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| Registros recuperados: 35 | |
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| Artigas,Luis Felipe; Vendeville,Philippe; Leopold,Marc; Guiral,Daniel; Ternon,Jean-François. |
| Marine biodiversity in French Guiana is strongly influenced by the amagon River waters of the river Amazon, which constitute a major structuring factor for the estuarine, coastal, and shelf marine ecosystems. Moreover, the marked seasonal and interannual variabilities play important roles in the stability or fluctuations in the environmental parameters that influence biodiversity at the ecological, population, and genetic levels. Previous and ongoing studies of the marine and littoral biota relate mostly to commercial marine species, protected species in danger of extinction and, specially, to the biodiversity and functioning of local coastal and littoral ecosystems such as estuaries, mudflats, sandy beaches and, particularly, littoral mangroves. A more... |
| Tipo: Journal article |
Palavras-chave: French Guiana; Marine biodiversity; Coastal systems; Amazon river waters; Intertropical Convergence Zone; Ecological and conservation studies. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382003000200013 |
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| Abascal-zorrilla, Noelia; Vantrepotte, Vincent; Huybrechts, Nicolas; Ngoc, Dat Dinh; Anthony, Edward J.; Gardel, Antoine. |
| The estuarine turbidity maximum (ETM) zone occurs in river estuaries due to the effects of tidal dynamics, density-driven residual circulation and deposition/erosion of fine sediments. Even though tropical river estuaries contribute proportionally more to the sediment supply of coastal areas, the ETM in them has been hardly studied. In this study, surface suspended particulate matter (SPM) determined from OLI (Operational Land Imager)-Landsat 8images was used to gain a better understanding of the spatio-temporal dynamics of the ETM of the tropical Maroni estuary (located on the Guianas coast, South America). A method to estimate the remotely-sensed ETM location and its spatiotemporal evolution between 2013 and 2019 was developed. Each ETM was defined from... |
| Tipo: Text |
Palavras-chave: Estuarine turbidity maximum; Landsat-8; Tropical estuary; Mud banks; French Guiana. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00641/75263/75468.pdf |
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| Mosnier, Emilie; Dusfour, Isabelle; Lacour, Guillaume; Saldanha, Raphael; Guidez, Amandine; Gomes, Margarete S.; Sanna, Alice; Epelboin, Yanouk; Restrepo, Johana; Davy, Damien; Demar, Magalie; Djossou, Félix; Douine, Maylis; Ardillon, Vanessa; Nacher, Mathieu; Musset, Lise; Roux, Emmanuel. |
| Background In 2017, inhabitants along the border between French Guiana and Brazil were affected by a malaria outbreak primarily due to Plasmodium vivax (Pv). While malaria cases have steadily declined between 2005 and 2016 in this Amazonian region, a resurgence was observed in 2017. Methods Two investigations were performed according to different spatial scales and information details: (1) a local study on the French Guiana border, which enabled a thorough investigation of malaria cases treated at a local village health center and the entomological circumstances in the most affected neighborhood, and (2) a regional and cross-border study, which enabled exploration of the regional spatiotemporal epidemic dynamic. Number and location of malaria cases were... |
| Tipo: Text |
Palavras-chave: Plasmodium vivax; Anopheles darlingi; French Guiana; Brazil; Transnational; Outbreak investigation; Indigenous south Americans; Malaria; Amazonia. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00632/74387/74081.pdf |
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| Pujos, M; Latouche, C; Maillet, N. |
| Marine muds deposited on the French Guiana coast mostly originate in the Amazon. Recent sediments are composed of (a) illite (33 %) and chlorite (13 %) of Andean mountain origin; and (b) kaolinite (28 %) and smectite (26 %), principally from the Amazonian lowlands but also from the Guiana Shield. In the coastal mud prism, high-resolution seismic profiles, together with sedimentological, micropaleontological and soil engineering studies, supplemented by C-14 dates, permitted a stratigraphic interpretation of eight cores. Three episodes have been determined on the basis of clay-mineral variations related to Amazonian lowland, Andean and Guiana shield sources. The older episodes 3 (3000-1700 y BP) and 2 (1700-1000 y BP) are predominantly characterized by... |
| Tipo: Text |
Palavras-chave: Late quaternary; French Guiana; Shelf; Clay minerals; ENSO. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00094/20506/18175.pdf |
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| Pujos, M; Pons, Jc; Parra, M. |
| The distribution of heavy minerals on beaches and beach ridges sands of French Guiana shows three distinct suites from East to West: amphibole (largely dominant), staurolite, epidote and pyroxene off the Cayenne region, tourmaline and amphibole mainly off the Kourou-Mana, garnet, staurolite and tourmaline off the Mana-Maroni. A very good continuity exists between the assemblages of heavy minerals from the catchment area parent-rocks, the fluviatile sediments, the coastal zone and the shelf. The results of this study indicate and strengthen a local origin for the sandy sediments and do not support a possibility of an Amazonian source. |
| Tipo: Text |
Palavras-chave: Guyane française; Plages; Cordons sableux; Minéraux lourds; French Guiana; Beaches; Beach ridges sands; Heavy minerals. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00291/40271/38643.pdf |
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| Stier, Anna; De Carvalho, William D.; Rostain, Stephen; Catzeflis, Francois; Claessens, Olivier; Dewynter, Mael; Mckey, Doyle; Mustin, Karen; Palisse, Marianne; De Thoisy, Benoit. |
| The Amazonian savannas of French Guiana are rare and of high ecological and cultural value but are also highly threatened. They are socioecological systems that have been coconstructed by humans and nature and today form mosaic landscapes along the country's coast. From pre-Columbian raised fields through colonial and Creole uses to contemporary uses, they have been largely shaped and modified by human activities. They are currently threatened by changes in fire regimes, agricultural practices, invasive species, and infrastructure development. Less than 3% are protected, despite their importance for several endangered animal and plant species. A shift is required in the way we think about their conservation to create a new strategy that would be completely... |
| Tipo: Text |
Palavras-chave: Archeology; Biodiversity; Conservation; French Guiana; Savanna; Socioecological systems. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00607/71928/70614.pdf |
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| Van Langenhove, Leandro; Depaepe, Thomas; Vicca, Sara; Van Den Berge, Joke; Stahl, Clement; Courtois, Elodie; Weedon, James; Urbina, Ifigenia; Grau, Oriol; Asensio, Dolores; Peñuelas, Josep; Boeckx, Pascal; Richter, Andreas; Van Der Straeten, Dominique; Janssens, Ivan A.. |
| Background and aims Biological fixation of atmospheric nitrogen (N2) is the main pathway for introducing N into unmanaged ecosystems. While recent estimates suggest that free-living N fixation (FLNF) accounts for the majority of N fixed in mature tropical forests, the controls governing this process are not completely understood. The aim of this study was to quantify FLNF rates and determine its drivers in two tropical pristine forests of French Guiana. Methods We used the acetylene reduction assay to measure FLNF rates at two sites, in two seasons and along three topographical positions, and used regression analyses to identify which edaphic explanatory variables, including carbon (C), nitrogen (N), phosphorus (P) and molybdenum (Mo) content, pH, water... |
| Tipo: Text |
Palavras-chave: Free-living nitrogen fixation; Tropical forest; French Guiana; Nutrients; Phosphorus; Molybdenum. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00487/59901/63083.pdf |
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| Muresan Paslaru, Bogdan. |
| The mercury cycle was explored in the Petit-Saut reservoir / Sinnamary Estuary continuum in French Guiana. Main processes involve (i) photo-induced reduction, (ii) adsorption and desorption at the particle surfaces, (iii) methylating bacterial activity, (iv) precipitation and dissolution of iron oxyhydroxides and sulfides. Sources of mercury to the Petit-Saut reservoir consist of the partly impacted river-tributaries, the atmospheric deposition and the flooded soils or vegetation. Once into the reservoir, divalent mercury undergoes a large spectrum of transformations including speciation and phase changes. We, here, probe these processes and demonstrate that the Petit-Saut reservoir behaves as a privileged site for atmospheric recycling and in situ... |
| Tipo: Text |
Palavras-chave: Atmosphere; Estuary; Reservoir; French Guiana; Methylmercury; Mercury; Atmosphère; Estuaire; Retenue; Guyane française; Methylmercure; Mercure. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/these-1508.pdf |
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| Verryckt, Lore T.; Van Langenhove, Leandro; Ciais, Philippe; Courtois, Elodie A.; Vicca, Sara; Peñuelas, Josep; Stahl, Clément; Coste, Sabrina; Ellsworth, David S.; Posada, Juan M.; Obersteiner, Michael; Chave, Jérôme; Janssens, Ivan A.. |
| Measuring leaf gas exchange from canopy leaves is fundamental for our understanding of photosynthesis and for a realistic representation of carbon uptake in vegetation models. Since canopy leaves are often difficult to reach, especially in tropical forests with emergent trees up to 60 m at remote places, canopy access techniques such as canopy cranes or towers have facilitated photosynthetic measurements. These structures are expensive and therefore not very common. As an alternative, branches are often cut to enable leaf gas exchange measurements. The effect of branch excision on leaf gas exchange rates should be minimized and quantified to evaluate possible bias. We compared light‐saturated leaf net photosynthetic rates measured on excised and intact... |
| Tipo: Text |
Palavras-chave: Branch cutting; Canopy physiology; French Guiana; Gas exchange; Photosynthesis; Rainforest; Stomatal conductance. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00613/72466/71949.pdf |
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| Donald, Julian; Roy, Mélanie; Suescun, Uxue; Iribar, Amaia; Manzi, Sophie; Péllissier, Léonie; Gaucher, Philippe; Chave, Jérôme. |
| 1.Community assembly theory assumes that ecological communities are spatially delimited into patches. Within these patches, coexistence results from environmental filtering, competition, and immigration. Truly delineated communities exist in laboratory studies of microbial cultures in Petri dishes, yet empirical tests conducted in continuous environments often use patches defined by convention as opposed to realised boundaries. 2.Here we perform a test of ecological community assembly rules using foliar endophyte communities from a tropical rainforest, where leaves are considered as patches for both fungal and bacterial communities. We determined the diversity of fungal and bacterial endophytes using environmental DNA sequencing of 365 top‐canopy leaves,... |
| Tipo: Text |
Palavras-chave: Bacteria; Distribution; French Guiana; Fungi; Metabarcoding; Plant–pathogen interactions; Rainforest. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00606/71808/70296.pdf |
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| Le Joncour, Anna; Blanchard, Fabian; Tagliarolo, Morgana. |
| Estuarine and coastal areas are often considered as hotspots due to their high diversity and ecological importance. However, communities living on those areas are often submitted to fishery and climate change pressures causing modifications on fish assemblages. French Guiana’s coastal shelf is characterised by warm waters with high turbidity and low salinity caused by the large river discharges from the Amazon and nearby estuaries. The high productivity of these areas supports fisheries and aquaculture activities. However, the structure and dynamics of coastal fish populations in French Guiana have seldom been studied. The aim of this study was to understand the effect of environmental conditions, as well as the influence of the coast and nearby estuaries... |
| Tipo: Text |
Palavras-chave: French Guiana; Coastal community; Estuary; Diversity; Tropical waters; Fisheries management. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00607/71929/73534.pdf |
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| Marchand, Cyril; Lallier Verges, E; Baltzer, F; Alberic, P; Cossa, Daniel; Baillif, P. |
| The accumulation of nine heavy metals in fine-grained sediments from the mangrove fringed coast of French Guiana is evaluated. The dynamic features of the South American tropical coastline, from the Amazon to the Orinoco Rivers, result in mangrove sediments being alternately submitted to phases of erosion and net sedimentation a few tens of years long. This process influences the distribution of the heavy metals associated with these frequently re-mobilized deposits. Sedimentary cores and mangrove plant samples were collected, at different seasons, in various swamps characterized by different properties (content of sedimentary organic matter, distance from sea water and fresh water). The ranges of measured concentrations expressed in mu mol g(-1) were the... |
| Tipo: Text |
Palavras-chave: French Guiana; Mangrove; Fe/Mn cycling; Heavy metals. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1041.pdf |
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| Aschenbroich, Adelaide; Michaud, Emma; Stieglitz, Thomas; Fromard, Francois; Gardel, Antoine; Tavares, Marcos; Thouzeau, Gerard. |
| This study in French Guiana evaluates the changes of crab assemblages and their bioturbation activities between mangrove early stages (pioneer and young mangrove) and within stages by taking their spatial heterogeneity (tidal channels, flat areas, pools) into account. The results show differences in crab assemblage structure between and within the early stages of mangrove in relation to microhabitat and sediment characteristics. The sediment reworking rates are a function of the biomass or density of particular species (Ucides cordatus, Uca cumulanta) and burrower functional groups. Crab species or functional interaction mediate changes in sediment reworking rates suggesting the need to consider entire benthic communities rather than single species. This... |
| Tipo: Text |
Palavras-chave: Mangroves; Crabs; Community composition; Bioturbation; French Guiana; Amazon. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00350/46154/45852.pdf |
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| Ray, Raghab; Thouzeau, Gerard; Walcker, Romain; Vantrepotte, Vincent; Gleixner, Gerd; Morvan, Sylvain; Devesa, Jeremy; Michaud, Emma. |
| There is growing evidence that a substantial fraction of the dissolved organic and inorganic carbon (DOC and DIC) and particulate organic carbon (POC) can be exported from mangroves to the ocean. Yet our understanding of C fluxes in mangrove forests is limited to only few regional studies that exclude the world's longest sediment dispersal system connected to the Amazon River. The present study aims at (1) examining tidal fluctuations of DOC, POC, and DIC; their isotopes; and optical properties such as chromophoric dissolved organic matter (CDOM) and (2) estimating their exchange fluxes between the mangroves and adjacent coastal water in the Sinnamary estuary, French Guiana. Time series observation highlighted that physical processes coupled to tides... |
| Tipo: Text |
Palavras-chave: Organic matter; Tidal cycle; Carbon flux; Mangroves; French Guiana. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75488/76339.pdf |
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| Cisse, Abdoul; Blanchard, Fabian; Guyader, Olivier. |
| Like many tropical small-scale fisheries, the French Guiana coastal fishery is characterized by the high fish biodiversity of its ecosystem, the weak selectivity of the fleets exploiting the resources, and the heterogeneity of the vessels in terms of size and fishing techniques. The Rapfish method is used to assess sustainability within 11 fishery systems by means of 27 attributes relating to ecological, economic, social, and technological fields. Overall results indicate an average performance in the weak sustainability range. Comparisons made among the FSs show a gradient of sustainability performance from the western portion of the coast to the eastern portion. Several recommendations are formulated to raise the current “sustainability” status, such as... |
| Tipo: Text |
Palavras-chave: French Guiana; Small scale fishery; Sustainability; Rapfish; Ecosystem approach. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00162/27310/25662.pdf |
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| Registros recuperados: 35 | |
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