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Plant Translocations in France: Identifying Gaps between Knowledge, Practice and Perception by Conservation Actors
No full textInternational audienceIn the current context of global changes, threatened flora is declining and homogenising at the expense of rare and protected species. Among conservation biology and ecological restoration techniques, plant translocation is one of the recommendations increasingly used. However, translocation remains risky and is recommended as a last resort to conserve protected flora in land use planning. Furthermore, it raises ethical questions partly linked to genetic processes. In this context, we studied how plant translocations are perceived by conservation actors in France, including their genetic aspects. The analysis of translocation perception complements that of feedback on concrete translocation operations and allows us to provide a qualitative assessment of current practices. We have adopted an interdisciplinary approach to survey different types of actors in nature conservation, involved or not in at least one stage of translocation operations (preparation, implementation and monitoring). Three main types of translocation perception divide our sample quite strongly (50% favourable/ 45% unfavourable/ 5% undecided). Surprisingly, their professional activity or the level of involvement in such an operation have no influence on their opinion on translocation, nor on the proposals of alternative measures. Only 15% of the actors involved in translocations used genetic data at least once. To conclude, it would be necessary to promote the sharing of feedback from past experiences. This would allow an up-to-date list of species unacceptable for translocation. Comparing the results of different protocols and implementation conditions for the same species or group should improve overall translocation success rates
Une nouvelle étude décortique l'origine des mutations génétiques PUBLIÉ LE 2 MARS 2024 À 16:00
No full textInternational audienceÀ l'occasion de la parution dans la revue PNAS de notre article scientifique sur les origines des mutations héritables chez deux espèces d'arbres tropicaux de la forêt guyanaise, plongeons dans le Votre abonnement Science & Vie à 2€ seulement ! J'en profite X ABONNEZ-VOUS × 9/24/24, 8:54 AM Une nouvelle étude décortique l'origine des mutations génétiques https://www.science-et-vie.com/nature-et-environnement/une-nouvelle-etude-decortique-lorigine-des-mutations-genetiques-127937.html 1/12 par Taboolaprocessus fascinant de la mutation. Les mutations sont des modifications accidentelles de l'ADN.Bien qu'accidentelles, les mutations génétiques sont essentielles. En ce sens, la mutation peut même être considérée comme le terreau de l'évolution. Toutes ces modifications contribuent à accroître la diversité génétique des espèces.</div
Forest composition and density shaped long-term fire regimes and catchment-lake interactions in the temperate-mixed mountain forests of Central Europe
No full textInternational audienc
Greater aperture counteracts effects of reduced stomatal density on water use efficiency: a case study on sugarcane and meta-analysis
No full textInternational audienceStomata regulate CO 2 and water vapor exchange between leaves and the atmosphere. Stomata are a target for engineering to improve crop intrinsic water use efficiency (iWUE). One example is by expressing genes that lower stomatal density (SD) and reduce stomatal conductance (g sw ). However, the quantitative relationship between reduced SD, g sw , and the mechanisms underlying it is poorly understood. We addressed this knowledge gap using low-SD sugarcane (Saccharum spp. hybrid) as a case study alongside a meta-analysis of data from 10 species. Transgenic expression of EPIDERMAL PATTERNING FACTOR 2 from Sorghum bicolor (SbEPF2) in sugarcane reduced SD by 26-38% but did not affect g sw compared with the wild type. Further, no changes occurred in stomatal complex size or proxies for photosynthetic capacity. Measurements of gas exchange at low CO 2 concentrations that promote complete stomatal opening to normalize aperture size between genotypes were combined with modeling of maximum g sw from anatomical data. These data suggest that increased stomatal aperture is the only possible explanation for maintaining g sw when SD is reduced. Meta-analysis across C 3 dicots, C 3 monocots, and C 4 monocots revealed that engineered reductions in SD are strongly correlated with lower g sw (r 2 =0.60-0.98), but this response is damped relative to the change in anatomy.</div
Extracellular vesicles from olive wastewater and pomace by‐products: Isolation, characterization of their lipid and phenolic profiles, and evaluation of their radical scavenging activity
No full textInternational audienceExtracellular vesicles (EVs) are nanoscopic structures that are involved in intercellular communication. Recent works have highlighted the existence of these assemblies in several plants and shown that they are able to vectorize hydrophilic and lipophilic molecules. In this study, we have isolated EVs from the two main olive oil by-products (wastewaters [WWs] and pomace) by differential centrifugation/ultracentrifugation and have characterized their main physicochemical properties (size, charge, multimolecular structure, lipid and phenolic contents) and radical scavenging activity. Lipid content in EV fractions was 3.4 (0.2) % (% dry material) for WWEVs and 7.7 (0.3) % and 5.9 (0.9) % for EVs, respectively, from plurivarietal or monovarietal pomaces. Polar lipids represented around 49% of total lipids, and their profiles were globally similar in all EVs. Phosphatidylcholine and phosphatidic acid were the more abundant molecules. Their phenolic contents ranged from 2.1 to 4.6 mg hydroxytyrosol (HT) eq g−1 of raw material, with HT, oleuropein, and verbascoside being among the most abundant. Transmission electron cryomicroscopy showed the presence of spherical vesicles delimited by a single bilayer of amphiphilic lipids. Finally, the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of EVs was high and depended on their original by-product type.Practical Application: Recent works have highlighted the existence of extracellular vesicles in several plants and shown that they are able to vectorize hydrophilic and lipophilic molecules. Herein, we have isolated and provided a chemical characterization of such vesicles from olive wastewater and pomace. Results showed that these vesicles are rich in the phenolic compounds that are generally found in olives and that the potential radical scavenging activity of extracellular vesicles from olive could be valorized as new antioxidants for the food or cosmetic sectors
À la recherche de l'écologie temporelle. Vivre des temps libérés dans les collectifs néo-paysans autogérés : une analyse anthropologique [Compte-rendu de lecture]
No full textNational audienceRecension de l'ouvrage :Madeleine Sallustio, À la recherche de l'écologie temporelle. Vivre des temps libérés dans les collectifs néo-paysans autogérés : une analyse anthropologique, Rennes, Presses Universitaires de Rennes, 2022, 441 p
Detecting ecological signatures of long-term human activity across an elevational gradient in the Šumava Mountains, Central Europe
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Apport du lidar spatial pour le développement de méthodes d’inventaire forestier multisource adaptées à la gestion durable des forêts dans un contexte de changement global
No full textThe thesis focuses on the contribution of spaceborne lidar to the development of Multisource Forest Inventory (MFI) methods. In France, the National Forest Inventory (NFI) method addresses the requirements of public policies at regional and national levels. However, on smaller territories, precision is often insufficient to meet the needs of management activities. MFI methods better address these needs by combining inventory data with remote sensing data. This thesis aims to improve NFI accuracy at sub-regional to local scales by integrating data from the spaceborne lidar GEDI into multisource approaches.Unfortunately, this integration is complicated due to the lack of spatial correspondence between field samples (inventory plots) and GEDI footprints. Additionally, GEDI data are poorly georeferenced, making them difficult to integrate into certain MFI approaches. This thesis focuses on these issues and is divided into three main parts.As a first step, a method for improving GEDI georeferencing, based on a high-resolution reference digital elevation model (DEM) was developed. This method compares, for a series of positions around the location indicated in the GEDI products, the ground elevations of the GEDI footprints with those of the reference DEM, generating an errormapaccording to X and Y offsets. Using a flowaccumulation algorithm on this errormap, an improved position minimizing the distance from the DEM is proposed for each GEDI footprint.Next, two approaches for using GEDI data with NFI data were developed. The study sites are located in the Vosges and use ∼ 500NFI plots and over 100,000 GEDI footprints.The first approach is a double sampling for post-stratification (DSPS) approach, based on common variables between GEDI and NFI, without requiring spatial correspondence of the two data sources. DSPS approaches are generally based on probabilistic data samples, which is not a priori the case for GEDI’s samplingpattern. Thus, a preliminary analysis was required to understand the characteristics of the spatial distribution of the GEDI sample. The relevance of the chosen common variable, i.e. the maximum tree height, wasalso verified. Compared with estimates based only on NFI data, the DSPS approach improved the variance of growing stock volume estimates by up to 56%.The second approach is based on a link between GEDI data and NFI data, established indirectly by using spatially exhaustive data sources, the Sentinel-2 and Sentinel-1 images. To establish the model linking the different data sources, we chose to use the k-nearest neighbor (kNN) method combined with bagging (bootstrap aggregation). The aim is to propagate information from field plots to GEDI footprints in order to "densify" NFI plots by taking advantage of GEDI forest structure measurements, which are well correlated with the forest attributes of interest (e.g. growing stock volume). First, for each NFI plot, we looked for the GEDI footprints with the characteristics of the Sentinel link variables, supplemented or not with a height link variable, that are closest to those of the NFI point. Using a kNN-bagging approach, the set of GEDI variables is therefore estimated for each NFI plot. Next, a regression model is established by kNN-bagging to estimate the volume using the best predicted GEDI variables from the previous step and the Sentinel variables. Thevolume is estimated at the level of all GEDI footprints. The strategy supplemented by a height link variable performed best and reached a coefficient of determination of 58%. Subsequently, using the resulting densesample of volume plots, standard methods for small area estimation (scale of the municipality or district) or high-resolution volume mapping can be implemented.En France, la méthode de l’Inventaire Forestier National (IFN) répond à des besoins de politique publique aux échelles nationales et régionales. Sur des plus petits territoires, la précision est souvent insuffisante pour répondre aux besoins des activités de gestion. Les méthodes IFM peuvent répondre à ce besoin en combinant des données d’inventaire et des données de télédétection. La thèse vise à améliorer la précision de l’IFN à des échelles subrégionales à locales en intégrant les données du système lidar spatial GEDI dans des approches multisources.Cependant, cette intégration se heurte à un verrou majeur, lié à l’absence de correspondance spatiale entre les échantillons sur le terrain (placettes d’inventaire) et les empreintes GEDI. Par ailleurs, les données GEDI sont mal géoréférencées, ce qui complexifie leur intégration dans certaines approches d’IFM. Cette thèse se concentre sur ces problématiques et est divisée en trois parties principales.Premièrement, une méthode d’amélioration du géoréférencement de GEDI a été développée en se basant uniquement sur un modèle numérique de terrain (MNT) de référence à haute résolution spatiale. Cette méthode compare, pour une série de positions autour de la localisation indiquée dans les produits GEDI,les élévations du terrain des empreintes GEDI avec celles du MNT de référence, générant une carte d’écarts en fonction des décalages en X et Y. En utilisant un algorithme d’accumulation de flux sur cette carte, une position améliorée qui minimise l’écart avec le MNT est proposée pour chaque empreinte GEDI.Ensuite, deux approches d’utilisation des données GEDI avec les données de l’IFN ont été élaborées. Les zones d’étude se situent dans les Vosges et utilisent environ 500 placettes IFN et plus de 100,000 empreintes GEDI. La première approche est une approche d’échantillonnage double pour la post-stratification (DSPS), reposant sur des variables communes entre GEDI et IFN, sans nécessiter de coïncidence spatiale entre les deux sources de données. Les approches DSPS reposent généralement sur des échantillons de donnéesprobabilistes, ce qui n’est a priori pas le cas de l’échantillonnage de GEDI. Ainsi, une analyse préliminaire a été nécessaire pour comprendre les caractéristiques spécifiques de l’échantillon des mesures GEDI. La pertinence de la variable commune choisie, la hauteur maximale des arbres, a également été vérifiée. Par rapport aux estimations basées uniquement sur les données IFN, l’approche DSPS a amélioré la variance des estimations de volume de 56%.La deuxième approche utilise un lien entre données GEDI et données IFN établi indirectement en utilisant les images Sentinel-2 et Sentinel-1, avec la méthode des k-plus proches voisins (kNN) combinée avec du bagging (bootstrap aggregation). Il s’agit de propager l’information des placettes terrain au niveau des empreintes GEDI pour densifier les placettes IFN en tirant parti des mesures de structure forestière GEDI,bien corrélées aux attributs forestiers d’intérêt (ex. le volume de bois). Tout d’abord, en utilisant un kNNbagging,oncherche pour chaque placette IFN les empreintes GEDI ayant les caractéristiques les plus proches de celles du point IFN pour des variables de lien Sentinel, complétées ou non avec une variable de lien supplémentairede hauteur. Onestime ainsi l’ensemble des variables GEDI pour chaque placette IFN. Ensuite, un modèle de régression est établi par kNN-bagging pour estimer le volume de bois à partir des variables GEDI les mieux prédites à l’étape précédente et les variables Sentinel. Le volume est estimé au niveau de toutesles empreintes GEDI. La stratégie complétée par une variable de lien de hauteur a atteint un coefficient de détermination de 58%. Par la suite, sur la base du réseau dense de placettes avec volume ainsi obtenu, desméthodes standards d’estimation sur de petites surfaces (small area estimation) ou de cartographie haute résolution, pourront être implémentés
Individual variability in trajectories of key plasma biomarkers involved in body reserves dynamics inmeat ewes
No full textSession 27. Physiology of resilience and adaptation to climate changeInternational audienceThe mobilization and accretion of body reserves (BR) constitute one of the key mechanisms in ruminants for resilience and adaptation. A better understanding of inter-individual variability for candidate proxies of such mechanism is required before their use in breeding strategies. Primiparous and multiparous ewes were monitored during successive productive cycles in two contrasting farming systems (FS, indoor vs extensive) at five key physiological stages (Mating; mid-Pregnancy; 2 weeks Pre-Lambing; 3 weeks Post-Lambing; Weaning) for plasma biomarkers (NEFA, non-esterified fatty acids; BHB, β-hydroxybutyrate; T3, Triiodothyronine; INS, insulin). Unsupervised cluster analysis was done to investigate the variability in BR biomarkers trajectories. Overall mean trajectories for biomarkers followed BR dynamics throughout cycles and were mainly characterized by increases and decreases in NEFA, BHB, T3 and INS levels during BR mobilization and accretion phases, respectively. For each biomarker, two to three clusters of ewes were found depending on the parity and/or the FS. Trajectories between clusters differed in the levels and/or the shape. One of the major discrepancies between clusters was levels and/or time point when peaks of biomarkers were observed during BR mobilization. Higher individual variability in biomarkers was thus particularly observed around lambing. Genetic contribution in such variability for BR biomarkers was also investigated before considering these traits for breeding purpose. [Funding with H2020 iSAGE project 679302]
Production and consumption of horse meat in France: overview and perspectives
No full textSession 57. Socio-economic approaches to address the contemporary issues of the horse industryInternational audienceThis communication aims to present an overview of the horse meat market in France. It relies on a literature review and a research program whose goal was to understand consumption motivations and barriers, through qualitative and quantitative surveys among horse meat (non- )consumers and chefs. In France, draft foals bred for this market (producing light red meat) are 80% exported, whereas France imports reformed horses (dark red meat) to satisfy 80% of the national consumption. French horse meat consumption is currently declining significantly. Nevertheless, it seems to exist a substantial potential to develop this market for two reasons. First, this meat has nutritional, organoleptic and environmental qualities that are interesting in the current context of a sought for diversification of protein sources. Second, our work showed that out of all French people who do not eat horse meat, 15% would be ready to do so if they had the opportunity, mainly with friends and relatives, or in restaurants. According to the chefs, horse meat is rarely on the menu but is an interesting product for certain types of restaurants. Targeted managerial strategies can be proposed in light of these results, differentiating customers according to their profiles. People with strong moral opposition or having a distant relationship with meat in general mustn’t be targeted. However, people who already consume it or those who are open to it would be sensitive to a better availability and visibility of the offer, for consumption at home, but also in commercial catering that appears to be relevant to familiarize new potential consumers with this product. Moreover, it appears important to enhance the qualities of this product, which can meet the current challenges of food sustainability