Résumé
The aim of this study, which was conducted in French Guiana, was to characterize the karyotypes of nine ant species belonging to the genera Anochetus, Apterostigma, Cyphomyrmex, Camponotus, Gigantiops, Myrmicocrypta, Odontomachus and Pseudomyrmex, and to compare them with published data. We present the first descriptions of the karyotypes of Gigantiops destructor (Fabricius), an endemic Formicinae of the Amazonian region, which is the only living species in the tribe Gigantiopini, and of a species from the poorly-known cryptic genus Myrmicocrypta, which belongs to the Myrmicinae tribe Attini.
Auteurs, date et publication :
Auteurs Cléa S.F. Mariano , Igor da Silva Santos , Sarah Groc , Céline Leroy , Pierre Jean Malé , Mario X. Ruiz-González , Philippe Cerdan , Alain Dejean , Jacques H.C. Delabie
Publication : Annales de la Societe Entomologique de France
Date : 2025
Volume : 47
Issue : 1-2
Pages : 140–146
Catégorie(s)
#CIRAD #FORET ParacouRésumé
Quantifying and monitoring the structure and degradation of tropical forests over regional to global scales is gaining increasing scientific and societal importance. Reliable automated methods are only beginning to appear; for instance, through the recent development of textural approaches applied to high resolution optical imagery. In particular, the Fourier Transform Textural Ordination (FOTO) method shows some potential to provide non-saturating estimates of tropical forest structure, including for large scale applications. However, we need to understand more precisely how canopy structure interacts with physical signals (light) to produce a given texture, notably to assess the method's sensitivity to varying sun-view acquisition conditions. In this study, we take advantage of the detailed description of canopy topography provided by airborne small footprint LiDAR data acquired over the Paracou forest experimental station in French Guiana. Using hillshade models and a range of sun-view angles identical to the actual parameter distributions found for Quickbird™ images over the Amazon, we study noise and bias in texture estimation induced by the changing configurations. We introduce the bidirectional texture function, which summarizes these effects, and in particular the existence of a textural ‘hot spot', similar to a well-known feature of bidirectional reflectance studies. For texture, this effect implies that coarseness decreases in configurations for which shadows are concealed to the observer. We also propose a method, termed partitioned standardization, that allows mitigating acquisition effects and discuss the potential for an operational use of VHR optical imagery and the FOTO method in the current context of international decisions to reduce CO2 emissions due to deforestation and forest degradation.
Auteurs, date et publication :
Auteurs Nicolas Barbier , Christophe Proisy , Cédric Véga , Daniel Sabatier , Pierre Couteron
Publication : Remote Sensing of Environment
Date : 2011
Volume : 115
Issue : 1
Pages : 167–179
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Grégoire Vincent , Jean-François Molino , Lucile Marescot , Karim Barkaoui , Daniel Sabatier , Vincent Freycon , Jean Baptiste Roelens
Publication : Annals of Forest Science
Date : 2011
Volume : 68
Issue : 2
Pages : 357–370
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs J. Paul McLean , Tian Zhang , Sandrine Bardet , Jacques Beauchêne , Anne Thibaut , Bruno Clair , Bernard Thibaut
Publication : Annals of Forest Science
Date : 2011
Volume : 68
Issue : 4
Pages : 681–688
Catégorie(s)
#CIRAD #FORET ParacouAuteurs, date et publication :
Auteurs Clément Stahl , Benoit Burban , Jean-Yves Goret , Damien Bonal
Publication : Annals of Forest Science
Date : 2011
Volume : 68
Issue : 4
Pages : 771–782
Catégorie(s)
#CIRAD #FORET ParacouRésumé
The TropiSAR campaign has been conducted in August 2009 in French Guiana with the ONERA airborne radar system SETHI. The main objective of this campaign was to collect data to support the Phase A of the 7th Earth Explorer candidate mission, BIOMASS. Several specific questions needed to be addressed to consolidate the mission concept following the Phase 0 studies, and the data collection strategy was constructed accordingly. More specifically, a tropical forest data set was required in order to provide test data for the evaluation of the foreseen inversion algorithms and data products. The paper provides a description of the resulting data set which is now available through the European Space Agency website under the airborne campaign link. First results from the TropiSAR database analysis are presented with two in-depth analyses about both the temporal radiometric variation and temporal coherence at P-band. The temporal variations of the backscatter values are less than 0.5 dB throughout the campaign, and the coherence values are observed to stay high even after 22 days. These results are essential for the BIOMASS mission. The observed temporal stability of the backscatter is a good indicator of the expected robustness of the biomass estimation in tropical forests, from cross-polarized backscatter values as regarding environmental changes such as soil moisture. The high temporal coherence observed after a 22-day period is a prerequisite for SAR Polarimetric Interferometry and Tomographic applications in a single satellite configuration. The conclusion then summarizes the paper and identifies the next steps in the analysis.
Auteurs, date et publication :
Auteurs Pascale C. Dubois-Fernandez , Thuy Le Toan , Sandrine Daniel , Hélène Oriot , Jerôme Chave , Lilian Blanc , Ludovic Villard , Malcolm W.J. Davidson , Michel Petit
Publication : IEEE Transactions on Geoscience and Remote Sensing
Date : 2025
Volume : 50
Issue : 8
Pages : 3228–3241
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouRésumé
The present work aimed to evaluate the seasonal increment in diameter of Eucalyptus grandis trees for 24 months and its relationship with the climatic variables and fertilization with nitrogen and with sewer mud. The trees were planted in the spacing of 3 x 2 m and fertilized with nitrogen (planting, 6, 12, 18 months) and sewer mud (planting and 8 months). 20 trees were selected by treatment according witch the distribution of basal area and installed dendrometer bands at a 1.3 meter. The results showed a clear effect of the climatic variables on the seasonal increment in diameter of trees, being observed a delay period (lag) of 28 days for the answer of the trees in relation to the climatic variables. Regading to the fertilization effect, it was observed that the increment of trunk diameter was higher in the eucalyptus trees with organic in relation to mineral fertilization with nitrogen. (Résumé d'auteur)
Auteurs, date et publication :
Auteurs Carlos Roberto Sette Junior , Mario Tomazello Filho , José Luis Lousada , Jean-Paul Laclau
Publication : Ciência Florestal
Date : 2025
Volume : 22
Issue : 4
Pages : 771-783
Catégorie(s)
#CIRAD #FORET Itatinga #INRAEAuteurs, date et publication :
Auteurs C.-R. Sette Jr , M.-T. Filho , J.-L. Lousada , J.-P. Laclau
Publication : Ciencias Florestal, Santa Maria
Date : 2025
Volume : 22
Pages : 771-783
Catégorie(s)
#CIRAD #FORET Itatinga #INRAEAuteurs, date et publication :
Auteurs O.-C. Campoe , J.-L. Stape , J.-P. Laclau , C. Marsden , Y. Nouvellon
Publication : Tree Physiology Advance Access
Date : 2025
Volume : 00
Pages : 1-11
Catégorie(s)
#CIRAD #FORET Itatinga #INRAEAuteurs, date et publication :
Auteurs Eric Marcon , Bruno Hérault , Christopher Baraloto , Gabriel Lang
Publication : Oikos
Date : 2012
Volume : 121
Issue : 4
Pages : 516–522