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Author Sarmiento, C.; Patino, S.; Paine, C.E.T.; Beauchene, J.; Thibaut, A.; Baraloto, C. openurl 
  Title Within-Individual Variation of Trunk and Branch Xylem Density in Tropical Trees Type Journal Article
  Year 2011 Publication American Journal of Botany Abbreviated Journal Am. J. Bot.  
  Volume 98 Issue 1 Pages 140-149  
  Keywords branch xylem density; French Guiana; functional trait; tropical trees; trunk xylem density; wood economics  
  Abstract Premise of the study : Wood density correlates with mechanical and physiological strategies of trees and is important for estimating global carbon stocks. Nonetheless, the relationship between branch and trunk xylem density has been poorly explored in neotropical trees. Here, we examine this relationship in trees from French Guiana and its variation among different families and sites, to improve the understanding of wood density in neotropical forests. Methods : Trunk and branch xylem densities were measured for 1909 trees in seven sites across French Guiana. A major-axis fit was performed to explore their general allometric relationship and its variation among different families and sites. Key results : Trunk xylem and branch xylem densities were significantly positively correlated, and their relationship explained 47% of the total variance. Trunk xylem was on average 9% denser than branch xylem. Family-level differences and interactions between family and site accounted for more than 40% of the total variance, whereas differences among sites explained little variation. Conclusions : Variation in xylem density within individual trees can be substantial, and the relationship between branch xylem and trunk xylem densities varies considerably among families and sites. As such, whole-tree biomass estimates based on non-destructive branch sampling should correct for both taxonomic and environmental factors. Furthermore, detailed estimates of the vertical distribution of wood density within individual trees are needed to determine the extent to which relying solely upon measures of trunk wood density may cause carbon stocks in tropical forests to be overestimated.  
  Address [Sarmiento, Carolina; Patino, Sandra; Baraloto, Christopher] INRA, UMR Ecol Forets Guyane, Kourou 97310, French Guiana, Email: carolinasar@gmail.com  
  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 (down) Series Issue Edition  
  ISSN 0002-9122 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000285747900019 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 290  
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Author Orivel, J.; Leroy, C. openurl 
  Title The diversity and ecology of ant gardens (Hymenoptera: Formicidae; Spermatophyta: Angiospermae) Type Journal Article
  Year 2011 Publication Myrmecological News Abbreviated Journal Myrmecol. News  
  Volume 14 Issue Pages 73-85  
  Keywords Ant-plant interactions; epiphytes; mutualisms; Neotropics; Paleotropics; phytotelm; parabiosis; seed dispersal; review  
  Abstract Mutualistic interactions between ants and plants are important features of many ecosystems, and they can be divided into three main categories: dispersal and protective mutualisms and myrmecotrophy. In both the Neotropics and the Southeastern Asian Paleotropics, ant gardens (AGs), a particular type of ant-plant interaction, are frequent. To initiate AGs, ants integrate the seeds of certain epiphyte species into the carton of their nest. The development of the plants leads to the formation of a cluster of epiphytes rooted in the carton. They have been defined as one of the most complex associations between ants and plants known because of the plurispecific, but also specialized nature of the association involving several phylogenetically-distant ant and plant species. The aim of this review is to provide a synthesis of the diversity and ecology of AGs, including the outcomes experienced by the partners in the interaction and the direct and indirect impacts ant-garden ants have on the plant and arthropod communities.  
  Address [Orivel, Jerome; Leroy, Celine] CNRS, UMR Ecol Forets Guyane, Kourou 97379, French Guiana, Email: jerome.orivel@ecofog.gf  
  Corporate Author Thesis  
  Publisher OESTERREICHISCHE GESELL ENTOMOFAUNISTIK, C/O NATURHISTOR MUSEUM WIEN Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume (down) Series Issue Edition  
  ISSN 1994-4136 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000286844100009 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 292  
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Author Rutishauser, E.; Barthelemy, D.; Blanc, L.; Nicolini, E.A. openurl 
  Title Crown fragmentation assessment in tropical trees: Method, insights and perspectives Type Journal Article
  Year 2011 Publication Forest Ecology and Management Abbreviated Journal For. Ecol. Manage.  
  Volume 261 Issue 3 Pages 400-407  
  Keywords Crown assessment; Crown fragmentation; Tree mortality; Forest dynamics  
  Abstract Decreasing growth rate (Feeley et al., 2007) and large die-back due to drought (Phillips et al., 2009) suggest that tropical forests are suffering recent climate changes. Forest vulnerability to external factors (e.g. air pollution, acid rain) is widely studied in northern countries, while only a few attempts have investigated crown integrity in the Tropics. The method needs to be generic enough to account for the large number of species and crown shapes encountered in tropical forests. In the present study, we developed and tested a novel field method that estimates crown fragmentation (main branch mortality (MB) and secondary branch mortality (SB)), liana infestation (LI) and crown position (CP) in the canopy. The relationship between crown fragmentation and annual growth rate (agr) was investigated through multiple regression. Six out of eight canopy tree species showed significant growth decline with increasing crown fragmentation. Higher probability of death was also found in trees with severe crown fragmentation. The capacity of such crown assessment to depict tree vitality in a forest stand is discussed along with potential applications in both forest science and management. (C) 2010 Elsevier B.V. All rights reserved.  
  Address [Rutishauser, Ervan; Eric-Andre, Nicolini] Cirad UMR AMAP, F-34398 Montpellier 5, France, Email: er.rutishauser@gmail.com  
  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 (down) Series Issue Edition  
  ISSN 0378-1127 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287333000009 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 293  
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Author Le Lann, C.; Roux, O.; Serain, N.; Van Alphen, J.J.M.; Vernon, P.; Van Baaren, J. openurl 
  Title Thermal tolerance of sympatric hymenopteran parasitoid species: does it match seasonal activity? Type Journal Article
  Year 2011 Publication Physiological Entomology Abbreviated Journal Physiol. Entomol.  
  Volume 36 Issue 1 Pages 21-28  
  Keywords Climate change; critical thermal limits; CTmax; CTmin; dry mass; guild; hind tibia length; seasonal activities; surface to volume ratio  
  Abstract Climatic changes result in an increased in mean temperature and in a higher incidence of extreme weather events such as heat and cold waves. For ectotherms, such as insect parasitoids, the ability to remain active under extreme climatic conditions is a significant key to fitness. The body size of individuals, and in particular their surface to volume ratio, may play a role in their resistance to thermal conditions. The thermal tolerances are investigated of two closely-related sympatric parasitoid species [Aphidius avenae Haliday and Aphidius rhopalosiphi De Stefani-Perez (Hymenoptera: Aphidiinae)] that have a similar ecology but differ in body size and phenologies. The critical thermal limits of individuals are assessed in both sexes of each parasitoid species and the influence of surface volume ratios on their thermal tolerances. Aphidius avenae is less resistant to low temperatures and more resistant to high temperatures than A. rhopalosiphi. The lower surface to volume ratio of A. avenae individuals may help them to remain active in summer when experiencing heat waves. However, body size is not the sole factor that plays a role in differences of thermal tolerance between species and body size may not be an adaptation to extreme temperatures but rather a by-product of developmental regulation. Closely-related sympatric species from the same ecological guild can have different thermal tolerances that may allow them to occur within the same habitat. The present study also highlights the importance of clearly defining how to measure critical thermal limits to determine the thermal tolerance of a species.  
  Address [Le Lann, Cecile; Serain, Nelly; Van Alphen, Jacques J. M.; Vernon, Philippe; Van Baaren, Joan] Univ Rennes 1, UMR CNRS ECOBIO 6553, F-35042 Rennes, France, Email: cecile.lelann@univ-rennes1.fr  
  Corporate Author Thesis  
  Publisher Wiley-Blackwell Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume (down) Series Issue Edition  
  ISSN 0307-6962 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287790900004 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 294  
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Author Orivel, J.; Lambs, L.; Male, P.J.G.; Leroy, C.; Grangier, J.; Otto, T.; Quilichini, A.; Dejean, A. openurl 
  Title Dynamics of the association between a long-lived understory myrmecophyte and its specific associated ants Type Journal Article
  Year 2011 Publication Oecologia Abbreviated Journal Oecologia  
  Volume 165 Issue 2 Pages 369-376  
  Keywords Allomerus decemarticulatus; Hirtella physophora; Lifespan; Mutualism; Myrmecophyte  
  Abstract Myrmecophytic symbioses are widespread in tropical ecosystems and their diversity makes them useful tools for understanding the origin and evolution of mutualisms. Obligate ant-plants, or myrmecophytes, provide a nesting place, and, often, food to a limited number of plant-ant species. In exchange, plant-ants protect their host plants from herbivores, competitors and pathogens, and can provide them with nutrients. Although most studies to date have highlighted a similar global pattern of interactions in these systems, little is known about the temporal structuring and dynamics of most of these associations. In this study we focused on the association between the understory myrmecophyte Hirtella physophora (Chrysobalanaceae) and its obligate ant partner Allomerus decemarticulatus (Myrmicinae). An examination of the life histories and growth rates of both partners demonstrated that this plant species has a much longer lifespan (up to about 350 years) than its associated ant colonies (up to about 21 years). The size of the ant colonies and their reproductive success were strongly limited by the available nesting space provided by the host plants. Moreover, the resident ants positively affected the vegetative growth of their host plant, but had a negative effect on its reproduction by reducing the number of flowers and fruits by more than 50%. Altogether our results are important to understanding the evolutionary dynamics of ant-plant symbioses. The highly specialized interaction between long-lived plants and ants with a shorter lifespan produces an asymmetry in the evolutionary rates of the interaction which, in return, can affect the degree to which the interests of the two partners converge.  
  Address [Orivel, Jerome; Leroy, Celine; Quilichini, Angelique; Dejean, Alain] CNRS, UMR Ecol Forets Guyane, F-97379 Kourou, France, Email: jerome.orivel@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 (down) Series Issue Edition  
  ISSN 0029-8549 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000286224900012 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 295  
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Author Haettenschwiler, S.; Coq, S.; Barantal, S.; Handa, I.T. openurl 
  Title Leaf traits and decomposition in tropical rainforests: revisiting some commonly held views and towards a new hypothesis Type Journal Article
  Year 2011 Publication New Phytologist Abbreviated Journal New Phytol.  
  Volume 189 Issue 4 Pages 950-965  
  Keywords energy starvation; French Guiana; litter quality; mycorrhizas; nutrient cycling; nutrient limitation; phosphorus; soil fauna  
  Abstract Proper estimates of decomposition are essential for tropical forests, given their key role in the global carbon (C) cycle. However, the current paradigm for litter decomposition is insufficient to account for recent observations and may limit model predictions for highly diverse tropical ecosystems. In light of recent findings from a nutrient-poor Amazonian rainforest, we revisit the commonly held views that: litter traits are a mere legacy of live leaf traits; nitrogen (N) and lignin are the key litter traits controlling decomposition; and favourable climatic conditions result in rapid decomposition in tropical forests. Substantial interspecific variation in litter phosphorus (P) was found to be unrelated to variation in green leaves. Litter nutrients explained no variation in decomposition, which instead was controlled primarily by nonlignin litter C compounds at low concentrations with important soil fauna effects. Despite near-optimal climatic conditions, tropical litter decomposition proceeded more slowly than in a climatically less favourable temperate forest. We suggest that slow decomposition in the studied rainforest results from a syndrome of poor litter C quality beyond a simple lignin control, enforcing energy starvation of decomposers. We hypothesize that the litter trait syndrome in nutrient-poor tropical rainforests may have evolved to increase plant access to limiting nutrients via mycorrhizal associations.  
  Address [Haettenschwiler, Stephan; Coq, Sylvain; Barantal, Sandra; Handa, Ira Tanya] CNRS, CEFE, F-34293 Montpellier 5, France, Email: stephan.hattenschwiler@cefe.cnrs.fr  
  Corporate Author Thesis  
  Publisher Wiley-Blackwell Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume (down) Series Issue Edition  
  ISSN 0028-646x ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000286940500009 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 296  
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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 (down) Series Issue Edition  
  ISSN 0022-0477 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287785300024 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 297  
Permanent link to this record
 

 
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 (down) Series Issue Edition  
  ISSN 1452-3981 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287820500026 Approved no  
  Call Number 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 (down) Series Issue Edition  
  ISSN 0010-938x ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287004700021 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 299  
Permanent link to this record
 

 
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 (down) Series Issue Edition  
  ISSN 1567-1739 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000288183300088 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 300  
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