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Author Groc, S.; Delabie, J.H.C.; Fernández, F.; Leponce, M.; Orivel, J.; Silvestre, R.; Vasconcelos, H.L.; Dejean, A. openurl 
  Title Leaf-litter ant communities in a pristine Guianese rainforest: stable functional structure versus high species turnover Type Journal Article
  Year 2013 Publication Myrmecological News Abbreviated Journal Myrmecol. News  
  Volume 19 Issue Pages 43-51  
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  Call Number EcoFoG @ webmaster @ Serial (up) 523  
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Author Salhi, L.; Nait-Rabah, O.; Deyrat, C.; Roos, C. pdf  url
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  Title Numerical Modeling of Single Helical Pile Behavior under Compressive Loading in Sand Type Journal Article
  Year 2013 Publication Electronic Journal of Geotechnical Engineering Abbreviated Journal Electron. J. Geotech. Eng.  
  Volume 18 Issue Bundle T Pages 4119-4338  
  Keywords helical pile; finite element method; failure mechanisms; sand  
  Abstract The present research deals with helical piles behavior in cohesionless soil through finite element modeling. An approach of modeling of the screw-pile geometry has been proposed through the Finite Element Analysis (FEA) computer program Plaxis. The numerical results are compared with measurements from large scale test and the bearing capacity has been estimated using both cylindrical and individual bearing model. Moreover, different failure criterions have been applied to estimate the ultimate capacity. The effect of spacing ratio (S/Dh) on the screw-pile behavior has been further studied. It has found that results from the model fit the field results. Through the study of the load transfer mechanism, the transition from cylindrical shear to individual plate behavior occurs at a value of spacing ratio (1.5 to 2).  
  Address Laboratoire des matériaux et molécules en milieu amazonien, EcoFoG-Université des Antilles-Guyane, 97351 Cayenne, French Guiana  
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  Call Number EcoFoG @ webmaster @ Serial (up) 525  
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Author Houel, E.; Rodrigues, A.M.S.; Jahn-Oyac, A.; Bessière, J.-M.; Eparvier, V.; Deharo, E.; Stien, D. url  openurl
  Title In vitro antidermatophytic activity of Otacanthus azureus (Linden) Ronse essential oil alone and in combination with azoles Type Journal Article
  Year 2014 Publication Journal of Applied Microbiology Abbreviated Journal J. Appl. Microbiol.  
  Volume 116 Issue 2 Pages 288-294  
  Keywords Antifungal activity; Azoles; Dermatophytes; Essential oil; Otacanthus azureus; Synergy  
  Abstract Aims: We determined the chemical composition and investigated the antifungal activity of Otacanthus azureus (Linden) Ronse essential oil (EO) against a range of dermatophytes alone or in combination with azole antifungals. Methods and Results: Aerial parts of the plant were steam-distilled and the obtained oil was analysed by gas chromatography/mass spectrometry and 1H-NMR. It was shown to be largely composed of sesquiterpenes, with the main component being β-copaen-4-α-ol. Using broth microdilution techniques, this oil was found to have remarkable in vitro antifungal activities. Minimum inhibitory concentrations as low as 4 μg ml-1 were recorded. The analysis of the combined effect of the O. azureus EO with azoles using chequerboard assays revealed a synergism between the EO and ketoconazole, fluconazole or itraconazole against Trichophyton mentagrophytes. Notably, the O. azureus essential oil showed low cytotoxicity to VERO cells. Conclusions: The O. azureus essential oil alone or in combination with azoles is a promising antifungal agent in the treatment for human dermatomycoses caused by filamentous fungi. Significance and Impact of the Study: There is much interest in the study of essential oils for the discovery of new antimicrobial drugs. This study has highlighted the antidermatophytic activity of the O. azureus EO. © 2013 The Society for Applied Microbiology.  
  Address Institut de Recherche pour le Développement (IRD), UMR 152 Pharma-DEV, Toulouse, France  
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  ISSN 13645072 (Issn) ISBN Medium  
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  Notes Export Date: 9 February 2014; Source: Scopus; Coden: Jamif; Language of Original Document: English; Correspondence Address: Houël, E.; CNRS – UMR Ecologie des Forêts de Guyane (EcoFoG), Institut Pasteur de la Guyane, 23 Avenue Pasteur, BP6010, 97306 Cayenne Cedex, French Guiana; email: emeline.houel@ecofog.gf Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 526  
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Author Woolfit, M.; Iturbe-Ormaetxe, I.; Brownlie, J.C.; Walker, T.; Riegler, M.; Seleznev, A.; Popovici, J.; Rancès, E.; Wee, B.A.; Pavlides, J.; Sullivan, M.J.; Beatson, S.A.; Lane, A.; Sidhu, M.; McMeniman, C.J.; McGraw, E.A.; O'Neill, S.L. pdf  url
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  Title Genomic evolution of the pathogenic Wolbachia strain, wMelPop Type Journal Article
  Year 2013 Publication Genome Biology and Evolution Abbreviated Journal Genome Biolog. Evol.  
  Volume 5 Issue 11 Pages 2189-2204  
  Keywords Endosymbiont; Evolution; Genomics; Wolbachia  
  Abstract Most strains of the widespread endosymbiotic bacterium Wolbachia pipientis are benign or behave as reproductive parasites. The pathogenic strain wMelPop is a striking exception, however: it overreplicates in its insect hosts and causes severe life shortening. The mechanism of this pathogenesis is currently unknown. We have sequenced the genomes of three variants of wMelPop and of the closely related nonpathogenic strain wMelCS. We show that the genomes of wMelCS and wMelPop appear to be identical in the nonrepeat regions of the genome and differ detectably only by the triplication of a 19-kb region that is unlikely to be associated with life shortening, demonstrating that dramatic differences in the host phenotype caused by this endosymbiont may be the result of only minor genetic changes. We also compare the genomes of the original wMelPop strain from Drosophila melanogaster and two sequentialderivatives, wMelPop-CLA and wMelPop-PGYP. To develop wMelPop as a novel biocontrol agent, it was first transinfected into and passaged in mosquito cell lines for approximately 3.5 years, generating wMelPop-CLA. This cell line-passaged strain was then transinfected into Aedesaegypti mosquitoes, creating wMelPop-PGYP,which wassequenced after 4yearsin the insecthost. We observe a rapid burst of genomic changes during cell line passaging, but no further mutations were detected after transinfection into mosquitoes, indicating either that host preadaptation had occurred in cell lines, that cell lines are a more selectively permissive environment than animal hosts, or both. Our results provide valuable data on the rates of genomic and phenotypic change in Wolbachia associated with host shifts over short time scales. © The Author(s) 2013. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.  
  Address Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia  
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  Notes Export Date: 9 February 2014; Source: Scopus; Language of Original Document: English; Correspondence Address: O'Neill, S.L.; School of Biological Sciences, Monash University, Clayton, VIC, Australia; email: scott.oneill@monash.edu; Funding Details: NIH, National Institutes of Health Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 527  
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Author Rockwell, C.A.; Kainer, K.A.; d'Oliveira, M.V.N.; Staudhammer, C.L.; Baraloto, C. url  openurl
  Title Logging in bamboo-dominated forests in southwestern Amazonia: Caveats and opportunities for smallholder forest management Type Journal Article
  Year 2014 Publication Forest Ecology and Management Abbreviated Journal For. Ecol. Manage.  
  Volume 315 Issue Pages 202-210  
  Keywords Bamboo; Community forest management; Guadua; Logging; Timber management; Tropical forest  
  Abstract Guadua sarcocarpa and Guadua weberbaueri (Poaceae: Bambuseae) have a negative influence on tree regeneration and recruitment in bamboo-dominated forests of southwestern Amazonia. The lack of advanced regeneration and sparse canopy in this forest type present a considerable challenge for developing sustainable timber management plans. We conducted field studies in the Porto Dias Agroextractive Settlement Project in Acre, Brazil to assess influences of logging in bamboo-dominated forest sites. Taxonomic composition, stand structure, aboveground biomass, commercial timber volume, and commercial tree seedling and bamboo culm density were compared between five logged vs. unlogged sites in different landholdings, using modified 0.5. ha Gentry plots. No differences in taxonomic composition, aboveground biomass, adult and juvenile stem density, or woody seedling and bamboo culm density were detected between paired logged and unlogged sites. Commercial timber volume, however, was reduced by almost two-thirds in logged plots, suggesting that long-term timber management goals in this forest type are compromised since so few future crop trees remained onsite. Our findings indicate that in order to maximize local management objectives, community forest managers must approach logging in bamboo-dominated forests with caution. We suggest an integration of non-timber forest product extraction with low harvest intensity and low-impact logging, tending of natural regeneration, and diversification of commercial species. © 2014 Elsevier B.V.  
  Address INRA, UMR Ecologie des Forêts de Guyane, 97387 Kourou Cedex, French Guiana  
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  Notes Export Date: 15 February 2014; Source: Scopus; Coden: Fecmd; Language of Original Document: English; Correspondence Address: Rockwell, C.A.; School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611, United States; email: rockwell_cara@yahoo.com; Funding Details: DGE-0221599, NSF, National Science Foundation Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 528  
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Author Rowland, L.; Hill, T.C.; Stahl, C.; Siebicke, L.; Burban, B.; Zaragoza-Castells, J.; Ponton, S.; Bonal, D.; Meir, P.; Williams, M. url  openurl
  Title Evidence for strong seasonality in the carbon storage and carbon use efficiency of an Amazonian forest Type Journal Article
  Year 2014 Publication Global Change Biology Abbreviated Journal Global Change Biol.  
  Volume 20 Issue 3 Pages 979-991  
  Keywords Carbon use efficiency; Dalec; Data assimilation; Ecosystem respiration; French Guiana; Seasonal carbon fluxes; Tropical forest  
  Abstract The relative contribution of gross primary production and ecosystem respiration to seasonal changes in the net carbon flux of tropical forests remains poorly quantified by both modelling and field studies. We use data assimilation to combine nine ecological time series from an eastern Amazonian forest, with mass balance constraints from an ecosystem carbon cycle model. The resulting analysis quantifies, with uncertainty estimates, the seasonal changes in the net carbon flux of a tropical rainforest which experiences a pronounced dry season. We show that the carbon accumulation in this forest was four times greater in the dry season than in the wet season and that this was accompanied by a 5% increase in the carbon use efficiency. This seasonal response was caused by a dry season increase in gross primary productivity, in response to radiation and a similar magnitude decrease in heterotrophic respiration, in response to drying soils. The analysis also predicts increased carbon allocation to leaves and wood in the wet season, and greater allocation to fine roots in the dry season. This study demonstrates implementation of seasonal variations in parameters better enables models to simulate observed patterns in data. In particular, we highlight the necessity to simulate the seasonal patterns of heterotrophic respiration to accurately simulate the net carbon flux seasonal tropical forest. © 2013 The Authors Global Change Biology Published by John Wiley & Sons Ltd.  
  Address Research School of Biology, Division of Plant Sciences, Australian National University, Canberra, ACT, 0200, Australia  
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  Notes Cited By (since 1996):1; Export Date: 24 February 2014; Source: Scopus; Language of Original Document: English; Correspondence Address: Rowland, L.; School of Geosciences, University of Edinburgh, Edinburgh, EH9 3JN, United Kingdom; email: lucy.rowland@ed.ac.uk; Funding Details: FT110100457, ARC, Australian Research Council; Funding Details: NE/F002149/1, NERC, Natural Environment Research Council; Funding Details: NE/J011002/1, NERC, Natural Environment Research Council Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 529  
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Author Lamarre, G.P.A.; Mendoza, I.; Fine, P.V.A.; Baraloto, C. url  openurl
  Title Leaf synchrony and insect herbivory among tropical tree habitat specialists Type Journal Article
  Year 2014 Publication Plant Ecology Abbreviated Journal Plant Ecol.  
  Volume 215 Issue 2 Pages 209-220  
  Keywords Escape; French Guiana; Herbivorous insects; Phenology; Resource availability; Time lag  
  Abstract Growth defense tradeoff theory predicts that plants in low-resource habitats invest more energy in defense mechanisms against natural enemies than growth, whereas plants in high-resource habitats can afford higher leaf loss rates. A less-studied defense against herbivores involves the synchrony of leaf production, which can be an effective defense strategy if leaf biomass production exceeds the capacity of consumption by insects. The aim of this study was to determine whether leaf synchrony varied across habitats with different available resources and whether insects were able to track young leaf production among tree habitat specialists in a tropical forest of French Guiana. We predicted that high-resource habitats would exhibit more synchrony in leaf production due to the low cost and investment to replace leaf tissue. We also expected closer patterns of leaf synchrony and herbivory within related species, assuming that they shared herbivores. We simultaneously monitored leaf production and herbivory rates of five pairs of tree species, each composed of a specialist of terra firme or white-sand forests within the same lineage. Our prediction was not supported by the strong interaction of habitat and lineage for leaf synchrony within individuals of the same species; although habitat specialists differed in leaf synchrony within four of five lineages, the direction of the effect was variable. All species showed short time lags for the correlation between leaf production and herbivory, suggesting that insects are tightly tracking leaf production, especially for the most synchronous species. Leaf synchrony may provide an important escape defense against herbivores, and its expression appears to be constrained by both evolutionary history and environmental factors. © 2014 Springer Science+Business Media Dordrecht.  
  Address Department of Biology, University of Florida, Gainesville, FL, 32611, United States  
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  Notes Export Date: 24 February 2014; Source: Scopus; Coden: Plecf; Language of Original Document: English; Correspondence Address: Lamarre, G. P. A.; Université Antilles Guyane, UMR Ecologie des Forêts de Guyane, 97310 Kourou, French Guiana; email: greglamarre973@gmail.com; Funding Details: DEB-0743103/0743800, NSF, National Science Foundation Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 530  
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Author Fortunel, C.; Ruelle, J.; Beauchene, J.; Fine, P.V.A.; Baraloto, C. url  openurl
  Title Wood specific gravity and anatomy of branches and roots in 113 Amazonian rainforest tree species across environmental gradients Type Journal Article
  Year 2014 Publication New Phytologist Abbreviated Journal New Phytol.  
  Volume 202 Issue 1 Pages 79-94  
  Keywords Amazonian forests; Branch; Environmental gradients; Neotropical trees; Root; Wood anatomical traits; Wood density; Wood functions  
  Abstract Wood specific gravity (WSG) is a strong predictor of tree performance across environmental gradients. Yet it remains unclear how anatomical elements linked to different wood functions contribute to variation in WSG in branches and roots across tropical forests. We examined WSG and wood anatomy in white sand, clay terra firme and seasonally flooded forests in French Guiana, spanning broad environmental gradients found throughout Amazonia. We measured 15 traits relating to branches and small woody roots in 113 species representing the 15 most abundant species in each habitat and representative species from seven monophyletic lineages occurring in all habitats. Fiber traits appear to be major determinants of WSG, independent of vessel traits, in branches and roots. Fiber traits and branch and root WSG increased from seasonally flooded species to clay terra firme species and lastly to white sand species. Branch and root wood traits were strongly phylogenetically constrained. Lineages differed in wood design, but exhibited similar variation in wood structure across habitats. We conclude that tropical trees can invest differently in support and transport to respond to environmental conditions. Wind disturbance and drought stress represent significant filters driving tree distribution of Amazonian forests; hence we suggest that biophysical explanations should receive more attention. © 2013 New Phytologist Trust.  
  Address Department of Biology, University of Florida, Gainesville, FL, 32611, United States  
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  Notes Export Date: 10 March 2014; Source: Scopus; Coden: Nepha; Language of Original Document: English; Correspondence Address: Fortunel, C.; INRA, UMR Ecologie des Forêts de Guyane, BP 709, Kourou Cedex, 97387, France; email: claire.fortunel@ecofog.gf; Funding Details: DEB-0743103, NSF, National Science Foundation; Funding Details: DEB-0743800, NSF, National Science Foundation Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 531  
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Author Traissac, S.; Pascal, J.-P. url  openurl
  Title Birth and life of tree aggregates in tropical forest: Hypotheses on population dynamics of an aggregated shade-tolerant species Type Journal Article
  Year 2014 Publication Journal of Vegetation Science Abbreviated Journal J. Veg. Sci.  
  Volume 25 Issue 2 Pages 491-502  
  Keywords Clusters; Colonization strategy; Janzen-Connell; Spatial analysis; Spatial pattern; Vouacapoua americana  
  Abstract Questions: Several studies have described aggregated spatial patterns in tropical tree species. This study investigates aggregate dynamics of Vouacapoua americana (Aublet), a climax species whose spatial pattern is not simply related to light and soil conditions or to its short seed dispersal range. Location: Two rain forest sites: Nouragues and Paracou, in the Guiana Shield. Methods: We described the spatial pattern of tree locations and spatial autocorrelation of tree diameters, using statistics derived from Ripley's K. We particularly used methods to define analysis subplots according to local density or local mean diameter. We investigated relationships between spatial distributions of adults and saplings. Results: At both sites, populations of Vouacapoua demonstrated several nested levels of aggregation. Tree diameters were spatially autocorrelated, revealing the existence of clusters with similar diameters. In the largest aggregates, tree diameters declined from the centre to the edge. Regeneration was aggregated and occurred mainly at cluster edges and around rare isolated trees, and sapling densities and basal area of adults were negatively correlated. We show that long-distance dispersal events are rare. Conclusions: Environmental factors and seed dispersal only explain part of the observed spatial patterns. We provide two main hypotheses about Vouacapoua population dynamics. First, the lack of regeneration in aggregate centres results in the ageing of existing aggregates. We suggest that this lack of recruitment close to mature trees is due to a Janzen-Connell effect. However, aggregates can continue to grow along colonization fronts. Second, long-distance dispersal events allow the formation of new clusters and play a crucial role in the colonization process. We investigate aggregate dynamics of Vouacapoua americana (Aublet) whose spatial pattern is not simply related to environmental conditions or to its seed dispersal. Regeneration does not occur in centers of aggregate of adults. We suggest that rare long-distance dispersal events and density-dependence predation of seeds and seedlings play a crucial role in formation of new clusters and structuration of larger aggregates. © 2013 International Association for Vegetation Science.  
  Address Université Claude Bernard Lyon 1, 43 Boulevard 11 Novembre 1918, Villeurbanne, 69100, France  
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  Notes Export Date: 10 March 2014; Source: Scopus; Coden: Jvese; Language of Original Document: English; Correspondence Address: Traissac, S.; AgroParisTech, UMR ECOlogie des Forêts de Guyane, Campus Agronomique, BP 709, Kourou, 97387, France; email: stephane.traissac@ecofog.gf Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 532  
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Author Malé, P.-J.G.; Ferdy, J.-B.; Leroy, C.; Roux, O.; Lauth, J.; Avilez, A.; Dejean, A.; Quilichini, A.; Orivel, J. url  openurl
  Title Retaliation in Response to Castration Promotes a Low Level of Virulence in an Ant-Plant Mutualism Type Journal Article
  Year 2014 Publication Evolutionary Biology Abbreviated Journal Evol. Biol.  
  Volume 41 Issue 1 Pages 22-28  
  Keywords Allomerus decemarticulatus; Cheater; Evolutionary conflict; Hirtella physophora; Mutualism breakdown; Overexploitation  
  Abstract The diversion of a host's energy by a symbiont for its own benefit is a major source of instability in horizontally-transmitted mutualisms. This instability can be counter-balanced by the host's retaliation against exploiters. Such responses are crucial to the maintenance of the relationship. We focus on this issue in an obligate ant-plant mutualism in which the ants are known to partially castrate their host plant. We studied plant responses to various levels of castration in terms of (1) global vegetative investment and (2) investment in myrmecophytic traits. Castration led to a higher plant growth rate, signalling a novel case of gigantism induced by parasitic castration. On the other hand, completely castrated plants produced smaller nesting and food resources (i.e. leaf pouches and extra floral nectaries). Since the number of worker larvae is correlated to the volume of the leaf pouches, such a decrease in the investment in myrmecophytic traits demonstrates for the first time the existence of inducible retaliation mechanisms against too virulent castrating ants. Over time, this mechanism promotes an intermediate level of castration and enhances the stability of the mutualistic relationship by providing the ants with more living space while allowing the plant to reproduce. © 2013 Springer Science+Business Media New York.  
  Address Laboratoire Evolution and Diversité Biologique, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France  
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  Notes Export Date: 10 March 2014; Source: Scopus; Language of Original Document: English; Correspondence Address: Malé, P.-J. G.; Laboratoire Evolution and Diversité Biologique, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France; email: pjg.male@gmail.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 533  
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