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Gonzalez, M.A.; Roger, A.; Courtois, E.A.; Jabot, F.; Norden, N.; Paine, C.E.T.; Baraloto, C.; Thebaud, C.; Chave, J. |
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Title |
Shifts in species and phylogenetic diversity between sapling and tree communities indicate negative density dependence in a lowland rain forest |
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Journal Article |
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Year |
2010 |
Publication |
Journal of Ecology |
Abbreviated Journal |
J. Ecol. |
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Volume |
98 |
Issue |
1 |
Pages |
137-146 |
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Keywords |
APG II plus rbcL megatree; density dependence; DNA barcoding; French Guiana; phylogenetic diversity; species diversity; tropical plant communities |
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Abstract |
P>1. As trees in a given cohort progress through ontogeny, many individuals die. This risk of mortality is unevenly distributed across species because of many processes such as habitat filtering, interspecific competition and negative density dependence. Here, we predict and test the patterns that such ecological processes should inscribe on both species and phylogenetic diversity as plants recruit from saplings to the canopy. 2. We compared species and phylogenetic diversity of sapling and tree communities at two sites in French Guiana. We surveyed 2084 adult trees in four 1-ha tree plots and 943 saplings in sixteen 16-m2 subplots nested within the tree plots. Species diversity was measured using Fisher's alpha (species richness) and Simpson's index (species evenness). Phylogenetic diversity was measured using Faith's phylogenetic diversity (phylogenetic richness) and Rao's quadratic entropy index (phylogenetic evenness). The phylogenetic diversity indices were inferred using four phylogenetic hypotheses: two based on rbcLa plastid DNA sequences obtained from the inventoried individuals with different branch lengths, a global phylogeny available from the Angiosperm Phylogeny Group, and a combination of both. 3. Taxonomic identification of the saplings was performed by combining morphological and DNA barcoding techniques using three plant DNA barcodes (psbA-trnH, rpoC1 and rbcLa). DNA barcoding enabled us to increase species assignment and to assign unidentified saplings to molecular operational taxonomic units. 4. Species richness was similar between saplings and trees, but in about half of our comparisons, species evenness was higher in trees than in saplings. This suggests that negative density dependence plays an important role during the sapling-to-tree transition. 5. Phylogenetic richness increased between saplings and trees in about half of the comparisons. Phylogenetic evenness increased significantly between saplings and trees in a few cases (4 out of 16) and only with the most resolved phylogeny. These results suggest that negative density dependence operates largely independently of the phylogenetic structure of communities. 6. Synthesis. By contrasting species richness and evenness across size classes, we suggest that negative density dependence drives shifts in composition during the sapling-to-tree transition. In addition, we found little evidence for a change in phylogenetic diversity across age classes, suggesting that the observed patterns are not phylogenetically constrained. |
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[Gonzalez, Mailyn A.; Roger, Aurelien; Courtois, Elodie A.; Jabot, Franck; Norden, Natalia; Thebaud, Christophe; Chave, Jerome] Univ Toulouse 3, Lab Evolut & Diversite Biol, UMR 5174, CNRS, F-31062 Toulouse, France, Email: gonzalez.mailyn@gmail.com |
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WILEY-BLACKWELL PUBLISHING, INC |
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0022-0477 |
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ISI:000272657400015 |
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EcoFoG @ eric.marcon @ |
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88 |
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Barriault, I.; Barabe, D.; Cloutier, L.; Gibernau, M. |
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Title |
Pollination ecology and reproductive success in Jack-in-the-pulpit (Arisaema triphyllum) in Quebec (Canada) |
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Journal Article |
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Year |
2010 |
Publication |
Plant Biology |
Abbreviated Journal |
Plant Biol. |
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Volume |
12 |
Issue |
1 |
Pages |
161-171 |
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Keywords |
Araceae; bisexual inflorescence; deceptive pollination; Mycetophilidae; pollen load; Thysanoptera; visitation rates |
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Abstract |
Pollination ecology and reproductive success of Jack-in-the-pulpit (Arisaema triphyllum) were studied in two natural populations in Quebec, Canada. Individual A. triphyllum plants can be of three types: male, female or bisexual. In both populations studied, the presence of bisexual inflorescences was not negligible (13%), where 'female' and 'male' bisexual plants were categorised according to the relative number of stamens and ovaries. 'Male bisexual' plants produce only pollen and 'female bisexual' plants produce only fruit. Hence, A. triphyllum is a true dioecious plant, as each plant only reproduces through either the male or the female function. 'Female bisexual' plants were equivalent to female plants in terms of visitation rate by insects, fructification rate and production of berries and seeds. Neither agamospermy in female plants nor self-pollination in 'female bisexual' plants was found, thus A. triphyllum relies on insects for cross-pollination. Despite the long flowering cycle, a low visitation rate was documented: only 20-40% of inflorescences were visited, according to gender, by a mean of 1.5 insects. In this study, Mycetophilidae represented the most generically diversified and abundant family, as well as the most efficient insect pollinator, especially the genera Docosia and Mycetophila. |
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[Gibernau, M.] Univ Toulouse 3, Lab Evolut & Divers Biol, UMR, CNRS, F-31062 Toulouse 9, France, Email: gibernau@cict.fr |
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WILEY-BLACKWELL PUBLISHING, INC |
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1435-8603 |
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ISI:000272589700017 |
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EcoFoG @ eric.marcon @ |
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89 |
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Boisse, P.; Aimene, Y.; Dogui, A.; Dridi, S.; Gatouillat, S.; Hamila, N.; Khan, M.A.; Mabrouki, T.; Morestin, F.; Vidal-Sallé, E. |
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Title |
Hypoelastic, hyperelastic, discrete and semi-discrete approaches for textile composite reinforcement forming |
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Journal Article |
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Year |
2010 |
Publication |
International Journal of Material Forming |
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3 |
Issue |
Supplement 2 |
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1229-1240 |
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Keywords |
Textile composites Forming simulations Continuous/discrete approaches Hyperelasticity Hypoelasticity Semi-discrete finite element |
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Abstract |
The clear multi-scale structure of composite textile reinforcements leads to develop continuous and discrete approaches for their forming simulations. In this paper two continuous modelling respectively based on a hypoelastic and hyperelastic constitutive model are presented. A discrete approach is also considered in which each yarn is modelled by shell finite elements and where the contact with friction and possible sliding between the yarns are taken into account. Finally the semi-discrete approach is presented in which the shell finite element interpolation involves continuity of the displacement field but where the internal virtual work is obtained as the sum of tension, in-plane shear and bending ones of all the woven unit cells within the element. The advantages and drawbacks of the different approaches are discussed. |
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Hypoelastic, hyperelastic, discrete and semi-discrete approaches for textile composite reinforcement forming |
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EcoFoG @ eric.marcon @ 8 |
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90 |
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Author |
Guitet, S.; Blanc, L.; Trombe, P.J.; Lehallier, B. |
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Title |
Silvicultural Treatments in the Tropical Forests of Guiana: A Review of Ten Years of Trials |
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Journal Article |
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Year |
2009 |
Publication |
Bois et Forets des Tropiques |
Abbreviated Journal |
Bois For. Trop. |
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63 |
Issue |
301 |
Pages |
7-19 |
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Keywords |
cutting cycle; thinning; stand dynamics; logging; French Guiana |
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This article reviews an experimental system set up in French Guiana to test different selective thinning methods that started ten to fifteen years after logging in order to reconstitute commercially viable stands within the shortest time. The thinning methods tested involve a combination of selective intervention within a radius of 10 metres around crop trees and systematic intervention applied uniformly to the entire forest parcel. The resulting thinning intensity produces an 8% to 45% reduction in basal area. While the growth of the residual stand is strongly boosted in all species and for all diameters, there is little change in basal area because of high mortality and lower recruitment of commercial species. Standing commercial capital, however, is strongly affected by the thinning operations as defined. In effect, these thinning methods that benefit crop stems do not meet the objective of shorter rotations in Guiana's tropical logging forests. On the other hand, the measurements made in under-treatment stands agree with those obtained at the Paracou experimental station and confirm the need to adopt long cutting cycles of more than fifty years to ensure that the extraction of valuable species is sustainable in the current logging context in French Guiana. |
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[Guitet, Stephane; Trombe, Pierre-Julien; Lehallier, Benoit] Direct Reg Guyane, Off Natl Forets, F-97307 Cayenne, France |
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CIRAD-CENTRE COOPERATION INT RECHERCHE AGRONOMIQUE POUR |
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0006-579X |
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ISI:000272488700002 |
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EcoFoG @ eric.marcon @ |
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91 |
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Fyllas, N.M.; Patino, S.; Baker, T.R.; Nardoto, G.B.; Martinelli, L.A.; Quesada, C.A.; Paiva, R.; Schwarz, M.; Horna, V.; Mercado, L.M.; Santos, A.; Arroyo, L.; Jimenez, E.M.; Luizao, F.J.; Neill, D.A.; Silva, N.; Prieto, A.; Rudas, A.; Silviera, M.; Vieira, I.C.G.; Lopez-Gonzalez, G.; Malhi, Y.; Phillips, O.L.; Lloyd, J. |
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Basin-wide variations in foliar properties of Amazonian forest: phylogeny, soils and climate |
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Journal Article |
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2009 |
Publication |
Biogeosciences |
Abbreviated Journal |
Biogeosciences |
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6 |
Issue |
11 |
Pages |
2677-2708 |
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We analysed 1040 individual trees, located in 62 plots across the Amazon Basin for leaf mass per unit area (M-A), foliar carbon isotopic composition (delta C-13) and leaf level concentrations of C, N, P, Ca, Mg, K and Al. All trees were identified to the species level with the dataset containing 58 families, 236 genera and 508 species, distributed across a wide range of soil types and precipitation regimes. Some foliar characteristics such as M-A, [C], [N] and [Mg] emerge as highly constrained by the taxonomic affiliation of tree species, but with others such as [P], [K], [Ca] and delta C-13 also strongly influenced by site growing conditions. By removing the environmental contribution to trait variation, we find that intrinsic values of most trait pairs coordinate, although different species ( characterised by different trait suites) are found at discrete locations along a common axis of coordination. Species that tend to occupy higher fertility soils are characterised by a lower M-A and have a higher intrinsic [N], [P], [K], [Mg] and delta C-13 than their lower fertility counterparts. Despite this consistency, different scaling patterns were observed between low and high fertility sites. Inter-relationships are thus substantially modified by growth environment. Analysing the environmental component of trait variation, we found soil fertility to be the most important predictor, influencing all leaf nutrient concentrations and delta C-13 and reducing M-A. Mean annual temperature was negatively associated with leaf level [N], [P] and [K] concentrations. Total annual precipitation positively influences M-A, [C] and delta C-13, but with a negative impact on [Mg]. These results provide a first basis for understanding the relationship between the physiological functioning and distribution of tree species across Amazonia. |
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[Fyllas, N. M.; Baker, T. R.; Quesada, C. A.; Lopez-Gonzalez, G.; Phillips, O. L.; Lloyd, J.] Univ Leeds, Sch Geog, Earth & Biosphere Inst, Leeds LS2 9JT, W Yorkshire, England, Email: n.fyllas@leeds.ac.uk |
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COPERNICUS PUBLICATIONS |
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1726-4170 |
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ISI:000272232200025 |
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EcoFoG @ eric.marcon @ |
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92 |
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Author |
Fortunel, C.; Violle, C.; Rourmet, C.; Buatois, B.; Navas, M.L.; Garnier, E. |
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Title |
Allocation strategies and seed traits are hardly affected by nitrogen supply in 18 species differing in successional status |
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Journal Article |
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Year |
2009 |
Publication |
Perspectives in Plant Ecology Evolution and Systematics |
Abbreviated Journal |
Perspect. Plant Ecol. Evol. Syst. |
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Volume |
11 |
Issue |
4 |
Pages |
267-283 |
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Keywords |
Allometry; Reproductive output; Seed mass; Nitrogen concentration of organs; Succession; Nitrogen supply |
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Species performance depends on ecological strategies, revealed by suites of traits, conferring different relative ecological advantages in different environments. Although current knowledge on plant strategies along successional gradients is derived from studies conducted in situ, actually quantifying these strategies requires disentangling the effects of environmental factors from intrinsic differences between species. Here we tested whether allocation strategies and seed traits differ among successional stages and nitrogen levels. To this aim, we assessed biomass and nitrogen allocations and seed traits variations for 18 species, differing in life history and belonging to three stages of a Mediterranean old-field succession. These species were grown as monocultures in an experimental garden under limiting and non-limiting nitrogen supply. Early successional species allocated allometrically more nitrogen and proportionally more biomass to reproduction, and set more seeds than later successional species. Seed mass increased with successional status and was negatively related to seed number. Early successional species thus produced more but less-provisioned seeds, suggesting better colonization abilities. These patterns were not the sole consequence of the replacement of annuals by perennials along the successional gradient, since comparable trends were also observed within each life history. Allocation patterns were generally not altered by nitrogen supply and the higher nitrogen content in vegetative organs of plants grown under high nitrogen supply was not retranslocated from leaves to seeds during seed development. We therefore conclude that differences in plant ecological strategies in species characteristics from contrasting successional stages appear to be intrinsic properties of the studied species, and independent from environmental conditions. (c) 2009 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved. |
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[Fortunel, Claire; Violle, Cyrille; Rourmet, Catherine; Buatois, Bruno; Garnier, Eric] Ctr Ecol Fonct & Evolut, CNRS, UMR 5175, F-34293 Montpellier 5, France, Email: claire.fortunel@ecofog.gf |
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ELSEVIER GMBH, URBAN & FISCHER VERLAG |
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1433-8319 |
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ISI:000271799900003 |
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EcoFoG @ eric.marcon @ |
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93 |
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Houel, E.; Bertani, S.; Bourdy, G.; Deharo, E.; Jullian, V.; Valentin, A.; Chevalley, S.; Stien, D. |
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Title |
Quassinoid constituents of Quassia amara L. leaf herbal tea. Impact on its antimalarial activity and cytotoxicity |
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Journal Article |
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Year |
2009 |
Publication |
Journal of Ethnopharmacology |
Abbreviated Journal |
J. Ethnopharmacol. |
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Volume |
126 |
Issue |
1 |
Pages |
114-118 |
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Keywords |
Quassia amara L.; Simaroubaceae; Leaf tea; Antimalarial activity; Cytotoxicity; Simalikalactone D |
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Aim of the study: Our objective was to assess whether it could be contemplated to recommend Quassia amara young leaf tea for treatment against malaria. and if yes. set up a standard protocol for preparing the herbal tea. Materials and methods: The leaf tea was extracted with methylene chloride and the organic extract was fractionated with HPLC. Pure compounds were characterized and their in vitro cytotoxicity and antiplasmodial activity was determined. Results and discussion: We discovered that antimalarial Quassia amara young leaf tea contains several quassinoids: simalikalactone D (SkD. 1), picrasin B (2). picrasin H (3), neoquassin (4), quassin (5), picrasin 1(6) and picrasin J (7). These last two compounds are new. In addition. our experiments demonstrate that both biological activity and cytotoxicity of the remedy may be attributed solely to the presence of SkD. Conclusion: In conclusion, this preparation Should not be recommended for treatment of malaria until a clinical Study in humans is performed with SkD. (C) 2009 Elsevier Ireland Ltd. All rights reserved |
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[Stien, Didier] Univ Antilles Guyane, CNRS, UMR Ecofog, Inst Enseignement Super Guyane, F-97337 Cayenne, France, Email: didier.stien@guyane.cnrs.fr |
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ELSEVIER IRELAND LTD |
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0378-8741 |
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ISI:000271790800015 |
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EcoFoG @ eric.marcon @ |
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94 |
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Odonne, G.; Bourdy, G.; Castillo, D.; Estevez, Y.; Lancha-Tangoa, A.; Alban-Castillo, J.; Deharo, E.; Rojas, R.; Stien, D.; Sauvain, M. |
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Ta'ta', Huayani: Perception of leishmaniasis and evaluation of medicinal plants used by the Chayahuita in Peru. Part II |
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Journal Article |
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Year |
2009 |
Publication |
Journal of Ethnopharmacology |
Abbreviated Journal |
J. Ethnopharmacol. |
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Volume |
126 |
Issue |
1 |
Pages |
149-158 |
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Keywords |
Leishmaniasis; Medicinal plants; Traditional medicine; Chayahuita; Peru |
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Aim of the study v: A knowledge attitude and practice study centred on leishmaniasis and its treatment was performed among the Chayahuita, in Amazonian Peruvian ethnic group living in ail endemic area. This study documents traditional Chayahuita plant's use and disease concepts. Also, activity of some medicinal Plants Used by the Chayahuita is highlighted and discussed. Materials and methods: Ninety-three Chayahuita people were interviewed, following a semi-structured questionnaire focussed oil disease knowledge and perception, personal attitude and healing practices. Simultaneously, a collection of plants was performed in different ecotopes, in order to make ail extensive inventory of the pharmacopoeia. Results: For the Chayahuita, cutaneous (CL) and muco-cutaneous leishmaniasis (MCL) are considered as diseases of their own, with specific names, aetiologics, mode of transmission. Regarding CL, Chayahuita people consider that the humid characteristic of the Skill ulcer is a discriminative fact orienting the diagnostic for Ta'ta' (leishmaniasis). Forty-six different species were designated useful against LC and /or MCL (29 species by means of the questionnaire and 27 species when collecting in different ecotopes). Thirty-seven extracts corresponding to 31 Species used medicinally were screened in vitro against Leishmania amazonensis axenic amastigotes, assessing their viability by the reduction Of tetrazolium salt (MTT). Six species displayed a good activity (10 μg/ml < IC50 < 20 μg/ml): all undetermined hemi-epiphytic Clusiaceae. Cybianthus anthuriophyllus Pipoly (Myrsinaceae), two Piper, Piper sanguineispicum Trel., and Piper loretoanum Trel. (Piperaceae), Desmodium axillare Sw. DC. (Fabaceae), and Clibadium sylvestre (Aubl.) Baill (Asteraceae). Conclusion: Perception of leishmaniasis, attitude. treatments and diet prohibitions still largely reflects traditional Chayahuita cosmovision, even if some tentative of bio-medical re-interpretation is arising. (C) 2009 Elsevier Ireland Ltd. All rights reserved. |
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[Odonne, G.; Bourdy, G.; Estevez, Y.; Deharo, E.; Sauvain, M.] Univ Toulouse, UPS, UMR 152, Lab Pharmacochim Subst Nat & Pharmacophores Redox, F-31062 Toulouse 9, France, Email: Genevieve.bourdy@ird.fr |
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ELSEVIER IRELAND LTD |
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0378-8741 |
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ISI:000271790800020 |
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EcoFoG @ eric.marcon @ |
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95 |
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Author |
Almeras, T.; Derycke, M.; Jaouen, G.; Beauchene, J.; Fournier, M. |
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Title |
Functional diversity in gravitropic reaction among tropical seedlings in relation to ecological and developmental traits |
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Journal Article |
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Year |
2009 |
Publication |
Journal of Experimental Botany |
Abbreviated Journal |
J. Exp. Bot. |
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Volume |
60 |
Issue |
15 |
Pages |
4397-4410 |
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Keywords |
Biomechanics; French Guiana; functional diversity; gravitropism; reaction wood; tropical rainforest |
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Gravitropism is necessary for plants to control the orientation of their axes while they grow in height. In woody plants, stem re-orientations are costly because they are achieved through diameter growth. The functional diversity of gravitropism was studied to check if the mechanisms involved and their efficiency may contribute to the differentiation of height growth strategies between forest tree species at the seedling stage. Seedlings of eight tropical species were grown tilted in a greenhouse, and their up-righting movement and diameter growth were measured over three months. Morphological, anatomical, and biomechanical traits were measured at the end of the survey. Curvature analysis was used to analyse the up-righting response along the stems. Variations in stem curvature depend on diameter growth, size effects, the increase in self-weight, and the efficiency of the gravitropic reaction. A biomechanical model was used to separate these contributions. Results showed that (i) gravitropic movements were based on a common mechanism associated to similar dynamic patterns, (ii) clear differences in efficiency (defined as the change in curvature achieved during an elementary diameter increment for a given stem diameter) existed between species, (iii) the equilibrium angle of the stem and the anatomical characters associated with the efficiency of the reaction also differed between species, and (iv) the differences in gravitropic reaction were related to the light requirements: heliophilic species, compared to more shade-tolerant species, had a larger efficiency and an equilibrium angle closer to vertical. This suggests that traits determining the gravitropic reaction are related to the strategy of light interception and may contribute to the differentiation of ecological strategies promoting the maintenance of biodiversity in tropical rainforests. |
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[Almeras, Tancrede; Derycke, Morgane; Jaouen, Gaelle] INRA, UMR Ecol Forets Guyane, F-97310 Kourou, France, Email: t_almeras@hotmail.com |
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OXFORD UNIV PRESS |
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0022-0957 |
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ISI:000271389400017 |
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EcoFoG @ eric.marcon @ |
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96 |
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Kenne, M.; Feneron, R.; Djieto-Lordon, C.; Malherbe, M.C.; Tindo, M.; Ngnegueu, P.R.; Dejean, A. |
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Nesting and foraging habits in the arboreal ant Atopomyrmex mocquerysi ANDRE, 1889 (Hymenoptera: Formicidae: Myrmicinae) |
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2009 |
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Myrmecological News |
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Myrmecol. News |
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12 |
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109-115 |
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Cameroon; wood-excavating ant; nest site selection; pest ant; predatory behavior; rhythm of activity; life history |
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Atopomyrmex mocquerysi ANDRE, 1889 is a West-Central African wood-excavating myrmicine species whose colonies construct galleries in the main live branches of their host trees, causing the distal parts of these branches to dry out. In southeastern Cameroon, this species was mainly found in woody savannahs that are burned annually. It was also present in the canopy of a secondary forest, but was relatively rare on trees growing along forest edges and entirely absent from the canopy of an old-growth forest. It was absent from oil palm and coffee tree plantations, rare on cocoa trees. present on 0.2% to 5.3% of the avocado, guava, mango and Citrus spp. trees monitored, and frequent on safoo trees (12.4%). A fire in a mango plantation seems to have favored its presence. The colonies generally exploit Aleyrodidae, Aphididae, Coccidae, and Stictococcidae. Workers forage for prey diurnally, mostly on the ground. Their predatory behavior is characterized by detection through contact. Workers recruit nestmates at short-range (within range of an alarm pheromone), rarely at long-range, after which they spread-eagle the prey and immediately cut it up on the spot. Individual workers retrieve the prey pieces. Unlike other territorially-dominant arboreal ants, A. mocquerysi is a threat to host trees because. in addition to being a wood-excavating species, its workers only slightly protect the foliage of their host tree from herbivorous insects since they mostly hunt on the ground. |
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[Kenne, Martin; Tindo, Maurice] Univ Douala, Fac Sci, Dept Biol Organismes Anim, Douala, Cameroon, Email: medoum68@yahoo.fr |
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OESTERREICHISCHE GESELL ENTOMOFAUNISTIK, C/O NATURHISTOR MUSEUM WIEN |
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1994-4136 |
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ISI:000271357700012 |
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EcoFoG @ eric.marcon @ |
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97 |
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