Auteurs, date et publication :
Auteurs J. F. Le Galliard , J. M. Guarini , F. Gaill
Date : 2025
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENS #PLANAQUARésumé
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 ParacouAuteurs, date et publication :
Auteurs J. C. Clement , T. M. Robson , R. Guillemin , P. Saccone , J. Lochet , S. Aubert , S. Lavorel
Publication : Biogeochemistry
Date : 2025
Volume : 108
Issue : 1-3
Pages : 297-315
Catégorie(s)
#CNRS #Lautaret #UGARésumé
DNA metabarcoding refers to the DNA-based identification of multiple species from a single complex and degraded environmental sample. We developed new sampling and extraction protocols suitable for DNA metabarcoding analyses targeting soil extracellular DNA. The proposed sampling protocol has been designed to reduce, as much as possible, the influence of local heterogeneity by processing a large amount of soil resulting from the mixing of many different cores. The DNA extraction is based on the use of saturated phosphate buffer. The sampling and extraction protocols were validated first by analysing plant DNA from a set of 12 plots corresponding to four plant communities in alpine meadows, and, second, by conducting pilot experiments on fungi and earthworms. The results of the validation experiments clearly demonstrated that sound biological information can be retrieved when following these sampling and extraction procedures. Such a protocol can be implemented at any time of the year without any preliminary knowledge of specific types of organisms during the sampling. It offers the opportunity to analyse all groups of organisms using a single sampling ⁄ extraction procedure and opens the possibility to fully standardize biodiversity surveys.
Auteurs, date et publication :
Auteurs Pierre Taberlet , Sophie M. Prud’Homme , Etienne Campione , Julien Roy , Christian Miquel , Wasim Shehzad , Ludovic Gielly , Delphine Rioux , Philippe Choler , Jean-Christophe Clément , Christelle Melodelima , François Pompanon , Eric Coissac
Publication : Molecular Ecology
Date : 2025
Volume : 21
Issue : 8
Pages : 1816-1820
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Bacteria play a major role in environmental processes. However, the spatial and seasonal variations and environmental impact factors on different bacterial groups have been poorly studied. In the present study, we compared the spatial and seasonal variations of two bacterial groups (Acidobacteria, Actinobacteria) from Early Snow Melt and Late Snow Melt locations in Alpine tundra by CE-SSCP method. We examined correlation between the two groups and environmental factors. The results revealed that pH of soil is the
essential factor for structure of two bacterial groups. The SSCP pattern of Acidobacteria is very similar to the overall bacterial communities in our previous study, while both bacterial communities are highly influenced by seasonal variations with an independent pattern
Auteurs, date et publication :
Auteurs Bahar Shahnavaz , Roberto A. Geremia
Publication : Journal of Cell and Molecular Research
Date : 2025
Volume : 4
Issue : 1
Pages : 28-33
Catégorie(s)
#⛔ No DOI found #CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Eric Marcon , Bruno Hérault , Christopher Baraloto , Gabriel Lang
Publication : Oikos
Date : 2012
Volume : 121
Issue : 4
Pages : 516–522
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouAuteurs, date et publication :
Auteurs Flore Viard-Crétat , Florence Baptist , Hanna Secher-Fromell , Christiane Gallet
Publication : Plant Ecology
Date : 2025
Volume : 213
Issue : 12
Pages : 1963-1973
Catégorie(s)
#CNRS #Lautaret #UGARésumé
The congruence of ecosystem services (ESs) and the congruence of ES ‘hotspots’ and ‘hotspots’ of biodiversity are receiving growing interest. The thresholds used in such analyses to assess the ES presence vary widely but their effects have not been questioned. We provide an analysis of the effect of the choice of these thresholds on the overlap among ESs and the distribution of hotspots. Focusing on grasslands from the Central French Alps, we first systematically varied thresholds for three ESs (agronomic, regulation and aesthetic values), then considered triplets of thresholds representing three contrasted stakeholder perspectives on the importance of each of these services. Overlap between ESs depended strongly on thresholds. The extent of ES hotspots and their overlap with biodiversity hotspots varied widely across perspectives. Coldspots never overlapped with areas of interest for biodiversity, whatever be the perspective. Overlap was less informative than the diagnostic test of the capacity of individual ESs to capture each other's distribution. Agronomic value poorly captured other ESs. Biodiversity was well captured by regulation and aesthetic values, but poorly captured by service hotspots. This analysis emphasizes the importance of accounting for varying stakeholders' expectations in ES hotspot assessments.
Auteurs, date et publication :
Auteurs Pierre Gos , Sandra Lavorel
Publication : International Journal of Biodiversity Science, Ecosystem Services & Management
Date : 2012
Volume : 8
Issue : 1-2
Pages : 93-106
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Here we show that Daceton armigerum, an arboreal myrmicine ant whose workers are equipped with hypertrophied trap-jaw mandibles, is characterized by a set of unexpected biological traits including colony size, aggressiveness, trophobiosis and hunting behavior. The size of one colony has been evaluated at ca. 952,000 individuals. Intra- and interspecific aggressiveness were tested and an equiprobable null model used to show how D. armigerum colonies react vis-à-vis other arboreal ant species with large colonies; it happens that D. armigerum can share trees with certain of these species. As they hunt by sight, workers occupy their hunting areas only during the daytime, but stay on chemical trails between nests at night so that the center of their home range is occupied 24 hours a day. Workers tend different Hemiptera taxa (i.e., Coccidae, Pseudococcidae, Membracidae and Aethalionidae). Through group-hunting, short-range recruitment and spread-eagling prey, workers can capture a wide range of prey (up to 94.12 times the mean weight of foraging workers).
Auteurs, date et publication :
Auteurs Alain Dejean , Jacques H. C. Delabie , Bruno Corbara , Fréderic Azémar , Sarah Groc , Jérôme Orivel , Maurice Leponce , William Hughes
Publication : Plos One
Date : 2012
Volume : 7
Issue : 5
Pages : e37683
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouRésumé
Dispersal of organisms generates gene flow between populations. Identifying factors that influence dispersal will help predict how species will cope with rapid environmental change. We developed an innovative infrastructure, the Metatron, composed of 48 interconnected patches, designed for the study of terrestrial organism movement as a model for dispersal. Corridors between patches can be flexibly open or closed. Temperature, humidity and illuminance can be independently controlled within each patch. The modularity and adaptability of the Metatron provide the opportunity for robust experimental design for the study of 'meta-systems'. We describe a pilot experiment on populations of the butterfly Pieris brassicae and the lizard Zootoca vivipara in the Metatron. Both species survived and showed both disperser and resident phenotypes. The Metatron offers the opportunity to test theoretical models in spatial ecology.
Auteurs, date et publication :
Auteurs Delphine Legrand , Olivier Guillaume , Michel Baguette , Julien Cote , Audrey Trochet , Olivier Calvez , Susanne Zajitschek , Felix Zajitschek , Jane Lecomte , Quentin Bénard , Jean-François Le Galliard , Jean Clobert
Publication : Nature Methods
Date : 2012
Volume : 9
Issue : 8
Pages : 828-833