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Author Ntawuhiganayo, E.B.; Uwizeye, F.K.; Zibera, E.; Dusenge, M.E.; Ziegler, C.; Ntirugulirwa, B.; Nsabimana, D.; Wallin, G.; Uddling, J.
Title Traits controlling shade tolerance in tropical montane trees Type Journal Article
Year 2020 Publication Tree physiology Abbreviated Journal Tree Physiol.
Volume (up) 40 Issue 2 Pages 183-197
Keywords biomass allocation; leaf temperature; plant traits; Rwanda; shade intolerance; shade tolerance; tropical montane forest; article; biomass allocation; breathing; canopy; carbon balance; compensation; photosynthesis; plant leaf; plant stem; rain forest; Rwanda; shade tolerance; species difference; sweating
Abstract Tropical canopies are complex, with multiple canopy layers and pronounced gap dynamics contributing to their high species diversity and productivity. An important reason for this complexity is the large variation in shade tolerance among different tree species. At present, we lack a clear understanding of which plant traits control this variation, e.g., regarding the relative contributions of whole-plant versus leaf traits or structural versus physiological traits. We investigated a broad range of traits in six tropical montane rainforest tree species with different degrees of shade tolerance, grown under three different radiation regimes (under the open sky or beneath sparse or dense canopies). The two distinct shade-tolerant species had higher fractional biomass in leaves and branches while shade-intolerant species invested more into stems, and these differences were greater under low radiation. Leaf respiration and photosynthetic light compensation point did not vary with species shade tolerance, regardless of radiation regime. Leaf temperatures in open plots were markedly higher in shade-tolerant species due to their low transpiration rates and large leaf sizes. Our results suggest that interspecific variation in shade tolerance of tropical montane trees is controlled by species differences in whole-plant biomass allocation strategy rather than by difference in physiological leaf traits determining leaf carbon balance at low radiation. © The Author(s) 2019. Published by Oxford University Press.
Address Rwanda Agriculture and Animal Resources Development, PO Box 5016Kigali, Rwanda
Corporate Author Thesis
Publisher NLM (Medline) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 17584469 (Issn) ISBN Medium
Area Expedition Conference
Notes Export Date: 16 March 2020 Approved no
Call Number EcoFoG @ webmaster @ Serial 922
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Author Bourguignon, T.; Sobotnik, J.; Lepoint, G.; Martin, J.M.; Roisin, Y.
Title Niche differentiation among neotropical soldierless soil-feeding termites revealed by stable isotope ratios Type Journal Article
Year 2009 Publication Soil Biology & Biochemistry Abbreviated Journal Soil Biol. Biochem.
Volume (up) 41 Issue 10 Pages 2038-2043
Keywords Anoplotermes; Termitidae; Isoptera; Resource partitioning; Food web; Decomposition gradient
Abstract Termites represent one of the most abundant belowground animal taxa in tropical rainforests, where their species richness is much higher than in any other ecosystem. This high diversity in soil ecosystems is however difficult to explain by classical Hutchinsonian niche theory, as there is little evidence for spatial or temporal separation between species. Using delta C-13 and delta N-15 isotopic ratios, we tested if resource partitioning along the humification gradient occurs; in neotropical soldierless termites of the Anoplotermes-group. Two distinct sites were investigated to check if interspecific differences are transposable between sites. Significant differences in delta N-15 were found between species of the Anoplotermes-group. Although some species displayed higher intersite delta N-15 variation than others, species-average delta N-15 values for both sites were highly correlated, showing that sympatric soldierless soil-feeding termites feed on distinct components of the soil. Our data also suggest that some species are more likely to shift along this gradient than others, in response to overall habitat conditions or to the presence of competitors. Feeding niche differentiation can therefore account for the high species richness and diversity of soldierless soil-feeding termites in neotropical rainforests. (C) 2009 Elsevier Ltd. All rights reserved.
Address [Bourguignon, Thomas; Roisin, Yves] Univ Libre Bruxelles, B-1050 Brussels, Belgium, Email: yroisin@ulb.ac.be
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:000271047800003 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 98
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Author Fang, C.H.; Clair, B.; Gril, J.; Almeras, T.
Title Transverse shrinkage in G-fibers as a function of cell wall layering and growth strain Type Journal Article
Year 2007 Publication Wood Science and Technology Abbreviated Journal Wood Sci. Technol.
Volume (up) 41 Issue 8 Pages 659-671
Keywords
Abstract Transverse drying shrinkage was measured at microscopic and mesoscopic levels in poplar wood characterised by an increasing growth strain (GS), from normal to tension wood. Results show that: (a) the drying shrinkage, measured as a relative thickness decrease, was significantly higher for G-layer (GL) than for the other layers (OL), GL shrinkage was not significantly correlated with GS, and OL shrinkage was negatively correlated with GS. (b) In gelatinous fibre (G-fibre), lumen size increased during drying and this increase was positively related with GS, but in normal wood fibre, lumen size decreased during drying. These findings suggest that GL shrank outwards (i.e., its internal perimeter increases), so that its shrinkage weakly affected the total cell shrinkage and the mesoscopic shrinkage was controlled by the OL shrinkage which shrank inwards (i.e., its external perimeter decreases). (c) Measurements done on 7 x 7 mm(2) thin sections evidenced a negative correlation between transverse shrinkage and GS, significant in T direction but weak in R direction. These observations at both levels allow to discuss the contribution of GL to the mesoscopic shrinkage of tension wood.
Address Univ Montpellier 2, Lab Mech & Gene Civil, F-34095 Montpellier, France, Email: fang1979@gmail.com
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:000250381500003 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 155
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Author Malé, P.-J.G.; Ferdy, J.-B.; Leroy, C.; Roux, O.; Lauth, J.; Avilez, A.; Dejean, A.; Quilichini, A.; Orivel, J.
Title Retaliation in Response to Castration Promotes a Low Level of Virulence in an Ant-Plant Mutualism Type Journal Article
Year 2014 Publication Evolutionary Biology Abbreviated Journal Evol. Biol.
Volume (up) 41 Issue 1 Pages 22-28
Keywords Allomerus decemarticulatus; Cheater; Evolutionary conflict; Hirtella physophora; Mutualism breakdown; Overexploitation
Abstract The diversion of a host's energy by a symbiont for its own benefit is a major source of instability in horizontally-transmitted mutualisms. This instability can be counter-balanced by the host's retaliation against exploiters. Such responses are crucial to the maintenance of the relationship. We focus on this issue in an obligate ant-plant mutualism in which the ants are known to partially castrate their host plant. We studied plant responses to various levels of castration in terms of (1) global vegetative investment and (2) investment in myrmecophytic traits. Castration led to a higher plant growth rate, signalling a novel case of gigantism induced by parasitic castration. On the other hand, completely castrated plants produced smaller nesting and food resources (i.e. leaf pouches and extra floral nectaries). Since the number of worker larvae is correlated to the volume of the leaf pouches, such a decrease in the investment in myrmecophytic traits demonstrates for the first time the existence of inducible retaliation mechanisms against too virulent castrating ants. Over time, this mechanism promotes an intermediate level of castration and enhances the stability of the mutualistic relationship by providing the ants with more living space while allowing the plant to reproduce. © 2013 Springer Science+Business Media New York.
Address Laboratoire Evolution and Diversité Biologique, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 00713260 (Issn) ISBN Medium
Area Expedition Conference
Notes Export Date: 10 March 2014; Source: Scopus; Language of Original Document: English; Correspondence Address: Malé, P.-J. G.; Laboratoire Evolution and Diversité Biologique, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France; email: pjg.male@gmail.com Approved no
Call Number EcoFoG @ webmaster @ Serial 533
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Author Wagner, F.; Rutishauser, E.; Blanc, L.; Herault, B.
Title Effects of Plot Size and Census Interval on Descriptors of Forest Structure and Dynamics Type Journal Article
Year 2010 Publication Biotropica Abbreviated Journal Biotropica
Volume (up) 42 Issue 6 Pages 664-671
Keywords Amazonia; biomass fluxes; coefficient of variation; forest permanent plots; turnover rates; WinBUGS
Abstract This study was designed to explicitly formulate the effect of census interval and plot size on the variability of descriptors of tropical forest structure (stand density, basal area, aboveground biomass [AGB]) and dynamic (tree growth, mortality and recruitment rates, biomass fluxes). A unique dataset from a broad plot network (37.5 ha) surveyed every 2 yr over a 16-yr period was used to develop and parameterize a new statistical model predicting the coefficients of variation for each forest descriptor. More than 90 percent of the inherent variability of these coefficients was predicted using a simple model including plot size and census interval in a Bayesian modeling framework. All descriptors of forest structure varied by <10 percent for plot sizes 42 ha. Among the descriptors of forest dynamics, AGB loss was the most variable. The number of 6.25 ha plots required to estimate its mean, over a 16-yr period, within a 20 percent error of the mean remains above four. This contrasts with a relative constant flux of biomass entering the plot through tree growth and tree recruitment. Tree growth was remarkably well estimated with <15 percent variability for a 2-yr census in a plot of 2 ha. This study provides an easy method to assess dataset limitations in efforts to estimate descriptors of forest structure and dynamic, which is of primary importance to decipher any clear consequences of global change in tropical forests.
Address [Wagner, Fabien; Herault, Bruno] Univ Antilles Guyane, UMR Ecol Forets Guyane, Kourou 97379, French Guiana, Email: bruno.herault@ecofog.gf
Corporate Author Thesis
Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3606 ISBN Medium
Area Expedition Conference
Notes ISI:000283949700006 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 16
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Author Vantaux, A.; Roux, O.; Magro, A.; Ghomsi, N.T.; Gordon, R.D.; Dejean, A.; Orivel, J.
Title Host-Specific Myrmecophily and Myrmecophagy in the Tropical Coccinellid Diomus thoracicus in French Guiana Type Journal Article
Year 2010 Publication Biotropica Abbreviated Journal Biotropica
Volume (up) 42 Issue 5 Pages 622-629
Keywords ants; ladybird; mimicry; parasite; Wasmannia auropunctata
Abstract A variety of arthropods, particularly insects, have developed myrmecophilous interactions with ants to gain access to resources and/or for protection. Among these myrmecophiles, only a few examples have been documented in the Coccinellidae, most of them involving species able to feed on ant-tended Hemiptera. We report here a new case of obligate myrmecophily in the coccinellid Diomus thoracicus. Larvae are invariably and exclusively found in the nests of the ant Wasmannia auropunctata and seem to rely on ant brood as their only food source. Not only do ant workers show no aggressiveness toward the D. thoracicus larvae in their behavioral interactions at the colonial level, but also at the species level; while coccinellid adults are always attacked. The integration of the larvae inside of the ant nests is based on their chemical mimicry of the host's cuticular cues. Therefore, given the presence of the D. thoracicus larvae inside of the ant's nest, their predation on Wasmannia brood and their chemical mimicry, this species can be considered a specific parasite of W. auropunctata. Overall, this new case of myrmecophily not only specifically involves a highly invasive ant species, but also provides insights into the evolution of myrmecophily and myrmecophagy in coccinellids.
Address [Vantaux, Amelie; Magro, Alexandra; Orivel, Jerome] Univ Toulouse, UPS, EDB Lab Evolut & Diversite Biol, F-31062 Toulouse, France, Email: orivel@cict.fr
Corporate Author Thesis
Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3606 ISBN Medium
Area Expedition Conference
Notes ISI:000281707700025 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 27
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Author Ruiz-Gonzalez, M.X.; Corbara, B.; Leroy, C.; Dejean, A.; Orivel, J.
Title The Weaver Wasp: Spinning Fungus into a Nest Type Journal Article
Year 2010 Publication Biotropica Abbreviated Journal Biotropica
Volume (up) 42 Issue 4 Pages 402-404
Keywords Allomerus decemarticulatus; French Guiana; Hirtella physophora; nest architecture; Nitela constructor; wasp biology
Abstract Wasp nests range from simple to complex structures made of paper or mud. Here, we show that a Neotropical wasp of the genus Nitela builds its nest entirely by weaving endophytic fungal hyphae and spider silk harvested from the leaves growing in the understory of the rain forest in French Guiana.
Address [Ruiz-Gonzalez, Mario X.; Orivel, Jerome] Univ Toulouse, UPS, EDB, Lab Evolut & Divers Biol, F-31062 Toulouse, France, Email: orivel@cict.fr
Corporate Author Thesis
Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3606 ISBN Medium
Area Expedition Conference
Notes ISI:000279438900002 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 54
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Author Baraloto, C.; Couteron, P.
Title Fine-scale Microhabitat Heterogeneity in a French Guianan Forest Type Journal Article
Year 2010 Publication Biotropica Abbreviated Journal Biotropica
Volume (up) 42 Issue 4 Pages 420-428
Keywords canopy gap; geostatistics; light availability; microclimate; soil moisture; soil nutrients; topography
Abstract We examined fine-scale heterogeneity of environmental conditions in a primary rain forest in French Guiana to describe variation in microhabitats that plants may experience during establishment. We characterized both the range as well as the spatial structuring of 11 environmental factors important for seedling establishment in six hexagonal sampling grids, one each in gap and understory sites at three points representing the predominant geomorphic units in this primary forest. Each grid contained 37 sampling points separated by 31 cm-20 m. Monte-Carlo tests of semivariograms against complete spatial randomness indicated that for many variables in all six sampling grids, spatial dependence did not exceed 1 m. A principal component analysis of all sampling points revealed a lack of spatial microhabitat structure, rather than homogeneous patches associated with canopy structure or geomorphology. Our results suggest that ample fine-scale spatial heterogeneity exists to support the coexistence of plant species with differential abiotic requirements for regeneration.
Address [Baraloto, Christopher] INRA, UMR Ecol Forets Guyane, F-97387 Kourou, France, Email: chris.baraloto@ecofog.gf
Corporate Author Thesis
Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3606 ISBN Medium
Area Expedition Conference
Notes ISI:000279438900005 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 55
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Author Maron, P.A.; Schimann, H.; Ranjard, L.; Brothier, E.; Domenach, A.M.; Lensi, R.; Nazaret, S.
Title Evaluation of quantitative and qualitative recovery of bacterial communities from different soil types by density gradient centrifugation Type Journal Article
Year 2006 Publication European Journal of Soil Biology Abbreviated Journal Eur. J. Soil Biol.
Volume (up) 42 Issue 2 Pages 65-73
Keywords bacterial community; soil; density gradient; DNA fingerprint
Abstract Extracting and purifying a representative fraction of bacteria from soil is necessary for the application of many techniques of microbial ecology. Here the influence of different soil types on the quantitative and qualitative recovery of bacteria by soil grinding and Nycodenz density gradient centrifugation was investigated. Three soils presenting contrasted physicochemical characteristics were used for this study. For each soil, the total (AODC: acridine orange direct count) and culturable (cfa: colony-forming units) bacterial densities were measured in three distinct fractions: (i) the primary soil, (ii) the soil pellet (soil remaining after centrifugation), and (iii) the extracted cells. The automated-ribosomal intergenic spacer analysis (A-RISA) was used to characterize the community structure directly from the DNA extracted from each fraction. The physicochemical characteristics of soils were found to influence both the efficiency of bacterial cell recovery and the representativeness of the extracted cells in term of community structures between the different fractions. Surprisingly, the most representative extracted cells were obtained from the soil exhibiting the lowest efficiency of cell recovery. Our results demonstrated that quantitative and qualitative cell recovery using Nycodenz density gradient centrifugation are not necessarily related and could be differentially biased according to soil type. (c) 2006 Elsevier SAS. All rights reserved.
Address Univ Lyon 1, CNRS, UMR 5557, Ctr Microbial Ecol, F-69622 Villeurbanne, France, Email: nazaret@biomserv.univ-lyon1.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 1164-5563 ISBN Medium
Area Expedition Conference
Notes ISI:000238534500001 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 181
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Author Barabe, D.; Lacroix, C.; Gibernau, M.
Title Developmental floral morphology of Syngonium in the context of the tribe Caladieae (Araceae) Type Journal Article
Year 2012 Publication Willdenowia – Annals of the Botanic Garden and Botanical Museum Berlin-Dahlem Abbreviated Journal
Volume (up) 42 Issue 2 Pages 297-305
Keywords Aroids; Inflorescence; Phylogeny; Oxalate Crystals; Flower
Abstract The floral development of Syngonium angustatum is analysed in the context of a recently published molecular phylogeny of the Araceae. The initiation of discoid floral primordia occurs acropetally on the surface of the inflorescence. Female flowers, atypical bisexual flowers, sterile male flowers and male flowers are inserted on the same phyllotactic spirals on the spadix. Stamen primordia are initiated simultaneously on the periphery of more or less circular floral primordia. There are four stamens per flower (rarely three). In a synandrium, the fusion of stamens occurs very early during their developmental cycle. In some flowers one or two stamens remain free. The staminodes are also initiated on the periphery of the discoid floral primordium and their number varies from four to six. The growth of the fused staminodes will eventually form a longitudinal cavity in the centre of the mature synandrode. On the synandrodes located near the female zone, one or two staminodes remain free during development. No atypical bisexual flowers were observed on the inflorescence of Syngonium. The presence of a few calcium oxalate crystals was observed on the surface of all types of flowers. All the atypical flowers located at the base of the sterile zone corresponded to sterile male flowers and resulted from a more or less random disorganisation of the typical structure of a synandrode. In the Aroideae, free stamens or staminodes represent a plesiomorphic condition. The association of synandria and synandrodes is present in all early diverging genera of the tribe Caladieae and could represent the ancestral state. It is not clear if free stamens have evolved once or twice in the tribe Caladieae, both scenarios are possible.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 460
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