes through which Norway spruce recolonized the Alps after the last ice age were investigated at the genetic level. Seven populations along the Alpine range plus one Apennine population were characterized for seven sequence-characterized amplified region (SCAR) loci, detecting an overall FST = 0.118. This rather high value for forest species reflects an uneven distribution of genetic variability, and was analysed through different statistical methods. Alternative hypotheses were tested under the isolation-by-distance model and using the analysis of molecular variance (amova) frame. We conclude that the hypothesis of the existence of a glacial refugium in the Apennines should be rejected, while a putative relict population is identified in the Maritime Alps. The Alpine range of Norway spruce appears to be split in two parts across a north-south line. The results are discussed in comparison with data based on morphological markers, isozymes, chloroplast microsatellites and mitochondrial markers.
ISSN: 0962-1083

hal-01031243
https://hal.archives-ouvertes.fr/hal-01031243
DOI : 10.1046/j.1365-294x.2000.00911.x

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Studies focusing on the effect of invasive species on the genetic diversity of native marine invertebrates remain scant. Here we report diversity among French populations of the intertidal gastropod Ocenebra erinacea (Linnaeus, 1758) sampled in the presence and absence of the invasive Ocenebra inornata (Recluz, 1851). Between 1999 and 2004, a total of 352 individuals of O. erinacea was collected from 15 sites, five of which had the invasive present, and genotyped at the mitochondrial locus cox1. No statistical difference was observed between polymorphism levels recorded within native populations exposed to the invasive, compared with populations sampled in the absence of O. inornata. No sign of native population decline was detected in response to the invader. While significant shifts in native O. erinacea population sizes have previously been reported in the literature, genetic effects may take longer to accumulate, or may be undetectable without a larger panel of genetic markers. By contrast, large genetic distances and significant population differentiation were recorded between Atlantic and Mediterranean O. erinacea samples, suggesting that these populations have distinct evolutionary histories. Comparison of genetic divergence within the closely related genus Nucella suggests that the Atlantic populations of O. erinacea and those from Thau Lagoon in the Mediterranean may belong to different species or subspecies.
ISSN: 0173-9565

hal-01064464
https://hal.archives-ouvertes.fr/hal-01064464
https://hal.archives-ouvertes.fr/hal-01064464/document
https://hal.archives-ouvertes.fr/hal-01064464/file/Ocenebra_revision_submission_to_MarEcol.pdf
DOI : 10.1111/maec.12208

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Le Bénin, pays de l’Afrique de l’Ouest est confronté à la destruction des terres humides particulièrement dans la partie sud du pays. Les terres humides riches biodiversité sont importantes tant pour les humains que pour milieu naturel. La menace la plus importante est la pression de l’anthropique. Même si ce territoire est reconnu par la Convention Ramsar, la destruction continue. En 1995 le gouvernement a décidé de créer une aire de gestion communautaire pour ces territoires. L’objectif de cette recherche est de comprendre les grands défis liés à la mise en œuvre de la gestion communautaire des milieux humides à travers une étude de cas, en l’occurrence celui de la vallée du Sitatunga. Pour atteindre cet objectif, un séjour de 3 mois a été effectué sur le site. Des entrevues semi-dirigées ont été alors réalisées. Les résultats montrent que la vallée du Sitatunga est considérée comme inutile, voire nuisible, par les populations riveraines rencontrées dans le cadre de l’étude, qui sont davantage préoccupées à se sortir de leur état de pauvreté. Les traditions et valeurs autrefois attribuées à la conservation des milieux humides ont quasiment disparu et l’individualisme est grandissant. Il importe de tenir compte de tous ces facteurs pour espérer véritablement préserver ces milieux. D’un autre côté, parlant de gestion de l’environnement et plus particulièrement de gestion des milieux humides à l’échelle béninoise, le constat n’est pas reluisant. En effet, l’État étant donné son état de sous-développement et donc de manque de ressources, à du mal à coordonner ces activités. Il est de même pour les ONG. La situation est accentuée par l’état des relations entre ONG et structures de l’État qui se considèrent davantage comme des adversaires que comme des partenaires ce qui affecte l’efficacité des activités menées. Pour que la gestion communautaire devienne une réalité, il importe qu’un partenariat soit établi entre les différents acteurs liés à la gestion de la vallée du Sitatunga en particulier et des milieux humides en général : les ONG, l’État et les communautés locales.
Bénin, a country in West Africa is actually facing the destruction of its wetlands, especially those in the southern part of the country. The wetlands which their richness in natural resources are important for both human and wildlife are also threatened by many factors. The most important threat is population pressure. Although recognised as Ramsar sites, the destruction continues. In 1995, the Government has decided to create community protected areas in this part of the country. The objective of this research is to understand the main challenges around the community management of wetlands. The case of the Sitatunga valley, in south Bénin has been studied. The methodology used consisted on interviews with stakeholders during a period of 3 months. The results show that, although the good intentions of community management, its practical application is not easy, and reveal many difficulties in its practical application. The site although rich in biodiversity and used as refuge for several species, is regarded as useless even harmful by the bordering populations, which are more worried by their poverty state. The traditions and values formerly allotted to the wetlands almost disappeared and individualism is growing. It is important to take into account all these factors to truly hope to preserve these wetlands. The study shows that management of the wetlands on a Beninese scale is also difficult. Indeed, the government through its structures struggles to coordinate its activities. It is the same for NGOs. The situation is accentuated by the poor relations between NGOs and government institutions which consider each other more as adversaries than as partners. This affects the effectiveness of the undertaken activities. It is then important for all the stakeholders (NGOs, Government and local communities) to install a partnership to help achieve community management objectives.
Bénin

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.3630
http://journals.openedition.org/etudescaribeennes/3630

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Ecological signs of Earth's biosphere forewarn an alarming trajectory towards a global mass-extinction. Assessing species performance and susceptibilities to decline is essential to comprehend and reverse this trend. Yet it is challenging, given difficulties associated with quantifying individual and population processes that are variable across time, space, and life-stages. We describe a new approach to estimating and comparing species performances that combines empirical data, a novel theoretical consideration of population dynamics, and modern statistics. Our approach allows for a more realistic continuous representation of individual performances along development stages while taking into account non-linearity, and natural variability as captured by spatio-temporally replicated observations. We illustrate its application in a coral meta-assemblage composed of populations of the three major reef-building taxa Acropora, Pocillopora, Porites. Using a unique set of highly replicated observations of individual coral dynamics under various environmental conditions, we show how taxa differ in their investment in recruitment and size-specific aptitude for growth and survival, notably through different use of clonal shrinkage, fragmentation, fission, and fusion processes. Our results reveal contrasting life-history trade-offs among taxa which, along with differing patterns of density-dependent recruitment, modulate species responses to decline. These differences in coral life history traits reflect opposing life-strategies, imply regulation at differing life-stages, and explain divergence in species trajectories. Our findings indicate a high potential for resilience in Pocillopora and Porites populations, thanks respectively to a sustained recruitment that promotes demographic elasticity through replacement of individuals, and a steady resistance to mortality which confers persistence through lingering of individuals. Resilience in Acropora appears more arbitrary, given high susceptibility to perturbations and dependency of recruitment on presence of established local populations. We identify management actions that can complement Acropora's life history and benefit recovery of its populations following mortality events. Our regression-modelling approach to quantifying and comparing species performances in different population processes is applicable to all taxa, as illustrated even those with complex clonal life histories, and can be implemented at wide spatio-temporal and taxonomic coverage. It can promote more accurate representation of species dynamics in both descriptive and predictive modelling approaches. The semi-parametric contrast curve method we develop facilitates comparing response variables along continuous explicative metrics while accounting for multiple sources of complexity in empirical data. It should widely benefit investigations in ecology and quantitative science.
ISSN: 1476-945X

hal-01212337
https://hal-univ-perp.archives-ouvertes.fr/hal-01212337
DOI : 10.1016/j.ecocom.2015.07.003

Éditeur(s) : HAL CCSD Elsevier
Résumé : URL de l'article : http://www.sciencedirect.com/science/article/B6WPN-4XY3KDK-2/2/fd8508af63d82e29b4f9829c65194e26
The impact of climatic changes that occurred during the last glacial maximum and the Holocene on vegetation changes in the Amazon Basin and the Guiana Shield are still widely debated. The aim of our study was to investigate whether major changes in vegetation (i.e. transitions between rainforests and C4 savannas) occurred in northern French Guiana during the Holocene. We measured variations in the δ13C of soil organic matter at eight sites now occupied by forest or savannah. The forest sites were selected to cover two regions (forest refugia and peneplains) which are thought to have experienced different intensities of disturbance during the latest Pleistocene and the Holocene. We found that none of the forest sites underwent major disturbances during the Holocene, i.e. they were not replaced by C4 savannahs or C4 forest savannahs for long periods. Our results thus suggest that tropical rainforests in northern French Guiana were resilient to drier climatic conditions during the Holocene. Nevertheless, geographical and vertical variations in the 13C of SOM were compatible with minor changes in vegetation, variations in soil processes or in soil physical properties.
ISSN: 0033-5894

halshs-00551758
https://halshs.archives-ouvertes.fr/halshs-00551758
DOI : 10.1016/j.yqres.2009.11.007

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
High 3He/4He ratios in some basalts have generally been interpreted as originating in an incompletely degassed lower-mantle source1, 2, 3, 4, 5, 6, 7, 8, 9. This helium source may have been isolated at the core-mantle boundary region since Earth's accretion4, 5, 6. Alternatively, it may have taken part in whole-mantle convection and crust production over the age of the Earth7, 8, 9; if so, it is now either a primitive refugium at the core-mantle boundary8 or is distributed throughout the lower mantle7, 9. Here we constrain the problem using lavas from Baffin Island, West Greenland, the Ontong Java Plateau, Isla Gorgona and Fernandina (Galapagos). Olivine phenocryst compositions show that these lavas originated from a peridotite source that was about 20 per cent higher in nickel content than in the modern mid-ocean-ridge basalt source. Where data are available, these lavas also have high 3He/4He. We propose that a less-degassed nickel-rich source formed by core-mantle interaction during the crystallization of a melt-rich layer or basal magma ocean5, 6, and that this source continues to be sampled by mantle plumes. The spatial distribution of this source may be constrained by nickel partitioning experiments at the pressures of the core-mantle boundary.
ISSN: 0028-0836

hal-00941025
https://hal.archives-ouvertes.fr/hal-00941025
DOI : 10.1038/nature11771