toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Bonal, D.; Ponton, S.; Le Thiec, D.; Richard, B.; Ningre, N.; Herault, B.; Ogee, J.; Gonzalez, S.; Pignal, M.; Sabatier, D.; Guehl, J.M. openurl 
  Title (down) Leaf functional response to increasing atmospheric CO(2) concentrations over the last century in two northern Amazonian tree species: a historical delta(13)C and delta(18)O approach using herbarium samples Type Journal Article
  Year 2011 Publication Plant Cell and Environment Abbreviated Journal Plant Cell Environ.  
  Volume 34 Issue 8 Pages 1332-1344  
  Keywords carbon isotope composition; environmental change; herbarium; oxygen isotope composition; photosynthesis; stomata; tropical rainforests  
  Abstract We assessed the extent of recent environmental changes on leaf morphological (stomatal density, stomatal surface, leaf mass per unit area) and physiological traits (carbon isotope composition, delta(13)C(leaf), and discrimination, Delta(13)C(leaf), oxygen isotope composition, delta(18)O(leaf)) of two tropical rainforest species (Dicorynia guianensis; Humiria balsamifera) that are abundant in the Guiana shield (Northern Amazonia). Leaf samples were collected in different international herbariums to cover a 200 year time-period (1790-2004) and the whole Guiana shield. Using models describing carbon and oxygen isotope fractionations during photosynthesis, different scenarios of change in intercellular CO(2) concentrations inside the leaf (C(i)), stomatal conductance (g), and photosynthesis (A) were tested in order to understand leaf physiological response to increasing air CO(2) concentrations (C(a)). Our results confirmed that both species displayed physiological response to changing C(a). For both species, we observed a decrease of about 1.7% in delta(13)C(leaf) since 1950, without significant change in Delta(13)C(leaf) and leaf morphological traits. Furthermore, there was no clear change in delta(18)O(leaf) for Humiria over this period. Our simulation approach revealed that an increase in A, rather than a decrease in g, explained the observed trends for these tropical rainforest species, allowing them to maintain a constant ratio of C(i)/C(a).  
  Address [Bonal, D] INRA, UMR Ecofog, F-97387 Kourou, France, Email: bonal@nancy.inra.fr  
  Corporate Author Thesis  
  Publisher Wiley-Blackwell Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0140-7791 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000292698900010 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 330  
Permanent link to this record
 

 
Author Sommeria-Klein, G.; Zinger, L.; Coissac, E.; Iribar, A.; Schimann, H.; Taberlet, P.; Chave, J. doi  openurl
  Title (down) Latent Dirichlet Allocation reveals spatial and taxonomic structure in a DNA-based census of soil biodiversity from a tropical forest Type Journal Article
  Year 2020 Publication Molecular Ecology Resources Abbreviated Journal Mol. Ecol. Resour.  
  Volume 20 Issue 2 Pages 371-386  
  Keywords community ecology; environmental DNA; metabarcoding; OTU presence–absence; soil microbiome; topic modelling; bacterium; biodiversity; biology; classification; eukaryote; fungus; genetics; high throughput sequencing; isolation and purification; microbiology; parasitology; procedures; soil; Bacteria; Biodiversity; Computational Biology; Eukaryota; Fungi; High-Throughput Nucleotide Sequencing; Soil; Soil Microbiology  
  Abstract High-throughput sequencing of amplicons from environmental DNA samples permits rapid, standardized and comprehensive biodiversity assessments. However, retrieving and interpreting the structure of such data sets requires efficient methods for dimensionality reduction. Latent Dirichlet Allocation (LDA) can be used to decompose environmental DNA samples into overlapping assemblages of co-occurring taxa. It is a flexible model-based method adapted to uneven sample sizes and to large and sparse data sets. Here, we compare LDA performance on abundance and occurrence data, and we quantify the robustness of the LDA decomposition by measuring its stability with respect to the algorithm's initialization. We then apply LDA to a survey of 1,131 soil DNA samples that were collected in a 12-ha plot of primary tropical forest and amplified using standard primers for bacteria, protists, fungi and metazoans. The analysis reveals that bacteria, protists and fungi exhibit a strong spatial structure, which matches the topographical features of the plot, while metazoans do not, confirming that microbial diversity is primarily controlled by environmental variation at the studied scale. We conclude that LDA is a sensitive, robust and computationally efficient method to detect and interpret the structure of large DNA-based biodiversity data sets. We finally discuss the possible future applications of this approach for the study of biodiversity. © 2019 John Wiley & Sons Ltd  
  Address Laboratoire d’Ecologie des Forêts de Guyane (EcoFoG, UMR 745), INRA, AgroParisTech, CIRAD, CNRS, University of the French West Indies, University of French Guiana, Kourou, France  
  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1755098x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 981  
Permanent link to this record
 

 
Author Nirma, C.; Rodrigues, A.M.S.; Basset, C.; Chevolot, L.; Girod, R.; Moretti, C.; Stien, D.; Dusfour, I.; Eparvier, V. doi  openurl
  Title (down) Larvicidal activity of isoflavonoids from Muellera frutescens extracts against Aedes aegypti Type Journal Article
  Year 2012 Publication Natural Product Communications Abbreviated Journal  
  Volume 7 Issue 10 Pages 1319-1322  
  Keywords Aedes aegypti; French Guiana; Insecticides; Isoflavonoids; Muellera frutescens  
  Abstract The biological activity of extracts from the leaves, bark and roots of Muellera frutescens, an Amazonian ichtyotoxic plant, were evaluated to find new environmentally safe insecticides. The n-hexane extracts of bark, leaf, and root showed a strong toxic activity against Aedes aegypti mosquito larvae. Bioguided fractionation of the bark extract led to the isolation of seven isoflavonoids (12a-hydroxyelliptone, elliptone, (-)-variabilin, rotenone, rotenolone, tephrosin and deguelin). Rotenone and deguelin are responsible for the larvicidal activity of the plant. M. frutescens leaves contain up to 0.6%, w/w, deguelin. These results justify the traditional ichtyotoxic use of M. frutescens. The leaves contain a relatively high proportion of deguelin and, therefore, can be considered as a renewable source of this environmentally friendly insecticidal isoflavonoid.  
  Address CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette, 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 ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 6 December 2012; Source: Scopus Approved no  
  Call Number EcoFoG @ webmaster @ Serial 448  
Permanent link to this record
 

 
Author Talaga, S.; Dejean, A.; Mouza, C.; Dumont, Y.; Leroy, C. doi  openurl
  Title (down) Larval interference competition between the native Neotropical mosquito Limatus durhamii and the invasive Aedes aegypti improves the fitness of both species Type Journal Article
  Year 2018 Publication Insect Science Abbreviated Journal Insect Science  
  Volume 25 Issue Pages 1102-1107  
  Keywords Aedes aegypti; increased fitness; interference competition; Limatus durhamii; phenotypic plasticity; resistance to invasion  
  Abstract Abstract Interspecific competition with native species during biological invasions can sometimes limit alien expansion. We aimed to determine the potential ecological effects of Limatus durhamii Theobald 1901, a native Neotropical mosquito (Diptera: Culicidae) species, on the invasive species Aedes (Stegomyia) aegypti (Linnaeus 1762) that breeds in the same artificial water containers. Development time and adult dry mass were measured in 3 rearing conditions: control (a single larva), intraspecific competition (2 conspecific larvae), and interspecific competition (2 heterospecific larvae). Food was provided ad libitum to eliminate exploitative competition. For Ae. aegypti, development time was not affected by interspecific interference competition (nonsignificant differences with the control) and the adult dry mass was significantly higher, meaning that individual fitness likely increased. Yet, because previous studies showed longer development time and lighter adults during competition with other invasive mosquitoes, it is likely that Ae. aegypti can express a different phenotype depending on the competing species. The similar pattern found for Li. durhamii females and the nonsignificant difference with the control for males explain in part why this species can compete with Ae. aegypti.  
  Address  
  Corporate Author Thesis  
  Publisher John Wiley & Sons, Ltd (10.1111) Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1672-9609 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 836  
Permanent link to this record
 

 
Author Ziegler, C.; Coste, S.; Stahl, C.; Delzon, S.; Levionnois, S.; Cazal, J.; Cochard, H.; Esquivel-Muelbert, A.; Goret, J.-Y.; Heuret, P.; Jaouen, G.; Santiago, L.S.; Bonal, D. url  doi
openurl 
  Title (down) Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought Type Journal Article
  Year 2019 Publication Annals of Forest Science Abbreviated Journal Ann. Forest Sci.  
  Volume 76 Issue 4 Pages 115  
  Keywords Amazon rainforest; Embolism resistance; Hydraulic safety margins; Turgor loss point; Water potential  
  Abstract Key message: Abundant Neotropical canopy-tree species are more resistant to drought-induced branch embolism than what is currently admitted. Large hydraulic safety margins protect them from hydraulic failure under actual drought conditions. Context: Xylem vulnerability to embolism, which is associated to survival under extreme drought conditions, is being increasingly studied in the tropics, but data on the risk of hydraulic failure for lowland Neotropical rainforest canopy-tree species, thought to be highly vulnerable, are lacking. Aims: The purpose of this study was to gain more knowledge on species drought-resistance characteristics in branches and leaves and the risk of hydraulic failure of abundant rainforest canopy-tree species during the dry season. Methods: We first assessed the range of branch xylem vulnerability to embolism using the flow-centrifuge technique on 1-m-long sun-exposed branches and evaluated hydraulic safety margins with leaf turgor loss point and midday water potential during normal- and severe-intensity dry seasons for a large set of Amazonian rainforest canopy-tree species. Results: Tree species exhibited a broad range of embolism resistance, with the pressure threshold inducing 50% loss of branch hydraulic conductivity varying from − 1.86 to − 7.63 MPa. Conversely, we found low variability in leaf turgor loss point and dry season midday leaf water potential, and mostly large, positive hydraulic safety margins. Conclusions: Rainforest canopy-tree species growing under elevated mean annual precipitation can have high resistance to embolism and are more resistant than what was previously thought. Thanks to early leaf turgor loss and high embolism resistance, most species have a low risk of hydraulic failure and are well able to withstand normal and even severe dry seasons. © 2019, The Author(s).  
  Address Smithsonian Tropical Research Institute, Balboa, Ancon, Panama  
  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 12864560 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 901  
Permanent link to this record
 

 
Author Richard-Hansen, C.; Jaouen, G.; Denis, T.; Brunaux, O.; Marcon, E.; Guitet, S. url  openurl
  Title (down) Landscape patterns influence communities of medium-to large-bodied vertebrates in undisturbed terra firme forests of French Guiana Type Journal Article
  Year 2015 Publication Journal of Tropical Ecology Abbreviated Journal Journal of Tropical Ecology  
  Volume 31 Issue 5 Pages 423-436  
  Keywords Animal communities; diversity; environmental heterogeneity; French Guiana; landscape ecology; species-habitat association  
  Abstract Whereas broad-scale Amazonian forest types have been shown to influence the structure of the communities of medium-to large-bodied vertebrates, their natural heterogeneity at smaller scale or within the terra firme forests remains poorly described and understood. Diversity indices of such communities and the relative abundance of the 21 most commonly observed species were compared from standardized line-transect data across 25 study sites distributed in undisturbed forests in French Guiana. We first assessed the relevance of a forest typology based on geomorphological landscapes to explain the observed heterogeneity. As previously found for tree beta-diversity patterns, this new typology proved to be a non-negligible factor underlying the beta diversity of the communities of medium-to large bodied vertebrates in French Guianan terra firme forests. Although the species studied are almost ubiquitous across the region, they exhibited habitat preferences through significant variation in abundance and in their association index with the different landscape types. As terra firme forests represent more than 90% of the Amazon basin, characterizing their heterogeneity-including faunal communities-is a major challenge in neotropical forest ecology. © 2015 Cambridge University Press.  
  Address ONCFS, EcoFoG, Kourou Cedex, 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 ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 16 November 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 638  
Permanent link to this record
 

 
Author Salas-Lopez, A.; Violle, C.; Mallia, L.; Orivel, J. url  doi
openurl 
  Title (down) Land-use change effects on the taxonomic and morphological trait composition of ant communities in French Guiana Type Journal Article
  Year 2018 Publication Insect Conservation and Diversity Abbreviated Journal Insect Conserv Divers  
  Volume 11 Issue 2 Pages 162-173  
  Keywords Community assembly; Formicidae; functional diversity; gradient analysis; habitat filtering; land-use intensification; n-dimensional hypervolume approach  
  Abstract Abstract Land-use changes frequently lead to major changes in the composition and diversity of organisms. A reduction in the range of strategies enabling organisms to survive in a given environment and changes in the average trait values of species may potentially be associated with variations in species? number and identity. We investigated the variation in ant taxonomic composition and morphological trait diversity along a land-use gradient in French Guiana. We measured 13 core ant morphological traits on all species sampled. We then selected the set of five traits that best captured changes along the land-use gradient. Potential effects of the variation in morphological trait diversity and average values were evaluated by examining morphological traits individually as well as in combination. We found that variation in taxonomic diversity was unrelated to the plot-level morphospace. Conversely, a significant shift in taxonomic composition was accompanied by changes in the average values of community traits along the studied gradient, examined both individually and in combination. We argue that morphological trait values may be related to the success of different species in surviving in a given environment and, therefore, are indicative of the taxonomic turnover in ants along the land-use gradient. Nevertheless, in contradiction with theoretical expectations, the morphospace is only slightly affected by habitat filtering and loosely impacted by taxonomic changes. Examining the sensitivity of the morphospace to abiotic and biotic factors and how it reflects varying ecological pressures for species is thus of the utmost importance.  
  Address  
  Corporate Author Thesis  
  Publisher John Wiley & Sons, Ltd (10.1111) Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1752-458x ISBN Medium  
  Area Expedition Conference  
  Notes doi: 10.1111/icad.12248 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 892  
Permanent link to this record
 

 
Author Epelboin, L.; Bourhy, P.; Le Turnier, P.; Schaub, R.; Mosnier, E.; Berlioz-Arthaud, A.; Reynaud, Y.; Nacher, M.; De Thoisy, B.; Carles, G.; Richard-Hansen, C.; Demar, M.; Picardeau, M.; Djossou, F. url  doi
openurl 
  Title (down) La leptospirose en Guyane française et sur le bouclier des Guyanes. État des connaissances en 2016 Type Journal Article
  Year 2017 Publication Bulletin de la Société de pathologie exotique Abbreviated Journal  
  Volume 110 Issue 3 Pages 165-179  
  Keywords  
  Abstract La leptospirose est une zoonose cosmopolite causée par les bactéries du genre Leptospira. Si sa répartition est vaste sur le globe, le climat chaud et humide de la zone intertropicale est particulièrement propice à son expansion. Dans la plupart des départements et territoires français d’outremer, la leptospirose est considérée comme un problème de santé publique. En Guyane, département français situé au nord-est de la forêt amazonienne, elle est considérée comme rare. L’objectif de cette revue est de faire l’état des lieux des connaissances sur la leptospirose humaine et animale en Guyane française et dans les pays environnants. Une recherche exhaustive a été conduite, à travers la littérature médicale indexée et informelle en français, anglais, espagnol et portugais. Ainsi, respectivement dix et quatre publications ont pu être identifiées sur la leptospirose humaine et animale en Guyane, publiées entre 1940 et 1995, sous formes de cas cliniques ou de séries de cas. Les publications concernant cette maladie dans les autres pays du plateau des Guyanes, Venezuela oriental, Guyana, Suriname, et État brésilien de l’Amapá, étaient également rares voire inexistantes. En revanche, les données récentes du centre national de la leptospirose français ont montré une augmentation récente et brutale du nombre de cas dans le département, probablement en partie due à la mise en place d’outils diagnostiques tels que la sérologie IgM Elisa. Il est en fait probable que la leptospirose soit une maladie négligée dans la région, du fait de l’absence d’outils diagnostiques rapidement disponibles, de la méconnaissance des cliniciens de cette pathologie et de l’existence de nombreux autres pathogènes à présentation clinique similaire (paludisme, arboviroses, fièvre Q, toxoplasmose amazonienne). La mise en place d’études de plus grande ampleur sur la leptospirose animale et humaine est nécessaire et urgente pour connaître le véritable poids de cette maladie dans notre région.  
  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 1961-9049 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Epelboin2017 Serial 785  
Permanent link to this record
 

 
Author Hérault, B.; Piponiot, C. pdf  url
doi  openurl
  Title (down) Key drivers of ecosystem recovery after disturbance in a neotropical forest: Long-term lessons from the Paracou experiment, French Guiana Type Journal Article
  Year 2018 Publication Forest Ecosystems Abbreviated Journal Forest Ecosystems  
  Volume 5 Issue 2 Pages  
  Keywords Amazonia; Carbon fluxes; Climate change; Ecological resilience; Ecosystem modeling; Tropical forests  
  Abstract Background: Natural disturbance is a fundamental component of the functioning of tropical rainforests let to natural dynamics, with tree mortality the driving force of forest renewal. With ongoing global (i.e. land-use and climate) changes, tropical forests are currently facing deep and rapid modifications in disturbance regimes that may hamper their recovering capacity so that developing robust predictive model able to predict ecosystem resilience and recovery becomes of primary importance for decision-making: (i) Do regenerating forests recover faster than mature forests given the same level of disturbance? (ii) Is the local topography an important predictor of the post-disturbance forest trajectories? (iii) Is the community functional composition, assessed with community weighted-mean functional traits, a good predictor of carbon stock recovery? (iv) How important is the climate stress (seasonal drought and/or soil water saturation) in shaping the recovery trajectory? Methods: Paracou is a large scale forest disturbance experiment set up in 1984 with nine 6.25 ha plots spanning on a large disturbance gradient where 15 to 60% of the initial forest ecosystem biomass were removed. More than 70,000 trees belonging to ca. 700 tree species have then been censused every 2 years up today. Using this unique dataset, we aim at deciphering the endogenous (forest structure and composition) and exogenous (local environment and climate stress) drivers of ecosystem recovery in time. To do so, we disentangle carbon recovery into demographic processes (recruitment, growth, mortality fluxes) and cohorts (recruited trees, survivors). Results: Variations in the pre-disturbance forest structure or in local environment do not shape significantly the ecosystem recovery rates. Variations in the pre-disturbance forest composition and in the post-disturbance climate significantly change the forest recovery trajectory. Pioneer-rich forests have slower recovery rates than assemblages of late-successional species. Soil water saturation during the wet season strongly impedes ecosystem recovery but not seasonal drought. From a sensitivity analysis, we highlight the pre-disturbance forest composition and the post-disturbance climate conditions as the primary factors controlling the recovery trajectory. Conclusions: Highly-disturbed forests and secondary forests because they are composed of a lot of pioneer species will be less able to cope with new disturbance. In the context of increasing tree mortality due to both (i) severe droughts imputable to climate change and (ii) human-induced perturbations, tropical forest management should focus on reducing disturbances by developing Reduced Impact Logging techniques.  
  Address Université de la Guyane, UMR EcoFoG (AgroParistech, Cirad, CNRS, Inra, Université des Antilles), Campus Agronomique, Kourou, French Guiana, 97310, 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 ISBN Medium  
  Area Expedition Conference  
  Notes Cited By :1; Export Date: 1 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 812  
Permanent link to this record
 

 
Author Craine, J.M.; Elmore, A.J.; Wang, L.; Aranibar, J.; Bauters, M.; Boeckx, P.; Crowley, B.E.; Dawes, M.A.; Delzon, S.; Fajardo, A.; Fang, Y.; Fujiyoshi, L.; Gray, A.; Guerrieri, R.; Gundale, M.J.; Hawke, D.J.; Hietz, P.; Jonard, M.; Kearsley, E.; Kenzo, T.; Makarov, M.; Marañón-Jiménez, S.; McGlynn, T.P.; McNeil, B.E.; Mosher, S.G.; Nelson, D.M.; Peri, P.L.; Roggy, J.C.; Sanders-DeMott, R.; Song, M.; Szpak, P.; Templer, P.H.; Van der Colff, D.; Werner, C.; Xu, X.; Yang, Y.; Yu, G.; Zmudczyńska-Skarbek, K. url  doi
openurl 
  Title (down) Isotopic evidence for oligotrophication of terrestrial ecosystems Type Journal Article
  Year 2018 Publication Nature Ecology & Evolution Abbreviated Journal  
  Volume 2 Issue 11 Pages 1735-1744  
  Keywords  
  Abstract Human societies depend on an Earth system that operates within a constrained range of nutrient availability, yet the recent trajectory of terrestrial nitrogen (N) availability is uncertain. Examining patterns of foliar N concentrations and isotope ratios (delta15N) from more than 43,000 samples acquired over 37 years, here we show that foliar N concentration declined by 9% and foliar delta15N declined by 0.6–1.6 per thousand. Examining patterns across different climate spaces, foliar delta15N declined across the entire range of mean annual temperature and mean annual precipitation tested. These results suggest declines in N supply relative to plant demand at the global scale. In all, there are now multiple lines of evidence of declining N availability in many unfertilized terrestrial ecosystems, including declines in delta15N of tree rings and leaves from herbarium samples over the past 75–150 years. These patterns are consistent with the proposed consequences of elevated atmospheric carbon dioxide and longer growing seasons. These declines will limit future terrestrial carbon uptake and increase nutritional stress for herbivores.  
  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 2397-334x ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Craine2018 Serial 827  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: