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Author Dejean, A.; Leroy, C.; Corbara, B.; Roux, O.; Cereghino, R.; Orivel, J.; Boulay, R. pdf  openurl
  Title Arboreal Ants Use the "Velcro (R) Principle'' to Capture Very Large Prey Type Journal Article
  Year 2010 Publication PLoS One Abbreviated Journal PLoS One  
  Volume 5 Issue (down) 6 Pages e11331  
  Keywords  
  Abstract Plant-ants live in a mutualistic association with host plants known as "myrmecophytes'' that provide them with a nesting place and sometimes with extra-floral nectar (EFN) and/or food bodies (FBs); the ants can also attend sap-sucking Hemiptera for their honeydew. In return, plant-ants, like most other arboreal ants, protect their host plants from defoliators. To satisfy their nitrogen requirements, however, some have optimized their ability to capture prey in the restricted environment represented by the crowns of trees by using elaborate hunting techniques. In this study, we investigated the predatory behavior of the ant Azteca andreae which is associated with the myrmecophyte Cecropia obtusa. We noted that up to 8350 ant workers per tree hide side-by-side beneath the leaf margins of their host plant with their mandibles open, waiting for insects to alight. The latter are immediately seized by their extremities, and then spread-eagled; nestmates are recruited to help stretch, carve up and transport prey. This group ambush hunting technique is particularly effective when the underside of the leaves is downy, as is the case for C. obtusa. In this case, the hook-shaped claws of the A. andreae workers and the velvet-like structure of the underside of the leaves combine to act like natural Velcro (R) that is reinforced by the group ambush strategy of the workers, allowing them to capture prey of up to 13,350 times the mean weight of a single worker.  
  Address [Dejean, Alain; Leroy, Celine; Roux, Olivier; Orivel, Jerome] CNRS, Ecol Forets Guyane UMR CNRS 8172, Kourou, France, Email: alain.dejean@wanadoo.fr  
  Corporate Author Thesis  
  Publisher PUBLIC LIBRARY SCIENCE Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000279140800028 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 56  
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Author Roggy, J.C.; Nicolini, E.; Imbert, P.; Caraglio, Y.; Bosc, A.; Heuret, P. openurl 
  Title Links between tree structure and functional leaf traits in the tropical forest tree Dicorynia guianensis Amshoff (Caesalpiniaceae) Type Journal Article
  Year 2005 Publication Annals of Forest Science Abbreviated Journal Ann. For. Sci.  
  Volume 62 Issue (down) 6 Pages 553-564  
  Keywords Dicorynia guianensis; leaf structure; functional leaf traits; plasticity; tree structure  
  Abstract This study looked at the interactive effects of tree architectural stage of development (ASD) and light availability on different plant traits (growth parameters, leaf morpho-anatomy and photosynthetic capacities) in the tropical species Dicorynia guianensis. A qualitative architectural analysis was used to categorize tree individuals sampled along a natural light gradient. The results show that some traits could have an ASD-dependence at the whole plant and leaf level without control of light. The changes observed relate to vigour thresholds the plant has to reach to shift from one ASD to another (i.e., the number of nodes and the internodes length per Growth Unit). Light conditions do not modify these thresholds but may modify the time they are crossed. Tree height was found strongly modulated by light conditions; hence, at a similar height, individuals may belong to different ASD. At the functional level, a decrease in N-m, and A(maxm) was observed with increasing light availability, while N-a increased and A(maxa) remained unaffected. An ASD effect was also observed on Amaxa and LMA but not on Amaxm. These results demonstrated a weak ability of photosynthetic plasticity in response to light conditions, and that variations of leaf photosynthetic variables according to ASD can be explained by modifications in leaf nitrogen and LMA. Questions on the reliability of a height-based sampling strategy for evaluating the phenotypic plasticity of trees in relation to light conditions are raised.  
  Address INRA, Ecol Forets Guyane, ENGREF, UMR CIRAD, F-97387 Kourou, Guyane Francais, France, Email: roggy.j@cirad.fr  
  Corporate Author Thesis  
  Publisher EDP SCIENCES S A Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1286-4560 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000232084400009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 229  
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Author Blanc, L.; Echard, M.; Herault, B.; Bonal, D.; Marcon, E.; Chave, J.; Baraloto, C. openurl 
  Title Dynamics of aboveground carbon stocks in a selectively logged tropical forest Type Journal Article
  Year 2009 Publication Ecological Applications Abbreviated Journal Ecol. Appl.  
  Volume 19 Issue (down) 6 Pages 1397-1404  
  Keywords aboveground biomass; carbon sequestration; deforestation; French Guiana; global change; timber stand improvement; tropical forests  
  Abstract The expansion of selective logging in tropical forests may be an important source of global carbon emissions. However, the effects of logging practices on the carbon cycle have never been quantified over long periods of time. We followed the fate of more than 60 000 tropical trees over 23 years to assess changes in aboveground carbon stocks in 48 1.56-ha plots in French Guiana that represent a gradient of timber harvest intensities, with and without intensive timber stand improvement (TSI) treatments to stimulate timber tree growth. Conventional selective logging led to emissions equivalent to more than a third of aboveground carbon stocks in plots without TSI (85 Mg C/ha), while plots with TSI lost more than one-half of aboveground carbon stocks (142 Mg C/ha). Within 20 years of logging, plots without TSI sequestered aboveground carbon equivalent to more than 80% of aboveground carbon lost to logging (-70.7 Mg C/ha), and our simulations predicted an equilibrium aboveground carbon balance within 45 years of logging. In contrast, plots with intensive TSI are predicted to require more than 100 years to sequester aboveground carbon lost to emissions. These results indicate that in some tropical forests aboveground carbon storage can be recovered within half a century after conventional logging at moderate harvest intensities.  
  Address [Bonal, Damien; Baraloto, Christopher] INRA, UMR Ecol Forets Guyane, Kourou 97379, French Guiana, Email: chris.baraloto@ecofog.gf  
  Corporate Author Thesis  
  Publisher ECOLOGICAL SOC AMER Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-0761 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000269075200003 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 105  
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Author Strasburg, J.L.; Scotti-Saintagne, C.; Scotti, I.; Lai, Z.; Rieseberg, L.H. openurl 
  Title Genomic Patterns of Adaptive Divergence between Chromosomally Differentiated Sunflower Species Type Journal Article
  Year 2009 Publication Molecular Biology and Evolution Abbreviated Journal Mol. Biol. Evol.  
  Volume 26 Issue (down) 6 Pages 1341-1355  
  Keywords species boundaries; chromosomal rearrangements; positive selection; hybridization; sunflowers; Helianthus  
  Abstract Understanding the genetic mechanisms of speciation and basis of species differences is among the most important challenges in evolutionary biology. Two questions of particular interest are what roles divergent selection and chromosomal differentiation play in these processes. A number of recently proposed theories argue that chromosomal rearrangements can facilitate the development and maintenance of reproductive isolation and species differences by suppressing recombination within rearranged regions. Reduced recombination permits the accumulation of alleles contributing to isolation and adaptive differentiation and protects existing differences from the homogenizing effects of introgression between incipient species. Here, we examine patterns of genetic diversity and divergence in rearranged versus collinear regions in two widespread, extensively hybridizing sunflower species, Helianthus annuus and Helianthus petiolaris, using sequence data from 77 loci distributed throughout the genomes of the two species. We find weak evidence for increased genetic divergence near chromosomal break points but not within rearranged regions overall. We find no evidence for increased rates of adaptive divergence on rearranged chromosomes; in fact, collinear chromosomes show a far greater excess of fixed amino acid differences between the two species. A comparison with a third sunflower species indicates that much of the nonsynonymous divergence between H. annuus and H. petiolaris probably occurred during or soon after their formation. Our results suggest a limited role for chromosomal rearrangements in genetic divergence, but they do document substantial adaptive divergence and provide further evidence of how species integrity and genetic identity can be maintained at many loci in the face of extensive hybridization and gene flow.  
  Address [Strasburg, Jared L.; Scotti-Saintagne, Caroline; Rieseberg, Loren H.] Indiana Univ, Dept Biol, Bloomington, IN 47405 USA, Email: jstrasbu@indiana.edu  
  Corporate Author Thesis  
  Publisher OXFORD UNIV PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0737-4038 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000266116500012 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 111  
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Author Yamamoto, H.; Almeras, T. doi  openurl
  Title A mathematical verification of the reinforced-matrix hypothesis using the Mori-Tanaka theory Type Journal Article
  Year 2007 Publication Journal of Wood Science Abbreviated Journal J. Wood Sci.  
  Volume 53 Issue (down) 6 Pages 505-509  
  Keywords Engineering  
  Abstract This article presents a theoretical verification of the reinforced-matrix hypothesis derived from tensor equations, σ W = σ f + σ m and ε W = ε f = ε m (Wood Sci Technol 32:171–182, 1998; Wood Sci Technol 33:311–325, 1999; J Biomech Eng 124:432–440, 2002), using classical Mori-Tanaka theory on the micromechanics of fiber-reinforced materials (Acta Metall 21:571–574, 1973; Micromechanics — dislcation and inclusions (in Japanese), pp 141–147, 1976). The Mori-Tanaka theory was applied to a small fragment of the cell wall undergoing changes in its physical state, such as those arising from sorption of moisture, maturation of wall components, or action of an external force, to obtain ⟨σ A⟩D = ϕ·⟨σ F⟩I + (1−ϕ)·⟨σ M⟩D−I. When the constitutive equation of each constituent material was applied to the equation ⟨σ A⟩D = ϕ·⟨σ F⟩I + (1−ϕ)·⟨σ M⟩D−I, the equations σ W = σ f + σ m and ε W = ε f = ε m were derived to lend support to the concept that two main phases, the reinforcing cellulose microfibril and the lignin-hemicellulose matrix, coexist in the same domain. The constitutive equations for the cell wall fragment were obtained without recourse to additional parameters such as Eshelby’s tensor S and Hill’s averaged concentration tensors AF and AM. In our previous articles, the coexistence of two main phases and σ W = σ f + σ m and ε W = ε f =ε m had been taken as our starting point to formulate the behavior of wood fiber with multilayered cell walls. The present article provides a rational explanation for both concepts.  
  Address  
  Corporate Author Thesis  
  Publisher Springer Japan Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1435-0211 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 215  
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Author Baraloto, C.; Forget, P.M. openurl 
  Title Seed size, seedling morphology, and response to deep shade and damage in neotropical rain forest trees Type Journal Article
  Year 2007 Publication American Journal of Botany Abbreviated Journal Am. J. Bot.  
  Volume 94 Issue (down) 6 Pages 901-911  
  Keywords cotyledons; French Guiana; functional morphology; herbivory; life history; phylogeny; regeneration strategy; shade tolerance  
  Abstract To investigate the existence of coordinated sets of seedling traits adapted to contrasting establishment conditions, we examined evolutionary convergence in seedling traits for 299 French Guianan woody plant species and the stress response in a shadehouse of species representing seed size gradients within five major cotyledon morphology types. The French Guianan woody plant community has larger seeds than other tropical forest communities and the largest proportion of hypogeal cotyledon type (59.2%) reported for tropical forests. Yet the community includes many species with intermediate size seeds that produce seedlings with different cotyledonal morphologies. A split-plot factorial design with two light levels (0.8% and 16.1% PAR) and four damage treatments (control, seed damage, leaf damage, stem damage) was used in the shadehouse experiment. Although larger-seeded species had higher survival and slower growth, these patterns were better explained by cotyledon type than by seed mass. Even larger-seeded species with foliar cotyledons grew faster than species with reserve-type cotyledons, and survival after stem grazing was five times higher in seedlings with hypogeal cotyledons than with epigeal cotyledons. Thus, to predict seedling performance using seed size, seedling morphology must also be considered.  
  Address Inst Natl Rech Agronom, UMR, Ecol Forets Guyane, Kourou, France, Email: baraloto.c@kourou.cirad.fr  
  Corporate Author Thesis  
  Publisher BOTANICAL SOC AMER INC Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-9122 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000249830600001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 159  
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Author Veron, V.; Caron, H.; Degen, B. openurl 
  Title Gene flow and mating system of the tropical tree Sextonia rubra Type Journal Article
  Year 2005 Publication Silvae Genetica Abbreviated Journal Silvae Genet.  
  Volume 54 Issue (down) 6 Pages 275-280  
  Keywords genetic diversity; gene flow; heterozygosity; microsatellites; mixed mating; tropical tree; twogener  
  Abstract In this paper we report a study of the mating system and gene flow of Sextonia rubra, a hermaphroditic, insect pollinated tropical tree species with a geographic distribution in the Guyana Plateau and the Amazon. Using five microsatellites we analysed 428 seeds of 27 open pollinated families at the experimental site “Paracou” in French Guiana. We observed, compared to other tropical tree species, a high level of genetic diversity. We estimated parameters of the mating system and gene flow by using the mixed mating model and the TwoGener approach. The estimated multilocus outcrossing rate, t(m), was 0.992 indicating nearly complete outcrossing. A significant level of biparental inbreeding and a:small proportion. of full-sibs were estimated for the 27 seed arrays. The differentiation of allelic frequencies among the pollen pools was (Phi(FT) = 0.061. We estimated mean pollen dispersal distances between 65 m and 89 m according to the dispersal models used. The joint estimation of pollen dispersal and density of reproductive trees gave an effective density estimate of 2.1-2.2 trees/ha.  
  Address INRA, UMR, ECOFOG, Kourou 9738, French Guiana, Email: b.degen@holz.uni-hamburg.de  
  Corporate Author Thesis  
  Publisher J D SAUERLANDERS VERLAG Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0037-5349 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000235239400005 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 182  
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Author Baraloto, C.; Forget, P.M.; Goldberg, D.E. openurl 
  Title Seed mass, seedling size and neotropical tree seedling establishment Type Journal Article
  Year 2005 Publication Journal of Ecology Abbreviated Journal J. Ecol.  
  Volume 93 Issue (down) 6 Pages 1156-1166  
  Keywords French Guiana; life-history trade-offs; microhabitat; path analysis; regeneration strategy; relative growth rate; seedling survival; shade tolerance  
  Abstract 1 We examined among- and within-species effects of seed mass for seedling establishment from seed to 5 years of age in a field experiment at Paracou, French Guiana. 2 Six seeds of each of eight species were weighed and planted into each of 120 plots (1 m(2)) throughout closed-canopy forest along 12 100-m transects in 1998. 3 We described the microhabitat of each planting site using principal components derived from measurements of light availability, soil moisture, carbon and nitrogen content, and soil phosphorus availability. Although both survival and relative growth rate (RGR) increased with increasing light availability, no other microhabitat variable significantly affected seedling performance. Nor did the magnitude of microhabitat effects on survival or RGR differ among species. 4 Larger-seeded species were more likely to survive from germination to 1 year as well as from 1 to 5 years of age. RGR for seedling height during the first year post-germination was not related to seed mass, but smaller-seeded species did grow slightly faster thereafter. Path analyses revealed that correlations between seed mass and performance were explained in part because larger seeds produced larger initial seedlings, which tended to survive better but grow more slowly. 5 We also analysed within-species effects of seed mass for the larger-seeded Eperua grandiflora and Vouacapoua americana (both Caesalpiniaceae). Larger seeds produced larger seedlings in both species, but larger seeds survived better only for Eperua. Larger seedlings grew more slowly in both species, but did not offset the early (Eperua) and later (Vouacapoua) positive direct effects of seed mass on RGR that may represent contrasting strategies for reserve deployment. 6 Our results demonstrate that seed size influences performance within and among species in part because of indirect effects of initial seedling size. However, we suggest that traits tightly correlated with seed mass at the species level, such as specific leaf area, leaf longevity and photosynthetic capacity, may also contribute to interspecific performance differences.  
  Address Museum Natl Hist Nat, Dept Ecol & Gest Biodivers, UMR 5176, CNRS, Brunoy, France, Email: baraloto.c@kourou.cirad.fr  
  Corporate Author Thesis  
  Publisher BLACKWELL PUBLISHING Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-0477 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000233287500012 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 250  
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Author Cohen, M.C.L.; Behling, H.; Lara, R.J.; Smith, C.B.; Matos, H.R.S.; Vedel, V. openurl 
  Title Impact of sea-level and climatic changes on the Amazon coastal wetlands during the late Holocene Type Journal Article
  Year 2009 Publication Vegetation History and Archaeobotany Abbreviated Journal Veg. Hist. Archaeobot.  
  Volume 18 Issue (down) 6 Pages 425-439  
  Keywords Mangrove; Marajo Island; Pollen analysis; Sea-level  
  Abstract Wetland dynamics in northern Brazil during the Holocene were studied by pollen analysis and AMS radiocarbon dating of three cores. Near the Amazon mouth region, covered mainly by primary Amazon coastal forest and herbaceous vegetation, the pollen record indicates the dominance of mangroves between 4800 and 1100 cal yr B.P. A contraction of the mangrove area and an expansion of herbaceous and fern vegetation occurred between 1100 and 750 cal yr B.P. The period between 750 and 200 cal yr B.P. is characterized by an expansion of mangrove and a decrease in herbaceous and fern vegetation. This trend continued until the present. On Atalaia Island, the sediment core indicates a period with poor pollen preservation between 830 and 630 cal yr B.P. Between 630 and 330 cal yr B.P., mangroves expanded. Later, up to 45 cal yr B.P., the mangrove area decreased and the herbaceous vegetation expanded. During the last hundred years, the relative sea-level rise most probably favored the mangrove expansion as far as the topographically highest sector on this island, while the herbaceous vegetation decreased. The pollen data from Agua Preta Lake indicate dry conditions, as reflected by the poor pollen preservation between 390 and 240 cal yr B.P. Between 240 and 60 cal yr B.P., restinga and Amazon coastal forest with palms dominated this region. For the last 120 years, the record indicates an expansion of the mangrove area. However, recent confinement of mangrove development to the topographically highest area, and the loss of mangrove areas on the lowest surfaces have led to a net loss of mangrove coverage during the last decades.  
  Address [Lisboa Cohen, Marcelo Cancela; Smith, Clarisse Beltrao; Soares Matos, Hellen Rosy] Fed Univ Para, Postgrad Program Geol & Geochem, Lab Coastal Dynam, BR-66077530 Belem, PA, Brazil, Email: mcohen@ufpa.br  
  Corporate Author Thesis  
  Publisher SPRINGER Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0939-6314 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000271191800001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 193  
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Author Clair, B.; Jaouen, G.; Beauchene, J.; Fournier, M. openurl 
  Title Mapping radial, tangential and longitudinal shrinkages and relation to tension wood in discs of the tropical tree Symphonia globulifera Type Journal Article
  Year 2003 Publication Holzforschung Abbreviated Journal Holzforschung  
  Volume 57 Issue (down) 6 Pages 665-671  
  Keywords drying shrinkage; tension wood; Symphonia globulifera L. f.  
  Abstract A method for measuring shrinkage resulting from drying in the three anisotropic directions is developed and tested. Measurements are performed on sawn discs, a technique which simplifies preparation and enables large numbers of measurements. Shrinkage values can be represented as a map of the disc surface. The results indicate that comparisons between shrinkage distribution and tension wood distribution on the discs show a clear relationship and can be measured with relatively high accuracy in reference to the shrinkage map. In the long term, this method could be useful in the timber industry as a means for choosing the direction in which logs are cut depending on their type of wood composition.  
  Address CIRAD ENGREF INRA, UMR Ecol Forets Guyane, Kourou 97379, French Guiana  
  Corporate Author Thesis  
  Publisher WALTER DE GRUYTER & CO Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0018-3830 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000186257800016 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 243  
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