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Pathogenic bacterial taxa constitute a substantial portion of fecal microbiota in common migratory bats and birds in Europe
No full textInternational audienceABSTRACT Identifying the wildlife reservoirs of bacterial pathogens, spatially and temporally, is important for assessing the threats to human and the rest of the biosphere. Our objective was to study Europe-wide characteristics of the fecal microbiota of four highly mobile migratory vertebrates, that is, one bat ( Pipistrellus nathusii ) and three bird species ( Turdus merula , Anas platyrhynchos , Columba palumbus ). The 351 sample PacBio data set of almost the entire 16S rRNA gene with 438,997 amplicon sequence variants (ASVs) assigned 3,277 bacterial species. A significant proportion of the ASVs were assigned to bacterial genera having species pathogenic to human or animals. These pathogen ASVs accounted for 45% of all the ASVs and statistically were more frequent at higher latitudes and in younger age groups. In 36 samples, more than >90% of all the PacBio reads were assigned to these pathogenic genera. We designate to individuals of these samples a new term, that is, a pathogen bloomer. The pathogen bloomers, which did not display apparent macroscopic disease symptoms, were detected in Nathusius bat ( n = 8; Finland and Latvia), blackbird ( n = 6; Finland, Latvia and Denmark), and wood pigeon ( n = 22; Finland and France), but not in mallard. Key species-level taxonomic assignments in the pathogen bloomers were the two well-known enteropathogens ( Campylobacter jejuni or Escherichia coli ) and one emerging enteropathogen ( Escherichia marmotae ). Our data imply that the studied common migratory vertebrates may contribute to the transmission of bacterial pathogens across the European continent. IMPORTANCE The understanding of gut microbiota composition and dynamics in wild vertebrate populations, especially in highly mobile vertebrates, birds and bats, remains limited. Our study sheds light on the critical knowledge gap in how common pathogenic bacterial taxa of fecal microbiota are in migratory bats and birds in Europe. We found out that bacterial genera having species pathogenic to human or animals constituted a substantial portion of the fecal microbiota in all the studied host taxa. Most importantly, we identified asymptomatic individuals that were dysbiotic with bacterial pathogen overgrowth. These previously unknown pathogen bloomers appear as potent Europe-wide transmitters of bacterial pathogens, which cause, for example, diarrhea and bacteremia in human. Our findings may contribute to better understanding of seasonal disease hotspots and pathogen spillover risks related to migratory vertebrates
Analyse critique des propositions de protocole européen de suivi des insectes pollinisateurs
No full textThe EU PoMS (European Union Pollinator Monitoring Scheme) aims to evaluate the composition of pollinating insect communities to assess their long-term population trends. A pilot protocol was carried out and, following the first results, discussions on the sampling methods to adopt continue. We underline that using pan traps with identification of specimens by experts to sample pollinators does not seem feasible in terms of human and financial resources (a minima several million euros for France). We instead suggest combining two existing participatory science protocols (id est SPIPOLL protocol for insects requiring flowers and STERF/eBMS protocol for butterflies) and Malaise traps with identification of specimens by metabarcoding. These associations would make it possible to have pollinator population trends, to assess the specific richness of pollinator communities and to involve citizens, at lower financial costs. We also highlighted that no sampling strategy has been established while this step is crucial to define before any field campaign. Finally, we stress the urgent need for France to reinvest in many areas, particularly in the recruitment and training of professional taxonomists and naturalist experts. This point is currently a limiting factor and we have to remediate it to reverse the trend of declining pollinator population sizes.Le protocole EU PoMS (European Union Pollinator Monitoring Scheme) a pour objectif d’évaluer la composition des communautés d’insectes pollinisateurs pour établir leurs tendances de population sur le long terme. Un protocole-pilote a été réalisé et, suite aux premiers résultats, les réflexions sur les méthodes d’échantillonnage à adopter continuent. Nous mettons en évidence que, contrairement à ce qui est pressenti, utiliser la méthode des coupelles colorées avec identification des spécimens par des experts pour échantillonner les pollinisateurs ne parait pas réalisable à la vue des moyens humains et financiers engendrés (a minima plusieurs millions d’euros par an pour la France). Nous suggérons plutôt de combiner deux protocoles de sciences participatives existants (c’est-à-dire protocole SPIPOLL pour les insectes floricoles et protocole STERF/eBMS pour les papillons de jour) ainsi que de poser des pièges Malaise avec identification des spécimens par metabarcoding. Ces associations permettraient de disposer de tendances de population des insectes pollinisateurs, d’évaluer la richesse spécifique des communautés et d’impliquer le grand public, et ce, pour des moyens humains et financiers moindres. Nous attirons aussi l’attention sur le fait qu’aucune stratégie d’échantillonnage n’a été établie et que cette étape est cruciale à mettre en œuvre avant tout échantillonnage de terrain. Enfin, nous soulignons l’importance pour la France de réinvestir dans de nombreux domaines, notamment dans le recrutement et la formation de taxonomistes et d’experts naturalistes professionnels. Ce point est actuellement un facteur limitant et il est nécessaire d’y remédier afin de pouvoir faire face au déclin en cours du service de pollinisation
Segregation of floricolous ants along latitudinal and urbanization gradients
No full textRecent call has been made to study the biogeography of species interactions in order to better understand ecosystems' states and processes, as well as their response to global anthropogenic disturbances. Ants (Formicidae) are a dominant group of arthropods with a central role in ecosystem functioning. Many ant species, those feeding on liquids, are floricolous and consume nectar. The biogeography of ant-flower interactions is still poorly studied and especially in temperate area. Here we quantify variations in ant-flower interaction frequency in response to latitudinal and urbanization gradients at a country scale.We used data from a flower-visitor monitoring program that includes pictures on 2511 flower plants across Continental France (Mainland) and over 4 years. We analysed the occurrence of the ant-flower interactions along two gradients: latitude and urbanization, this for 10 ant taxa corresponding to different taxonomical level (from family to species).Ants visited 26 % of the sampled plants. Most of the observed ant-flower interaction involved the subfamily Formicinae (82.1 %), followed by Myrmicinae and Dolichoderinae (6.9 % and 4.6 % respectively). Globally, (i) the probability of occurrence was negatively related to latitudes (ii) and to urbanization at lower latitude. (iii) Responses to latitude among sub families, genus and species level responses were segregated and taxonomically aggregated.At lower taxonomic levels we found clear latitudinal niche partitioning among ant taxa suggesting that competition, on both evolutionary and ecological time scales, is a major process structuring ant communities. Finally, our results highlight that the effects of large scale perturbation like urbanization can vary and affect latitudinal gradient.</div
Proposition d'indicateur de suivi de la fréquentation des sites de diffusion de la connaissance - Stratégie nationale biodiversité 2030
No full textLa Stratégie nationale pour la biodiversité (SNB) a pour ambition de renverser la tendance actuelle du déclin de la biodiversité en France. Pour garantir la mise en œuvre effective de cette stratégie à l'échelle nationale et assurer l'atteinte de ses objectifs, des indicateurs de suivi doivent être définis. Ces indicateurs permettront de mesurer le déploiement des 40 mesures de cette stratégie.La Stratégie nationale biodiversité souligne l'importance de la connaissance scientifique comme base essentielle des actions en faveur de la préservation de la biodiversité. Les plateformes d'accès aux données jouent un rôle clé, en rendant accessibles au public des informations sur l'état de la biodiversité et les pressions qui l'affectent. Leur mission est de diffuser cette connaissance de manière large et de mobiliser l'ensemble de la société autour des enjeux de la biodiversité.Pour suivre cet objectif de diffusion de la connaissance, un indicateur de suivi de la fréquentation des sites dédiés a été proposé. Dans un premier temps, une liste de plateformes concernées a été établie et des variables, dont les données sont disponibles et facilement mobilisables pour un suivi annuel, ont été sélectionnées. Enfin, pour mesurer de manière précise l'atteinte de l’objectif fixé par la Stratégie nationale biodiversité, un indicateur global a été défini, tout en identifiant les limites que pose un tel indicateur
Human Footprint and Forest Disturbance Reduce Space Use of Brown Bears (<i>Ursus arctos</i>) Across Europe
No full textInternational audienceThree-quarters of the planet's land surface has been altered by humans, with consequences for animal ecology, movements and related ecosystem functioning. Species often occupy wide geographical ranges with contrasting human disturbance and environmental conditions, yet, limited data availability across species' ranges has constrained our understanding of how human pressure and resource availability jointly shape intraspecific variation of animal space use. Leveraging a unique dataset of 758 annual GPS movement trajectories from 375 brown bears (Ursus arctos) across the species' range in Europe, we investigated the effects of human pressure (i.e., human footprint index), resource availability and predictability, forest cover and disturbance, and area-based conservation measures on brown bear space use. We quantified space use at different spatiotemporal scales during the growing season (May–September): home range size; representing general space requirements, 10-day long-distance displacement distances, and routine 1-day displacement distances. We found large intraspecific variation in brown bear space use across all scales, which was profoundly affected by human footprint index, vegetation productivity, and recent forest disturbances creating opportunity for resource pulses. Bears occupied smaller home ranges and moved less in more anthropized landscapes and in areas with higher resource availability and predictability. Forest disturbances reduced space use while contiguous forest cover promoted longer daily movements. The amount of strictly protected and roadless areas within bear home ranges was too small to affect space use. Anthropized landscapes may hinder the expansion of small and isolated populations, such as the Apennine and Pyrenean, and obstruct population connectivity, for example between the Dinaric Pindos population and the Alpine or Carpathian population. Our findings call for actions to maintain bear movements across landscapes with high human footprint, for example by maintaining forest integrity, to support viable bear populations and their ecosystem functions
Organic farming and semi‐natural habitats for multifunctional agriculture: A case study in hedgerow landscapes of Brittany
No full textInternational audienceFinding more sustainable ways to produce food is a major challenge for humanity in the face of biodiversity extinction and climate change. Consequently, research on the ability of agroecosystems to provide multiple functions is growing. In this regard, the relative importance of organic farming and landscape‐scale measures for improving multifunctionality has recently been debated. We investigated the effects of farming system (conventional vs. organic) at field scale, total length of hedgerows in the landscape and their interaction on the multifunctionality of 40 winter cereal fields in Brittany (France). Our multifunctionality assessment integrated 21 indicators of five agroecosystem goods: biodiversity conservation, nutrient cycling and soil structure, pest and disease regulation, food production and socio‐economic performance. Many indicators of biodiversity conservation, pest and disease regulation, and socio‐economic performance were higher in organic than in conventional systems. However, indicators of nutrient cycling and soil structure did not improve and food production was much lower in organic systems. Total hedgerow length in the landscape had less influence than organic farming on indicators, although we observed positive interactions. Granivorous carabid abundance and semi‐net margin were highest in organic fields located in well‐preserved hedgerow landscapes. Synthesis and applications . Our study suggests that field‐scale organic farming is necessary to promote biodiversity conservation and associated ecological functioning in crop fields, whereas landscape‐scale preservation of semi‐natural habitats alone is likely insufficient. Preservation of hedgerows in the landscape brings additional ecological and socio‐economic benefits for organic systems without compromising agricultural production. More broadly, our results call for more ambitious research into the myriad possible combinations of farming practices and agri‐environmental measures at both field and landscape scales, to improve both below‐ground and above‐ground functioningEvoluer vers une production agricole durable est un défi majeur pour l'humanité face à l'extinction de la biodiversité et au changement climatique. Par conséquent, les recherches sur la capacité des agroécosystèmes à assurer de nombreuses fonctions se multiplient. À cet égard, l'importance relative de l'agriculture biologique et des mesures paysagères pour améliorer la multifonctionnalité a récemment été débattue. Nous avons étudié les effets de l’agriculture biologique, de la longueur totale de haies dans le paysage et de leur interaction sur la multifonctionnalité de 40 champs de céréales d'hiver en Bretagne (France). Notre évaluation de la multifonctionnalité est basée sur 21 indicateurs de cinq biens agroécosystémiques : la conservation de la biodiversité, le cycle des nutriments et la structure du sol, la régulation des bio‐agresseurs et des maladies, la production agricole, et la performance socio‐économique. De nombreux indicateurs de conservation de la biodiversité, de régulation des bio‐agresseurs et des maladies et de performance socio‐économique étaient plus élevés en agriculture biologique qu’en agriculture conventionnelle. Cependant, les indicateurs du cycle des nutriments et de la structure du sol n’étaient pas améliorés et la production agricole était beaucoup plus faible en agriculture biologique. La longueur totale de haies dans le paysage avait moins d'influence que l'agriculture biologique sur les indicateurs, bien que nous ayons observé des interactions positives. L'abondance des carabes granivores et la marge semi‐nette étaient plus élevées dans les champs en agriculture biologique situés dans les paysages bocagers les mieux préservés. Synthèse et applications. Notre étude suggère que l'agriculture biologique est nécessaire pour promouvoir la conservation de la biodiversité et le fonctionnement écologique associé dans les champs cultivés, tandis que la préservation des habitats semi‐naturels à l'échelle du paysage est probablement insuffisante à elle seule. La préservation des haies dans les paysages apporte des avantages écologiques et socio‐économiques supplémentaires en agriculture biologique sans compromettre la production agricole. Plus généralement, nos résultats appellent à une recherche plus ambitieuse sur la myriade de combinaisons possibles de pratiques agricoles et de mesures agro‐environnementales à l'échelle du champ et du paysage, afin d'améliorer à la fois le fonctionnement souterrain et aérien des agroécosystème
La Liste rouge des écosystèmes en France : les forêts de montagne, Hexagone et Corse 2025
No full textTowards a New Interpretative Framework for Air Quality and Climate Biomonitoring With Lichens: A Meta‐Analysis of Surveys Using the European Protocol
No full textInternational audienceABSTRACT Air pollution and climate change remain critical environmental challenges, particularly in urban areas, where conventional monitoring networks are often too sparse to capture fine‐scale exposure gradients due to their high operational costs. Epiphytic lichen biomonitoring provides a valuable complementary approach, as these organisms are sensitive to both air pollutants and climate conditions. Despite the existence of a standardized European protocol, large‐scale implementation is hindered by the absence of a robust interpretative framework and incomplete knowledge of species‐specific responses to pollutants and climate variables. This study initiated the development of a standardized interpretative framework for European lichen biomonitoring data by identifying a core set of indicator species with clear responses to major air pollutants and climate variables. To achieve this, we compiled and harmonized raw lichen data from 58 studies that applied the European protocol and modeled the response of 43 lichen species to dominant air pollutants (NH 3 , NO x , and SO 2 ) and climate variables (mean air temperature, mean relative humidity, and temperature seasonality). While confirming established trends, our models allowed us to decouple species responses to reduced (NH 3 ) vs. oxidized (NO x ) nitrogen compounds, a distinction rarely achievable in local studies due to insufficient contrast in pollutant gradients. We also provided actionable recommendations to enhance comparability, such as prioritizing widespread, well‐studied tree species and standardizing lichen taxa groupings. Our study established a foundation for a harmonized European interpretative framework by identifying low‐bias, ecologically meaningful indicator species. Future efforts should focus on translating sensitivity classifications into actionable air quality indices and refining regional‐scale assessments
Choisir des débits écologiques : quels compromis entre usages et milieux ?
No full textInternational audienc
Vers des systèmes viticoles économes en pesticides. Étude du réseau DEPHY-Vigne
No full textInternational audienceCreated in 2010, the DEPHY-Vigne network is formed of winegrowers who are committed to reducing the use of pesticides, and thus aims to demonstrate that such a change is possible using currently available techniques. The DEPHY-Vigne network showed an average reduction in pesticide use of 32 % over 10 years, with high inter- and intra-annual variability indicating a wide range of pesticide reduction pathways (Fouillet et al., 2022).Créé en 2010, le réseau DEPHY-Vigne s’appuie sur des viticulteurs qui s’engagent dans la réduction de l’usage des pesticides et vise ainsi à démontrer qu’une telle évolution est possible avec des moyens techniques aujourd’hui connus. Le réseau DEPHY-Vigne a montré une réduction moyenne de l’utilisation des pesticides de 32 % sur 10 ans avec une forte variabilité inter- et intra-annuelle indiquant une grande diversité de trajectoires de réduction des pesticides (Fouillet et al., 2022)