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Author Courtois, E.A.; Paine, C.E.T.; Blandinieres, P.A.; Stien, D.; Bessiere, J.M.; Houel, E.; Baraloto, C.; Chave, J. openurl 
  Title Diversity of the Volatile Organic Compounds Emitted by 55 Species of Tropical Trees: a Survey in French Guiana Type Journal Article
  Year 2009 Publication Journal of Chemical Ecology Abbreviated Journal J. Chem. Ecol.  
  Volume 35 Issue 11 Pages 1349-1362  
  Keywords VOCs; Chemical diversity; Sesquiterpenes; Tropical; French Guiana  
  Abstract Volatile organic compounds (VOCs) are produced by a broad range of organisms, from bacteria to mammals, and they represent a vast chemical diversity. In plants, one of the preeminent roles of VOCs is their repellent or cytotoxic activity, which helps the plant deter its predators. Most studies on VOCs emitted by vegetative parts have been conducted in model plant species, and little is known about patterns of VOC emissions in diverse plant communities. We conducted a survey of the VOCs released immediately after mechanical damage of the bark and the leaves of 195 individual trees belonging to 55 tropical tree species in a lowland rainforest of French Guiana. We discovered a remarkably high chemical diversity, with 264 distinct VOCs and a mean of 37 compounds per species. Two monoterpenes (alpha-pinene and limonene) and two sesquiterpenes (beta-caryophyllene and alpha-copaene), which are known to have cytotoxic and deterrent effects, were the most frequent compounds in the sampled species. As has been established for floral scents, the blend of VOCs is largely species-specific and could be used to discriminate among 43 of the 55 sampled species. The species with the most diverse blends were found in the Sapindales, Laurales, and Magnoliales, indicating that VOC diversity is not uniformly distributed among tropical species. Interspecific variation in chemical diversity was caused mostly by variation in sesquiterpenes. This study emphasizes three aspects of VOC emission by tropical tree species: the species-specificity of the mixtures, the importance of sesquiterpenes, and the wide-ranging complexity of the mixtures.  
  Address (up) [Courtois, Elodie A.; Blandinieres, Pierre-Alain; Stien, Didier; Houel, Emeline] CNRS, UMR Ecofog, F-97337 Cayenne, France, Email: courtois@cict.fr  
  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 0098-0331 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000273086100009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 73  
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Author Coutand, C.; Dupraz, C.; Jaouen, G.; Ploquin, S.; Adam, B. openurl 
  Title Mechanical stimuli regulate the allocation of biomass in trees: Demonstration with young Prunus avium trees Type Journal Article
  Year 2008 Publication Annals of Botany Abbreviated Journal Ann. Bot.  
  Volume 101 Issue 9 Pages 1421-1432  
  Keywords Prunus avium; growth; mechanical stress; bending; biomass; shoot/root ratio; wind; shelter  
  Abstract Background and Aims Plastic tree-shelters are increasingly used to protect tree seedlings against browsing animals and herbicide drifts. The biomass allocation in young seedlings of deciduous trees is highly disturbed by common plastic tree-shelters, resulting in poor root systems and reduced diameter growth of the trunk. The shelters have been improved by creating chimney-effect ventilation with holes drilled at the bottom, resulting in stimulated trunk diameter growth, but the root deficit has remained unchanged. An experiment was set up to elucidate the mechanisms behind the poor root growth of sheltered Prunus avium trees. Methods Tree seedlings were grown either in natural windy conditions or in tree-shelters. Mechanical wind stimuli were suppressed in ten unsheltered trees by staking. Mechanical stimuli (bending) of the stem were applied in ten sheltered trees using an original mechanical device. Key Results Sheltered trees suffered from poor root growth, but sheltered bent trees largely recovered, showing that mechano-sensing is an important mechanism governing C allocation and the shoot-root balance. The use of a few artificial mechanical stimuli increased the biomass allocation towards the roots, as did natural wind sway. It was demonstrated that there was an acclimation of plants to the imposed strain. Conclusions This study suggests that if mechanical stimuli are used to control plant growth, they should be applied at low frequency in order to be most effective. The impact on the functional equilibrium hypothesis that is used in many tree growth models is discussed. The consequence of the lack of mechanical stimuli should be incorporated in tree growth models when applied to environments protected from the wind (e.g. greenhouses, dense forests).  
  Address (up) [Coutand, Catherine; Jaouen, Gaelle; Ploquin, Stephane; Adam, Boris] Univ Clermont Ferrand, INRA, UMR PIAF, F-63100 Clermont Ferrand, France, Email: coutand@clermont.inra.fr  
  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 0305-7364 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000255987500013 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 211  
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Author Coutand, C.; Chevolot, M.; Lacointe, A.; Rowe, N.; Scotti, I. openurl 
  Title Mechanosensing of stem bending and its interspecific variability in five neotropical rainforest species Type Journal Article
  Year 2010 Publication Annals of Botany Abbreviated Journal Ann. Bot.  
  Volume 105 Issue 2 Pages 341-347  
  Keywords Mechanosensing; interspecific variability; trees; lianas; rain forest; neotropical species; bending; biomechanics; Bauhinia; Eperua; Symphonia; Tachigali  
  Abstract In rain forests, sapling survival is highly dependent on the regulation of trunk slenderness (height/diameter ratio): shade-intolerant species have to grow in height as fast as possible to reach the canopy but also have to withstand mechanical loadings (wind and their own weight) to avoid buckling. Recent studies suggest that mechanosensing is essential to control tree dimensions and stability-related morphogenesis. Differences in species slenderness have been observed among rainforest trees; the present study thus investigates whether species with different slenderness and growth habits exhibit differences in mechanosensitivity. Recent studies have led to a model of mechanosensing (sum-of-strains model) that predicts a quantitative relationship between the applied sum of longitudinal strains and the plant's responses in the case of a single bending. Saplings of five different neotropical species (Eperua falcata, E. grandiflora, Tachigali melinonii, Symphonia globulifera and Bauhinia guianensis) were subjected to a regimen of controlled mechanical loading phases (bending) alternating with still phases over a period of 2 months. Mechanical loading was controlled in terms of strains and the five species were subjected to the same range of sum of strains. The application of the sum-of-strain model led to a dose-response curve for each species. Dose-response curves were then compared between tested species. The model of mechanosensing (sum-of-strain model) applied in the case of multiple bending as long as the bending frequency was low. A comparison of dose-response curves for each species demonstrated differences in the stimulus threshold, suggesting two groups of responses among the species. Interestingly, the liana species B. guianensis exhibited a higher threshold than other Leguminosae species tested. This study provides a conceptual framework to study variability in plant mechanosensing and demonstrated interspecific variability in mechanosensing.  
  Address (up) [Coutand, Catherine; Lacointe, Andre] Univ Clermont Ferrand, INRA, PIAF, UMR 547, F-63000 Clermont Ferrand, France, Email: coutand@clermont.inra.fr  
  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 0305-7364 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000274347000025 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 71  
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Author Maia, A.C.D.; Schlindwein, C.; Navarro, D.M.A.F.; Gibernau, M. openurl 
  Title Pollination of Philodendron Acutatum (Araceae) in the Atlantic Forest of Northeastern Brazil: A Single Scarab Beetle Species Guarantees High Fruit Set Type Journal Article
  Year 2010 Publication International Journal of Plant Sciences Abbreviated Journal Int. J. Plant Sci.  
  Volume 171 Issue 7 Pages 740-748  
  Keywords Cyclocephala; floral volatiles; pollination specificity; reproductive success; thermogenesis  
  Abstract Philodendron acutatum (Araceae) is a hemiepiphyte common to the Atlantic Forest of northeastern Brazil. In two localities, we studied the species' breeding system and associations with flower-visiting insects, along with an analysis of its floral scent composition. The fruit set of self-incompatible P. acutatum was high, more than 90%, and inflorescences were exclusively pollinated by one species of scarab beetle, Cyclocephala celata (Scarabaeidae, Dynastinae). Pollinators are drawn toward the inflorescences at dusk by strong floral fragrances given off during the female phase of anthesis, along with endogenous heating of the spadix, whose temperatures were recorded at more than 11 degrees C above ambient air. Two other species of flower-visiting Cyclocephala were also consistently recovered in blacklight trappings during the flowering period of P. acutatum. The fact that only C. celata was found in association with P. acutatum suggests a local reproductive dependence of the plant to this scarab beetle species. Dihydro-beta-ionone and 2-hydroxy-5-methyl-3-hexanone, a rare volatile molecule so far unreported as a floral compound, together accounted for more than 97% of the unique scent composition of P. acutatum and might be involved in specific attraction of C. celata.  
  Address (up) [Dalia Maia, Artur Campos] Univ Fed Paraiba, Programa Posgrad Ciencias Biol, BR-58059900 Joao Pessoa, Paraiba, Brazil, Email: arturcamposmaia@yahoo.com.br  
  Corporate Author Thesis  
  Publisher UNIV CHICAGO PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1058-5893 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000280855800003 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 46  
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Author Dejean, A.; Carpenter, J.M.; Gibernau, M.; Leponce, M.; Corbara, B. openurl 
  Title Nest relocation and high mortality rate in a Neotropical social wasp: Impact of an exceptionally rainy La Nina year Type Journal Article
  Year 2010 Publication Comptes Rendus Biologies Abbreviated Journal C. R. Biol.  
  Volume 333 Issue 1 Pages 35-40  
  Keywords Vespidae; Population size variation; Microevolution; La Nina; French Guiana  
  Abstract After noting the forecast of a La Nina episode, associated with heavy rainfall in French Guiana, we monitored the fate of wasp nests before and during the 2006 short rainy season. The population of the most abundant epiponine wasp species, Polybia bistriata, decreased dramatically during the short rainy season (60.6% of the nests disappeared) then remained low for at least 18 months. Colonies that survived moved from the shelter of large, low leaves (a situation well adapted to the previous dry season) of the most frequent substrate tree, Clusia grandiflora (Clusiaceae), to upper leaves, better ventilated and whose orientation provides good protection from the rain. Therefore, the possibility of moving the nest higher during the first rains following the dry season seems very adaptive as colonies that do not do so are eliminated during the La Nina years, whose frequency will increase with global climate change. (C) 2009 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.  
  Address (up) [Dejean, Alain; Gibernau, Marc] CNRS, UMR Ecofog 8172, F-97387 Kourou, France, Email: alain.dejean@wanadoo.fr  
  Corporate Author Thesis  
  Publisher ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1631-0691 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000275984200006 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 64  
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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 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 (up) [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 Dejean, A.; Leroy, C.; Corbara, B.; Cereghino, R.; Roux, O.; Herault, B.; Rossi, V.; Guerrero, R.J.; Delabie, J.H.C.; Orivel, J.; Boulay, R. openurl 
  Title A temporary social parasite of tropical plant-ants improves the fitness of a myrmecophyte Type Journal Article
  Year 2010 Publication Naturwissenschaften Abbreviated Journal Naturwissenschaften  
  Volume 97 Issue 10 Pages 925-934  
  Keywords Ant-plant relationships; Biotic defense; Parasites of mutualisms; Temporary social parasites; Azteca; Cecropia  
  Abstract Myrmecophytes offer plant-ants a nesting place in exchange for protection from their enemies, particularly defoliators. These obligate ant-plant mutualisms are common model systems for studying factors that allow horizontally transmitted mutualisms to persist since parasites of ant-myrmecophyte mutualisms exploit the rewards provided by host plants whilst providing no protection in return. In pioneer formations in French Guiana, Azteca alfari and Azteca ovaticeps are known to be mutualists of myrmecophytic Cecropia (Cecropia ants). Here, we show that Azteca andreae, whose colonies build carton nests on myrmecophytic Cecropia, is not a parasite of Azteca-Cecropia mutualisms nor is it a temporary social parasite of A. alfari; it is, however, a temporary social parasite of A. ovaticeps. Contrarily to the two mutualistic Azteca species that are only occasional predators feeding mostly on hemipteran honeydew and food bodies provided by the host trees, A. andreae workers, which also attend hemipterans, do not exploit the food bodies. Rather, they employ an effective hunting technique where the leaf margins are fringed with ambushing workers, waiting for insects to alight. As a result, the host trees' fitness is not affected as A. andreae colonies protect their foliage better than do mutualistic Azteca species resulting in greater fruit production. Yet, contrarily to mutualistic Azteca, when host tree development does not keep pace with colony growth, A. andreae workers forage on surrounding plants; the colonies can even move to a non-Cecropia tree.  
  Address (up) [Dejean, Alain; Leroy, Celine; Roux, Olivier; Orivel, Jerome] CNRS, F-97379 Kourou, France, Email: alain.dejean@wanadoo.fr  
  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 0028-1042 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000282094100006 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 77  
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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 (up) [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 EcoFoG @ webmaster @ Serial 306  
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Author Dejean, A.; Grangier, J.; Leroy, C.; Orivel, J. openurl 
  Title Predation and aggressiveness in host plant protection: a generalization using ants from the genus Azteca Type Journal Article
  Year 2009 Publication Naturwissenschaften Abbreviated Journal Naturwissenschaften  
  Volume 96 Issue 1 Pages 57-63  
  Keywords Aggressiveness; Ant-plant relationships; Biotic defence; Predation  
  Abstract In studying the ant genus Azteca, a Neotropical group of arboreal species, we aimed to determine the extent to which the ants use predation and/or aggressiveness to protect their host plants from defoliating insects. We compared a territorially dominant, carton-nester, Azteca chartifex, and three plant-ant species. Azteca alfari and Azteca ovaticeps are associated with the myrmecophyte Cecropia (Cecropiaceae) and their colonies shelter in its hollow branches; whereas Azteca bequaerti is associated with Tococa guianensis (Melastomataceae) and its colonies shelter in leaf pouches situated at the base of the laminas. Whereas A. bequaerti workers react to the vibrations transmitted by the lamina when an alien insect lands on a leaf making it unnecessary for them to patrol their plant, the workers of the three other species rather discover prey by contact. The workers of all four species use a predatory behaviour involving spread-eagling alien insects after recruiting nestmates at short range, and, in some cases, at long range. Because A. alfari and A. ovaticeps discard part of the insects they kill, we deduced that the workers' predatory behaviour and territorial aggressiveness combine in the biotic defence of their host tree.  
  Address (up) [Dejean, Alain; Leroy, Celine] CNRS, UMR Ecol Forets Guyane 8172, F-97379 Kourou, France, Email: alain.dejean@wanadoo.fr  
  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 0028-1042 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000261791000006 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 125  
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Author Dejean, A.; Djieto-Lordon, C.; Cereghino, R.; Leponce, M. openurl 
  Title Ontogenetic succession and the ant mosaic: An empirical approach using pioneer trees Type Journal Article
  Year 2008 Publication Basic and Applied Ecology Abbreviated Journal Basic Appl. Ecol.  
  Volume 9 Issue 3 Pages 316-323  
  Keywords ant-plant relationships; dynamics of associations; myrmecophytes; species turnover; tropical rainforests  
  Abstract Arboreal ant mosaics have been intensively investigated, but what generates these mosaics remains poorly understood. In this paper, we hypothesize that the dynamics of arboreal ant mosaics could be better understood by examining the ontogenetic succession of ants in tropical trees. We used three African pioneer tree species as biological models. Lophira alata (Ochnaceae) is a long-lived species that does not furnish any reward (i.e., extra-floral nectaries [EFNs], shelter) to ants, Anthocleista vogelii (Gentianaceae) bears extremely well-developed EFNs, and Barteria fistulosa (Passifloraceae) is a long-lived myrmecophyte providing both EFNs and domatia. For both L. alata and A. vogelii, we noted a succession of different associated ants as the plants grew and aged. Ground-nesting, arborealforaging ant species were the first associates, followed by arboreal species that build nests with the leaves of their host trees, together with some species nesting opportunistically in pre-existing cavities. Carton-building Crematogaster species were the last in this succession. The presence of EFNs on A. vogelii slows species turnover, demonstrating that the plant exerts some control over its ant associates. The comparison with B. fistulosa, which generally remains associated with the same plant-ant species during its entire ontogeny, highlights the importance of the selective attractiveness of the trees for their associated ants – or, perhaps, the existence of plant filters that screen arriving ants. (C) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.  
  Address (up) [Dejean, Alain] CNRS Guyane, UPS 2561, F-97300 Cayenne, France, Email: alain.dejean@wanadoo.fr  
  Corporate Author Thesis  
  Publisher ELSEVIER GMBH, URBAN & FISCHER VERLAG Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1439-1791 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000256734600013 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 138  
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