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Dejean, A.; Rodríguez-Pérez, H.; Carpenter, J.M.; Azémar, F.; Corbara, B. |
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The predatory behavior of the Neotropical social wasp Polybia rejecta |
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Journal Article |
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2017 |
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Behavioural Processes |
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140 |
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161-168 |
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Epiponine wasps; Polistinae; Predation; Prey selection; Recruitment; Vespidae |
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Abstract We experimentally studied the predatory behavior of Polybia rejecta (Vespidae, Polistinae, Epiponini) towards 2–88 mm-long insects attracted to a UV light trap. Foragers, which began to hunt at 6:30, selected 4–14 mm-long prey insects. Prey detection by sight by hovering wasps was confirmed using decoys. After the wasps landed and walked along a sinuous path, prey were detected by contact or from a distance (1–3 cm). This was followed by seizure, stinging (contrarily to most other known cases), prey manipulation and retrieval. Prey that flew off might be caught in flight. The prey load, representing 30.7% of a forager’s weight, was optimized by capturing up to six small prey or two medium-sized prey successively (both of which might be consumed in situ). The foragers cut off the wings of larger prey or cut them into two pieces and returned to gather the second piece. The handling time increased exponentially with the weight of the prey. Partial loading (i.e., retrieving a load much inferior to the maximum possible) was likely related to social facilitation, a form of nest-based recruitment that was demonstrated through the experimental elimination of local enhancement by removing foragers (both mechanisms favor the exploitation of favorable patches). |
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0376-6357 |
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EcoFoG @ webmaster @ |
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751 |
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Van Langenhove, L.; Janssens, I.A.; Verryckt, L.; Brechet, L.; Hartley, I.P.; Stahl, C.; Courtois, E.; Urbina, I.; Grau, O.; Sardans, J.; Peguero, G.; Gargallo-Garriga, A.; Peñuelas, J.; Vicca, S. |
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Rapid root assimilation of added phosphorus in a lowland tropical rainforest of French Guiana |
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Journal Article |
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2020 |
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Soil Biology and Biochemistry |
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Soil Biol. Biochem. |
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140 |
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107646 |
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Fertilization; Nitrogen; Phosphorus; Plant root simulator probes; Root system; Tropical forest; Nitrogen; Nitrogen fertilizers; Phosphorus; Plants (botany); Soils; Tropics; Fertilization; Mycorrhizal fungus; N and P fertilizer; P availabilities; Plant root simulators; Root system; Tropical forest; Tropical rain forest; Forestry; Fungi |
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Tree growth on weathered soils in lowland tropical forests is limited by low phosphorous (P) availability. However, nutrient manupulation experiments do not always increase the P content in these trees, which raises the question whether trees are taking up added P. In French Guianese lowland rainforest, we measured changes in nitrogen (N) and P availability before and up to two months after N and P fertilizer addition, in soils with intact root systems and in soils where roots and mycorrhizal fungi were excluded by root exclusion cylinders. When the root system was excluded, P addition increased P availability to a much greater extent and for a longer time than in soils with an intact root system. Soil N dynamics were unaffected by root presence/absence. These results indicate rapid P uptake, but not N uptake, by tree roots, suggesting a very effective P acquisition process in these lowland rainforests. |
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Global Change Research Institute, Czech Academy of Sciences, Czech Republic |
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Elsevier Ltd |
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00380717 (Issn) |
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Export Date: 19 November 2019; Coden: Sbioa; Correspondence Address: Van Langenhove, L.; Centre of Excellence PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Wilrijk, Belgium; email: leandro.vanlangenhove@uantwerpen.be |
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EcoFoG @ webmaster @ |
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897 |
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Yazdani, R.; Scotti, I.; Jansson, G.; Plomion, C.; Mathur, G. |
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Inheritance and diversity of simple sequence repeat (SSR) microsatellite markers in various families of Picea abies |
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2003 |
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Hereditas |
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Hereditas |
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138 |
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3 |
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219-227 |
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A large number of sequence-specific SSRs were screened by using electrophoresis on metaphore agarose gels with the bands visualized by ethidium bromide staining. Many SSRs appeared as codominant and many as dominant markers, with presence or absence of bands. A simple Mendelian inheritance pattern for most codominant and dominant SSR loci was found. For many codominant SSR markers, null alleles were detected. The proportion of dominant microsatellites detected in this study (close to 50 %) was much higher than that commonly reported in many other studies. A high proportion of dominant markers together with a high frequency of codominant markers with null alleles may represent two important limitations for the use of microsatellites in different studies. On the other hand, many polymorphic codominant SSR microsatellite markers were found to be highly repeatable, and can be used for population studies, seed certification, quality control of controlled crosses, paternity analysis, pollen contamination, and mapping of QTL in related families. In this paper, we report on the inheritance pattern and diversity of codominant and dominant SSR microsatellites in seven families of Picea abies sharing a common mother. |
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Swedish Univ Agr Sci, Dept Plant Biol & Forest Genet, Uppsala, Sweden |
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BLACKWELL MUNKSGAARD |
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0018-0661 |
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ISI:000187074000010 |
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EcoFoG @ eric.marcon @ |
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268 |
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Alméras, T.; Gronvold, A.; van der Lee, A.; Clair, B.; Montero, C. |
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Contribution of cellulose to the moisture-dependent elastic behaviour of wood |
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2017 |
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Composites Science and Technology |
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Composites Science and Technology |
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138 |
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151-160 |
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Cellulose; Crystal strain; Micromechanics; Wood; X-ray diffraction |
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Wood has a hierarchical structure involving several levels of organisation. The stiffness of wood relies on its capacity to transfer mechanical stress to its stiffest element at the lowest scale, namely crystalline cellulose. This study aims at quantifying to what extend crystalline cellulose contributes to wood stiffness depending on its moisture content. The crystal strains of cellulose were measured using X-ray diffraction on wet and dry specimens of spruce, based on a previously published methodology. The comparison between crystal strain and macroscopic strain shows that, during elastic loading, cellulose strain is lower than macroscopic strain. The means ratio of crystal/macroscopic strain amounts 0.85 for dry specimens and 0.64 for wet specimens. This strain ratio cannot be explained just by the projection effect due to the difference in orientation between cellulose microfibrils and cell wall, but results from deformation mechanisms in series with cellulose. Analysis shows that this series contribution represents a non-negligible contribution to wood compliance and is strongly moisture-dependent. This contribution amounts 9% for dry specimens and 33% for wet specimens, corresponding to a 4-fold increase in compliance for the series contribution. The origin of these strains is ascribed to mechanisms involving bending or shear strain at different scales, due to the fact that reinforcing element are neither perfectly straight nor infinitely long. © 2016 |
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CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), AgroParisTech, Cirad, INRA, Université des Antilles, Université de Guyane, Kourou, France |
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Export Date: 26 December 2016 |
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EcoFoG @ webmaster @ |
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701 |
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Odonne, G.; Berger, F.; Stien, D.; Grenand, P.; Bourdy, G. |
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Treatment of leishmaniasis in the Oyapock basin (French Guiana): A K.A.P. survey and analysis of the evolution of phytotherapy knowledge amongst Wayãpi Indians |
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Journal Article |
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2011 |
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Journal of Ethnopharmacology |
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J. Ethnopharmacol. |
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137 |
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3 |
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1228-1239 |
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Camopi River; French Guiana; Intercultural exchanges; K.A.P.; Knowledge attitude and practices; Knowledge evolution; Leishmaniasis; Oyapock River; Quantitative ethnopharmacology; Teko; Traditional remedies; Wayãpi |
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Ethnopharmacological relevance: Cutaneous leishmaniasis is a neglected disease with a high incidence in French Guiana, mainly in the middle and upper Oyapock basin, where Amerindian and some Brazilian people live. The main goals of this work were (i) to assess the knowledge about leishmaniasis in the different populations of the middle and upper Oyapock basin, (ii) to study the therapeutic strategies adopted by people affected by leishmaniasis and (iii) to document the use of phytotherapeutic remedies for leishmaniasis. Knowledge, attitudes and practices (K.A.P.) related to this disease and its treatments have been studied according to cultural group and geographical settlement. Within the Wayãpi group, the evolution of the knowledge of phytoremedies over the last 20 years has been characterised by literature-based comparisons. Materials and methods: A total of 144 questionnaires were administered in all the villages of the upper Oyapock and Camopi basins. Correspondence analyses were used for multivariate analysis. Plant species were identified at the Cayenne Herbarium (CAY). Results: The biomedical concept of leishmaniasis correlates well with the Teko and Wayãpi concepts of kalasapa and kalasapau. Although the vector of this disease was not correctly identified, the most commonly cited aetiology (74.5%) was vector-borne, and related epidemiological schemes correlate well with the one encountered in French Guiana. Theoretically and practically, health centres were the most commonly used resource for diagnostic in instances of leishmaniasis infection (65.9%), independently of the patient's cultural group, along with the use of pharmaceutical drugs (85.3%). Pharmaceuticals were commonly utilised despite the frequent (51.5%) use of phytotherapeutic remedies, alone or in combination with drugs. The most cited medicinal plant species for the treatment of leishmaniasis included Eleutherine bulbosa (Mill.) Urb. (Iridaceae, cited 14 times), Euterpe oleracea Mart. (Arecaceae, 9), Cecropia obtusa Trecul (Cecropiaceae, 8), Jatropha curcas L. (Euphorbiaceae, 7), Ceiba pentandra (L.) Gaertn. (Bombacaceae, 6) and Carica papaya L. (Caricaceae, 6). Multiple correspondence analyses demonstrated that the species used in leishmaniasis remedies are more prone to vary by the user's place of residence than by their cultural origin, which indicates that exchange of knowledge about leishmaniasis remedies has occurred across different cultural groups. Literature-based comparisons between the remedies for leishmaniasis used by the Wayãpi during the 1980s showed a striking evolution, both in terms of diversity of species and number of plants used. The large number of species shared with other Guianese groups argues for intercultural exchange and may explain the majority (57.1%) of the newly used species highlighted in our study. Conclusions: Leishmaniasis is a well-known disease in the studied area. Phytotherapeutic treatments are still in use, although they are not the main source of remedies, and should undergo pharmacological studies to evaluate their potential therapeutic value. © 2011 Elsevier Ireland Ltd. All rights reserved. |
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IRD, UMR152, F-31062 Toulouse Cedex 9, France |
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03788741 (Issn) |
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Export Date: 8 November 2011; Source: Scopus; Article in Press; Coden: Joetd; doi: 10.1016/j.jep.2011.07.044; Language of Original Document: English; Correspondence Address: Odonne, G.; CNRS-UMR Ecofog, Université des Antilles et de la Guyane, 97337 Cayenne Cedex, Franceemail: guillaume.odonne@gmail.com |
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EcoFoG @ webmaster @ |
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368 |
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Odonne, G.; Herbette, G.; Eparvier, V.; Bourdy, G.; Rojas, R.; Sauvain, M.; Stien, D. |
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Antileishmanial sesquiterpene lactones from Pseudelephantopus spicatus, a traditional remedy from the Chayahuita Amerindians (Peru). Part III |
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Journal Article |
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2011 |
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Journal of Ethnopharmacology |
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J. Ethnopharmacol. |
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137 |
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1 |
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875-879 |
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Asteraceae; Chayahuita; Hirsutinolides; Leishmaniasis; Peru; Pseudelephantopus spicatus; Traditional remedy; 8,13 diacetylpiptocarphol; acetyl 13 o ethylpiptocarphol; amphotericin B; antileishmanial agent; plant extract; Pseudelephantopus spicatus extract; sesquiterpene lactone derivative; unclassified drug; ursolic acid; amastigote; article; biological activity; Ic 50; in vitro study; Leishmania; leishmaniasis; medicinal plant; nonhuman; Peru; Pseudelephantopus spicatus; traditional medicine; Asteraceae; Leishmania amazonensis; Pseudelephantopus spicatus |
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Ethnopharmacological relevance: The study of traditional remedies used by the Chayahuita, an ethnic group from the Peruvian Amazonia, has prompted us to investigate in detail the ethanolic extract of Pseudelephantopus spicatus (Juss. ex Aubl.) C.F. Baker, which has demonstrated strong biological activity towards Leishmania amazonensis. Our goal was to discover the active compound of this plant-based remedy. Materials and methods: A bioguided fractionation of the crude extract was undertaken based on the biological activity recorded against Leishmania amazonensis axenic amastigotes in in vitro bioassays. Results: Three strongly to moderately active compounds were isolated: two hirsutinolides (the 8,13-diacetyl-piptocarphol and the 8-acetyl-13-O-ethyl-piptocarphol) and ursolic acid. IC50 against Leishmania amazonensis axenic amastigotes are respectively 0.2, 0.37 and 0.99 μM (while IC50 of amphotericin B is 0.41 μM). These compounds have never been isolated from this plant species, and germacranolides have never been identified as potential antileishmanial agents. Conclusions: The compounds isolated from Pseudelephantopus spicatus account for the antileishmanial activity of the plant, thus giving support to its use by the Chayahuita in Peru. © 2011 Elsevier Ireland Ltd All rights reserved. |
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Laboratorio de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Avenida Honorio Delgado 430, San Martin de Porres, Lima, Peru |
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03788741 (Issn) |
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Export Date: 21 October 2011; Source: Scopus; Coden: Joetd; doi: 10.1016/j.jep.2011.07.008; Language of Original Document: English; Correspondence Address: Odonne, G.; Bureau du CNRS en Guyane, CNRS – UPS 2561, 2 Avenue Gustave Charlery, 97300 Cayenne, France; email: guillaume.odonne@gmail.com; Chemicals/CAS: amphotericin B, 1397-89-3, 30652-87-0; ursolic acid, 77-52-1 |
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EcoFoG @ webmaster @ |
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350 |
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Suedile, F.; Robert, F.; Roos, C.; Lebrini, M. |
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Corrosion inhibition of zinc by Mansoa alliacea plant extract in sodium chloride media: Extraction, Characterization and Electrochemical Studies |
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2014 |
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Electrochimica Acta |
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Electrochim Acta |
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133 |
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631-638 |
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Corrosion; Inhibition; Mansoa alliacea; sodium chloride; zinc |
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Ethanol extract of Mansoa alliacea was tested as corrosion inhibitor for zinc in NaCl 3% media using polarization and electrochemical impedance spectroscopy (EIS). Potentiodynamic polarization curves indicated that the plant extract behaves as mixed-type inhibitor. Impedance measurements showed that there are two phenomena in the process of inhibition. The results obtained show that this plant extract could serve as an effective inhibitor for the corrosion of zinc in NaCl 3% media. The extract obtained give inhibition around 90%. 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 curves show that Mansoa alliacea extract affects the anodic and cathodic reactions and the corrosion potential values were shifted to the positive potentials in the presence of the crude extract. Studies on the phytochemical constituents of the total extract were also established. Electrochemical studies, on the chemical families present in the crude extract, were also carried out to find the main constituents responsible for corrosion inhibition properties of the plant extract. © 2014 Elsevier Ltd. |
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Laboratoire Matériaux et Molécules en Milieux Amazonien, UAG – UMR ECOFOG Campus Troubiran, Route de Baduel, 97337 Cayenne, French Guiana |
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Elsevier Ltd |
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00134686 (Issn) |
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Export Date: 18 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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548 |
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Dejean, Alain ; Petitclerc, Frédéric ; Azémar, Frédéric ; Rossi, Vivien |
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Nutrient provisioning of its host myrmecophytic tree by a temporary social parasite of a plant-ant |
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2021 |
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Biological Journal of the Linnean Society |
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133 |
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3 |
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744-750 |
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One of the most advanced ant–plant mutualisms is represented by myrmecophytes sheltering colonies of some plant-ant species in hollow structures called domatia. In turn, the myrmecophytes benefit from biotic protection and sometimes nutrient provisioning (myrmecotrophy). Furthermore, over the course of evolution, some ant species have become social parasites of others. In this general context, we studied the relationship between its host trees and Azteca andreae (Dolichoderinae), a temporary social parasite of the plant-ant Azteca ovaticeps, and, as such, obligatorily associated with myrmecophytic Cecropia obtusa trees (Urticaceae). A first experiment showed that the δ15N values of the young leaves of Cecropia sheltering a mature A. andreae colony were very similar to those for trees sheltering Azteca alfari or A. ovaticeps, two typical Cecropia mutualists for which myrmecotrophy is known. In a second experiment, by injecting a 15N-labelled glycine solution into locusts given as prey to A. andreae colonies, we triggered an increase in δ15N in the young leaves of their host Cecropia. Thus, 15N passed from the prey to the host trees, explaining the outcomes of the first experiment. We discuss these results in light of the notion of ‘by-product benefits’. |
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Oxford Academy |
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EcoFoG @ webmaster @ |
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1009 |
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Hmimina, G.; Dufrêne, E.; Pontailler, J.-Y.; Delpierre, N.; Aubinet, M.; Caquet, B.; de Grandcourt, A.; Burban, B.; Flechard, C.; Granier, A.; Gross, P.; Heinesch, B.; Longdoz, B.; Moureaux, C.; Ourcival, J.-M.; Rambal, S.; Saint André, L.; Soudani, K. |
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Evaluation of the potential of MODIS satellite data to predict vegetation phenology in different biomes: An investigation using ground-based NDVI measurements |
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2013 |
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Remote Sensing of Environment |
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132 |
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145-158 |
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Crops; Deciduous forests; Evergreen forests; Ground-based NDVI; Modis; Phenology |
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Vegetation phenology is the study of the timing of seasonal events that are considered to be the result of adaptive responses to climate variations on short and long time scales. In the field of remote sensing of vegetation phenology, phenological metrics are derived from time series of optical data. For that purpose, considerable effort has been specifically focused on developing noise reduction and cloud-contaminated data removal techniques to improve the quality of remotely-sensed time series. Comparative studies between time series composed of satellite data acquired under clear and cloudy conditions and from radiometric data obtained with high accuracy from ground-based measurements constitute a direct and effective way to assess the operational use and limitations of remote sensing for predicting the main plant phenological events. In the present paper, we sought to explicitly evaluate the potential use of MODerate resolution Imaging Spectroradiometer (MODIS) remote sensing data for monitoring the seasonal dynamics of different types of vegetation cover that are representative of the major terrestrial biomes, including temperate deciduous forests, evergreen forests, African savannah, and crops. After cloud screening and filtering, we compared the temporal patterns and phenological metrics derived from in situ NDVI time series and from MODIS daily and 16-composite products. We also evaluated the effects of residual noise and the influence of data gaps in MODIS NDVI time series on the identification of the most relevant metrics for vegetation phenology monitoring. The results show that the inflexion points of a model fitted to a MODIS NDVI time series allow accurate estimates of the onset of greenness in the spring and the onset of yellowing in the autumn in deciduous forests (RMSE ≤ one week). Phenological metrics identical to those provided with the MODIS Global Vegetation Phenology product (MDC12Q2) are less robust to data gaps, and they can be subject to large biases of approximately two weeks or more during the autumn phenological transitions. In the evergreen forests, in situ NDVI time series describe the phenology with high fidelity despite small temporal changes in the canopy foliage. However, MODIS is unable to provide consistent phenological patterns. In crops and savannah, MODIS NDVI time series reproduce the general temporal patterns of phenology, but significant discrepancies appear between MODIS and ground-based NDVI time series during very localized periods of time depending on the weather conditions and spatial heterogeneity within the MODIS pixel. In the rainforest, the temporal pattern exhibited by a MODIS 16-day composite NDVI time series is more likely due to a pattern of noise in the NDVI data structure according to both rainy and dry seasons rather than to phenological changes. More investigations are needed, but in all cases, this result leads us to conclude that MODIS time series in tropical rainforests should be interpreted with great caution. © 2013 Elsevier Inc. |
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INRA, Unité Biogéochimie des Ecosystèmes Forestiers, Champenoux, France |
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Export Date: 21 February 2013; Source: Scopus |
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EcoFoG @ webmaster @ |
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467 |
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Degen, B.; Blanc, L.; Caron, H.; Maggia, L.; Kremer, A.; Gourlet-Fleury, S. |
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Impact of selective logging on genetic composition and demographic structure of four tropical tree species |
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2006 |
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Biological Conservation |
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Biol. Conserv. |
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131 |
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3 |
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386-401 |
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demography; genetic diversity; logging; phenology; pollen and seed dispersal; simulation; trees; tropics |
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Over-exploitation and fragmentation are serious problems for tropical forests. Most sustainable forest management practices avoid clear-cuts and apply selective logging systems focused on a few commercial species. We applied a simulation model to estimate the impact of such selective logging scenarios on the genetic diversity and demography of four tropical tree species from French Guiana. The simulations used data on genetic and demographic composition, growth, phenology and pollen and seed dispersal obtained for Dicorynia guianensis, Sextonia rubra, Symphonia globulifera and Vouacapoua americana at the experimental site in Paracou. Whereas Symphonia globulifera serves as a model for a species with low logging pressure, the other three species represent the most exploited tree species in French Guiana. In simulations with moderate logging, typical for French Guiana, with large cutting diameter (> 60 cm diameter) and long cutting cycles (65 years), the two species V. americana and Sextonia rubra were not able to recover their initial stock at the end of the rotation period, with a large decrease in the number of individuals and in basal area. Under a more intensive logging system (cutting diameter > 45 cm diameter, cutting cycles of 30 years) that is common practice in the Brazilian Amazon, only Symphonia globulifera showed no negative impact. Generally, the differences between the genetic parameters in the control scenarios without logging and the logging scenarios were surprisingly small. The main reasons for this were the overlapping of generations and the effective dispersal ability of gene vectors in all species, which guarantee relative homogeneity of the genetic structure in different age classes. Nevertheless, decreasing the population size by logging reduced the number of genotypes and caused higher genetic distances between the original population and the population at the end of the logging cycles. Sensitivity analysis showed that genetic changes in the logging scenarios were principally determined by the growth, densities and cutting diameter of each species, and only to a very small extent by the reproductive system including factors such as pollen and seed dispersal and flowering phenology. (c) 2006 Elsevier Ltd. All rights reserved. |
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BFH, Inst Forstgenet & Forstpflanzenzuchtung, D-22927 Grosshansdorf, Germany, Email: b.degen@holz.uni-hamburg.de |
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ELSEVIER SCI LTD |
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0006-3207 |
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ISI:000239139400004 |
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EcoFoG @ eric.marcon @ |
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180 |
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