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Author Baraloto, C.; Rabaud, S.; Molto, Q.; Blanc, L.; Fortunel, C.; Herault, B.; Davila, N.; Mesones, I.; Rios, M.; Valderrama, E.; Fine, P.V.A. openurl 
  Title Disentangling stand and environmental correlates of aboveground biomass in Amazonian forests Type Journal Article
  Year 2011 Publication Global Change Biology Abbreviated Journal Glob. Change Biol.  
  Volume 17 Issue 8 Pages 2677-2688  
  Keywords carbon stocks; climate; flooded forest; forest structure; French Guiana; Peru; REDD; soil properties; tropical rainforest; white-sand forest; wood specific gravity  
  Abstract Tropical forests contain an important proportion of the carbon stored in terrestrial vegetation, but estimated aboveground biomass (AGB) in tropical forests varies two-fold, with little consensus on the relative importance of climate, soil and forest structure in explaining spatial patterns. Here, we present analyses from a plot network designed to examine differences among contrasting forest habitats (terra firme, seasonally flooded, and white-sand forests) that span the gradient of climate and soil conditions of the Amazon basin. We installed 0.5-ha plots in 74 sites representing the three lowland forest habitats in both Loreto, Peru and French Guiana, and we integrated data describing climate, soil physical and chemical characteristics and stand variables, including local measures of wood specific gravity (WSG). We use a hierarchical model to separate the contributions of stand variables from climate and soil variables in explaining spatial variation in AGB. AGB differed among both habitats and regions, varying from 78 Mg ha(-1) in white-sand forest in Peru to 605 Mg ha(-1) in terra firme clay forest of French Guiana. Stand variables including tree size and basal area, and to a lesser extent WSG, were strong predictors of spatial variation in AGB. In contrast, soil and climate variables explained little overall variation in AGB, though they did co-vary to a limited extent with stand parameters that explained AGB. Our results suggest that positive feedbacks in forest structure and turnover control AGB in Amazonian forests, with richer soils (Peruvian terra firme and all seasonally flooded habitats) supporting smaller trees with lower wood density and moderate soils (French Guianan terra firme) supporting many larger trees with high wood density. The weak direct relationships we observed between soil and climate variables and AGB suggest that the most appropriate approaches to landscape scale modeling of AGB in the Amazon would be based on remote sensing methods to map stand structure.  
  Address [Baraloto, Christopher; Rabaud, Suzanne; Fortunel, Claire; Rios, Marcos; Valderrama, Elvis] INRA, UMR Ecol Forets Guyane, Kourou 97387, French Guiana, Email: chris.baraloto@ecofog.gf  
  Corporate Author Thesis  
  Publisher Wiley-Blackwell Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1354-1013 ISBN Medium  
  Area Expedition Conference  
  Notes (down) ISI:000292308300013 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 325  
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Author Hattenschwiler, S.; Fromin, N.; Barantal, S. openurl 
  Title Functional diversity of terrestrial microbial decomposers and their substrates Type Journal Article
  Year 2011 Publication Comptes Rendus Biologies Abbreviated Journal C. R. Biol.  
  Volume 334 Issue 5-6 Pages 393-402  
  Keywords Bacteria; Biogeochemical cycles; Decomposition; Dissimilarity; Ecosystem functioning; Functional diversity indices; Fungi; Leaf litter  
  Abstract The relationship between biodiversity and biogeochemical processes gained much interest in light of the rapidly decreasing biodiversity worldwide. In this article, we discuss the current status, challenges and prospects of functional concepts to plant litter diversity and microbial decomposer diversity. We also evaluate whether these concepts permit a better understanding of how biodiversity is linked to litter decomposition as a key ecosystem process influencing carbon and nutrient cycles. Based on a literature survey, we show that plant litter and microbial diversity matters for decomposition, but that considering numbers of taxonomic units appears overall as little relevant and less useful than functional diversity. However, despite easily available functional litter traits and the well-established theoretical framework for functional litter diversity, the impact of functional litter diversity on decomposition is not yet well enough explored. Defining functional diversity of microorganisms remains one of the biggest challenges for functional approaches to microbial diversity. Recent developments in microarray and metagenomics technology offer promising possibilities in the assessment of the functional structure of microbial communities. This might allow significant progress in measuring functional microbial diversity and ultimately in our ability to predict consequences of biodiversity loss in the decomposer system for biogeochemical processes. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.  
  Address [Haettenschwiler, Stephan; Fromin, Nathalie; Barantal, Sandra] CNRS, CEFE, F-34293 Montpellier 5, France, Email: stephan.hattenschwiler@cefe.cnrs.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 (down) ISI:000292013400008 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 323  
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Author Roux, O.; Cereghino, R.; Solano, P.J.; Dejean, A. pdf  openurl
  Title Caterpillars and Fungal Pathogens: Two Co-Occurring Parasites of an Ant-Plant Mutualism Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS One  
  Volume 6 Issue 5 Pages e20538  
  Keywords  
  Abstract In mutualisms, each interacting species obtains resources from its partner that it would obtain less efficiently if alone, and so derives a net fitness benefit. In exchange for shelter (domatia) and food, mutualistic plant-ants protect their host myrmecophytes from herbivores, encroaching vines and fungal pathogens. Although selective filters enable myrmecophytes to host those ant species most favorable to their fitness, some insects can by-pass these filters, exploiting the rewards supplied whilst providing nothing in return. This is the case in French Guiana for Cecropia obtusa (Cecropiaceae) as Pseudocabima guianalis caterpillars (Lepidoptera, Pyralidae) can colonize saplings before the installation of their mutualistic Azteca ants. The caterpillars shelter in the domatia and feed on food bodies (FBs) whose production increases as a result. They delay colonization by ants by weaving a silk shield above the youngest trichilium, where the FBs are produced, blocking access to them. This probable temporal priority effect also allows female moths to lay new eggs on trees that already shelter caterpillars, and so to occupy the niche longer and exploit Cecropia resources before colonization by ants. However, once incipient ant colonies are able to develop, they prevent further colonization by the caterpillars. Although no higher herbivory rates were noted, these caterpillars are ineffective in protecting their host trees from a pathogenic fungus, Fusarium moniliforme (Deuteromycetes), that develops on the trichilium in the absence of mutualistic ants. Therefore, the Cecropia treelets can be parasitized by two often overlooked species: the caterpillars that shelter in the domatia and feed on FBs, delaying colonization by mutualistic ants, and the fungal pathogen that develops on old trichilia. The cost of greater FB production plus the presence of the pathogenic fungus likely affect tree growth.  
  Address [Roux, Olivier; Dejean, Alain] CNRS, Ecol Forets Guyane UMR 8172, Kourou, France, Email: olivier.roux@ird.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 (down) ISI:000291097600091 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 322  
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Author Verbeeck, H.; Peylin, P.; Bacour, C.; Bonal, D.; Steppe, K.; Ciais, P. openurl 
  Title Seasonal patterns of CO2 fluxes in Amazon forests: Fusion of eddy covariance data and the ORCHIDEE model Type Journal Article
  Year 2011 Publication Journal Of Geophysical Research-Biogeosciences Abbreviated Journal J. Geophys. Res.-Biogeosci.  
  Volume 116 Issue 2 Pages G02018  
  Keywords  
  Abstract [1] In some regions of the Amazon, global biogeophysical models have difficulties in reproducing measured seasonal patterns of net ecosystem exchange (NEE) of carbon dioxide. The global process-based biosphere model Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) used in this study showed that a standard model parameterization produces seasonal NEE patterns that are opposite in phase to the eddy flux data of the tropical evergreen forest at the Tapajos km 67 site (Brazil), like many other global models. However, we optimized several key parameters of ORCHIDEE using eddy covariance data of the Tapajos km 67 site in order to identify the driving factors of the seasonal variations in CO2 flux in this tropical forest ecosystem. The validity of the retrieved parameter values was evaluated for two other flux tower sites in the Amazon. The different tested optimization scenarios showed that only a few parameters substantially improve the fit to NEE and latent heat data. Our results confirm that these forests have the ability to maintain high transpiration and photosynthesis during the dry season in association with a large soil depth (D-soil = 10 m) and a rooting system density that decreases almost linearly with depth (H-root = 0.1). Previous analyses of seasonal variations in eddy covariance fluxes indicated that higher GPP levels were reached in the dry season compared to the wet season. Our optimization analysis suggests that this pattern could be caused by a leaf flush at the start of the dry season increasing the photosynthetic capacity of the canopy. Nevertheless, the current model structure is not yet able to simulate such a leaf flush, and we therefore suggest improving the ORCHIDEE model by including a specific phenology module that is driven by light availability for the tropical evergreen plant functional types. In addition, our results highlight both the potential and the limitations of flux data to improve global terrestrial models. Several parameters were not identifiable, and the risk of overfitting of the model was illustrated. Nevertheless, we conclude that these models can be improved substantially by assimilating site level flux data over the tropics.  
  Address [Verbeeck, Hans; Steppe, Kathy] Univ Ghent, Plant Ecol Lab, Dept Appl Ecol & Environm Biol, Fac Biosci Engn, B-9000 Ghent, Belgium, Email: hans.verbeeck@ugent.be  
  Corporate Author Thesis  
  Publisher Amer Geophysical Union Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0148-0227 ISBN Medium  
  Area Expedition Conference  
  Notes (down) ISI:000290933500002 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 321  
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Author Brouard, O.; Le Jeune, A.H.; Leroy, C.; Cereghino, R.; Roux, O.; Pelozuelo, L.; Dejean, A.; Corbara, B.; Carrias, J.F. pdf  openurl
  Title Are Algae Relevant to the Detritus-Based Food Web in Tank-Bromeliads? Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS One  
  Volume 6 Issue 5 Pages e20129  
  Keywords  
  Abstract We assessed the occurrence of algae in five species of tank-bromeliads found in contrasting environmental sites in a Neotropical, primary rainforest around the Nouragues Research Station, French Guiana. The distributions of both algal abundance and biomass were examined based on physical parameters, the morphological characteristics of bromeliad species and with regard to the structure of other aquatic microbial communities held in the tanks. Algae were retrieved in all of the bromeliad species with mean densities ranging from similar to 10(2) to 10(4) cells/mL. Their biomass was positively correlated to light exposure and bacterial biomass. Algae represented a tiny component of the detrital food web in shaded bromeliads but accounted for up to 30 percent of the living microbial carbon in the tanks of Catopsis berteroniana, located in a highly exposed area. Thus, while nutrient supplies are believed to originate from wind-borne particles and trapped insects (i.e., allochtonous organic matter), our results indicate that primary producers (i.e., autochtonous organic matter) are present in this insectivorous bromeliad. Using a 24-h incubation of size-fractionated and manipulated samples from this plant, we evaluated the impact of mosquito foraging on algae, other microorganisms and rotifers. The prey assemblages were greatly altered by the predation of mosquito larvae. Grazing losses indicated that the dominant algal taxon, Bumilleriopsis sp., like protozoa and rotifers, is a significant part of the diet of mosquito larvae. We conclude that algae are a relevant functional community of the aquatic food web in C. berteroniana and might form the basis of a complementary non-detrital food web.  
  Address [Brouard, Olivier; Le Jeune, Anne-Helene; Corbara, Bruno; Carrias, Jean-Francois] Univ Clermont Ferrand, CNRS, Lab Microorganismes Genome & Environm, LMGE,UMR 6023, Aubiere, France, Email: j-francois.carrias@univ-bpclermont.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 (down) ISI:000290720200066 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 319  
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Author Coq, S.; Weigel, J.; Butenschoen, O.; Bonal, D.; Hattenschwiler, S. openurl 
  Title Litter composition rather than plant presence affects decomposition of tropical litter mixtures Type Journal Article
  Year 2011 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume 343 Issue 1-2 Pages 273-286  
  Keywords Amazonian lowland rainforest; Belowground/aboveground interactions; Litter decomposition; Non-additive effect; Nitrogen dynamic; Plant-soil feedback  
  Abstract Litter decomposition is strongly controlled by litter quality, but the composition of litter mixtures and potential interactions with live plants through root activity may also influence decomposers. In a greenhouse experiment in French Guiana we studied the combined effects of the presence of tropical tree seedlings and of distinct litter composition on mass and nitrogen (N) loss from decomposing litter and on microbial biomass. Different litter mixtures decomposed for 435 days in pots filled with sand and containing an individual seedling from one of four different tree species. We found both additive and negative non-additive effects (NAE) of litter mixing on mass loss, whereas N loss showed negative and positive NAE of litter mixing. If litter from the two tree species, Platonia insignis and Goupia glabra were present, litter mixtures showed more positive and more negative NAE on N loss, respectively. Overall, decomposition, and in particular non-additive effects, were only weakly affected by the presence of tree seedlings. Litter mass loss weakly yet significantly decreased with increasing fine root biomass in presence of Goupia seedlings, but not in the presence of seedlings of any other tree species. Our results showed strong litter composition effects and also clear, mostly negative, non-additive effects on mass loss and N loss. Species identity of tree seedlings can modify litter decomposition, but these live plant effects remain quantitatively inferior to litter composition effects.  
  Address [Coq, Sylvain; Haettenschwiler, Stephan] CNRS, CEFE, F-34293 Montpellier 5, France, Email: sylvain.coq@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 0032-079x ISBN Medium  
  Area Expedition Conference  
  Notes (down) ISI:000290688000020 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 320  
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Author Chevolot, M.; Louisanna, E.; Azri, W.; Leblanc-Fournier, N.; Roeckel-Drevet, P.; Scotti-Saintagne, C.; Scotti, I. openurl 
  Title Isolation of primers for candidate genes for mechano-sensing in five Neotropical tree species Type Journal Article
  Year 2011 Publication Tree Genetics & Genomes Abbreviated Journal Tree Genet. Genomes  
  Volume 7 Issue 3 Pages 655-661  
  Keywords Population genomics; Functional gene; Mechanical signals; Fabaceae  
  Abstract Mechanical signals have an impact on plant development. Tropical rainforest trees display large variability for life-history traits related to biomechanics and therefore are a unique study system to better understand biomechanical trait variability from an evolutionary perspective. From sequences and gene expression data available in model species, we developed specific primers for six candidate genes for mechano-sensing in five tropical species. Most of the gene sequences were polymorphic in most species.  
  Address [Chevolot, Malia; Louisanna, Eliane; Scotti-Saintagne, Caroline; Scotti, Ivan] INRA, Unite Mixte Rech Ecol Forets Guyane, Kourou 97310, French Guiana, Email: ivan.scotti@ecofog.gf  
  Corporate Author Thesis  
  Publisher Springer Heidelberg Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1614-2942 ISBN Medium  
  Area Expedition Conference  
  Notes (down) ISI:000290571900018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 315  
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Author Ruiz-Gonzalez, M.X.; Male, P.J.G.; Leroy, C.; Dejean, A.; Gryta, H.; Jargeat, P.; Quilichini, A.; Orivel, J. openurl 
  Title Specific, non-nutritional association between an ascomycete fungus and Allomerus plant-ants Type Journal Article
  Year 2011 Publication Biology Letters Abbreviated Journal Biol. Lett.  
  Volume 7 Issue 3 Pages 475-479  
  Keywords ant-fungus association; Cordia nodosa; Chaetothyriales; Hirtella physophora; myrmecophyte; population structure  
  Abstract Ant-fungus associations are well known from attine ants, whose nutrition is based on a symbiosis with basidiomycete fungi. Otherwise, only a few non-nutritional ant-fungus associations have been recorded to date. Here we focus on one of these associations involving Allomerus plant-ants that build galleried structures on their myrmecophytic hosts in order to ambush prey. We show that this association is not opportunistic because the ants select from a monophyletic group of closely related fungal haplotypes of an ascomycete species from the order Chaetothyriales that consistently grows on and has been isolated from the galleries. Both the ants' behaviour and an analysis of the genetic population structure of the ants and the fungus argue for host specificity in this interaction. The ants' behaviour reveals a major investment in manipulating, growing and cleaning the fungus. A molecular analysis of the fungus demonstrates the widespread occurrence of one haplotype and many other haplotypes with a lower occurrence, as well as significant variation in the presence of these fungal haplotypes between areas and ant species. Altogether, these results suggest that such an interaction might represent an as-yet undescribed type of specific association between ants and fungus in which the ants cultivate fungal mycelia to strengthen their hunting galleries.  
  Address [Leroy, Celine; Dejean, Alain; Quilichini, Angelique; Orivel, Jerome] CNRS, UMR Ecol Forets Guyane 8172, F-97379 Kourou, France, Email: jerome.orivel@ecofog.gf  
  Corporate Author Thesis  
  Publisher Royal Soc Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1744-9561 ISBN Medium  
  Area Expedition Conference  
  Notes (down) ISI:000290515100044 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 317  
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Author Dejean, A. pdf  openurl
  Title Prey Capture Behavior in an Arboreal African Ponerine Ant Type Journal Article
  Year 2011 Publication PLoS One Abbreviated Journal PLoS One  
  Volume 6 Issue 5 Pages e19837  
  Keywords  
  Abstract I studied the predatory behavior of Platythyrea conradti, an arboreal ponerine ant, whereas most species in this subfamily are ground-dwelling. The workers, which hunt solitarily only around dusk, are able to capture a wide range of prey, including termites and agile, nocturnal insects as well as diurnal insects that are inactive at that moment of the Nyctemeron, resting on tree branches or under leaves. Prey are captured very rapidly, and the antennal palpation used by ground-dwelling ponerine species is reduced to a simple contact; stinging occurs immediately thereafter. The venom has an instant, violent effect as even large prey (up to 30 times the weight of a worker) never struggled after being stung. Only small prey are not stung. Workers retrieve their prey, even large items, singly. To capture termite workers and soldiers defending their nest entrances, ant workers crouch and fold their antennae backward. In their role as guards, the termites face the crouching ants and end up by rolling onto their backs, their legs batting the air. This is likely due to volatile secretions produced by the ants' mandibular gland. The same behavior is used against competing ants, including territorially-dominant arboreal species that retreat further and further away, so that the P. conradti finally drive them from large, sugary food sources.  
  Address [Dejean, Alain] CNRS, Ecol Forets Guyane UMR 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 (down) ISI:000290483600033 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 316  
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Author Vincent, G.; Molino, J.F.; Marescot, L.; Barkaoui, K.; Sabatier, D.; Freycon, V.; Roelens, J.B. openurl 
  Title The relative importance of dispersal limitation and habitat preference in shaping spatial distribution of saplings in a tropical moist forest: a case study along a combination of hydromorphic and canopy disturbance gradients Type Journal Article
  Year 2011 Publication Annals of Forest Science Abbreviated Journal Ann. For. Sci.  
  Volume 68 Issue 2 Pages 357-370  
  Keywords Species assemblage; Dispersal limitation; Tropical moist forest; Niche  
  Abstract Various processes contribute to shaping the local assemblage of species in hyperdiverse tropical forest. The relative contribution of environmental factors and dispersal limitation in determining the spatial distribution of saplings at local scale is unclear. We examined two types of environmental factors: (a) soil type reflecting drainage regime and (b) past logging damages reflecting light regime in a neotropical moist forest site. We used a logistic model to predict presence or absence of a given species in a network of elementary small plots. The effect of mapped environmental factors and a spatial correlation term were jointly estimated providing a direct measure of the relative role of habitat specialisation and dispersal limitation. At community level, dispersal limitation was the most important determinant of species absence at local scale. The two environmental factors examined played a balanced role. Different species however showed different degrees of dispersal limitation and habitat specialisation. The distribution of a large proportion of species-the majority of the most abundant species-was significantly affected by at least one environmental factor. We provide a ranking of 49 species sensitive to canopy disturbance (from shade specialist to pioneer) and 41 species affected by seasonal flooding (either positively or negatively).  
  Address [Vincent, Gregoire; Marescot, Lucile; Barkaoui, Karim] IRD, Unite Mixte Rech AMAP, Kourou 97387, French Guiana, Email: gregoire.vincent@ird.fr  
  Corporate Author Thesis  
  Publisher Springer France Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1286-4560 ISBN Medium  
  Area Expedition Conference  
  Notes (down) ISI:000290448000014 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 318  
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