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Author Alméras, T.; Ghislain, B.; Clair, B.; Secerovic, A.; Pilate, G.; Fournier, M. url  doi
openurl 
  Title (down) Quantifying the motor power of trees Type Journal Article
  Year 2018 Publication Trees Abbreviated Journal  
  Volume 32 Issue 3 Pages 689-702  
  Keywords  
  Abstract Wood maturation strains can be estimated from the change in curvature that occurs when a stem grown staked in tilted position is released from the stake.
Trees have a motor system to enable upright growth in the field of gravity. This motor function is taken on by reaction wood, a special kind of wood that typically develops in leaning axes and generates mechanical force during its formation, curving up the stem and counteracting the effect of gravity or other mechanical disturbances. Quantifying the mechanical stress induced in wood during maturation is essential to many areas of research ranging from tree architecture to functional genomics. Here, we present a new method for quantifying wood maturation stress. It consists of tilting a tree, tying it to a stake, letting it grow in tilted position, and recording the change in stem curvature that occurs when the stem is released from the stake. A mechanical model is developed to make explicit the link between the change in curvature, maturation strain and morphological traits of the stem section. A parametric study is conducted to analyse how different parameters influence the change in curvature. This method is applied to the estimation of maturation strain in two different datasets. Results show that the method is able to detect genotypic variations in motor power expression. As predicted by the model, we observe that the change in stem curvature is correlated to stem diameter and diameter growth. In contrast, wood maturation strain is independent from these dimensional effects, and is suitable as an intrinsic parameter characterising the magnitude of the plant’s gravitropic reaction.
 
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  ISSN 1432-2285 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Alméras2018 Serial 835  
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Author Shipley, B.; Timothy Paine, C.E.; Baraloto, C. url  openurl
  Title (down) Quantifying the importance of local niche-based and stochastic processes to tropical tree community assembly Type Journal Article
  Year 2012 Publication Ecology Abbreviated Journal Ecology  
  Volume 93 Issue 4 Pages 760-769  
  Keywords Community Assembly by Trait Selection, CATS; Demographic stochasticity; Dispersal limitation; Environmental filtering; French Guiana; Functional traits; Maxent; Neutral assembly; Tropical forests  
  Abstract Although niche-based and stochastic processes, including dispersal limitation and demographic stochasticity, can each contribute to community assembly, it is difficult to quantify the relative importance of each process in natural vegetation. Here, we extend Shipley's maxent model (Community Assembly by Trait Selection, CATS) for the prediction of relative abundances to incorporate both trait-based filtering and dispersal limitation from the larger landscape and develop a statistical decomposition of the proportions of the total information content of relative abundances in local communities that are attributable to traitbased filtering, dispersal limitation, and demographic stochasticity. We apply the method to tree communities in a mature, species-rich, tropical forest in French Guiana at 1-, 0.25-and 0.04-ha scales. Trait data consisted of species' means of 17 functional traits measured over both the entire meta-community and separately in each of nine 1-ha plots. Trait means calculated separately for each site always gave better predictions. There was clear evidence of trait-based filtering at all spatial scales. Trait-based filtering was the most important process at the 1-ha scale (34%), whereas demographic stochasticity was the most important at smaller scales (37-53%). Dispersal limitation from the meta-community was less important and approximately constant across scales (∼9%), and there was also an unresolved association between site-specific traits and meta-community relative abundances. Our method allows one to quantify the relative importance of local niche-based and meta-community processes and demographic stochasticity during community assembly across spatial and temporal scales. © 2012 by the Ecological Society of America.  
  Address INRA, UMR, Écologie des Forêts de Guyane, 97387 Kourou cedex, France  
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  ISSN 00129658 (Issn) ISBN Medium  
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  Notes Export Date: 6 June 2012; Source: Scopus; Coden: Ecola; doi: 10.1890/11-0944.1; Language of Original Document: English; Correspondence Address: Shipley, B.; Département de Biologie, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; email: Bill.Shipley@USherbrooke.ca Approved no  
  Call Number EcoFoG @ webmaster @ Serial 401  
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Author Paine, C.E.T.; Harms, K.E. openurl 
  Title (down) Quantifying the effects of seed arrival and environmental conditions on tropical seedling community structure Type Journal Article
  Year 2009 Publication Oecologia Abbreviated Journal Oecologia  
  Volume 160 Issue 1 Pages 139-150  
  Keywords Community assembly; Dispersal; Niche differentiation; Seed addition; Variance partitioning  
  Abstract Though it is recognized that both stochastic and deterministic processes structure all communities, empirical assessments of their relative importance are rare, particularly within any single community. In this paper, we quantify the dynamic effects of dispersal assembly and niche assembly on the seedling layer in a diverse neotropical rain forest. The two theories make divergent predictions regarding the roles of seed arrival and environmental heterogeneity in generating community structure. Put simply, dispersal assembly posits that the stochasticity inherent to seed arrival structures communities, whereas niche assembly suggests that heterogeneity in post-dispersal environmental conditions is more important. We experimentally sowed 15,132 seeds of eight tree species at varying levels of density and diversity. Every six months we censused the seedlings that germinated and assessed the abiotic and biotic conditions of each plot. We assessed the density, diversity, and species composition of three nested subsets of the seedling layer: seedlings germinated from sown seeds, all seedlings germinated between July 2003 and 2004, and all woody seedlings. We partitioned the variance in density and diversity of each subset of the seedling layer into components representing seed-addition treatments and environmental conditions at 6- to 12-month intervals. Seed additions initially explained more variance in the density and diversity than did environmental heterogeneity for seven of eight sown species, but explained little variance in the density or diversity of the entire seedling layer. Species composition was better explained by seed-addition treatments than by environmental heterogeneity for all three subsets and in all time periods. Nevertheless, the variance in community structure explained by seed-addition treatments declined over the two years following germination, presaging shifts in the relative importance of dispersal assembly and niche assembly. Our study quantifies how dispersal assembly and niche assembly may vary among the components of an ecological community and shift dynamically through time.  
  Address [Paine, C. E. Timothy; Harms, Kyle E.] Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA, Email: timothy.paine@ecofog.gf  
  Corporate Author Thesis  
  Publisher SPRINGER Place of Publication Editor  
  Language Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0029-8549 ISBN Medium  
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  Notes ISI:000265100500014 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 116  
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Author Morel, H.; Nicolini, E.; Bossu, J.; Blanc, L.; Beauchene, J. pdf  url
doi  openurl
  Title (down) Qualité et usages du bois de cinq espèces forestières adaptées à la plantation à vocation de bois d’oeuvre et testées en Guyane française Type Journal Article
  Year 2017 Publication Bois & Forêts des Tropiques Abbreviated Journal  
  Volume 334 Issue Pages 61-74  
  Keywords propriétés technologiques; qualité du bois; plantation; Guyane française  
  Abstract Des essais de plantations forestières ont été menés en Guyane française depuis le début des années 1960 sur plus de 138 espèces (70 espèces natives et 68 espèces exotiques). Une étude récente sur la productivité de ces espèces en plantation (projet ForesTreeCulture, 2013-2015) a mis en avant le fort potentieldeproductiondetroisespècesnatives ( Simarouba amara Aubl., Vochysia tomentosa (G. Mey.) DC., Bagassa guianensis ( Aubl.)) et d’une espèce d’Afrique de l’Ouest ( Tarrietia utilis Sprague) avec des volumes de bois produits supérieurs à 20 m3/ha/an. Cependant, les propriétés du bois de ces espèces commerciales ne sont connues qu’au travers d’arbres issus de forêt naturelle. Nous présentons les propriétés du bois de ces espèces en conditions de plantation – densité, retrait, élasticité, angle du fil,  durabilité – et discutons de leurs potentiels et de leurs usages respectifs futurs. Une autre espèce, Cordia alliodora ((Ruiz et Pavon) Oken), a également été retenue bien qu’elle n’ait pas encore été plantée en Guyane française. Cette espèce, native de Guyane, est bien connue en Amérique latine pour son bois et son fort potentiel de croissance en milieu anthropisé.  
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  Call Number EcoFoG @ webmaster @ Serial 786  
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Author Derroire, Géraldine ; Piponiot, Camille ; Descroix, Laurent ; Bedeau, Caroline ; Traissac, Stéphane ; Brunaux, Olivier ; Hérault, Bruno doi  openurl
  Title (down) Prospective carbon balance of the wood sector in a tropical forest territory using a temporally-explicit model Type Journal Article
  Year 2021 Publication Forest Ecology and Management Abbreviated Journal  
  Volume 497 Issue Pages  
  Keywords Exploitation forestière, Production du bois, Modélisation environnementale, planification de la gestion forestière, forêt tropicale, Aménagement forestier, Plantations, Évaluation de l'impac  
  Abstract Selective logging in tropical forests is often perceived as a source of forest degradation and carbon emissions. Improved practices, such as reduced-impact logging (RIL), and alternative timber production strategies (e.g. plantations) can drastically change the overall carbon impact of the wood production sector. Assessing the carbon balance of timber production is crucial but highly dependent on methodological approaches, especially regarding system boundaries and temporality. We developed a temporally-explicit and territory scale model of carbon balance calibrated with long-term local data using Bayesian inference. The model accounts for carbon fluxes from selective logging in natural forest, timber plantation, first transformation and avoided emissions through energy substitution. We used it to compare prospective scenarios of development for the wood sector in French Guiana. Results show that intensification of practices, through increased logging intensity conducted with RIL and establishment of timber plantations, are promising development strategies to reduce the carbon emissions of the French-Guianese wood sector, as well as the area needed for wood production and hence the pressure on natural forests. By reducing logging damage by nearly 50%, RIL allows increasing logging intensity in natural forest from 20 m3 ha−1 to 30 m3 ha−1 without affecting the carbon balance. The use of logging byproducts as fuelwood also improved the carbon balance of selective logging, when substituted to fossil fuel. Allocating less than 30 000 ha to plantation would allow producing 200 000 m3 of timber annually, while the same production in natural forest would imply logging more than 400 000 ha over 60 years. Timber plantation should be preferentially established on non-forested lands, as converting natural forests to plantation leads to high carbon emission peak over the first three decades. We recommend a mixed-strategy combining selective logging in natural forests and plantations as a way to improve long-term carbon balance while reducing short-term emissions. This strategy can reduce the pressure on natural forests while mitigating the risks of changing practices and allowing a diversified source of timber for a diversity of uses. It requires adaptation of the wood sector and development of technical guidelines. Research and monitoring efforts are also needed to assess the impacts of changing practices on other ecosystem services, especially biodiversity conservation.  
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  Publisher Elsevier Place of Publication Editor  
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  Call Number EcoFoG @ webmaster @ Serial 1019  
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Author Vedel, V.; Scotti, I. openurl 
  Title (down) Promoting the promoter Type Journal Article
  Year 2011 Publication Plant Science Abbreviated Journal Plant Sci.  
  Volume 180 Issue 2 Pages 182-189  
  Keywords cis-Regulation; Evolutionary and developmental biology; Integrative evolution; Plant development; Population genetics; Transcription  
  Abstract Recent evolutionary studies clearly indicate that evolution is mainly driven by changes in the complex mechanisms of gene regulation and not solely by polymorphism in protein-encoding genes themselves. After a short description of the cis-regulatory mechanism, we intend in this review to argue that by applying newly available technologies and by merging research areas such as evolutionary and developmental biology, population genetics, ecology and molecular cell biology it is now possible to study evolution in an integrative way. We contend that, by analysing the effects of promoter sequence variation on phenotypic diversity in natural populations, we will soon be able to break the barrier between the study of extant genetic variability and the study of major developmental changes. This will lead to an integrative view of evolution at different scales. Because of their sessile nature and their continuous development, plants must permanently regulate their gene expression to react to their environment, and can, therefore, be considered as a remarkable model for these types of studies. (C) 2010 Elsevier Ireland Ltd. All rights reserved.  
  Address [Vedel, Vincent; Scotti, Ivan] INRA, UMR ECOFOG, Kourou 97387, French Guiana, Email: vincent.vedel@ecofog.gf  
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  Publisher ELSEVIER IRELAND LTD Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9452 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000286562200002 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 291  
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Author Dejean, A. pdf  openurl
  Title (down) 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  
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  Publisher Public Library Science Place of Publication Editor  
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  ISSN 1932-6203 ISBN Medium  
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  Notes ISI:000290483600033 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 316  
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Author Molto, Q.; Herault, B.; Boreux, J.-J.; Daullet, M.; Rousteau, A.; Rossi, V. pdf  url
openurl 
  Title (down) Predicting tree heights for biomass estimates in tropical forests -A test from French Guiana Type Journal Article
  Year 2014 Publication Biogeosciences Abbreviated Journal Biogeosciences  
  Volume 11 Issue 12 Pages 3121-3130  
  Keywords  
  Abstract The recent development of REDD+ mechanisms requires reliable estimation of carbon stocks, especially in tropical forests that are particularly threatened by global changes. Even though tree height is a crucial variable for computing aboveground forest biomass (AGB), it is rarely measured in large-scale forest censuses because it requires extra effort. Therefore, tree height has to be predicted with height models. The height and diameter of all trees over 10 cm in diameter were measured in 33 half-hectare plots and 9 one-hectare plots throughout northern French Guiana, an area with substantial climate and environmental gradients. We compared four different model shapes and found that the Michaelis-Menten shape was most appropriate for the tree biomass prediction. Model parameter values were significantly different from one forest plot to another, and this leads to large errors in biomass estimates. Variables from the forest stand structure explained a sufficient part of plot-to-plot variations of the height model parameters to improve the quality of the AGB predictions. In the forest stands dominated by small trees, the trees were found to have rapid height growth for small diameters. In forest stands dominated by larger trees, the trees were found to have the greatest heights for large diameters. The aboveground biomass estimation uncertainty of the forest plots was reduced by the use of the forest structure-based height model. It demonstrated the feasibility and the importance of height modeling in tropical forests for carbon mapping. When the tree heights are not measured in an inventory, they can be predicted with a height-diameter model and incorporating forest structure descriptors may improve the predictions. © Author(s) 2014. CC Attribution 3.0 License.  
  Address Université de Liège, Liège, Belgium  
  Corporate Author Thesis  
  Publisher European Geosciences Union Place of Publication Editor  
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  ISSN 17264189 (Issn) ISBN Medium  
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  Notes Export Date: 3 July 2014; Correspondence Address: Molto, Q.; Université des Antilles et de la Guyane, UMR Ecologie des Forêts de Guyane, Kourou, France; email: quentin.molto@gmail.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial 550  
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Author Salas-Lopez, A. doi  openurl
  Title (down) Predicting resource use in ant species and entire communities by studying their morphological traits: Influence of habitat and subfamily Type Journal Article
  Year 2017 Publication Ecological Indicators Abbreviated Journal Ecol. Indic.  
  Volume 78 Issue Pages 183-191  
  Keywords Biodiversity-ecosystem functioning relationships; Ecosystem process; Food niche; Formicidae; Habitat filtering; Indicator; Land-use; Morphological traits; Taxonomic conservatism; Biodiversity; Ecology; Indicators (instruments); Land use; Natural resources management; Ecosystem functioning; Ecosystem process; Formicidae; Morphological traits; Taxonomic conservatism; Ecosystems; Formicidae  
  Abstract I investigated whether the morphological traits of Neotropical ants can be used to infer food resource use by individual species and by entire communities, and whether these relationships are related to habitat type and/or by morphological differences between ant subfamilies. I attracted ants using food baits that represented different ecological processes (e.g. predation, granivory, detritivory, nectarivory) in five habitat types along a land-use gradient (from forests to gardens). I assessed ant activity at the baits and characterized 64 species from six subfamilies according to their food use and community-level resource exploitation intensity in the different habitats. Next, I performed a Mantel test to reveal the relationships between 13 morphological measures and resource use at the species level. I then used ant clades (i.e. subfamily) and habitat to rank the ants along three axes of variation in relation to their morphology and food resource use. Finally, I tested whether associations existed between the community-level exploitation intensity for such resources and the distribution of morphological trait values using the “4th-corner” analysis. Morphological traits were closely linked to the species’ ability to exploit different resources. These relationships were affected by subfamily and, to a lesser extent, by habitat type. The characterization of trait sets for entire communities was not useful, however, in predicting the intensity of the exploitation of different types of resources in varying environmental conditions. I conclude that morphological traits are accurate predictors of the ecology of species, but they should be used with caution when trying to understand community-level patterns. © 2017 Elsevier Ltd  
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  Notes Export Date: 8 April 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 747  
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Author Dejean, A.; Orivel, J.; Rossi, V.; Roux, O.; Lauth, J.; Malé, P.-J.G.; Céréghino, R.; Leroy, C. pdf  url
doi  openurl
  Title (down) Predation Success By A Plant-Ant Indirectly Favours The Growth And Fitness Of Its Host Myrmecophyte Type Journal Article
  Year 2013 Publication PLoS ONE Abbreviated Journal  
  Volume 8 Issue 3 Pages e59405  
  Keywords  
  Abstract Mutualisms, or interactions between species that lead to net fitness benefits for each species involved, are stable and ubiquitous in nature mostly due to “byproduct benefits” stemming from the intrinsic traits of one partner that generate an indirect and positive outcome for the other. Here we verify if myrmecotrophy (where plants obtain nutrients from the refuse of their associated ants) can explain the stability of the tripartite association between the myrmecophyte Hirtella physophora, the ant Allomerus decemarticulatus and an Ascomycota fungus. The plant shelters and provides the ants with extrafloral nectar. The ants protect the plant from herbivores and integrate the fungus into the construction of a trap that they use to capture prey; they also provide the fungus and their host plant with nutrients. During a 9-month field study, we over-provisioned experimental ant colonies with insects, enhancing colony fitness (i.e., more winged females were produced). The rate of partial castration of the host plant, previously demonstrated, was not influenced by the experiment. Experimental plants showed higher δ15N values (confirming myrmecotrophy), plus enhanced vegetative growth (e.g., more leaves produced increased the possibility of lodging ants in leaf pouches) and fitness (i.e., more fruits produced and more flowers that matured into fruit). This study highlights the importance of myrmecotrophy on host plant fitness and the stability of ant-myrmecophyte mutualisms. © 2013 Dejean et al.  
  Address IRD, AMAP (botAnique et bioinforMatique de l'Architecture des Plantes; UMR-IRD 123), Montpellier, France  
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  Notes Export Date: 26 March 2013; Source: Scopus; Art. No.: e59405 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 478  
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