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Author Leroy, C.; Sejalon-Delmas, N.; Jauneau, A.; Ruiz-Gonzalez, M.X.; Gryta, H.; Jargeat, P.; Corbara, B.; Dejean, A.; Orivel, J. doi  openurl
  Title Trophic mediation by a fungus in an ant-plant mutualism Type Journal Article
  Year 2011 Publication Journal of Ecology Abbreviated Journal J. Ecol.  
  Volume 99 Issue 2 Pages 583-590  
  Keywords delta N-15; Allomerus decemarticulatus; ant-plant-fungus interactions; Ascomycete; fungal mediation; Hirtella physophora; mutualisms; myrmecophytes; nutrient provisioning; stable isotopes  
  Abstract 1. Plants often rely on external, mutualistic partners to survive and reproduce in resource-limited environments or for protection from enemies. Such interactions, including mycorrhizal symbioses and ant plant associations, are widespread and play an important role at the ecosystem and community levels. In ant-plant mutualisms, the plants may benefit from both the protection provided by the presence of ants and from the nutrients absorbed from insect debris. However, the role of third partners in plant nutrition, particularly ant-associated fungi, has never before been demonstrated. 2. We investigate this issue in the ant-plant Hirtella physophora. In this model system, Allomerus decemarticulatus ants are involved in two, highly specific interactions: first, with their host plant, and, secondly, with a fungus that they actively manipulate. Moreover, the ants combine both plant trichomes and fungal hyphae to make a trap to capture prey. 3. We empirically demonstrate the existence of a third type of interaction between the fungus and the plant through the use of both experimental enrichments with stable isotopes (N-15) and histological approaches. The fungus growing in the galleries plays a role in providing nutrients to the host plant, in addition to the structural role it plays for the ants. Fungus-facilitated nitrogen uptake occurs mainly in old domatia, where abundant hyphae are in close contact with the plant cells. Whether the fungi inside the domatia and those in the galleries are the same is still uncertain. 4. Synthesis. Together, our results show that a fungal partner in an ant-plant mutualism can benefit the plant by improving its nutrient uptake, and they demonstrate the existence of a true tripartite mutualism in this system. Our results add further evidence to the notion that interpretations of some ant plant symbioses as purely protective mutualisms have overlooked these nutritional aspects.  
  Address [Leroy, Celine; Dejean, Alain; Orivel, Jerome] CNRS, UMR Ecol Forets Guyane, F-97379 Kourou, France, Email: jerome.orivel@ecofog.gf  
  Corporate Author Thesis  
  Publisher Wiley-Blackwell 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:000287785300024 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 297  
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Author Lebrini, M.; Robert, F.; Roos, C. pdf  openurl
  Title Alkaloids Extract from Palicourea guianensis Plant as Corrosion Inhibitor for C38 Steel in 1 M Hydrochloric Acid Medium Type Journal Article
  Year 2011 Publication International Journal of Electrochemical Science Abbreviated Journal Int. J. Electrochem. Sci.  
  Volume 6 Issue 3 Pages 847-859  
  Keywords Palicourea guianensis; corrosion inhibitors; C38 steel; acidic media; adsorption  
  Abstract Corrosion inhibition effect of alkaloids extract from Palicourea guianensis plant (AEPG) on C38 tell in 1 M HCl medium has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. The polarization studies that AEPG acts as mixed-type inhibitor. The electrochemical impedance spectroscopy showed that the charge transfer resistance increases and the double layer capacitance decreases on increasing plant extract concentration. The inhibition efficiency of the extract obtained from impedance and polarization measurements was in a good agreement and was found to increase with increasing concentration of the extract. Inhibition efficiency of 89% was achieved with 100 mg L-1 of AEPG at 25 degrees C. The obtained results showed that, the Palicourea guianensis extract could serve as an effective inhibitor for the corrosion of steel in acid media. The adsorption of AEPG obeys the Langmuir adsorption isotherm.  
  Address [Lebrini, M.; Robert, F.; Roos, C.] UAG UMR ECOFOG, Lab Mat & Mol Milieu Amazonien, Cayenne 97337, French Guiana, Email: florent.robert@guyane.univ-ag.fr  
  Corporate Author Thesis  
  Publisher Electrochemical Science Group Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1452-3981 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287820500026 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 298  
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Author Lebrini, M.; Robert, F.; Lecante, A.; Roos, C. openurl 
  Title Corrosion inhibition of C38 steel in 1 M hydrochloric acid medium by alkaloids extract from Oxandra asbeckii plant Type Journal Article
  Year 2011 Publication Corrosion Science Abbreviated Journal Corrosion Sci.  
  Volume 53 Issue 2 Pages 687-695  
  Keywords Steel; EIS; Polarization; Raman spectroscopy; Acid inhibition  
  Abstract The inhibition effect of alkaloids extract from Oxandra asbeckii plant (OAPE) on the corrosion of C38 steel in 1 M hydrochloric acid solution has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency increases on increasing plant extracts concentration. Cathodic and anodic polarization curves show that OAPE is a mixed-type inhibitor. The effect of temperature on the corrosion behavior of C38 steel in 1 M HCl with and without addition of plant extract was studied in the temperature range 25-55 degrees C. The thermodynamic functions of dissolution and adsorption processes were calculated from experimental polarization data and the interpretation of the results are given. The adsorption of this plant extract on the C38 steel surface obeys the Langmuir adsorption isotherm. Surface analysis (Raman) was also carried out to establish the corrosion inhibitive property of this plant extract in HCl solution. (C) 2010 Elsevier Ltd. All rights reserved.  
  Address [Robert, F.; Lecante, A.; Roos, C.] UAG UMR ECOFOG, Lab Mat & Mol Milieu Amazonien, Cayenne 97337, French Guiana, Email: christophe.roos@guyane.univ-ag.fr  
  Corporate Author Thesis  
  Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0010-938x ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287004700021 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 299  
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Author Lecante, A.; Robert, F.; Blandinieres, P.A.; Roos, C. openurl 
  Title Anti-corrosive properties of S. tinctoria and G. ouregou alkaloid extracts on low carbon steel Type Journal Article
  Year 2011 Publication Current Applied Physics Abbreviated Journal Curr. Appl. Phys.  
  Volume 11 Issue 3 Pages 714-724  
  Keywords Low carbon steel; Acidic media; Corrosion inhibitor; Plant extract; EIS  
  Abstract The effect of alkaloid extracts from two Amazonian trees (Guatteria ouregou and Simira tinctoria) on low carbon steel corrosion was investigated in acidic solutions by using electrochemical techniques. All of these plant extracts inhibit the corrosion of low carbon steel in 0.1 M HCl solutions. As their concentration increases to 250 mg/L, the inhibition efficiencies of S. tinctoria and G. ouregou alkaloid extracts reach approximately 92% in 0.1 M HCl solutions. The adsorption of the inhibitor molecules was in accordance with the Langmuir adsorption isotherm. The results obtained show that these plant extracts could be serve as an effective inhibitor for the corrosion of low carbon steel in hydrochloric acid media. Furthermore, harmane was identified as the main component of S. tinctoria extract and that suggests that it is the active ingredient against corrosion of low carbon steel. (C) 2010 Elsevier B.V. All rights reserved.  
  Address [Lecante, A.; Robert, F.; Blandinieres, P. A.; Roos, C.] UAG UMR ECOFOG, Lab Mat & Mol Milieu Amazonien, F-97337 Cayenne, French Guiana, France, Email: florent.robert@guyane.univ-ag.fr  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1567-1739 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000288183300088 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 300  
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Author Dejean, A.; Lachaud, J.P. openurl 
  Title The hunting behavior of the African ponerine ant Pachycondyla pachyderma Type Journal Article
  Year 2011 Publication Behavioural Processes Abbreviated Journal Behav. Processes  
  Volume 86 Issue 2 Pages 169-173  
  Keywords Hunting behavior; Feeding specialization; Behavioral flexibility; Ponerine ants; Pachycondyla; Myriapoda  
  Abstract The hunting behavior of the African ponerine ant Pachycondyla pachyderma, a semi-specialized centipede predator, appears well adapted to this kind of prey and shows a graded complexity according to the difficulty it has in overwhelming prey. Small prey (5-to-8-mm-long termites) were detected by contact and seized by the thorax while larger prey (>= 30-mm-long centipedes) were frequently detected from a distance and seized by the anterior-most part of their body. Termites and 30-mm-long lithobiomorph centipedes were not always stung, whereas stinging and even repeated stinging was needed for 50-mm-long geophilomorphs and scolopendromorphs. Moreover, overwhelming wide and heavy scolopendromorphs, which have better defensive abilities, involved the use of additional behaviors allowing the workers to capture them safely: venom spreading, and a peculiar stinging posture, the “fatal embrace”. Here the workers seize scolopendromorphs by an antenna or by one of their first legs, wrap themselves around the prey while maintaining their grip with their mandibles and legs, and slowly inject venom into the prey's ventral surface. Workers retrieve small prey solitarily while, for large geophilomorphs and scolopendromorphs, nestmates can be recruited at short range or even at long range through tandem running. (C) 2010 Elsevier B.V. All rights reserved.  
  Address [Dejean, Alain] CNRS, Ecol Forets Guyane UMR CNRS 8172, F-97379 Kourou, France, Email: alain.dejean@wanadoo.fr  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0376-6357 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287984900001 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 301  
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Author Bourguignon, T.; Sobotnik, J.; Lepoint, G.; Martin, J.M.; Hardy, O.J.; Dejean, A.; Roisin, Y. openurl 
  Title Feeding ecology and phylogenetic structure of a complex neotropical termite assemblage, revealed by nitrogen stable isotope ratios Type Journal Article
  Year 2011 Publication Ecological Entomology Abbreviated Journal Ecol. Entomol.  
  Volume 36 Issue 2 Pages 261-269  
  Keywords Diet diversity; feeding groups; Isoptera; phylogenetic autocorrelation  
  Abstract 2. Nitrogen stable isotopes (hereafter delta 15N) were used to place termites from French Guiana rainforests along a wood-soil decomposition gradient, to test (i) whether feeding group assignation based on morphological characters was accurate and actually represented diet specialisation thresholds, and (ii) to what extent the dietary specialization of species is explained by phylogeny (phylogenetic autocorrelation). 3. delta 15N values vary over a range of 13 parts per thousand, suggesting that diet diversification contributes to the high species diversity in French Guiana. delta 15N values span a similar interval in all Termitidae subfamilies. Ranges of different subfamilies broadly overlap, although each of them diversified preferentially on one side of the wood-soil decomposition gradient. Congeneric species share similar feeding habits, whereas distant species tend to feed on distinct substrates. 4. Feeding groups did not completely match stable isotope data: there was no discontinuity between Groups III and IV, and no correlation between anatomical criteria used to distinguish these groups and delta 15N values. Nor was there any consistent difference in delta 15N values between wood feeders of the families Rhinotermitidae (Group I) and Termitidae (Group II). We also suggest that species feeding outside the wood-soil gradient should be distinguished for their peculiar feeding requirements.  
  Address [Sobotnik, Jan] Acad Sci Czech Republic, Inst Organ Chem & Biochem, Res Team Infochem, CR-16610 Prague 6, Czech Republic, Email: sobotnik@uochb.cas.cz  
  Corporate Author Thesis  
  Publisher Wiley-Blackwell Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0307-6946 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000288456300016 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 302  
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Author Siebicke, L.; Steinfeld, G.; Foken, T. openurl 
  Title CO2-gradient measurements using a parallel multi-analyzer setup Type Journal Article
  Year 2011 Publication Atmospheric Measurement Techniques Abbreviated Journal Atmos. Meas. Tech.  
  Volume 4 Issue 3 Pages 409-423  
  Keywords  
  Abstract Accurate CO2 concentration gradient measurements are needed for the computation of advective flux terms, which are part of the full Net Ecosystem Exchange (NEE) budget equation. A typical draw back of current gradient measurement designs in advection research is the inadequate sampling of complex flow phenomena using too few observation points in space and time. To overcome this draw back, a new measurement design is presented which allows the parallel measurement of several sampling points at a high frequency. Due to the multi-analyzer nature of the design, inter-instrument bias becomes more of a concern compared to conventional setups. Therefore a statistical approach is presented which allows for accurate observations of concentration gradients, which are typically small in relation to analyzer accuracy, to be obtained. This bias correction approach applies a conditional, time dependent signal correction. The correction depends on a mixing index based on cross correlation analysis, which characterizes the degree of mixing of the atmosphere between individual sample points. The approach assumes statistical properties of probability density functions (pdf) of concentration differences between a sample point and the field average which are common to the pdf's from several sample points. The applicability of the assumptions made was tested by Large Eddy Simulation (LES) using the model PALM and could be verified for a test case of well mixed conditions. The study presents concentration time series before and after correction, measured at a 2 m height in the sub-canopy at the FLUXNET spruce forest site Waldstein-Weidenbrunnen (DE-Bay), analyzes the dependence of statistical parameters of pdf's from atmospheric parameters such as stratification, quantifies the errors and evaluates the performance of the bias correction approach. The improvements that are achieved by applying the bias correction approach are one order of magnitude larger than possible errors associated with it, which is a strong incentive to use the correction approach. In conclusion, the presented bias correction approach is well suited for – but not limited to – horizontal gradient measurements in a multi-analyzer setup, which would not have been reliable without this approach. Finally, possible future improvements of the bias correction approach are outlined and further fields of application indicated.  
  Address [Siebicke, L.; Foken, T.] Univ Bayreuth, Dept Micrometeorol, Bayreuth, Germany, Email: lukas.siebicke@ecofog.gf  
  Corporate Author Thesis  
  Publisher Copernicus Gesellschaft Mbh Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1867-1381 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000288911000002 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 303  
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Author Fanin, N.; Hattenschwiler, S.; Barantal, S.; Schimann, H.; Fromin, N. openurl 
  Title Does variability in litter quality determine soil microbial respiration in an Amazonian rainforest? Type Journal Article
  Year 2011 Publication Soil Biology & Biochemistry Abbreviated Journal Soil Biol. Biochem.  
  Volume 43 Issue 5 Pages 1014-1022  
  Keywords Carbon forms; French Guiana; Litter quality; Microbial respiration process; Nitrogen; Phosphorus; Stoichiometry  
  Abstract Tree species-rich tropical rainforests are characterized by a highly variable quality of leaf litter input to the soil at small spatial scales. This diverse plant litter is a major source of energy and nutrients for soil microorganisms, particularly in rainforests developed on old and nutrient-impoverished soils. Here we tested the hypothesis that the variability in leaf litter quality produced by a highly diverse tree community determines the spatial variability of the microbial respiration process in the underlying soil. We analyzed a total of 225 litter-soil pairs from an undisturbed Amazonian rainforest in French Guiana using a hierarchical sampling design. The microbial respiration process was assessed using substrate-induced respiration (SIR) and compared to a wide range of quality parameters of the associated litter layer (litter nutrients, carbon forms, stoichiometry, litter mass and pH). The results show that the variability of both litter quality and SIR rates was more important at large than at small scales. SIR rates varied between 1.1 and 4.0 μg h(-1) and were significantly correlated with litter layer quality (up to 50% of the variability explained by the best mixed linear model). Total litter P content was the individual most important factor explaining the observed spatial variation in soil SIR, with higher rates associated to high litter P. SIR rates also correlated positively with total litter N content and with increasing proportions of labile C compounds. However, contrary to our expectation, SIR rates were not related to litter stoichiometry. These data suggest that in the studied Amazonian rainforest, tree canopy composition is an important driver of the microbial respiration process via leaf litter fall, resulting in potentially strong plant-soil feedbacks. (C) 2011 Elsevier Ltd. All rights reserved.  
  Address [Fanin, Nicolas; Haettenschwiler, Stephan; Barantal, Sandra; Fromin, Nathalie] CNRS, CEFE, UMR 5175, F-34293 Montpellier 5, France, Email: nicolas.fanin@cefe.cnrs.fr  
  Corporate Author Thesis  
  Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0038-0717 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000289219500019 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 304  
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Author Ruelle, J.; Beauchene, J.; Yamamoto, H.; Thibaut, B. openurl 
  Title Variations in physical and mechanical properties between tension and opposite wood from three tropical rainforest species Type Journal Article
  Year 2011 Publication Wood Science and Technology Abbreviated Journal Wood Sci. Technol.  
  Volume 45 Issue 2 Pages 339-357  
  Keywords  
  Abstract Growth strains were measured in situ in nine trees of three species from a French Guiana tropical rainforest in a clearly active verticality restoration process. The aim was to detect tension wood within the samples. Wood specimens were cut in the vicinity of the growth strain measurements in order to determine the microfibril angle and some mechanical and physical properties. As suspected, tensile growth strain was much higher in tension wood zones, as shown by the slightly higher longitudinal modulus of elasticity. Conversely, tension wood showed reduced compression strength. Longitudinal shrinkage was much higher in tension wood than in opposite wood. Clear relationships between the microfibril angle and longitudinal properties were noted in comparison (i) with those observed in gymnosperm compression wood and (ii) with expected relationships from the organization of wood fibres cell wall structure.  
  Address [Ruelle, Julien; Yamamoto, Hiroyuki] Nagoya Univ, Grad Sch Bioagr Sci, Nagoya, Aichi 4648601, Japan, Email: julien.ruelle@ecofog.gf  
  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 0043-7719 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000289477300013 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 305  
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Author Dejean, A.; Corbara, B.; Leroy, C.; Delabie, J.H.C.; Rossi, V.; Cereghino, R. pdf  openurl
  Title Inherited Biotic Protection in a Neotropical Pioneer Plant Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS One  
  Volume 6 Issue 3 Pages e18071  
  Keywords  
  Abstract Chelonanthus alatus is a bat-pollinated, pioneer Gentianaceae that clusters in patches where still-standing, dried-out stems are interspersed among live individuals. Flowers bear circum-floral nectaries (CFNs) that are attractive to ants, and seed dispersal is both barochorous and anemochorous. Although, in this study, live individuals never sheltered ant colonies, dried-out hollow stems – that can remain standing for 2 years – did. Workers from species nesting in dried-out stems as well as from ground-nesting species exploited the CFNs of live C. alatus individuals in the same patches during the daytime, but were absent at night (when bat pollination occurs) on 60.5% of the plants. By visiting the CFNs, the ants indirectly protect the flowers – but not the plant foliage – from herbivorous insects. We show that this protection is provided mostly by species nesting in dried-out stems, predominantly Pseudomyrmex gracilis. That dried-out stems remain standing for years and are regularly replaced results in an opportunistic, but stable association where colonies are sheltered by one generation of dead C. alatus while the live individuals nearby, belonging to the next generation, provide them with nectar; in turn, the ants protect their flowers from herbivores. We suggest that the investment in wood by C. alatus individuals permitting still-standing, dried-out stems to shelter ant colonies constitutes an extended phenotype because foraging workers protect the flowers of live individuals in the same patch. Also, through this process these dried-out stems indirectly favor the reproduction (and so the fitness) of the next generation including both their own offspring and that of their siblings, all adding up to a potential case of inclusive fitness in plants.  
  Address [Dejean, Alain; Leroy, Celine] 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:000289057200023 Approved no  
  Call Number (down) EcoFoG @ webmaster @ Serial 306  
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