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Author Levionnois, Sébastien ; Ziegler, Camille ; Heuret, Patrick ; Jansen, Steven ; Stahl, Clément ; Calvet, Emma ; Goret, Jean-Yves ; Bonal, Damien ; Coste, Sabrina doi  openurl
  Title Is vulnerability segmentation at the leaf‑stem transition a drought resistance mechanism? A theoretical test with a trait‑based model for Neotropical canopy tree species Type Journal Article
  Year 2021 Publication Annals of Forest Science Abbreviated Journal  
  Volume 78 Issue 4 Pages 78-87  
  Keywords Neotropics, bark, canopy, capacitance, drought, drought tolerance, embolism, leaves, models, transpiration, trees, tropical rain forests, xylem  
  Abstract Leaf-stem vulnerability segmentation predicts lower xylem embolism resistance in leaves than stem. However, although it has been intensively investigated these past decades, the extent to which vulnerability segmentation promotes drought resistance is not well understood. Based on a trait-based model, this study theoretically supports that vulnerability segmentation enhances shoot desiccation time across 18 Neotropical tree species. CONTEXT: Leaf-stem vulnerability segmentation predicts lower xylem embolism resistance in leaves than stems thereby preserving expensive organs such as branches or the trunk. Although vulnerability segmentation has been intensively investigated these past decades to test its consistency across species, the extent to which vulnerability segmentation promotes drought resistance is not well understood. AIMS: We investigated the theoretical impact of the degree of vulnerability segmentation on shoot desiccation time estimated with a simple trait-based model. METHODS: We combined data from 18 tropical rainforest canopy tree species on embolism resistance of stem xylem (flow-centrifugation technique) and leaves (optical visualisation method). Measured water loss under minimum leaf and bark conductance, leaf and stem capacitance, and leaf-to-bark area ratio allowed us to calculate a theoretical shoot desiccation time (tcᵣᵢₜ). RESULTS: Large degrees of vulnerability segmentation strongly enhanced the theoretical shoot desiccation time, suggesting vulnerability segmentation to be an efficient drought resistance mechanism for half of the studied species. The difference between leaf and bark area, rather than the minimum leaf and bark conductance, determined the drastic reduction of total transpiration by segmentation during severe drought. CONCLUSION: Our study strongly suggests that vulnerability segmentation is an important drought resistance mechanism that should be better taken into account when investigating plant drought resistance and modelling vegetation. We discuss future directions for improving model assumptions with empirical measures, such as changes in total shoot transpiration after leaf xylem embolism.  
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  Call Number EcoFoG @ webmaster @ Serial 1034  
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Author Fouquet, A.; Dubut, V.; Hataway, R.; Scotti-Saintagne, C.; Scotti, I.; Noonan, B. doi  openurl
  Title Isolation and characterisation of 19 microsatellite loci from the Amazonian frog Adenomera andreae (Amphibia: Anura: Leptodactylidae) Type Journal Article
  Year 2009 Publication Conservation Genetics Resources Abbreviated Journal Conserv. Genet. Res.  
  Volume 1 Issue 1 Pages 217-220  
  Keywords Biomedicine  
  Abstract Nineteen novel microsatellite loci were isolated from Adenomera andreae, a widespread Amazonian frog considered to be a species complex. Three multiplex kits were optimized. Genetic diversity was assessed in 66 individuals sampled in three populations along the West of the Approuague River catchment (French Guiana). We also tested the multiplex kits in four other Adenomera and nine Leptodactylus species with 43.4 and 17.5% success respectively.  
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  Publisher Springer Netherlands Place of Publication Editor  
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  ISSN 1877-7252 ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 185  
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Author Boisse, P.; Aimene, Y.; Dogui, A.; Dridi, S.; Gatouillat, S.; Hamila, N.; Khan, M.A.; Mabrouki, T.; Morestin, F.; Vidal-Sallé, E. doi  openurl
  Title Hypoelastic, hyperelastic, discrete and semi-discrete approaches for textile composite reinforcement forming Type Journal Article
  Year 2010 Publication International Journal of Material Forming Abbreviated Journal  
  Volume 3 Issue Supplement 2 Pages 1229-1240  
  Keywords Textile composites Forming simulations Continuous/discrete approaches Hyperelasticity Hypoelasticity Semi-discrete finite element  
  Abstract The clear multi-scale structure of composite textile reinforcements leads to develop continuous and discrete approaches for their forming simulations. In this paper two continuous modelling respectively based on a hypoelastic and hyperelastic constitutive model are presented. A discrete approach is also considered in which each yarn is modelled by shell finite elements and where the contact with friction and possible sliding between the yarns are taken into account. Finally the semi-discrete approach is presented in which the shell finite element interpolation involves continuity of the displacement field but where the internal virtual work is obtained as the sum of tension, in-plane shear and bending ones of all the woven unit cells within the element. The advantages and drawbacks of the different approaches are discussed.  
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  Notes Hypoelastic, hyperelastic, discrete and semi-discrete approaches for textile composite reinforcement forming Approved no  
  Call Number EcoFoG @ eric.marcon @ 8 Serial 90  
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Author Malé, P.-J.G.; Leroy, C.; Lusignan, L.; Petitclerc, F.; Quilichini, A.; Orivel, J. doi  openurl
  Title The reproductive biology of the myrmecophyte, Hirtella physophora, and the limitation of negative interactions between pollinators and ants Type Journal Article
  Year 2015 Publication Arthropod-Plant Interactions Abbreviated Journal Arthropod-Plant Interactions  
  Volume 9 Issue 1 Pages 23-31  
  Keywords Ant-plant; Ant–pollinator interactions; Floral structure and display; Plant reproductive biology; Spatial and temporal segregation  
  Abstract Myrmecophytism occurs in plants that offer ants a nesting space and, often, food rewards in exchange for protection from predators and competitors. Such biotic protection by ants can, however, interfere with the activity of pollinators leading to potential negative consequences for the plant’s reproduction. In this study, we focused on the association between the understory myrmecophyte, Hirtella physophora (Chrysobalanaceae), and its obligate ant partner, Allomerus decemarticulatus (Myrmicinae). We investigated the reproductive biology of H. physophora and the putative mechanisms that may limit ant–pollinator conflict. Our results show that H. physophora is an obligate outcrosser, self-incompatible, and potentially insect-pollinated species. The reproduction of H. physophora relies entirely on pollen transfer by pollinators that are likely quite specific. Potential interference between flower-visiting insects during pollination may also be lessened by a spatial and temporal segregation of ant and pollinator activities, thus enabling pollen transfer and fruit production. © 2014, Springer Science+Business Media Dordrecht.  
  Address IRD, UMR AMAP (botAnique et bioinforMatique de l’Architecture des Plantes), Boulevard de la Lironde, TA A-51/PS2Montpellier Cedex 5, France  
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  Notes Export Date: 9 April 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 593  
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Author Lenoir, A.; Boulay, R.; Dejean, A.; Touchard, A.; Cuvillier-Hot, V. doi  openurl
  Title Phthalate pollution in an Amazonian rainforest Type Journal Article
  Year 2016 Publication Environmental Science and Pollution Research Abbreviated Journal  
  Volume 23 Issue 16 Pages 16865-16872  
  Keywords  
  Abstract Phthalates are ubiquitous contaminants and endocrine-disrupting chemicals that can become trapped in the cuticles of insects, including ants which were recognized as good bioindicators for such pollution. Because phthalates have been noted in developed countries and because they also have been found in the Arctic, a region isolated from direct anthropogenic influence, we hypothesized that they are widespread. So, we looked for their presence on the cuticle of ants gathered from isolated areas of the Amazonian rainforest and along an anthropogenic gradient of pollution (rainforest vs. road sides vs. cities in French Guiana). Phthalate pollution (mainly di(2-ethylhexyl) phthalate (DEHP)) was higher on ants gathered in cities and along road sides than on those collected in the pristine rainforest, indicating that it follows a human-mediated gradient of disturbance related to the use of plastics and many other products that contain phthalates in urban zones. Their presence varied with the ant species; the cuticle of Solenopsis saevissima traps higher amount of phthalates than that of compared species. However, the presence of phthalates in isolated areas of pristine rainforests suggests that they are associated both with atmospheric particles and in gaseous form and are transported over long distances by wind, resulting in a worldwide diffusion. These findings suggest that there is no such thing as a “pristine” zone.  
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  ISSN 1614-7499 ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Lenoir2016 Serial 700  
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Author Lenoir, A.; Touchard, A.; Devers, S.; Christidès, J.-P.; Boulay, R.; Cuvillier-Hot, V. doi  openurl
  Title Ant cuticular response to phthalate pollution Type Journal Article
  Year 2014 Publication Environmental Science and Pollution Research Abbreviated Journal Environ. Sci. Pollut. Res.  
  Volume 21 Issue 23 Pages 13446-13451  
  Keywords Absorption; Ants; Bbp; Bioindicator; Cuticle; Dbp; Dehp; DiBP; Phthalates; Pollutants  
  Abstract Phthalates are common atmospheric contaminants used in the plastic industry. Ants have been shown to constitute good bioindicators of phthalate pollution. Hence, phthalates remain trapped on ant cuticles which are mostly coated with long-chain hydrocarbons. In this study, we artificially contaminated Lasius niger ants with four phthalates: dibutyl phthalate (DBP), diisobutyl phthalate (DiBP), di(2-ethylhexyl) phthalate (DEHP), and benzyl butyl phthalate (BBP). The first three have previously been found on ants in nature in Touraine (France), while the fourth has not. The four phthalates disappeared rapidly (less than 5 days) from the cuticles of live ants. In contrast, on the cuticles of dead ants, DEHP quantities remained unchanged over time. These results indicate that phthalates are actively absorbed by the cuticles of live ants. Cuticular absorption of phthalates is nonspecific because eicosane, a nonnatural hydrocarbon on L. niger cuticle, was similarly absorbed. Ants are important ecological engineers and may serve as bioindicators of ecosystem health. We also suggest that ants and more generally terrestrial arthropods may contribute to the removal of phthalates from the local environment.  
  Address CNRS, UMR Écologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316Kourou Cedex, France  
  Corporate Author Thesis  
  Publisher Springer Verlag Place of Publication Editor  
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  ISSN 09441344 (Issn) ISBN Medium  
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  Notes Export Date: 5 December 2014; Coden: Esple; Correspondence Address: Lenoir, A.; IRBI, Institut de Recherche sur la Biologie de l’Insecte, UMR CNRS 7261, Université François RabelaisFrance Approved no  
  Call Number EcoFoG @ webmaster @ Serial 570  
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Author Urbina, I.; Grau, O.; Sardans, J.; Ninot, J.M.; Peñuelas, J. doi  openurl
  Title Encroachment of shrubs into subalpine grasslands in the Pyrenees changes the plant-soil stoichiometry spectrum Type Journal Article
  Year 2020 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume 448 Issue 1-2 Pages 37-53  
  Keywords Nutrient stocks; Plant strategy; Plant-soil stoichiometry; Shrub encroachment; Subalpine grassland succession; aboveground biomass; biogeochemical cycle; carbon sequestration; ectomycorrhiza; fungus; grass; nitrogen; nutrient uptake; shrub; soil-vegetation interaction; stoichiometry; subalpine environment; succession; Europe; Pyrenees; Fungi  
  Abstract Aims: Shrub encroachment has been reported over a large proportion of the subalpine grasslands across Europe and is expected to have an important impact on the biogeochemical cycle of these ecosystems. We investigated the stoichiometric changes in the plant-soil system along the succession (e.g. increase in encroachment from unencroached grassland to mature shrubland) at two contrasting sites in the Pyrenees. Methods: We analyzed the chemical composition (C, N,15N, P, K, Ca, Mg and Fe) in the soil and in the aboveground plant compartments (leaves, leaf-litter and stems) of the main herbaceous species and shrubs at three contrasting stages of the succession: unencroached grassland, young shrubland and mature shrubland. Results: The plant-soil stoichiometry spectrum differed between the successional stages. Shrub encroachment generally increased the concentration of C and Ca and the C:N ratio and often reduced to concentrations of N, P and K in the leaves and leaf-litter, while several soil nutrient concentrations (N, P, K Ca and Mg) decreased. The stocks of C, N, P, Ca, and Mg in the total aboveground biomass increased with encroachment. Conclusions: Shrub encroachment favored the dominance of long-lived species with low concentrations of N and P in the plant-soil compartments, high C:nutrient ratios in the aboveground biomass and increase the uptake of N through ericoid or ectomycorrhizal fungi. We highlight the role of shrubs in the sequestration of C and nutrients through the allocation to the aboveground biomass. The changes in plant-soil elemental composition and stocks suggest a slowdown of the biogeochemical cycles in the subalpine mountain areas where shrub encroachment occurred. © 2020, Springer Nature Switzerland AG.  
  Address Biodiversity Research Institute (IRBio) and Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Catalonia, Spain  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
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  Series Volume Series Issue Edition  
  ISSN 0032079x (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 983  
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Author Van Langenhove, L.; Depaepe, T.; Vicca, S.; van den Berge, J.; Stahl, C.; Courtois, E.; Weedon, J.; Urbina, I.; Grau, O.; Asensio, D.; Peñuelas, J.; Boeckx, P.; Richter, A.; Van Der Straeten, D.; Janssens, I.A. doi  openurl
  Title Regulation of nitrogen fixation from free-living organisms in soil and leaf litter of two tropical forests of the Guiana shield Type Journal Article
  Year 2020 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume 450 Issue 1-2 Pages 93-110  
  Keywords Free-living nitrogen fixation; French Guiana; Molybdenum; Nutrients; Phosphorus; Tropical forest; acetylene; leaf litter; molybdenum; nitrogen fixation; nutrient cycling; phosphorus; rainforest; reduction; soil biota; soil carbon; soil nitrogen; soil water; topographic effect; tropical forest; French Guiana  
  Abstract 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 and available N and P, explained most of the variation in FLNF rates. Results: Overall, FLNF rates were lower than measured in tropical systems elsewhere. In soils seasonal variability was small and FLNF rates differed among topographies at only one site. Water, P and pH explained 24% of the variation. In leaf litter, FLNF rates differed seasonally, without site or topographical differences. Water, C, N and P explained 46% of the observed variation. We found no regulatory role of Mo at our sites. Conclusions: Rates of FLNF were low in primary rainforest on poor soils on the Guiana shield. Water was the most important rate-regulating factor and FLNF increased with increasing P, but decreased with increasing N. Our results support the general assumption that N fixation in tropical lowland forests is limited by P availability. © 2019, The Author(s).  
  Address Department of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, Vienna, 1090, Austria  
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  ISSN 0032079x (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 971  
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Author Bompy, F.; Lequeue, G.; Imbert, D.; Dulormne, M. doi  openurl
  Title Increasing fluctuations of soil salinity affect seedling growth performances and physiology in three Neotropical mangrove species Type Journal Article
  Year 2014 Publication Plant and Soil Abbreviated Journal Plant and Soil  
  Volume 380 Issue 1 Pages 399-413  
  Keywords Acclimation; Avicennia germinans; Hypersalinity; Laguncularia racemosa; Leaf gas exchange; Rhizophora mangle; Salt stress  
  Abstract Background: Micro-tidal wetlands are subject to strong seasonal variations of soil salinity that are likely to increase in amplitude according to climate model predictions for the Caribbean. Whereas the effects of constant salinity levels on the physiology of mangrove species have been widely tested, little is known about acclimation to fluctuations in salinity. Aims and methods: The aim of this experiment was to characterize the consequences of the rate of increase in salinity (slow versus fast) and salinity fluctuations over time versus constant salt level. Seedling mortality, growth, and leaf gas exchange of three mangrove species, Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle were investigated in semicontrolled conditions at different salt levels (0, 685, 1025, and 1370 mM NaCl). Results: Slow salinity increase up to 685 mM induced acclimation, improving the salt tolerance of A. germinans and L. racemosa, but had no effect on R. mangle. During fluctuations between 0 and 685 mM, A. germinans and R. mangle were not affected by a salinity drop to zero, whereas L. racemosa took advantage of the brief freshwater episode as shown by the durable improvement of photosynthesis and biomass production. Conclusions: This study provides new insights into physiological resistance and acclimation to salt stress. We show that seasonal variations of salinity may affect mangrove seedlings' morphology and physiology as much as annual mean salinity. Moreover, more severe dry seasons due to climate change may impact tree stature and species composition in mangroves through higher mortality rates and physiological disturbance at the seedling stage. © 2014 Springer International Publishing Switzerland.  
  Address EA 926 DYNECAR, UFR des Sciences Exactes et Naturelles, Université des Antilles et de la Guyane, BP 592, 97 159 Pointe-à-Pitre cedex, Guadeloupe (F.W.I.), France  
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  Notes Cited By :7; Export Date: 7 February 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 726  
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Author Dulormne, M.; Musseau, O.; Muller, F.; Toribio, A.; Bâ, A. doi  openurl
  Title Effects of NaCl on growth, water status, N2 fixation, and ion distribution in Pterocarpus officinalis seedlings Type Journal Article
  Year 2010 Publication Plant and Soil Abbreviated Journal Plant and Soil  
  Volume 327 Issue 1 Pages 23-34  
  Keywords Bradyrhizobium; Leaf water potential; Nodulation; Salt; Swamp forest  
  Abstract Pterocarpus officinalis (Fabaceae) dominates in the swamp forests of the Lesser Antilles, submitted to strong variations of soil salinity (30-445 mM). This study aimed to assess the effect of salinity on growth, nodulation, N2 fixation, water status and ions content in P. officinalis and to clarify the mechanisms involved. Seedlings inoculated or not with two strains from areas of contrasting salinity levels (< to 50 or 445 mM) were watered with 0, 171 and 342 mM solutions of NaCl in greenhouse conditions. Non-inoculated seedlings were tolerant to a salinity of 171 mM, with no significant effect on seedling biomass. Evapotranspiration per unit of leaf area (E/TLa) remained unchanged at 171 mM. Maintenance of a constant E/TLa and especially the control of ion transport to the upper parts of the plant could explain seedling salt tolerance up to intermediate salinity conditions (171 mM). The two strains have a 99.8% genetic identity in spite of differences in their original habitats, this explaining the similar response of the symbiosis to salinity. The higher salt sensitivity of inoculated seedlings was linked to the sensitivity of both Bradyrhizobium strains (reduction of free-living cells) and to that of the nodulation process (fewer nodules and inhibition of N2-fixation) to intermediate salinity. © Springer Science + Business Media B.V. 2009.  
  Address LSTM-UMR 113, Université des Antilles et de la Guyane, UFR des Sciences Exactes et Naturelles, B.P. 592, 97159 Pointe-à-Pitre, Guadeloupe (F.W.I.), France  
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  Notes Cited By :12; Export Date: 7 February 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 727  
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