Résumé
The influence of geomorphological features on rain-forest diversity has been reported in different Amazonian regions. Soil filtering is often assumed to underlie the observed geomorphic control on the floristic composition but other hypotheses related to biogeography or long-term forest dynamics are also possible. We tested relationships between geomorphology, soil properties and forest composition in French Guiana rain forest using a recent geomorphological map and a large dataset comprising 3132 0.2-ha plots and 421 soil cores. Soil properties were characterized by laboratory analyses and by field descriptions indicating drainage capacity and classification according to the World Reference Base (WRB). The influence of soils and geomorphology on beta-diversity was tested using variance partitioning and ANOVA-like tests. Our results confirm the hypothesis of a strong relationship between geomorphological landscapes and soil properties. Soil filtering significantly influenced the abundance of more than 40 species or groups of species. However geomorphic control of forest composition involves much more than the effects of the soil, which only explain a minor part of the broad-scale patterns of forest diversity related to geomorphological landscapes. These results reinforce the alternative hypotheses linking geomorphological landscapes to long-term forest change under the control of historical processes that shaped forest diversity.
Auteurs, date et publication :
Auteurs Stéphane Guitet , Vincent Freycon , Olivier Brunaux , Raphaël Pélissier , Daniel Sabatier , Pierre Couteron
Publication : Journal of Tropical Ecology
Date : 2025
Volume : 32
Pages : 22–40
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Christine Le Roux , Félix Muller , Jean-Marc Bouvet , Bernard Dreyfus , Gilles Béna , Antoine Galiana , Amadou M. Bâ
Publication : Microbial Ecology
Date : 2014
Volume : 68
Issue : 2
Pages : 329–338
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Marina Ciminera , Marie-Anne Auger-Rozenberg , Henri Caron , Melfran Herrera , Caroline Scotti-Saintagne , Ivan Scotti , Niklas Tysklind , Alain Roques
Publication : Journal of Medical Entomology
Date : 2018
Catégorie(s)
#CIRAD #FORET ParacouRésumé
Traditional measures of diversity, namely the number of species as well as Simpson's and Shannon's indices, are particular cases of Tsallis entropy. Entropy decomposition, i.e. decomposing gamma entropy into alpha and beta components, has been previously derived in the literature. We propose a generalization of the additive decomposition of Shannon entropy applied to Tsallis entropy. We obtain a self-contained definition of beta entropy as the information gain brought by the knowledge of each community composition. We propose a correction of the estimation bias allowing to estimate alpha, beta and gamma entropy from the data and eventually convert them into true diversity. We advocate additive decomposition in complement of multiplicative partitioning to allow robust estimation of biodiversity.
Auteurs, date et publication :
Auteurs Eric Marcon , Ivan Scotti , Bruno Hérault , Vivien Rossi , Gabriel Lang , Jean Thioulouse
Publication : Plos One
Date : 2014
Volume : 9
Issue : 3
Pages : e90289
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Bruno Hérault , Bénédicte Bachelot , Lourens Poorter , Vivien Rossi , Frans Bongers , Jérôme Chave , C. E. Timothy Paine , Fabien Wagner , Christopher Baraloto
Publication : Journal of Ecology
Date : 2011
Volume : 99
Issue : 6
Pages : 1431–1440
Catégorie(s)
#CIRAD #FORET ParacouRésumé
In Amazonia, the knowledge about Fungi remains patchy and biased towards accessible sites. This is particularly the case in French Guiana where the existing collections have been confined to few coastal localities. Here, we aimed at filling the gaps of knowledge in undersampled areas of this region, particularly focusing on the Basidiomycota. From 2011, we comprehensively collected fruiting-bodies with a stratified and reproducible sampling scheme in 126 plots. Sites of sampling reflected the main forest habitats of French Guiana in terms of soil fertility and topography. The dataset of 5219 specimens gathers 245 genera belonging to 75 families, 642 specimens are barcoded. The dataset is not a checklist as only 27% of the specimens are identified at the species level but 96% are identified at the genus level. We found an extraordinary diversity distributed across forest habitats. The dataset is an unprecedented and original collection of Basidiomycota for the region, making specimens available for taxonomists and ecologists. The database is publicly available in the GBIF repository (https://doi.org/10.15468/ymvlrp).
Auteurs, date et publication :
Auteurs Gaëlle Jaouen , Audrey Sagne , Bart Buyck , Cony Decock , Eliane Louisanna , Sophie Manzi , Christopher Baraloto , Mélanie Roy , Heidy Schimann
Publication : Scientific Data
Date : 2019
Volume : 6
Issue : 1
Pages : 206
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouAuteurs, date et publication :
Auteurs E. V. Da Silva , J.-P. Bouillet , J. L. M. Gonçalves , C. H. Abreu Junior , P. C. O. Trivelin , P. Hinsinger , C. Jourdan , Y. Nouvellon , J. L. Stape , J. P. Laclau
Publication : Functional Ecology
Date : 2025
Volume : 25
Pages : 996-1006
Catégorie(s)
#CIRAD #FORET Itatinga #INRAEAuteurs, date et publication :
Auteurs Marilyne Laurans , Olivier Martin , Eric Nicolini , Gregoire Vincent , Hans Cornelissen
Publication : Journal of Ecology
Date : 2012
Volume : 100
Issue : 6
Pages : 1440–1452
Catégorie(s)
#CIRAD #FORET ParacouRésumé
How tropical tree species respond to disturbance is a central issue of forest ecology, conservation and resource management. We define a hierarchical model to investigate how functional traits measured in control plots relate to the population change rate and to demographic rates for recruitment and mortality after disturbance by logging operations. Population change and demographic rates were quantified on a 12-year period after disturbance and related to seven functional traits measured in control plots. The model was calibrated using a Bayesian Network approach on 53 species surveyed in permanent forest plots (37.5 ha) at Paracou in French Guiana. The network analysis allowed us to highlight both direct and indirect relationships among predictive variables. Overall, 89% of interspecific variability in the population change rate after disturbance were explained by the two demographic rates, the recruitment rate being the most explicative variable. Three direct drivers explained 45% of the variability in recruitment rates, including leaf phosphorus concentration, with a positive effect, and seed size and wood density with negative effects. Mortality rates were explained by interspecific variability in maximum diameter only (25%). Wood density, leaf nitrogen concentration, maximum diameter and seed size were not explained by variables in the analysis and thus appear as independent drivers of post-disturbance demography. Relationships between functional traits and demographic parameters were consistent with results found in undisturbed forests. Functional traits measured in control conditions can thus help predict the fate of tropical tree species after disturbance. Indirect relationships also suggest how different processes interact to mediate species demographic response.
Auteurs, date et publication :
Auteurs Olivier Flores , Bruno Hérault , Matthieu Delcamp , Éric Garnier , Sylvie Gourlet-Fleury , Francesco de Bello
Publication : Plos One
Date : 2014
Volume : 9
Issue : 9
Pages : e105022
Catégorie(s)
#CIRAD #FORET ParacouRésumé
We consider competing functional groups of tree species and develop a model of network response dynamics in order to measure the impacts of perturbations on the population distribution and diversity. The analysis of the equilibrium states relies on the connection between mean field game dynamics and replicator dynamics. We simulate our theoretical results from the data inventoried in French Guiana. Our results show that different types of disturbances modify the competitive interactions by affecting the evolutions of group densities. At the high regimes of disturbance, the canopy shade-intolerant species supplant the canopy shade-tolerant species. Tropical forest managers can thus take advantage of the competitive interactions between the functional groups to stimulate the abundance of marketable timber species. We also validate the hypothesis of maximum diversity at the intermediate disturbance levels.
Auteurs, date et publication :
Auteurs Arnaud Z. Dragicevic
Publication : Journal of Bioeconomics
Date : 2016
Volume : 18
Issue : 1
Pages : 1–15