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Piponiot, C.; Derroire, G.; Descroix, L.; Mazzei, L.; Rutishauser, E.; Sist, P.; Hérault, B. |
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Assessing timber volume recovery after disturbance in tropical forests – A new modelling framework |
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Journal Article |
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2018 |
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Ecological Modelling |
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384 |
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353-369 |
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Disturbance; Ecosystem modelling; Recovery; Sustainability; Tropical forest management |
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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. |
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INPHB (Institut National Polytechnique Félix Houphouet Boigny), Yamoussoukro, Cote d'Ivoire |
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Export Date: 1 September 2018 |
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EcoFoG @ webmaster @ |
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813 |
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Medjigbodo, G.; Rozière, E.; Charrier, K.; Izoret, L.; Loukili, A. |
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Hydration, shrinkage, and durability of ternary binders containing Portland cement, limestone filler and metakaolin |
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Journal Article |
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2018 |
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Construction and Building Materials |
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183 |
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114-126 |
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Durability; Limestone filler; Metakaolin; Shrinkage; Strength; Ternary binders |
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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 |
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Association Technique de l'Industrie des Liants Hydrauliques (ATILH), 7 place de la Défense, Paris La Défense, 92974, France |
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Export Date: 1 September 2018 |
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EcoFoG @ webmaster @ |
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814 |
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Dejean, A.; Azémar, F.; Petitclerc, F.; Delabie, J.H.C.; Corbara, B.; Leroy, C.; Céréghino, R.; Compin, A. |
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Highly modular pattern in ant-plant interactions involving specialized and non-specialized myrmecophytes |
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Journal Article |
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2018 |
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Science of Nature |
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105 |
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43 |
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Ant-plant mutualism; Ecological network; Modularity; Myrmecophytes; Nestedness; Sympatric species |
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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. |
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AMAP, IRD, CIRAD, CNRS, INRA, Université de Montpellier, Montpellier, France |
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Export Date: 1 September 2018 |
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EcoFoG @ webmaster @ |
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815 |
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Chaves, C.L.; Degen, B.; Pakull, B.; Mader, M.; Honorio, E.; Ruas, P.; Tysklind, N.; Sebbenn, A.M. |
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Assessing the Ability of Chloroplast and Nuclear DNA Gene Markers to Verify the Geographic Origin of Jatoba (Hymenaea courbaril L.) Timber |
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Journal Article |
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2018 |
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Journal of Heredity |
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109 |
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5 |
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543-552 |
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forensics; illegal logging; nSSRs; SNPs; timber tracking; tropical trees |
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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. |
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Instituto Florestal de São Paulo, São Paulo, SP, Brazil |
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Export Date: 1 September 2018 |
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EcoFoG @ webmaster @ |
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817 |
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Coté, G.G.; Gibernau, M. |
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Distribution of calcium oxalate crystals in floral organs of araceae in relation to pollination strategy |
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Journal Article |
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2012 |
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American Journal of Botany |
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Am. J. Bot. |
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99 |
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7 |
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1231-1242 |
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Araceae; Beetles; Calcium oxalate; Crystal; Defense; Flowers; Herbivory; Pollination |
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Premise of the study: Many flowers are pollinated by potentially hungry insects, yet flowers also contain gametes and embryos which must be protected from predation. Microscopic calcium oxalate crystals in plant tissues have been proposed to protect against herbivory. Aroids, which have an unusual diversity of such crystals, also exhibit diverse pollination strategies. Many species have pollinators that do not feed while visiting the flowers, while other species, especially those pollinated by beetles, offer sterile staminodia as food rewards. We examined flowers of 21 aroid species with various pollination strategies to test the hypothesis that crystals protect vital gametes and embryos while allowing consumption of food bribes.Methods: Aroid inflorescences collected from the field or from greenhouse material were sectioned, cleared, and examined by bright field and polarization microscopy.Key results: All species examined, regardless of pollination strategy, arrayed crystals around unshed pollen and ovules. Less vital tissues, such as odoriferous appendages, had few crystals. Staminodia offered as food to beetle pollinators, however, differed greatly between species in their crystal contents. Some had minimal crystals; some had crystals in patterns suggesting they limit beetle feeding; still others had abundant crystals in no obvious pattern.Conclusions: The results are consistent with crystals protecting against insect predation of gametes and embryos. However, the role of crystals in food-bribe staminodia is unclear. They may limit and direct feeding by beetles in some species, while in others they might have no protective role. © 2012 Botanical Society of America. |
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CNRS-Ecolog (UMR 8172), Campus Agronomique BP316, Korou cedex 97379, France |
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00029122 (Issn) |
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Export Date: 10 August 2012; Source: Scopus; Coden: Ajboa; doi: 10.3732/ajb.1100499; Language of Original Document: English; Correspondence Address: Coté, G. G.; Biology Department, Radford University, Radford, VA 24142-6931, United States; email: gcote@radford.edu |
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EcoFoG @ webmaster @ |
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420 |
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Vedel, V.; Cerdan, A.; Martinez, Q.; Baraloto, C.; Petitclerc, F.; Orivel, J.; Fortunel, C. |
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Day-time vs. Night-time sampling does not affect estimates of spider diversity across a land use gradient in the Neotropics |
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2015 |
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Journal of Arachnology |
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Journal of Arachnology |
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43 |
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3 |
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413-416 |
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Araneae; community; day; night; sampling protocol |
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To obtain a reliable description of spider communities, robust sampling protocols are crucial. However, it remains unclear if descriptions of spider communities in tropical habitats require both day and night sampling. Here we tested whether sampling both day and night in high and low vegetation strata would lead to better diversity estimates of spider communities than sampling at only one period of the day. We determined spider taxonomic diversity in a network of 12 plots in French Guiana along a vegetation gradient. We found high alpha diversity of spiders as expected for a tropical area at every site. We showed strong differences in spider alpha and beta diversity between high and low vegetation strata, while they were similar between day and night sampling. Our results suggest that collecting spiders at only one period is sufficient to describe the diversity of spider communities across land use types in the neotropics. © The American Arachnological Society. |
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Department of Biology, University of Maryland, College Park, MD, United States |
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Export Date: 10 December 2015 |
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EcoFoG @ webmaster @ |
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641 |
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Menzel, F.; Orivel, J.; Kaltenpoth, M.; Schmitt, T. |
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What makes you a potential partner? Insights from convergently evolved ant-ant symbioses |
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Journal Article |
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2014 |
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Chemoecology |
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Chemoecology |
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24 |
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3 |
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105-119 |
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Aggression; Coevolution; Cuticular hydrocarbons; Formicidae; Interspecific association; Parabiosis; Recognition cues |
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Mutualistic, commensalistic or parasitic interactions are unevenly distributed across the animals and plants: in certain taxa, such interspecific associations evolved more often than in others. Within the ants, associations between species of the genera Camponotus and Crematogaster evolved repeatedly and include trail-sharing associations, where two species share foraging trails, and parabioses, where two species share a nest without aggression. Camponotus and Crematogaster may possess life-history traits that favour the evolution of associations. To identify which traits are affected by the association, we investigated a neotropical parabiosis of Ca. femoratus and Cr. levior and compared it to a paleotropical parabiosis and a trail-sharing association. The two neotropical species showed altered cuticular hydrocarbon profiles compared to non-parabiotic species accompanied by low levels of interspecific aggression. Both species occurred in two chemically distinct types. Camponotus followed artificial trails of Crematogaster pheromones, but not vice versa. The above traits were also found in the paleotropical parabiosis, and the trail-following results match those of the trail-sharing association. In contrast to paleotropical parabioses, however, Camponotus was dominant, had a high foraging activity and often fought against Crematogaster over food resources. We suggest three potential preadaptations for parabiosis. First, Crematogaster uses molecules as trail pheromones, which can be perceived by Camponotus, too. Second, nests of Camponotus are an important benefit to Crematogaster and may create a selection pressure for the latter to tolerate Camponotus. Third, there are parallel, but unusual, shifts in cuticular hydrocarbon profiles between neotropics and paleotropics, and between Camponotus and Crematogaster. © 2014 Springer Basel. |
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Department of Animal Ecology and Tropical Biology Biocentre, University of Würzburg, Am Hubland, 97074 Würzburg, Germany |
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Birkhauser Verlag AG |
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09377409 (Issn) |
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Export Date: 10 June 2014; Coden: Chmoe; Correspondence Address: Menzel, F.; Department of Evolutionary Biology, Institute of Zoology, University of Mainz, Johannes-von-Müller-Weg 6, 55099 Mainz, Germany; email: menzelf@uni-mainz.de |
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EcoFoG @ webmaster @ |
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547 |
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Chevalier, M.; Robert, F.; Amusant, N.; Traisnel, M.; Roos, C.; Lebrini, M. |
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Enhanced corrosion resistance of mild steel in 1 M hydrochloric acid solution by alkaloids extract from Aniba rosaeodora plant: Electrochemical, phytochemical and XPS studies |
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Journal Article |
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2014 |
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Electrochimica Acta |
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Electrochim Acta |
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131 |
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96-105 |
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Acidic media; Adsorption-XPS; Aniba rosaeodora extract; Anibine; C38 steel; Corrosion inhibitor |
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The present report continues to focus on the broadening application of plant extracts for metallic corrosion control and reports on the inhibiting effect of the Aniba rosaeodora alkaloidic extract on the corrosion of C38 steel in 1 M hydrochloric acid. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of inhibitor. Studies on the phytochemical constituents were established to determine the active(s) molecule(s). XPS was also carried out to establish the mechanism of corrosion inhibition of the active molecule of C38 steel in acid solution. The inhibitor extract acted as an efficient corrosion inhibitor in 1 M HCl. The experimental data obtained from EIS method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPEα, Q) has been used. Graphical methods are illustrated by synthetic data to determine the parameter of CPE (α, Q). Polarization studies showed that the Aniba rosaeodora alkaloidic extract was a mixed-type inhibitor and its inhibition efficiency increased with the inhibitor concentration. Studies on the phytochemical constituents of the total alkaloids extract shows that it contains the anibine as the major alkaloid. The results obtained from the electrochemical study have clearly showed that the inhibition efficiency of the total extract was due to the presence of anibine. The XPS studies showed the formation of inhibitor layer containing the Aniba rosaeodora alkaloidic extract and the anibine molecules. © 2014 Elsevier Ltd. All rights reserved. |
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Unité Matériaux et Transformations CNRS UMR 8207, Université Lille 1, École Nationale Supérieure de Chimie de Lille, Avenue Dimitri Mendeleïev-Bât. C7a BP 90108, 59652 Villeneuve d'Ascq, France |
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Elsevier Ltd |
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00134686 (Issn) |
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Export Date: 10 June 2014; Coden: Elcaa; Correspondence Address: Lebrini, M.; Laboratoire Matériaux et Molécules en Milieux Amazonien, UAG-UMR ECOFOG Campus Troubiran, Route de Baduel, 97337 Cayenne, French Guiana; email: mounim.lebrini@guyane.univ-ag.fr |
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EcoFoG @ webmaster @ |
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545 |
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Henkel, T.W.; Wilson, A.W.; Aime, M.C.; Dierks, J.; Uehling, J.K.; Roy, M.; Schimann, H.; Wartchow, F.; Mueller, G.M. |
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Cantharellaceae of Guyana II: New species of Craterellus, new South American distribution records for Cantharellus guyanensis and Craterellus excelsus, and a key to the Neotropical taxa |
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Journal Article |
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Year |
2014 |
Publication |
Mycologia |
Abbreviated Journal |
Mycologia |
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106 |
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2 |
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307-324 |
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Cantharellales; Coccoloba; Dicymbe; Ectomycorrhizae; Guiana shield; Tropical fungi |
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Craterellus olivaceoluteus sp. nov. and Craterellus cinereofimbriatus sp. nov. are described as new to science. These fungi were collected from Guyana in association with ectomycorrhizal host trees in the genera Dicymbe (Fabaceae subfam. Caesalpinioideae) and Pakaraimaea (Dipterocarpaceae). Cantharellus guyanensis Mont., originally described from French Guiana, is redescribed from recent collections from Guyana, with additional range extensions for the species provided based on material examined from French Guiana, Venezuela, and north central, northeastern and southern Brazil, circumscribing nearly the entire Guiana Shield region and beyond. A new distribution record from French Guiana is provided for Craterellus excelsus T.W. Henkel & Aime. Macromorphological, micromorphological and habitat data are provided for the new species and C. guyanensis as well as DNA sequence data from the nuclear ribosomal regions of the internal transcribed spacer (ITS) and 28S large subunit (LSU); additional sequence data is provided for C. guyanensis and C. excelsus specimens collected outside Guyana. The relationships of these taxa within the Cantharellaceae were evaluated with phylogenetic analyses of ITS and LSU sequence data. This work brings the total number of Cantharellaceae species known from Guyana to eight. A key to the Cantharellus and Craterellus species known from the lowland Neotropics and extralimital montane Central and South America is provided. © 2014 by The Mycological Society of America. |
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Department of Biological Sciences, Boise State University, Boise, ID, 83725, United States |
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Allen Press Inc. |
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15572536 (Issn) |
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Export Date: 10 June 2014; Coden: Mycoa; Correspondence Address: Henkel, T.W.; Department of Biological Sciences, Humboldt State University, Arcata, CA 95521, United States; email: twh5@humboldt.edu; Funding Details: DEB-0732968, NSF, National Science Foundation |
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EcoFoG @ webmaster @ |
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546 |
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Traissac, S.; Pascal, J.-P. |
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Birth and life of tree aggregates in tropical forest: Hypotheses on population dynamics of an aggregated shade-tolerant species |
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Journal Article |
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2014 |
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Journal of Vegetation Science |
Abbreviated Journal |
J. Veg. Sci. |
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25 |
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2 |
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491-502 |
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Clusters; Colonization strategy; Janzen-Connell; Spatial analysis; Spatial pattern; Vouacapoua americana |
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Questions: Several studies have described aggregated spatial patterns in tropical tree species. This study investigates aggregate dynamics of Vouacapoua americana (Aublet), a climax species whose spatial pattern is not simply related to light and soil conditions or to its short seed dispersal range. Location: Two rain forest sites: Nouragues and Paracou, in the Guiana Shield. Methods: We described the spatial pattern of tree locations and spatial autocorrelation of tree diameters, using statistics derived from Ripley's K. We particularly used methods to define analysis subplots according to local density or local mean diameter. We investigated relationships between spatial distributions of adults and saplings. Results: At both sites, populations of Vouacapoua demonstrated several nested levels of aggregation. Tree diameters were spatially autocorrelated, revealing the existence of clusters with similar diameters. In the largest aggregates, tree diameters declined from the centre to the edge. Regeneration was aggregated and occurred mainly at cluster edges and around rare isolated trees, and sapling densities and basal area of adults were negatively correlated. We show that long-distance dispersal events are rare. Conclusions: Environmental factors and seed dispersal only explain part of the observed spatial patterns. We provide two main hypotheses about Vouacapoua population dynamics. First, the lack of regeneration in aggregate centres results in the ageing of existing aggregates. We suggest that this lack of recruitment close to mature trees is due to a Janzen-Connell effect. However, aggregates can continue to grow along colonization fronts. Second, long-distance dispersal events allow the formation of new clusters and play a crucial role in the colonization process. We investigate aggregate dynamics of Vouacapoua americana (Aublet) whose spatial pattern is not simply related to environmental conditions or to its seed dispersal. Regeneration does not occur in centers of aggregate of adults. We suggest that rare long-distance dispersal events and density-dependence predation of seeds and seedlings play a crucial role in formation of new clusters and structuration of larger aggregates. © 2013 International Association for Vegetation Science. |
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Université Claude Bernard Lyon 1, 43 Boulevard 11 Novembre 1918, Villeurbanne, 69100, France |
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11009233 (Issn) |
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Export Date: 10 March 2014; Source: Scopus; Coden: Jvese; Language of Original Document: English; Correspondence Address: Traissac, S.; AgroParisTech, UMR ECOlogie des Forêts de Guyane, Campus Agronomique, BP 709, Kourou, 97387, France; email: stephane.traissac@ecofog.gf |
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EcoFoG @ webmaster @ |
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532 |
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