Contents
Academic literature on the topic 'Dicorynia guianensis'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Dicorynia guianensis.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Dicorynia guianensis"
1
CARAGLIO, YVES, ERIC NICOLINI, and PASCAL PETRONELLI. "Observations on the links between the architecture of a tree (Dicorynia guianensis Amshoff) and Cerambycidae activity in French Guiana." Journal of Tropical Ecology 17, no. 3 (April 27, 2001): 459–63. http://dx.doi.org/10.1017/s0266467401001316.
Full textAbstract:
The development of a given species in a natural forest depends on a multitude of factors. Insects are one of the factors that have an important impact. We would like to present initial observations about the behaviour of longicorns of the Onciderini tribe and their impact on the development of Dicorynia guianensis.A study of the development of D. guianensis was conducted in French Guiana (5°18'N, 5°48'W), at the Paracou silvicultural facility. We studied plots where the Dicorynia inventory was extended to trees 1 m tall or over. In order to describe the impact of longicorn activity on a Dicorynia stand in which spatial distribution is aggregative (Kokou 1992), we chose trees (156 observed trees) in a control plot (plot 11, area: 17 500 m2). Height, trunk basal diameter and DBH were measured on each tree. A precise morphological description was established for each tree. It was during morphological description that the signs of longicorn attacks were sought. In all the species of the genus Oncideres, the female girdles the tree by removing the bark and some of the wood using its mandibles. It then digs deep into the wood above the cut and lays its eggs. The branch then breaks and falls to the ground (Hequet 1996). All that is left on the tree is a stump with characteristic signs of insect activity (Figure 1a). When such signs were seen on a plant, the type of structure (trunk, branch) was noted.
2
Borges, Luisa M. S., Simon M. Cragg, Julien Bergot, John R. Williams, Ben Shayler, and Gervais S. Sawyer. "Laboratory screening of tropical hardwoods for natural resistance to the marine borer Limnoria quadripunctata: The role of leachable and non-leachable factors." Holzforschung 62, no. 1 (January 1, 2008): 99–111. http://dx.doi.org/10.1515/hf.2008.015.
Full textAbstract:
AbstractThe marine borerLimnoriaingests essential wood components including the extractives the wood contains. Some extractives may confer borer resistance on certain timbers. Feeding byLimnoriacorrelates with the rate of production of faecal pellets. The faecal pellet production rate and mortality on over 40 test timbers and non-resistantPinus sylvestrissapwood was measured over 15 days. By placing animals in leachate from wood and with wood in flowing seawater, the effects of leaching-resistant and water-soluble compounds were measured. Some previously untested timbers affectedLimnoriaas strongly as timbers reputed for durability in marine construction. Wood ofMinquartia guianensis,Nectandra rubraandBruguiera gymnorhizacaused high mortality, and pellet production on them was less than 10% of production onP. sylvestris. Suppressed feeding rates, but with no heavy mortality, were observed on known durable species such asChlorocardium rodiei,Dicorynia guianensis, Lophira alataandNauclea trillesii, but also onCynometra ananta,Distemonanthus benthamianus,Enterolobium schomburgkii,Goupia glabra,Hymenaea courabil,Mammea africana,Shoreasp. andSacoglottis guianensis. Leachate fromB. gymnorhiza,G. glabra,H. coubaril,N. rubraandShoreasp. caused high mortality. These short-term bioassays thus detected clear differences between wood species in their resistance toLimnoriathat matched findings from long-term marine trials, while indicating new species worthy of detailed testing.
3
Latouche-Halle, C., A. Ramboer, E. Bandou, H. Caron, and S. Decroocq. "Isolation and characterization of microsatellite markers in the tropical tree species Dicorynia guianensis (Caesalpinaceae)." Molecular Ecology Notes 2, no. 3 (September 2002): 228–30. http://dx.doi.org/10.1046/j.1471-8286.2002.00196.x.
Full text
4
NICOLINI, E. "Epicormic Branches: a Growth Indicator for the Tropical Forest Tree, Dicorynia guianensis Amshoff (Caesalpiniaceae)." Annals of Botany 92, no. 1 (May 9, 2003): 97–105. http://dx.doi.org/10.1093/aob/mcg119.
Full text
5
Caron, Henri, Cyril Dutech, and Éric Bandou. "Variations spatiotemporelles du régime de reproduction de Dicorynia guianensis Amshoff (Caesalpiniaceae) en forêt guyanaise." Genetics Selection Evolution 30, Suppl 1 (1998): S153. http://dx.doi.org/10.1186/1297-9686-30-s1-s153.
Full text
6
Béreau, Moïse, Damien Bonal, Eliane Louisanna, and Jean Garbaye. "Do mycorrhizas improve tropical tree seedling performance under water stress and low light conditions? A case study with Dicorynia guianensis (Caesalpiniaceae)." Journal of Tropical Ecology 21, no. 4 (June 27, 2005): 375–81. http://dx.doi.org/10.1017/s0266467405002348.
Full textAbstract:
We tested the response of seedlings of Dicorynia guianensis, a major timber tree species of French Guiana, to mycorrhizal symbiosis and water limitation in a semi-controlled experiment under natural light conditions. Under well-watered conditions, mycorrhizal colonization resulted in an increase of net photosynthesis, growth and phosphorus uptake. When submitted to water stress, no growth reduction of mycorrhizal seedlings was observed. Mycorrhizal seedlings were more sensitive to drought than non-mycorrhizal ones in terms of carbon assimilation, but not with regard to stomatal closure. In contrast to previous studies on temperate tree seedlings, this result precludes a mycorrhizal effect on the hydraulic properties of this species. Furthermore, our results suggest that below a specific threshold of soil moisture, carbon assimilation of D. guianensis seedlings was decreased by the mycorrhizal symbiosis. This is probably related to the competition between the plant and its host fungus for carbon allocation under low light intensity, even though it did not seem to have a significant effect on mortality in our experiment.
7
Anouhe, Jean-Baptiste Say, Augustin Amissa Adima, Florence Bobelé Niamké, Didier Stien, Brise Kassi Amian, Pierre-Alain Blandinières, David Virieux, Jean-Luc Pirat, Seraphin Kati-Coulibaly, and Nadine Amusant. "Dicorynamine and harmalan-N-oxide, two new β-carboline alkaloids from Dicorynia guianensis Amsh heartwood." Phytochemistry Letters 12 (June 2015): 158–63. http://dx.doi.org/10.1016/j.phytol.2015.03.012.
Full text
8
Bereau, Mo�se, T�t� S�v�rien Barigah, Eliane Louisanna, and Jean Garbaye. "Effects of endomycorrhizal development and light regimes on the growth of Dicorynia guianensis Amshoff seedlings." Annals of Forest Science 57, no. 7 (October 2000): 725–33. http://dx.doi.org/10.1051/forest:2000153.
Full text
9
Ramdial, Donna, Artie Sewdien, Jerry Rasdan, Shermaine Critchlow, Noraisah Tjong-A-Hung, Alejandra Ospina, Verginia Wortel, and Francis E. Putz. "Stump Sprout Characteristics of Three Commercial Tree Species in Suriname." Forests 11, no. 11 (October 24, 2020): 1130. http://dx.doi.org/10.3390/f11111130.
Full textAbstract:
We compared stump sprouting by three common timber species in Suriname on the basis of sprout origins on stumps, sprout densities, and sprout height:diameter ratios. We then compared some leaf and stem functional traits of 15–18-month-old resprouts and nearby conspecific saplings of the same height (0.5–3.5 m) but unknown age. Stumps of Dicorynia guianensis Amsh. (29–103 cm in diameter) produced the most sprouts (x = 9.2/stump), followed by the 50–71 cm diameter stumps of Eperua falcata Amsh. (10.6/stump), and the 30–78 cm diameter Qualea rosea Amsh. (5.9/stump); sprout density did not vary with stump diameter. Sprouts emerged from the lower, middle, and upper thirds of the stumps of all three species, but not from the vicinity of the exposed vascular cambium in Qualea. With increased resprout density, heights of the tallest sprout per stump tended to increase but height:diameter ratios increased only in Dicorynia. Compared to conspecific saplings, sprouts displayed higher height-diameter ratios, higher leaf-to-wood mass ratios (LWR), and lower wood densities, but did not differ in leaf mass per unit area (LMA) or leaf water contents. These acquisitive functional traits may reflect increased resprout access to water and nutrients via the extensive root system of the stump. That we did not encounter live stump sprouts from the previous round of selective logging, approximately 25 years before our study, suggests that stump sprouts in our study area grow rapidly but do not live long.
10
VAN DER MEER, PETER J., FRANK J. STERCK, and FRANS BONGERS. "Tree seedling performance in canopy gaps in a tropical rain forest at Nouragues, French Guiana." Journal of Tropical Ecology 14, no. 2 (March 1998): 119–37. http://dx.doi.org/10.1017/s026646749800011x.
Full textAbstract:
The effect of natural canopy gaps on the performance of naturally occurring tree seedling populations was studied in a tropical rain forest in French Guiana. This was done at two levels of scale. Firstly, on a 20 m × 250 m forest transect intersecting four canopy gaps, it was investigated how patterns of recruitment, growth and survival of seedlings of Cecropia obtusa, Dicorynia guianensis and Pourouma bicolor differed between canopy gaps and closed forest. Secondly, for one large natural canopy gap, performance of seedling cohorts established before (‘pre-gap’ cohorts) and after (‘post-gap’ cohorts) gap formation was studied in relation to environmental heterogeneity. The direct site factor (DSF) was used as an indicator of light availability in the gap zone. Cecropia specialised in large gaps, and also in specific sites within the large gap: seedling performance was increased by light, and by dead wood. Pourouma mainly germinated under closed forest conditions, where it can survive for a long period until a canopy gap is formed nearby. Pourouma seedlings adjusted well to the new gap environment but they did not specialise in specific places within the gap. Seedling location of Pourouma seedlings was mainly determined by accidental positioning before gap formation. Dicorynia was able to germinate both in gaps and under closed forest conditions. Although the number of gaps studied in this study was low, the results show that seedling establishment, early growth and survival of the three tree species were affected by canopy gaps and by the environmental heterogeneity within a large gap.
Dissertations / Theses on the topic "Dicorynia guianensis"
1
Latouche-Hallé, Céline. "Flux de gènes et structure génétique de Dicorynia guianensis en forêt tropicale humide." Paris 11, 2004. http://www.theses.fr/2004PA112003.
Full textAbstract:
Dicorynia guianensis est un arbre de la canopée, endémique de la forêt tropicale humide guyanaise. Tous les adultes reproducteurs situés sur un dispositif de 40 ha, ainsi que 375 juvéniles, et 246 graines provenant de 22 arbres reproducteurs ont été récoltés puis génotypés, à l'aide de 6 marqueurs microsatellites nucléaires, et d'une combinaison PCR-RFLP chloroplastique. Comme la majorité des espèces forestières tropicales, la diversité nucléaire intrapopulation est plus faible que celle des arbres des forêts tempérées. Quel que soit le génome considéré, la différentiation génétique est plus prononcée entre les agrégats qu'entre les cohortes. La structure spatiale est plus importante pour le marqueur chloroplastique, suggérant une forte asymétrie entre les flux de pollen et de graines. De plus, Dicorynia montre un niveau élevé de diversité intrapopulation chloroplastique. Un tel maintient de plusieurs haplotypes est attendu si les agrégats sont issus d'une colonisation récente, ou s'ils sont sujets à une dynamique d'extinction/recolonisation. Le taux d'allofécondation moyen de la population est élevé, mais la variation individuelle est importante. Ainsi, un individu a un système de reproduction mixte, ce qui suggère que les barrières d'auto-incompatibilité peuvent être contournées. Le succès reproducteur mâle n'est que peu corrélé à la distance de pollinisation intrapopulation. Par contre, il est corrélé au diamètre du tronc et à l'intensité de floraison. La majorité du pollen (66%) provient de l'extérieur du dispositif. Ces données suggèrent que la structure spatiale de la diversité génétique observée à cette échelle est principalement due à une dispersion limitée des graines, et que les flux de pollen n'ont qu'un impact limité. Le système de reproduction de D. Guianensis est une combinaison d'un flux de pollen à longue distance et d'une tolérance à l'autofécondationDicorynia guianensis is a canopy tree, endemic to the tropical rain forest of French Guiana. All adult trees within a continuous area of 40 ha (n=157), 375 saplings, and 246 progenies from 22 mature trees, were sampled and genotyped with 6 microsatellite loci and one PCR-RFLP cpDNA combination. Level of nuclear intrapopulation diversity was lower than temperate forest trees, as other tropical species. For both genomes, genetic differentiation was more pronounced between spatial aggregates than between cohorts. Spatial structure was larger for chloroplast than nuclear markers indicating a strong asymmetry between pollen and seed flow. Moreover, the species was able to maintain high levels of intrapopulation diversity for chloroplast genome. An avoidance of fixation of haplotypes is expected in recently formed aggregates for a colonizing species or in non-equilibrium situations where aggregates are subject to rapid extinction-recolonization dynamics. At the population level, the species was mostly outcrossing but there was marked variation among individuals. One tree exhibited mixed mating confirming that the self-incompatibility barriers could be relaxed. Male mating success was only moderately related to distance between trees within the study area. It was, however, related to the diameter of the stem and to the visual assessment of flowering intensity. The majority (66%) of pollen came from outside the study stand. These data suggest that the fine-scale spatial genetic structure is mainly the consequence of restricted seed dispersal, and that pollen flow has limited impact. The mating behavior of D. Guianensis is a combination of long distance pollen flow and occasional selfing
2
Flora, Claudiane. "Origine et prédiction de la variabilité de la durabilité naturelle chez Dicorynia guianensis Amsh." Thesis, Guyane, 2018. http://www.theses.fr/2018YANE0001/document.
Full textAbstract:
L'Angélique (Dicorynia guianensis Amsh.) est une espèce forestière de Guyane très exploitée pour son bois mais ce dernier est connu pour présenter une durabilité naturelle variable, dont les conséquences peuvent être très lourdes pour l'utilisateur. Dans le cadre de cette thèse nous avons souhaité comprendre l'origine de la durabilité naturelle du duramen se l'Angélique afin d'appréhender sa variabilité pour mieux la prédire. Dans un premier temps, nous avons mis en oeuvre une stratégie d'échantillonnage basée sur l'étude architecturale de l'arbre pour appréhender la variabilité de la durabilité naturelle, ce qui a été confirmé par les essais biologiques réalisés. Nous avons par la suite évalué l'influence de potentiels facteurs mesurés dans le bois sur la durabilité naturelle. A ce titre, le rôle des extractibles a été évalué par des approches métaboliques ciblées et non ciblées, couplées à une stratégie de déréplication. La lignine et l'infradensité ont également été retenues comme facteurs de durabilité naturelle de l'Angélique. Enfin, ses caractéristiques propres à l'ontogénie se l'arbre ont été pris en compte et les résultats mettent en lumière l'importance du stade de développement de l'arbre ainsi que son environnement. Enfin, nous avons proposé ses outils spectroscopiques (moyen et proche infrarouge) simples, rapides et fiables pour prédire la durabilité naturelle. Ces résultats sont encourageants et suggèrent leur utilisation potentielle pour la filière bois pour prédire la durabilité naturelle du bois de l'AngéliqueAngélique (Dicorynia guianensis Amsh.) is a tree species in French Guiana that is heavily exploited for its wood, but it is known to have variable natural durability, which can be of severe consequences for the user. In this thesis we wanted to understand the origin of the natural durability of Angelique heartwood in order to understand its variability, to beter predict it. This multidisciplinary work combines wood sciences, natural products chemistry and microbiology. First, we implemented a sampling strategy based on the architectural profile of tree individuals to understand the variability of natural durabilityn which was confirmed by biological assays. We then assessed the influence of potential natural durability factors that we measured in the wood samples. As such, the role of metabolies was investigated using targeted and untargeted metabolomics, coupled with a dereplication strategy. Lignin and infradensity have also been tested as factors of durability for Angelique heartwood. Finally, factors that are related to tree ontogeny have been taken into account and the results highlight the importance of the stage development and the environment of tree individuals. Lastly, we have proposez esasy, fast and reliable spectroscopie tools (medium and near infrared) to predict the nartural durability. These results are encouraging and suggest their potential use by the timber industry to predict durability of Angélique heartwood
3
Jesel, Sébastien. "Écologie et dynamique de la régénération de Dicorynia guianensis (Caesalpiniaceae) dans une forêt guyanaise." Phd thesis, INAPG (AgroParisTech), 2005. http://pastel.archives-ouvertes.fr/pastel-00002972.
Full textAbstract:
Dicorynia guianensis (Angélique) est un grand arbre de la forêt tropicale humide du plateau des Guyanes et la première espèce exploitée pour son bois en Guyane. La gestion durable de cette ressource exige de pouvoir prédire à long terme le renouvellement du stock exploitable et pour cela, de mieux cerner les processus écologiques qui déterminent la dynamique de sa régénération. Le travail présenté est la synthèse d'études menées sur l'écologie de la graine et la démographie de la régénération de D. guianensis en forêt naturelle et en forêt exploitée sur le site de Paracou, en Guyane. Les connaissances acquises, à l'échelle de la population, sur la régénération de l'espèce ont permis de calibrer un modèle de recrutement à partir de la graine intégrant la variabilité des processus d'installation, de croissance et de mortalité. Ce modèle constitue le point de départ d'un simulateur de la dynamique des populations naturelles de D. guianensis sélectivement exploitées en Guyane.
4
Jesel, Sébastien. "Ecologie et dynamique de la régénération de Dicorynia guianensis (Caesalpiniaceae) dans une forêt guyanaise." Paris, Institut national d'agronomie de Paris Grignon, 2005. http://www.theses.fr/2005INAP0008.
Full text
5
Vanbellingen, Quentin. "Imagerie de substances naturelles par spectrométrie de masse." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS172/document.
Full textAbstract:
Cette thèse a été consacrée à l’amélioration de méthodes en imagerie par spectrométrie de masse, et à leur utilisation pour l’analyse in situ de substances naturelles. Une première partie a été consacrée à développer une nouvelle méthode permettant d’acquérir en imagerie TOF-SIMS des images avec une résolution de 400 nm tout en préservant la résolution en masse. Pour cela, une extraction retardée des ions secondaires a été caractérisée et optimisée. Une seconde partie a eu pour objectif d’étudier le phénomène de duraminisation d’un arbre tropical de l’espèce Dicorynia guianensis, qui est l’un des plus exploités en Guyane française et dont le duramen est réputé être imputrescible. Les images par spectrométrie de masse TOF-SIMS enregistrées avec la méthode développée ont montré à l’échelle sub-micrométrique les changements métaboliques s’opérant autour de la zone de transition, où s’opère la duraminisation. Les techniques TOF-SIMS et MALDI-TOF ont ensuite été utilisées pour l’analyse d’une surface sur laquelle ont crû deux souches microbiennes en compétition. Les deux souches ont été extraites d’un if japonais (Cephalotaxus harringtonia), l’une étant un champignon endophyte (Paraconiothyrium variabile) et l’autre une bactérie pathogène à ce conifère (Bacillus subtilis). Les résultats ont montré que le champignon était capable d’hydrolyser les surfactines produites par la bactérie. Enfin, les imageries par spectrométrie de masse MALDI-TOF et TOF-SIMS sont deux méthodes de choix pour l’étude de modèle in vitro de ce qui pourrait se produire in vivoThis thesis was devoted to the improvement of mass spectrometry imaging methods, and to their use for in situ analysis of natural substances. The first part of this thesis has been dedicated to the development of a new acquisition mode in TOF-SIMS imaging able to acquire images with a high spatial resolution of 400 nm while keeping a good mass resolution. For that, a delayed extraction of the secondary ions has been characterized and optimized. Then, a second part has been dedicated to the study of heartwood production in a tropical species named Dicorynia guianensis. This species is one of the most exploited in French Guiana for its heartwood which exhibits a good durability. Metabolic changes are shown by sub-micrometric resolution ion images recorded in and around the transition zone, where the heartwood formation occurs. Then, TOF-SIMS and MALDI-TOF have both been used to analyse the surface of a bacterial competition. Species have been isolated from a Japanese conifer (Cephalotaxus harringtonia), from which the stains are an endophitic fungi (Paraconiothyrium variabile) and a pathogenic bacteria of the conifer (Bacillus subtilis). The results have shown that the fungus is able to hydrolyze surfactines produced by the bacteria during the competition. Furthermore, both the MALDI-TOF and the TOF-SIMS mass spectrometry imaging are methods of choice to study in vitro models of what could happen in vivo
6
De, Grandcourt Agnès. "Acquisition et utilisation du phosphore par les plantules ligneuses forestières associées à des endomycorhizes : comparaison de deux espèces de forêt tropicale humide de Guyane française et impact du niveau d'éclairement." Nancy 1, 2004. http://www.theses.fr/2004NAN10036.
Full textAbstract:
Le phosphore (P) est un élément capital à la croissance des plantes. En forêt tropicale humide, P serait le facteur limitant de la production primaire. Les plantes forment une mycorhize, symbiose reposant sur un échange de P (fourni par un champignon) et de carbone (C) (fourni par la plante). Le premier objectif de ce travail était d'étudier la dépendance (acquisition de P) et la sensibilité (croissance) de Dicorynia guianensis et d'Eperua falcata (deux Cesalpiniacées) vis-à-vis des mycorhizes. Au stade plantule, les deux espèces étaient dépendantes mais seule D. Guianensis était sensible. Les deux espèces stockaient du P en cas de forte teneur en P du sol. Le second objectif était d'étudier la compétition pour le C entre la plante et le champignon pour D. Guianensis. Sous fort éclairement, l'acquisition de P et la croissance étaient augmentés par la mycorhization. Sous faible éclairement, les champignons colonisaient les racines mais n'absorbaient pas de P. Dans ces conditions, l'acquisition de C du plant n'augmentait pas et la mycorhization avait un effet négatif sur la croissance des plantsPhosphorus (P) is an essential nutrient for plant growth. In tropical rainforest, P is thought to be a limiting factor for primary production. Plant can establish mycorrhiza, symbiosis between fungus (bringing nutrient) and plant (bringing carbon (C)). The first objective of this work was to study the dependency (P acquisition) and sensitivity (growth) of Dicorynia guianensis and Eperua falcata (two Ceasalpiniaceae) to mycorrhiza. At seedling stage, both species were dependant but only D. Guianensis was sensitive. Both species stocked P in case of elevated soil P rates. The second objective was to study competition for C between plant and fungus for D. Guianensis. At high irradiance, mycorhization increased P acquisition and growth. At low irradiance, fungi colonised roots but were unable to absorb P. At this irradiance, mycorhization did not improved C acquisition and had a negative effect on plant growth
7
Amusant, Nadine. "Durabilité naturelle et couleur des bois de Guyane : mesure, variabilité, déterminisme chimique : applications à Dicorynia guianensis (Angélique), Sextonia rubra (Grignon), Eperua falcata (Wapa) et Eperua grandiflora (Wapa courbaril)." Paris, ENGREF, 2003. http://www.theses.fr/2003ENGRA001.
Full textAbstract:
Il existe une grande variabilité de la résistance des bois aux agents de dégradation chez les espèces tropicales, qu'il faut maîtriser pour augmenter leur potentiel d'utilisation, notamment en Guyane. La thèse aborde deux problématiques : comment caractériser les structures de la variabilité intra-spécifique (inter et intra-arbre) de la résistance aux champignons basidiomycètes chez les espèces durables et surtout très variables? Quel est le rôle des différentes familles chimiques d'extraits dans la durabilité naturelle en comparant des espèces botaniquement proches (Eperua falcata et Eperua grandiflora) très durable d'une part, durable et variable d'autre part. La durabilité naturelle a été étudiée au travers de différents types d'essais. Elle est peu influencée par la hauteur de prélèvement, mais elle diminue du duramen externe vers le duranem interne. Il existe une corrélation significative mais peu étroite entre la couleur du bois et sa durabilité naturelle. La résistance de l'Angélique est liée au paramètre "a*" (axe rouge-vert du système CIELAB). De même pour le Wapa courbaril, les arbres présentant les valeurs de "a*" les plus élevées sont les plus résistants. Enfin, pour ce qui concerne [le] déterminisme chimique de la durabilité naturelle, les essais réalisés en conditions in-vivo ont montré que seuls les composés diterpénoïques issus d'Eperua falcata présentent une activité antifongique. Tandis que les composés polyphénoliques, participent activement au mécanisme de la durabilité naturelle pour les deux espèces de Wapa. Les résultats des analyses chimiques expliquent en partie les structures de variabilité observées pour la durabilité et la couleur d'Eperua grandifloraThere is a great variability of durability of tropical species against decay, which should be controlled to increase utilisations, especially in Guyana. This thesis deals with two topics : what are the structures of intraspecific variability (inter and intra-tree) of resistance to basidiomycetes fungus on some durable and very variable species? What is the role of the various extractives on natural durability thought the example of close species (Eperua falcata and Eperua grandiflora), that have not the same durability (respectively very durable, durable and variable). The wood resistance to fungi decay was studied from different kinds of tests. In the stem, the natural durability is little influenced by height, but decreases from the outermost heartwood to the innermost heartwood. There is a significant but not very narrow correlation between colour of wood and natural durability. Durability of Angelique is related to the "a*" parameter (axis red-green of system CIELAB). In the same way for Wapa courbaril, trees with highest values of "a*" are more resistant. Lastly, by using chemical analysis and in-vivo bioassays, we found that only diterpenoïc compounds from Wapa presented an antifongic activity. While the polyphenolic compounds for the same species play an important role in the mecanism of natural durability for both species. Theses analysis are helpful to explain the structures of variability of durability and colour observed in Eperua grandiflora