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Dans la peau des premiers paysans français » : sur France 5, les premiers agriculteurs de France
No full textArticle de presse présentant le documentaire diffusé sur France 5article de presse de Grégory Marin sur le documentaire dans lequel figure Caroline Pon
High-Resolution Chloroplast SNV Profiling of 409 Grapevine (Vitis vinifera L.) Cultivars Using Whole-Genome Shotgun Sequencing
No full textData Availability Statement: The datasets generated and analyzed during the current study are available in the NCBI Sequence Read Archive (SRA) repository (https://www.ncbi.nlm.nih.gov/sra accessed on 1 December 2025) under the BioProject accession number PRJNA1366753. The data are not officially released yet; the reviewer link for BioProject and associated SRA metadata are available at https://dataview.ncbi.nlm.nih.gov/object/PRJNA1366753?reviewer=pql2i9lp7e4kshurjbrel2nouv accessed on 21 December 2025) in read-only format.International audienceThe grapevine (Vitis vinifera L.) is one of the most important horticultural crops, with thousands of varieties cultivated worldwide. In this study, we analyzed chloroplast SNV markers using a whole-genome shotgun sequencing approach to investigate the genetic diversity and phylogeny of 409 cultivated V. vinifera accessions originating from nine countries across Southeast and Central Europe, as well as a heterogeneous set of additional accessions maintained by INRAE. Shotgun sequencing allowed high coverage, enabling the detection of 93 SNVs across 24 chloroplast genes, including 11 non-synonymous variants. The ycf1 gene showed the highest variability, consistent with its role in species differentiation. Haplotype analysis revealed 102 distinct haplotypes, with clear geographic structuring: ATT predominated in the eastern Mediterranean, ATA in western Europe, and GTA mainly in a heterogeneous group of varieties from a French collection. To validate the shotgun approach, seven SNV markers were analyzed using target capture sequencing, confirming the accuracy of detected variants with only minimal discrepancies, which is mostly attributable to homopolymeric regions and low-frequency alleles. Phylogenetic analyses using both trees and networks delineated three major haplotype clusters, reflecting human-mediated dispersal of grapevine cultivars through historical viticultural practices. This study represents the largest chloroplast genome analysis of cultivated V. vinifera to</div
Evaluating multi-source uncertainties in marine biogeochemical modelling: a case study on the Eco3M-Med model
No full textInternational audienceCoupled with ocean and atmosphere models, marine biogeochemical models are key tools for studying marine ecosystems, in particular the dynamics of planktonic food webs and biogeochemical cycles. They also provide possible long-term trajectories of the evolution of marine ecosystems under SSP–RCP scenarios. At the same time, they provide forcing in terms of available prey for high trophic level models and for fisheries dynamics. The evolution of biogeochemical models from early NPZD-type versions to more complex structures that incorporate plankton functional groups and variable stoichiometry within organisms has led to a rapid increase in the number of state variables and parameters, as well as to higher computational cost. This limits the ability to explore a large number of scenarios and to quantify model uncertainties, given the large number of ensemble simulations required.In this study, we propose a framework for “application-targeted model simplification” and for “assessing the parameter uncertainties introduced before and after model simplification.” The simplification is carried out using a semi-automatic iterative simplification framework, which we apply to the most recent version of the biogeochemical model Eco3M-MED in a 1DV configuration. We first perform a local sensitivity analysis by perturbing only a subset of independent parameters and by accounting for the dependencies between parameters, which allows us to identify parameters and processes with low impact on the targeted model outputs. We then simplify either the model structure or the identified processes. At each step, the fidelity of the simplified model relative to the reference model is evaluated using the Kling–Gupta Efficiency metric, and we ultimately obtain two simplified models corresponding to two different simplification objectives.After obtaining the simplified models, we perform a parameter uncertainty analysis to test whether simplification significantly changes the uncertainty range of key marine ecosystem indicators. Specifically, we use the Sobol’ sequence to generate 512 parameter vectors (selecting only the independent parameters common to the three models), and then run ensemble simulations for the reference model and for two simplified models. This strategy allows differences to be mainly attributed to structural changes in the model rather than to sampling effects. For several ecosystem indicators, we compare the ensemble mean, standard deviation, and quantiles, and we propose an uncertainty inflation index to quantify the change in uncertainty of the simplified model relative to the reference model
Substantial contribution of trees outside forests to above-ground carbon across China
No full textInternational audienceAccurately quantifying canopy height and above-ground carbon across diverse land-cover types is crucial for understanding carbon storage dynamics and guiding climate-mitigation strategies. Yet existing maps often overlook non-forest ecosystems. Here we present a deep learning framework based on a U-Net architecture that combines radar, optical, elevation and slope data to produce a 10 m canopy height map across China. The model is trained with laser measurements from NASA's GEDI mission validated using unmanned aerial vehicle lidar data ( MAE = 2.39 m ). We then estimate the above-ground biomass and carbon from these heights using a Random Forest model ( MAE = 37.71 Mg ha-1 ). By deriving carbon from canopy height, we take advantage of U-Net's ability to capture trees in non-forest ecosystems such as croplands, grasslands and urban areas. Our nationwide 30 m carbon map reveals that trees outside forests contribute 20.8-32.9% of China's above-ground carbon in 2019 (3.62-5.72 Pg C), underscoring their importance
Seasonal collection of in situ optical and thermal images dataset and meteorological measurements over an Indian semi-arid rice crop
No full textInternational audienc
Restorative selective cutting maintains tree-related microhabitats in mixed oak-dominated forests
No full textInternational audienceMixed-species forests in southern Fennoscandia have been subject to deforestation and degradation by land-use changes and intensive forest management. Given the importance of mixed forests for biodiversity and climate change adaptation, it is crucial to conserve remaining patches and manage them in ways that sustain or restore their associated habitats for biodiversity. We evaluated whether restorative selective cutting contributes to forest diversity by fostering tree-related microhabitats (TreMs). We inventoried TreMs on 2346 trees from 42 mixed oak-dominated forests in Sweden and Norway and compared the composition and diversity of TreMs at the plot and tree scale in selective cutting stands (25 % basal area removed 7 or 21 years ago, cutting conifers preferably and opening the space around large deciduous trees) and control stands (no recent intervention). At the tree scale, higher TreM diversity was observed on trees from selective cutting plots, but only in stands cut 7 years ago. Moreover, selective cutting had a positive effect on the epiphyte group that includes bryophytes and lichens. At the plot scale, however, there was no difference in TreM diversity between treatments. At both scales, diameter at breast height was the prevalent factor that positively affected TreM diversity, together with tree species and living status: conifers had a negative effect on TreMs, whereas higher proportion of standing dead trees explained higher TreM diversity. Our results indicate that selective cutting with clear ecological-restoration goals is a favourable approach to maintaining TreMs in mixed forests of hemiboreal regions, although its long-term implications need further research
Increasing pathlength resistance and within-canopy shading similarly attenuate transpiration in accruing collocated stands of five pine species
No full textInternational audienceIn forested regions dominated by management for timber production, quantifying biosphere-atmosphere exchange of mass and energy over accruing forests is essential for accurate estimates of water yield and carbon sequestration. Environmental conditions drive transpiration rates, a dominant portion of evapotranspiration in forests. However, differences among species and stand characteristics set limits to canopy-scale transpiration. Both canopy leaf area and height increase rapidly as stands develop, increasing within-canopy shading and pathlength resistance of water flow to leaves, respectively. Understanding these dynamics is important to accurately quantifying water use and informing forest and watershed management strategies. We measured sap-flux in five co-occurring Southeastern U.S. pine species for nearly five years at a common garden site on a sandy loam soil in the Duke Forest, Durham, NC. Despite significant differences among these species in crown architecture, sapwood area per unit of ground area, and canopy leaf area, their leaf-scale transpiration rate displayed similar sensitivity to vapor pressure deficit. Sensitivity to soil moisture decline varied among species. Under standard conditions, leaf and canopy transpiration declined with increased path-length resistance (greater height), ostensibly dominating over the impact of within-canopy shading (higher leaf area). The results suggest that transpiration of these pine species on sandy soil can be approximated assuming a similar physiology, but that accurately estimating it during the rapid phase of stand development requires not only accounting for the effect of increasing canopy leaf area, but also for increasing hydraulic resistance with tree height, especially in open or thinned stands
Evolution of the V/Ni Ratio in Response to IMO Regulation-Induced Fuel Shifts and Scrubber Use
No full textInternational audienc
A Model of Economic Growth and Biodiversity
No full textThis paper develops a macroeconomic growth model that integrates biodiversity as a productive input via its role in water regulation, a key ecosystem service. Land-use decisions drive biodiversity loss, which reduces water availability and, hence, productivity across all sectors.Using global input-output data, I estimate production functions that incorporate water and land as environmental inputs. Quantitatively, internalizing biodiversity's contribution to water supply leads to a significant reduction in land conversion, with about half of this optimal reduction attributable to the impact on industrial and service sectors, not just agriculture. Although GDP slightly declines, long-term welfare improves thanks to higher consumption and a more sustainable reliance on natural capital. The reallocation from produced to natural capital lowers investment requirements. The framework highlights biodiversity's macroeconomic value and its relevance for optimal land-use policy.</p
Drought preceding rain events drives shifts in phytoplankton composition and metabolome in Lake Aydat (France) revealing molecular strategies
No full textInternational audienceGlobal change is expected to increase cyanobacterial dominance and cyanotoxin production. However, cyanobacterial responses to meteorological events remain uncertain due to limited integrative approaches. Eco-metabolomics offers a promising tool to investigate drivers of phytoplankton successions and metabolite production. We investigated the spatio-temporal dynamics of phytoplankton and their metabolomes in relation to local meteorological conditions in Lake Aydat (France) during summer 2021, sampling both near the Veyre inflow and at the lake center. High-resolution mass spectrometry, combined with phytoplankton biovolumes and physicochemical parameters, revealed two distinct metabolomic fingerprints positively correlated with phytoplankton composition. The first metabolome is composed of mainly lipids and positively correlated with the presence of diatoms throughout the summer until the end of the drought. In contrast, the second metabolome is correlated with the presence of Dolichospermum , that occurrs after a 22-day period without rain and when there is a low nitrate concentration ( NO - 3 ∼ 0.4 mg.l -1 ). Interestingly, despite similar phytoplankton composition across sites, significant higher abundance of cyanopeptides are detected close to the river inflow during the second rain period, likely driven by higher nutrient inputs and warmer waters compared to the lake center. Overall, these findings demonstrate that fine-scale spatial monitoring can reveal distinct ecometabolomic niches, separated by only 200 m