Auteurs, date et publication :
Auteurs Laure Desutter-Grandcolas
Publication : Zootaxa
Date : 2025
Volume : 3768
Issue : 1
Pages : 1-22
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Abstract. Mapping in situ eddy covariance measurements of terrestrial land–atmosphere fluxes to the globe is a key method for diagnosing the Earth system from a data-driven perspective. We describe the first global products (called X-BASE) from a newly implemented upscaling framework, FLUXCOM-X, representing an advancement from the previous generation of FLUXCOM products in terms of flexibility and technical capabilities. The X-BASE products are comprised of estimates of CO2 net ecosystem exchange (NEE), gross primary productivity (GPP), evapotranspiration (ET), and for the first time a novel, fully data-driven global transpiration product (ETT), at high spatial (0.05°) and temporal (hourly) resolution. X-BASE estimates the global NEE at −5.75 ± 0.33 Pg C yr−1 for the period 2001–2020, showing a much higher consistency with independent atmospheric carbon cycle constraints compared to the previous versions of FLUXCOM. The improvement of global NEE was likely only possible thanks to the international effort to increase the precision and consistency of eddy covariance collection and processing pipelines, as well as to the extension of the measurements to more site years resulting in a wider coverage of bioclimatic conditions. However, X-BASE global net ecosystem exchange shows a very low interannual variability, which is common to state-of-the-art data-driven flux products and remains a scientific challenge. With 125 ± 2.1 Pg C yr−1 for the same period, X-BASE GPP is slightly higher than previous FLUXCOM estimates, mostly in temperate and boreal areas. X-BASE evapotranspiration amounts to 74.7×103 ± 0.9×103 km3 globally for the years 2001–2020 but exceeds precipitation in many dry areas, likely indicating overestimation in these regions. On average 57 % of evapotranspiration is estimated to be transpiration, in good agreement with isotope-based approaches, but higher than estimates from many land surface models. Despite considerable improvements to the previous upscaling products, many further opportunities for development exist. Pathways of exploration include methodological choices in the selection and processing of eddy covariance and satellite observations, their ingestion into the framework, and the configuration of machine learning methods. For this, the new FLUXCOM-X framework was specifically designed to have the necessary flexibility to experiment, diagnose, and converge to more accurate global flux estimates.
Auteurs, date et publication :
Auteurs Jacob A. Nelson , Sophia Walther , Fabian Gans , Basil Kraft , Ulrich Weber , Kimberly Novick , Nina Buchmann , Mirco Migliavacca , Georg Wohlfahrt , Ladislav Šigut , Andreas Ibrom , Dario Papale , Mathias Göckede , Gregory Duveiller , Alexander Knohl , Lukas Hörtnagl , Russell L. Scott , Weijie Zhang , Zayd Mahmoud Hamdi , Markus Reichstein
Publication : Biogeosciences
Date : 2024
Volume : 21
Issue : 22
Pages : 5079-5115
Catégorie(s)
#CNRS #FORET PuechabonAuteurs, date et publication :
Auteurs Olivier Bochet , Lorine Bethencourt , Alexis Dufresne , Julien Farasin , Mathieu Pédrot , Thierry Labasque , Eliot Chatton , Nicolas Lavenant , Christophe Petton , Benjamin W. Abbott , Luc Aquilina , Tanguy Le Borgne
Publication : Nature Geoscience
Date : 2025
Volume : 13
Issue : 2
Pages : 149-155
Catégorie(s)
#CNRS #EcoGenO #Université de RennesAuteurs, date et publication :
Auteurs Patrick A Jansen , Frans Bongers , Peter J Van Der Meer
Publication : Ecography
Date : 2025
Volume : 31
Issue : 1
Pages : 43-52
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Introduction Future climatic scenarios demand an increasing involvement of management for forest preservation, but little is known on how forestry practices will benefit stands in facing variation of climatic components. Objectives We investigated how selective thinning affected the response of an old Quercus ilex coppice to 6 years of throughfall reduction. Plots thinned from below (≈30% basal area removal) and unthinned plots were subject to either throughfall exclusion (TE; ≈33% throughfall reduction) or normal rainfall. Stem diameter growth, stem survival, and seed and sprout production were measured. Results TE did not have a significant effect on stem growth but it reduced the production of viable acorns. Also, in the absence of thinning, TE accelerated the mortality of small stems and stimulated the emergence of new sprouts. Thinning reduced stem mortality, enhanced growth of residual stems, and caused a profuse emission of resprouts. Thinning also increased total seed production, but the crop had a large proportion of aborted seeds, especially in those areas subject to TE. Conclusion The mere elimination of suppressed and diseased stems in abandoned Q. ilex coppice stands helps remaining trees to cope with current and future (probably longer and more intense) droughts. Potentially drier conditions might attenuate the success of thinning in producing a viable seed crop.
Auteurs, date et publication :
Auteurs Jesús Rodríguez-Calcerrada , Ignacio M. Pérez-Ramos , Jean-Marc Ourcival , Jean-Marc Limousin , Richard Joffre , Serge Rambal
Publication : Annals of Forest Science
Date : 2011
Volume : 68
Issue : 3
Pages : 575
Catégorie(s)
#CNRS #FORET PuechabonAuteurs, date et publication :
Auteurs Axel Touchard , Andreas Brust , Fernanda Caldas Cardoso , Yanni K-Y Chin , Volker Herzig , Ai-Hua Jin , Alain Dejean , Paul F Alewood , Glenn F King , Jérôme Orivel
Publication : Biochimica et Biophysica Acta (BBA)-General Subjects
Date : 2025
Volume : 1860
Issue : 11
Pages : 2553-2562
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Nicolas Dedieu , Régis Vigouroux , Philippe Cerdan , Régis Céréghino
Publication : Hydrobiologia
Date : 2025
Volume : 742
Issue : 1
Pages : 95-105
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Classifiers trained on airborne hyperspectral imagery are proficient in identifying tree species in hyperdiverse tropical rainforests. However, spectral fluctuations, influenced by intrinsic and environmental factors, such as the heterogeneity of individual crown properties and atmospheric conditions, pose challenges for large-scale mapping. This study proposes an approach to assess the instability of airborne imaging spectroscopy reflectance in response to environmental variability. Through repeated overflights of two tropical forest sites in French Guiana, we explore factors that affect the spectral similarity between dates and acquisitions. By decomposing acquisitions into subsets and analyzing different sources of variability, we analyze the stability of reflectance and various vegetation indices with respect to specific sources of variability. Factors such as the variability of the viewing and sun angles or the variability of the atmospheric state shed light on the impact of sources of spectral instability, informing processing strategies. Our experiments conclude that the environmental factors that affect the canopy reflectance the most vary according to the considered spectral domain. In the short wave infrared (SWIR) domain, solar angle variation is the main source of variability, followed by atmospheric and viewing angles. In the visible and near infrared (VNIR) domain, atmospheric variability dominates, followed by solar angle and viewing angle variabilities. Despite efforts to address these variabilities, significant spectral instability persists, highlighting the need for more robust representations and improved correction methods for reliable species-specific signatures.
Auteurs, date et publication :
Auteurs Colin Prieur , Antony Laybros , Giovanni Frati , Daniel Schläpfer , Jocelyn Chanussot , Grégoire Vincent
Publication : IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date : 2025
Volume : 17
Pages : 18751-18768
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouRésumé
Partitioning soil organic carbon (SOC) in fractions with different biogeochemical stability is useful to better understand and predict SOC dynamics and provide information related to soil health. Multiple SOC partition schemes exist, but few of them can be implemented on large sample sets and therefore be considered relevant options for soil monitoring. The well-established particulate organic carbon (POC) vs. mineral-associated organic carbon (MAOC) physical fractionation scheme is one of them. Introduced more recently, Rock-Eval® thermal analysis coupled with the PARTYSOC machine learning model can also fractionate SOC into active (Ca) and stable SOC (Cs). A debate is emerging as to which of these methods should be recommended for soil monitoring. To investigate the complementarity or redundancy of these two fractionation schemes, we compared the quantity and environmental drivers of SOC fractions obtained on an unprecedented dataset from mainland France. About 2000 topsoil samples were recovered all over the country, presenting contrasting land cover and pedoclimatic characteristics, and analysed. We found that the environmental drivers of the fractions were clearly different, the more stable MAOC and Cs fractions being mainly driven by soil characteristics, whereas land cover and climate had a greater influence on more labile POC and Ca fractions. The stable and labile SOC fractions provided by the two methods strongly differed in quantity (MAOC/Cs=1.88 ± 0.46 and POC/Ca=0.36 ± 0.17; n=843) and drivers, suggesting that they correspond to fractions with different biogeochemical stability. We argue that, at this stage, both methods can be seen as complementary and potentially relevant for soil monitoring. As future developments, we recommend comparing how they relate to indicators of soil health such as nutrient availability or soil structural stability and how their measurements can improve the accuracy of SOC dynamics models.
Auteurs, date et publication :
Auteurs Amicie A. Delahaie , Lauric Cécillon , Marija Stojanova , Samuel Abiven , Pierre Arbelet , Dominique Arrouays , François Baudin , Antonio Bispo , Line Boulonne , Claire Chenu , Jussi Heinonsalo , Claudy Jolivet , Kristiina Karhu , Manuel Martin , Lorenza Pacini , Christopher Poeplau , Céline Ratié , Pierre Roudier , Nicolas P. A. Saby , Florence Savignac
Publication : SOIL
Date : 2024
Volume : 10
Issue : 2
Pages : 795-812
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENSRésumé
Although animal dispersal is known to play key roles in ecological and evolutionary processes such as colonization, population extinction and local adaptation, little is known about its genetic basis, particularly in vertebrates. Untapping the genetic basis of dispersal should deepen our understanding of how dispersal behaviour evolves, the molecular mechanisms that regulate it and link it to other phenotypic aspects in order to form the so-called dispersal syndromes. Here, we comprehensively combined quantitative genetics, genome-wide sequencing and transcriptome sequencing to investigate the genetic basis of natal dispersal in a known ecological and evolutionary model of vertebrate dispersal: the common lizard, Zootoca vivipara. Our study supports the heritability of dispersal in semi-natural populations, with less variation attributable to maternal and natal environment effects. In addition, we found an association between natal dispersal and both variation in the carbonic anhydrase (CA10) gene, and in the expression of several genes (TGFB2, SLC6A4, NOS1) involved in central nervous system functioning. These findings suggest that neurotransmitters (serotonin and nitric oxide) are involved in the regulation of dispersal and shaping dispersal syndromes. Several genes from the circadian clock (CRY2, KCTD21) were also differentially expressed between disperser and resident lizards, supporting that the circadian rhythm, known to be involved in long-distance migration in other taxa, might affect dispersal as well. Since neuronal and circadian pathways are relatively well conserved across vertebrates, our results are likely to be generalisable, and we therefore encourage future studies to further investigate the role of these pathways in shaping dispersal in vertebrates.
Auteurs, date et publication :
Auteurs Luis M. San-Jose , Elvire Bestion , Félix Pellerin , Murielle Richard , Lucie Di Gesu , Jordi Salmona , Laurane Winandy , Delphine Legrand , Camille Bonneaud , Olivier Guillaume , Olivier Calvez , Kathryn R. Elmer , Andrey A. Yurchenko , Hans Recknagel , Jean Clobert , Julien Cote
Publication : Molecular Ecology
Date : 2025
Volume : 32
Issue : 12
Pages : 3060-3075