Résumé
The chemical investigations of Dicorynia guianensis heartwood led to the isolation of four new indole alkaloids for the first time in this plant. Compound (1) identified as spiroindolone 2′,3′,4′,9′-tetrahydrospiro [indoline-3,1′pyrido[3,4-b]-indol]-2-one, and compound (3) described as nitrone 1-methyl-4,9-dihydro-3H-pyrido [3,4-b] indole 2-oxide and were isolated for the first time as natural products. ABTS antioxidant activity guided their isolation.
Auteurs, date et publication :
Auteurs Jean-Baptiste Say Anouhe , Augustin Amissa Adima , Florence Bobelé Niamké , Didier Stien , Brise Kassi Amian , Pierre-Alain Blandinières , David Virieux , Jean-Luc Pirat , Seraphin Kati-Coulibaly , Nadine Amusant
Publication : Phytochemistry Letters
Date : 2015
Volume : 12
Pages : 158–163
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Sanna Olsson , Pedro Seoane-Zonjic , Rocío Bautista , M. Gonzalo Claros , Santiago C. González-Martínez , Ivan Scotti , Caroline Scotti-Saintagne , Olivier J. Hardy , Myriam Heuertz
Publication : Molecular Ecology Resources
Date : 2017
Volume : 17
Issue : 4
Pages : 614–630
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Barbara R. V. Meyer-Sand , Celine Blanc-Jolivet , Malte Mader , Kathelyn Paredes-Villanueva , Niklas Tysklind , Alexandre M. Sebbenn , Erwan Guichoux , Bernd Degen
Publication : Conservation Genetics Resources
Date : 2017
Pages : 1–3
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Clément Stahl , Bruno Hérault , Vivien Rossi , Benoit Burban , Claude Bréchet , Damien Bonal
Publication : Oecologia
Date : 2013
Volume : 173
Issue : 4
Pages : 1191–1201
Catégorie(s)
#CIRAD #FORET ParacouRésumé
Measuring functional or phylogenetic diversity is the object of an active literature. The main issues to address are relating measures to a clear conceptual framework, allowing unavoidable estimation‐bias correction and decomposing diversity along spatial scales. We provide a general mathematical framework to decompose measures of species‐neutral, phylogenetic or functional diversity into α and β components. We first unify the definitions of phylogenetic and functional entropy and diversity as a generalization of HCDT entropy and Hill numbers when an ultrametric tree is considered. We then derive the decomposition of diversity. We propose a bias correction of the estimates allowing meaningful computation from real, often undersampled communities. Entropy can be transformed into true diversity, that is an effective number of species or communities. Estimators of α‐ and β‐entropy, phylogenetic and functional entropy are provided. Proper definition and estimation of diversity is the first step towards better understanding its underlying ecological and evolutionary mechanisms.
Auteurs, date et publication :
Auteurs Eric Marcon , Bruno Hérault , Robert Freckleton
Publication : Methods in Ecology and Evolution
Date : 2015
Volume : 6
Issue : 3
Pages : 333–339
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Eric Nicolini , Jacques Beauchêne , Benjamin Leudet de la Vallée , Julien Ruelle , Thomas Mangenet , Patrick Heuret
Publication : Annals of Forest Science
Date : 2012
Volume : 69
Issue : 5
Pages : 543–555
Catégorie(s)
#CIRAD #FORET ParacouRésumé
This article presents the effects of logging on the dynamics of above-ground biomass from the results of the post-logging study within two forests: Cikel in Eastern Pará, Brazil and Paracou in French Guiana. The main objective is to compare the impact of commercial logging on the regeneration of the aboveground biomass in these forests whose characteristics differ in terms of structure and growth. In both sites, the intensity of exploitation is a key factor in determining the loss of biomass and the time required for its regeneration. In Paracou, the regeneration of biomass lost during conventional logging of 10 trees per hectare takes 45 years and more than 100 years when operating with higher intensity (21 trees/ha ). In Cikel the forest biomass regenerates after 49 years harvesting 6 trees/ha and that takes 87 years after removal of 8 trees/ha. This regeneration needs similar time on both sites but with lower logging intensity at Cikel, in which felled trees are larger with a greater biomass than those of Paracou. This post-logging study has established a direct correlation of the dynamics of the biomass with the initial structure of the forest, as well as with the parameters of forest dynamics: mortality, growth and recruitment. The accumulation of biomass by the tree growth of the two remaining stands is a key parameter for the net carbon storage, while the contribution of recruitment in Paracou becomes significant only after 10 years after felling. Therefore in view to improve the growth of residual trees, it is compulsory to apply adequate silvicultural treatments such as selective thinning or removal of vines. While the two forests are geographically close enough, their regenerative abilities differ and because of the significant difference in size of the trees, the forest could tolerate more intensive harvesting in French Guiana. (Résumé d'auteur)
Auteurs, date et publication :
Auteurs Plinio Sist , Lilian Blanc , Lucas Mazzei , Christopher Baraloto , Raphaël Aussenac
Publication : Bois et Forêts des Tropiques
Date : 2025
Catégorie(s)
#CIRAD #FORET ParacouRésumé
Upon advances in sequencing techniques, more and more morphologically identical organisms are identified as cryptic species. Often, mutualistic interactions are proposed as drivers of diversification. Species of the neotropical parabiotic ant association between Crematogaster levior and Camponotus femoratus are known for highly diverse cuticular hydrocarbon (CHC) profiles, which in insects serve as desiccation barrier but also as communication cues. In the present study, we investigated the association of the ants’ CHC profiles with genotypes and morphological traits, and discovered cryptic species pairs in both genera. To assess putative niche differentiation between the cryptic species, we conducted an environmental association study that included various climate variables, canopy cover, and mutualistic plant species. Although mostly sympatric, the two Camponotus species seem to prefer different climate niches. However in the two Crematogaster species, we could not detect any differences in niche preference. The strong differentiation in the CHC profiles may thus suggest a possible role during speciation itself either by inducing assortative mating or by reinforcing sexual selection after the speciation event. We did not detect any further niche differences in the environmental parameters tested. Thus, it remains open how the cryptic species avoid competitive exclusion, with scope for further investigations.
Auteurs, date et publication :
Auteurs Juliane Hartke , Philipp P. Sprenger , Jacqueline Sahm , Helena Winterberg , Jérôme Orivel , Hannes Baur , Till Beuerle , Thomas Schmitt , Barbara Feldmeyer , Florian Menzel
Publication : Ecology and Evolution
Date : 2025
Volume : 9
Issue : 16
Pages : 9160-9176
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouRésumé
Decreasing growth rate (Feeley et al., 2007) and large die-back due to drought (Phillips et al., 2009) suggest that tropical forests are suffering recent climate changes. Forest vulnerability to external factors (e.g. air pollution, acid rain) is widely studied in northern countries, while only a few attempts have investigated crown integrity in the Tropics. The method needs to be generic enough to account for the large number of species and crown shapes encountered in tropical forests. In the present study, we developed and tested a novel field method that estimates crown fragmentation (main branch mortality (MB) and secondary branch mortality (SB)), liana infestation (LI) and crown position (CP) in the canopy. The relationship between crown fragmentation and annual growth rate (agr) was investigated through multiple regression. Six out of eight canopy tree species showed significant growth decline with increasing crown fragmentation. Higher probability of death was also found in trees with severe crown fragmentation. The capacity of such crown assessment to depict tree vitality in a forest stand is discussed along with potential applications in both forest science and management.
Auteurs, date et publication :
Auteurs Ervan Rutishauser , Daniel Barthélémy , Lilian Blanc , Nicolini Eric-André
Publication : Forest Ecology and Management
Date : 2011
Volume : 261
Issue : 3
Pages : 400–407
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Louis S. Santiago , Mark E. De Guzman , Christopher Baraloto , Jacob E. Vogenberg , Max Brodie , Bruno Hérault , Claire Fortunel , Damien Bonal
Publication : New Phytologist
Date : 2025