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Author Alméras, T.; Ghislain, B.; Clair, B.; Secerovic, A.; Pilate, G.; Fournier, M. url  doi
openurl 
  Title Quantifying the motor power of trees Type Journal Article
  Year 2018 Publication Trees Abbreviated Journal  
  Volume 32 Issue 3 Pages 689-702  
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  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 Hérault, B.; Piponiot, C. pdf  url
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  Title 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  
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  Notes Cited By :1; Export Date: 1 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 812  
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Author Piponiot, C.; Derroire, G.; Descroix, L.; Mazzei, L.; Rutishauser, E.; Sist, P.; Hérault, B. doi  openurl
  Title Assessing timber volume recovery after disturbance in tropical forests – A new modelling framework Type Journal Article
  Year 2018 Publication Ecological Modelling Abbreviated Journal  
  Volume 384 Issue Pages 353-369  
  Keywords Disturbance; Ecosystem modelling; Recovery; Sustainability; Tropical forest management  
  Abstract One third of contemporary tropical forests is designated by national forest services for timber production. Tropical forests are also increasingly affected by anthropogenic disturbances. However, there is still much uncertainty around the capacity of tropical forests to recover their timber volume after logging as well as other disturbances such as fires, large blow-downs and extreme droughts, and thus on the long-term sustainability of logging. We developed an original Bayesian hierarchical model of Volume Dynamics with Differential Equations (VDDE) to infer the dynamic of timber volumes as the result of two ecosystem processes: volume gains from tree growth and volume losses from tree mortality. Both processes are expressed as explicit functions of the forest maturity, i.e. the overall successional stage of the forest that primarily depends on the frequency and severity of the disturbances that the forest has undergone. As a case study, the VDDE model was calibrated with data from Paracou, a long-term disturbance experiment in a neotropical forest where over 56 ha of permanent forest plots were logged with different intensities and censused for 31 years. With this model, we could predict timber recovery at Paracou at the end of a cutting cycle depending on the logging intensity, the rotation cycle length, and the proportion of commercial volume. The VDDE modelling framework developed presents three main advantages: (i) it can be calibrated with large tree inventories which are widely available from national forest inventories or logging concession management plans and are easy to measure, both on the field and with remote sensing; (ii) it depends on only a few input parameters, which can be an advantage in tropical regions where data availability is scarce; (iii) the modelling framework is flexible enough to explicitly include the effect of other types of disturbances (both natural and anthropogenic: e.g. blow-downs, fires and climate change) on the forest maturity, and thus to predict future timber provision in the tropics in a context of global changes. © 2018 Elsevier B.V.  
  Address INPHB (Institut National Polytechnique Félix Houphouet Boigny), Yamoussoukro, Cote d'Ivoire  
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  Notes Export Date: 1 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 813  
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Author Medjigbodo, G.; Rozière, E.; Charrier, K.; Izoret, L.; Loukili, A. url  doi
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  Title Hydration, shrinkage, and durability of ternary binders containing Portland cement, limestone filler and metakaolin Type Journal Article
  Year 2018 Publication Construction and Building Materials Abbreviated Journal  
  Volume 183 Issue Pages 114-126  
  Keywords Durability; Limestone filler; Metakaolin; Shrinkage; Strength; Ternary binders  
  Abstract A partial replacement of the clinker by latent hydraulic or pozzolanic materials is encouraged due to environmental and specific technical requirements. Such substitution remains limited to a relatively low level (less than 30% by mass of cementitious materials). An experimental research work was carried out on mortars made with binary and ternary binders (Portland cement; metakaolin; limestone filler) to reach 45% total replacement. In order to investigate the activating effect of reduced water-to-cement ratio, two series of mixtures were designed with W/C0 of 0.42 and 0.5. Their heat of hydration, portlandite content, shrinkage, porosity, and carbonation were monitored. The tests were performed to understand the evolution of their relative strength (activity index) and durability parameters. The strength development of mortars with ternary binders was found to depend on metakaolin properties, including manufacturing process and particle size distribution. Reducing W/C0 ratio accelerated pozzolanic reaction and allowed improving early-age strength and durability parameters. © 2018 Elsevier Ltd  
  Address Association Technique de l'Industrie des Liants Hydrauliques (ATILH), 7 place de la Défense, Paris La Défense, 92974, France  
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  Notes Export Date: 1 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 814  
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Author Dejean, A.; Azémar, F.; Petitclerc, F.; Delabie, J.H.C.; Corbara, B.; Leroy, C.; Céréghino, R.; Compin, A. url  doi
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  Title Highly modular pattern in ant-plant interactions involving specialized and non-specialized myrmecophytes Type Journal Article
  Year 2018 Publication Science of Nature Abbreviated Journal  
  Volume 105 Issue 43 Pages  
  Keywords Ant-plant mutualism; Ecological network; Modularity; Myrmecophytes; Nestedness; Sympatric species  
  Abstract Because Tachia guianensis (Gentianaceae) is a “non-specialized myrmecophyte” associated with 37 ant species, we aimed to determine if its presence alters the ant guild associated with sympatric “specialized myrmecophytes” (i.e., plants sheltering a few ant species in hollow structures). The study was conducted in a hilly zone of a neotropical rainforest where two specialized myrmecophytes grow at the bottom of the slopes, another at mid-slope, and a fourth on the hilltops. Tachia guianensis, which occurred everywhere, had its own guild of associated ant species. A network analysis showed that its connections with the four other myrmecophytes were rare and weak, the whole resulting in a highly modular pattern of interactions with one module (i.e., subnetwork) per myrmecophyte. Three ant species parasitized three out of the four specialized myrmecophytes (low nestedness noted), but were not or barely associated with T. guianensis that therefore did not influence the parasitism of specialized myrmecophytes. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.  
  Address AMAP, IRD, CIRAD, CNRS, INRA, Université de Montpellier, Montpellier, France  
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  Notes Export Date: 1 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 815  
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Author Chaves, C.L.; Degen, B.; Pakull, B.; Mader, M.; Honorio, E.; Ruas, P.; Tysklind, N.; Sebbenn, A.M. url  doi
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  Title Assessing the Ability of Chloroplast and Nuclear DNA Gene Markers to Verify the Geographic Origin of Jatoba (Hymenaea courbaril L.) Timber Type Journal Article
  Year 2018 Publication Journal of Heredity Abbreviated Journal  
  Volume 109 Issue 5 Pages 543-552  
  Keywords forensics; illegal logging; nSSRs; SNPs; timber tracking; tropical trees  
  Abstract Deforestation-reinforced by illegal logging-is a serious problem in many tropical regions and causes pervasive environmental and economic damage. Existing laws that intend to reduce illegal logging need efficient, fraud resistant control methods. We developed a genetic reference database for Jatoba (Hymenaea courbaril), an important, high value timber species from the Neotropics. The data set can be used for controls on declarations of wood origin. Samples from 308 Hymenaea trees from 12 locations in Brazil, Bolivia, Peru, and French Guiana have been collected and genotyped on 10 nuclear microsatellites (nSSRs), 13 chloroplast SNPs (cpSNP), and 1 chloroplast indel marker. The chloroplast gene markers have been developed using Illumina DNA sequencing. Bayesian cluster analysis divided the individuals based on the nSSRs into 8 genetic groups. Using self-assignment tests, the power of the genetic reference database to judge on declarations on the location has been tested for 3 different assignment methods. We observed a strong genetic differentiation among locations leading to high and reliable self-assignment rates for the locations between 50% to 100% (average of 88%). Although all 3 assignment methods came up with similar mean self-assignment rates, there were differences for some locations linked to the level of genetic diversity, differentiation, and heterozygosity. Our results show that the nuclear and chloroplast gene markers are effective to be used for a genetic certification system and can provide national and international authorities with a robust tool to confirm legality of timber. © 2018 The American Genetic Association. All rights reserved.  
  Address Instituto Florestal de São Paulo, São Paulo, SP, Brazil  
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  Notes Export Date: 1 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 817  
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Author Lambs, L.; Bompy, F.; Dulormne, M. url  doi
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  Title Using an “isotopic spike” from a tropical storm to understand water exchange on a large scale: Case study of Hurricane Rafael in the lesser antilles archipelago, October 2012 Type Journal Article
  Year 2018 Publication Rapid Communications in Mass Spectrometry Abbreviated Journal  
  Volume 32 Issue 6 Pages 457-468  
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  Abstract Rationale: Studies of wetland eco-hydrology in tropical coastal areas are scarce, and the use of water stable isotopes can be of great help. Key constraints for their analysis are (i) the small difference in delta18O values between seawater and old evaporated freshwater, and (ii) the fact that the presence of old brackish water limits the determination of the water origin and dynamic. Methods: The water from tropical storms displays distinctively depleted heavy stable isotopes, in comparison with usual tropical rainfall without strong convective thunderstorms. During tropical storms, such as Hurricane Rafael in mid-October 2012, the rainfall delta18O signal can be decreased by many units. This effect is called an “isotopic spike”, and it could be used as a temporal marker of the water fluxes. Results: Water samples, with delta18O values as low as −8.9/1000, were collected on the islands of Guadeloupe and Saint-Martin during Hurricane Rafael, whereas the usual range of groundwater or mean rainfall delta18O values is around −2.8 +/- 0.5 /1000, as measured from 2009 to 2012. These water “isotopic spikes” allow us to show a surface freshwater uptake by mangrove trees in Guadeloupe, and in Saint-Martin, to calculate the water renewal of the salt ponds and pools. Conclusions: The “isotopic spikes” generated by tropical storms are generally used to track back past storm events, as recorded in trees and stalagmites. Here, the propagation of isotopic spike is followed to improve the understanding of the freshwater circulation and the water dynamic within coastal ecosystems influenced by seawater.  
  Address UMR ECOFOG, Université des Antilles, Guadeloupe, Pointe-à-Pitre, 97159, France  
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  Notes Export Date: 2 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 818  
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Author Schmidt, M.; Dejean, A. doi  openurl
  Title A dolichoderine ant that constructs traps to ambush prey collectively: convergent evolution with a myrmicine genus Type Journal Article
  Year 2018 Publication Biological Journal of the Linnean Society Abbreviated Journal  
  Volume 124 Issue 1 Pages 41-46  
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  Abstract Azteca brevis Forel, a dolichoderine ant species, builds along the branches of its host plant galleries that bear numerous holes slightly wider than a worker’s head. We noted that the workers hide, mandibles open, beneath different holes, waiting for arthropod prey to walk by or alight. They seize the extremities of these arthropods and pull backwards, immobilizing the prey, which is then spreadeagled and later carved up or pulled into a gallery before being carved up. The total duration of the capture ranges from a few minutes to several hours. This ambush group hunting permits the capture of insects of a wide range of sizes, with the largest being 48.71 times heavier than the workers, something that we compared with other cases of group hunting by ants and trap use by other arthropods. A convergence with myrmicine ants of the genus Allomerus is shown. Thus, this study also shows that the genus Azteca presents the largest panel of group hunting strategies by ants and that there is polyethism related to polymorphism, as hunting workers are larger than their nestmates. We concluded that these gallery-shaped traps correspond to the notion of ‘extended phenotype’.  
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  ISSN 0024-4066 ISBN Medium  
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  Notes 10.1093/biolinnean/bly028 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 822  
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Author Hénaut, Y.; Corbara, B.; Azémar, F.; Céréghino, R.; Dézerald, O.; Dejean, A. url  doi
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  Title An arboreal spider protects its offspring by diving into the water of tank bromeliads Type Journal Article
  Year 2018 Publication Comptes Rendus Biologies Abbreviated Journal  
  Volume 341 Issue 3 Pages 196-199  
  Keywords Water used in protective behavior; Egg sacs; ; ; Cocons; Eau utilisée dans un comportement protecteur  
  Abstract Cupiennius salei (Ctenidae) individuals frequently live in association with tank bromeliads, including Aechmea bracteata, in Quintana Roo (Mexico). Whereas C. salei females without egg sacs hunt over their entire host plant, females carrying egg sacs settle above the A. bracteata reservoirs they have partially sealed with silk. There they avoid predators that use sight to detect their prey, as is known for many bird species. Furthermore, if a danger is more acute, these females dive with their egg sacs into the bromeliad reservoir. An experiment showed that this is not the case for males or females without egg sacs. In addition to the likely abundance of prey found therein, the potential of diving into the tank to protect offspring may explain the close association of this spider with bromeliads. These results show that, although arboreal, C. salei evolved a protective behavior using the water of tank bromeliads to protect offspring. Résumé L’araignée Cupiennius salei (Ctenidae) vit souvent en association avec la broméliacée à réservoir Aechmea bracteata. Dans le Quintana Roo (Mexique), les femelles qui transportent un cocon s’installent au-dessus d’un réservoir d’A. bracteata qu’elles obstruent partiellement de voiles de soie pour se camoufler des prédateurs. En présence de vibrations importantes et répétées, ces femelles plongent avec leur cocon dans l’eau du réservoir. Notre étude montre que les autres adultes (mâles et femelles sans cocon) n’utilisent pas les réservoirs d’eau. Ainsi, en plus de l’abondance de proies, la possibilité de pouvoir plonger pour protéger la descendance pourrait expliquer l’association entre cette espèce d’araignée et les broméliacées. Nos expériences montrent que les femelles porteuses d’un cocon manifestent une stratégie de protection vis-à-vis des cocons et d’elles-mêmes en s’immergeant durant 30, voire 90minutes.  
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  ISSN 1631-0691 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 823  
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Author Dejean, A.; Orivel, J.; Leponce, M.; Compin, A.; Delabie, J.H.C.; Azémar, F.; Corbara, B. doi  openurl
  Title Ant–plant relationships in the canopy of an Amazonian rainforest: the presence of an ant mosaic Type Journal Article
  Year 2018 Publication Biological Journal of the Linnean Society Abbreviated Journal  
  Volume 125 Issue 2 Pages 344-354  
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  Abstract Using different techniques to access the canopy of an Amazonian rainforest, we inspected 157 tree crowns for arboreal ants. Diversity statistics showed that our study sample was not representative of the tree and ant populations due to their high diversity in Amazonian rainforests, but permitted us to note that a representative part of territorially dominant arboreal ant species (TDAAs) was inventoried. Mapping of TDAA territories and use of a null model showed the presence of an ant mosaic in the upper canopy, but this was not the case in the sub-canopy. Among the TDAAs, carton-nesting Azteca dominated (52.98% of the trees) whereas ant-garden ants (Camponotus femoratus and Crematogaster levior), common in pioneer formations, were secondarily abundant (21.64% of the trees), and the remaining 25.37% of trees sheltered one of 11 other TDAAs. The distribution of the trees forming the upper canopy influences the structure of the ant mosaic, which is related to the attractiveness of some tree taxa for certain arboreal ant species and represents a case of diffuse coevolution.  
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  ISSN 0024-4066 ISBN Medium  
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  Notes 10.1093/biolinnean/bly125 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 824  
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