HAL Portal UPF (Université de la Polynésie française)
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Les importateurs brûleront-ils en Enfer ?
No full textArticle en ligne de vulgarisation scientifique, disponible sur : https://www.pacific-pirates-media.com/les-importateurs-bruleront-ils-en-enfer/Les importations sont mal aimées et le phénomène ne date pas d’hier. Il a toujours été au cœur des programmes politiques prônant une forme de repli sur soi. Il est notamment au cœur de la pensée anti-marché. La crise Covid, ces dernières années, en a été un renfort sensible. Elle a rapidement fait émerger le fantasme du « monde d’après » : le choc de la crise allait enfin faire comprendre qu’il fallait « relocaliser » les industries ; il en allait de la sauvegarde de la souveraineté des pays ou territoires. Au passage, ce même choc allait enfin déciller le consommateur jusqu’ici aveuglé et c’est de plein gré (« de son plein gré » me dicte un petit vélo tournant dans mon cerveau) qu’il changerait naturellement et béatement de comportement, pour son plus grand bien et celui de tous.Les économistes écoutaient ce mantra de l’époque avec un intérêt distant : cette mode durerait moins longtemps que celle des pin’s (si, si, souvenez-vous). Car l’économiste – et je m’en excuse d’avance auprès d’éventuels collègues qui se sentiraient choqués – est stupidement rationnel. Bien entendu, l’agent économique peut modifier ses choix, et notamment lorsque les informations dont il dispose évoluent (son « ensemble d’information », dit-on dans nos modélisations théoriques). Mais en l’occurrence, on ne voyait pas bien comment les économies de marché pouvaient être mises en cause dans la crise et ses conséquences. Les impacts les plus violents que nous avons subis ont précisément été le fait d’un arrêt brutal – et volontaire, c’est-à-dire politique – des libertés économiques. Il était donc probable que l’horizon à nouveau éclairci, les comportements anciens s’affirment de plus belle (au sens où un phénomène de « rattrapage » était prévisible). L’explosion des déplacements touristiques post-Covid en est un bel exemple (y compris à l’Autorité polynésienne de la concurrence, mais un article dédié serait sans doute nécessaire).Quoi qu’il en soit, la mode semble être à fustiger les importations, sans nécessairement de cohérence globale. On y trouve en effet un peu toutes les justifications, parfois contradictoires, un peu à l’image d’une auberge espagnole où chacun n’aurait que ce qu’il apporte : défense de l’environnement, lutte contre le consumérisme, défense des produits domestiques, ancrage culturel, « nationalisme » (ou « patriotisme », notamment « économique »), soutien à l’emploi local, rejet de la « mondialisation » (ou « globalisation »).Il ne paraît pourtant pas inintéressant de revenir aux fondamentaux en se demandant pourquoi nous importons. Lorsqu’on comprend pourquoi un individu agit d’une certaine façon, on favorise la lecture de ce qu’il fera par la suite. Cette recherche de la rationalité des choix – fût-elle limitée – est notamment à la base de la microéconomie (et d’une certaine façon de la science criminelle).Article disponible à l'adresse :https://www.pacific-pirates-media.com/les-importateurs-bruleront-ils-en-enfer
Modeling long‐distance seed dispersal of the invasive tree Spathodea campanulata in the Society Islands
No full textInternational audienceLong‐distance dispersal is a key factor explaining the success of invasive alien species, particularly across oceanic islands. However, it is often not feasible to reliably measure long‐distance seed dispersal (LDD) over many kilometers in the field. Here, we used a three‐dimensional kinematic trajectory model (Computing Atmospheric Trajectory tool [CAT]) initiated on the basis of regional wind field data to assess the potential for LDD of a wind‐dispersed invasive tree, Spathodea campanulata (African tulip tree), across the Society Islands (French Polynesia, South Pacific Ocean) following its initial planting and spread on the island of Tahiti. The main objective of our study was to determine whether S. campanulata could be expected to spread naturally among islands. Atmospheric dynamics, seed terminal velocity, precipitation, and temperature of air masses were considered to assess the potential for LDD between oceanic islands, with the island of Tahiti serving as the island source for multiple, geographically distant invasions. Aerial trajectories of modeled S. campanulata seeds indicated that wind‐dispersed seeds originating from trees on the island of Tahiti could reach most of the Society Islands and disperse as far as 1364 km. This result suggests that Spathodea can be expected to spread naturally among the Society Islands. When rainfall events were modeled as causal agents of seed settlement, fewer seeds reached distant islands, but more seeds settled on the closest island (20 km away). Including effects of island topography (“barrier effects”) also resulted in more seeds settling on the closest island and fewer seeds reaching the most distant islands. Overall, our findings suggest that recent atmospheric models can provide valuable insights into LDD and invasion patterns of wind‐dispersed invasive species
Effects of Madagascar marine reserves on juvenile and adult coral abundance, and the implication for population regulation
No full textInternational audienceRecruitment is a critical component in the dynamics of coral assemblages, and a key question is to determine the degree to which spatial heterogeneity of adults is influenced by pre-vs. post-settlement processes. We analyzed the density of juvenile and adult corals among 18 stations located at three regions around Madagascar, and examined the effects of Marine Protected Areas (MPAs). Our survey did not detect a positive effect of MPAs on juveniles, except for Porites at the study scale. The MPA effect was more pronounced for adults, notably for Acropora, Montipora, Seriatopora, and Porites at the regional scale. For most dominant genera, densities of juveniles and adults were positively correlated at the study scale, and at least at one of the three regions. These outcomes suggest recruitment-limitation relationships for several coral taxa, although differences in post-settlement events may be sufficiently strong to distort the pattern established at settlement for other populations. The modest benefits of MPAs on the density of juvenile corals demonstrated here argue in favor of strengthening conservation measures more specifically focused to protect recruitment processes
Exploring European Eel Anguilla anguilla (L.) Habitat Differences Using Otolith Analysis in Central-Western Mediterranean Rivers and Coastal Lagoons from Sardinia
No full textInternational audienceAn otolith shape and morphometric analysis was performed on European eel (Anguilla anguilla) subpopulations from five rivers and three coastal lagoons of Sardinia (central-western Mediterranean) to assess the role of different habitats on otolith development. Sagittal otolith shape was described by 11 harmonics from elliptic Fourier descriptors. Comparisons among the harmonics were run through canonical discriminant analyses (CDAs). The CDA reclassification rate (75.7%) demonstrated a spatial environmental discrimination among local eel subpopulations of Sardinia. The Euclidean distance values demonstrated a dissimilarity between the river and lagoon groups. The form factor and roundness shape indices were significantly higher in the river group than in the lagoon group. The distances of the first three rings to the otolith core revealed site-specific otolith development. Moreover, the annual otolith growth rate was faster in the lagoon group than in the river group. The differences among the studied sites in terms of sagittal otolith shape could relate to changes in different local stocks potentially related to environmental peculiarities. Establishing a direct correlation between otolith morphology and environmental factors is challenging, and further studies are needed to investigate the relationship between habitat type/environmental variation and growth/body characteristics of eels. Nevertheless, the achieved results suggest that this method can be considered to be a valuable tool for studying the ontogeny of the European eel
Possibilités et limites des jeux vidéo à thématique écologique : Analyse et étude de réception d’Abzû
No full textInternational audienceIncreasingly popular in the gaming culture, video games with an ecological theme seem to hold the potential to raise players’ awareness about environmental issues. This is the case for the underwater adventure game Abzû, whose ecocritical potential is highlighted in this article by a ludonarrative analysis, despite its valorisation of technosolutionism. Based on 2421 comments published on 14 platforms, however, a reception study of the game shows that its environmental message only captures the attention of a minority of players who nevertheless draw important lessons from it and post them on online forums to encourage their peer to do the same.De plus en plus populaires dans la culture vidéoludique, les jeux vidéo à thématique écologique semblent détenir le potentiel de conscientiser les joueur·ses aux problématiques environnementales. C’est notamment le cas du jeu d’aventure sous-marine Abzû, dont le potentiel écocritique est mis en évidence dans cet article par une analyse ludonarrative, malgré sa valorisation du technosolutionnisme. Basée sur 2421 commentaires publiés sur 14 plateformes, une étude de réception du jeu démontre toutefois que son message environnemental retient seulement l’attention d’une minorité de joueur·ses, qui en tirent néanmoins d’importantes leçons et les publient sur les forums en ligne pour encourager leurs homologues à faire de même
Crustose coralline algae can contribute more than corals to coral reef carbonate production
No full textInternational audienceUnderstanding the drivers of net coral reef calcium carbonate production is increasingly important as ocean warming, acidification, and other anthropogenic stressors threaten the maintenance of coral reef structures and the services these ecosystems provide. Despite intense research effort on coral reef calcium carbonate production, the inclusion of a key reef forming/accreting calcifying group, the crustose coralline algae, remains challenging both from a theoretical and practical standpoint. While corals are typically the primary reef builders of contemporary reefs, crustose coralline algae can contribute equally. Here, we combine several sets of data with numerical and theoretical modelling to demonstrate that crustose coralline algae carbonate production can match or even exceed the contribution of corals to reef carbonate production. Despite their importance, crustose coralline algae are often inaccurately recorded in benthic surveys or even entirely missing from coral reef carbonate budgets. We outline several recommendations to improve the inclusion of crustose coralline algae into such carbonate budgets under the ongoing climate crisis
UN GENTILHOMME-CAMPAGNARD ENTRE L’HISTOIRE ET LE CREPUSCULEJOURNAL DE PHILIPPE TAMIZEY DE LARROQUE(1889-1898)
No full textDe l’importance de la communication externe d’une autorité administrative indépendante
No full textInternational audienceOn 27 July 2022, at the instigation of the President of the New Caledonian Competition Authority, a symposium was organised in Noumea which brought together representatives of the three competition authorities of the French Republic in charge of applying competition rules in all the overseas territories. However, the Polynesian side did not prove to be up to the task and the stakes: significant factual errors have been made leaving the conference participants in the dark as far as the applicable law and the decision-making practice of the Polynesian Competition Authority were concerned. The external communication of independent administrative authorities is however an essential element of their credibility and of the success of the missions they have been entrusted with; it should therefore be considered with all the importance it requires and, more particularly, should make sure that their action is fully understood by all and sundry.Le 27 juillet 2022, était organisé à Nouméa, à l’instigation de la présidente de l’Autorité de la concurrence de la Nouvelle-Calédonie, un colloque réunissant des représentants des trois autorités de concurrence de la République française en charge de l’application des règles de concurrence dans l’ensemble des territoires ultramarins. La représentation polynésienne ne s’est cependant pas révélée à la hauteur de la mission et des enjeux, en commettant un certain nombre d’erreurs factuelles d’importance avec pour conséquence de laisser les auditeurs du colloque dans l’incompréhension du droit applicable et de la pratique décisionnelle de l’Autorité polynésienne de la concurrence. La communication externe des autorités administratives indépendantes est pourtant un élément essentiel de leur crédit et de la réussite des missions qui leur ont été confiées ; il convient donc de la considérer avec toute l’importance qu’elle requiert en s’assurant notamment de la pleine compréhension de leur action par chacun
Quelle influence des contextes sur les pratiques effectives en classe de géométrie en Polynésie française et en Guyane française eu égard auxcurriculaires ?
No full textInternational audienc
Arthropods and rats in organic sugarcane in Tahiti
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/609099/)International audienceAs organic sugarcane is promised to an important development in French Polynesia thank to the high-quality rum produced in this part of the world, preliminary studies on main biotic constraints were conducted on this crop between 2018 and 2021 to better apprehend their control. Visual observations at regular intervals and captures using different types of traps were carried out to collect and identify the arthropod fauna in Tahiti Island. With no surprise, stemborer insects were the most important pests of sugarcane in these different areas. We were also able to identify key predators and parasitoids that are important to preserve for natural control of these pests. Stem borers and rats are a big concern in most islands and like the other pests, we make propositions here to implement some tactics of agroecological crop protection