Portail HAL Institut Agro Montpellier
Not a member yet
54878 research outputs found
Sort by
Evolutionarily stable cleistogamy
No full textInternational audienceCleistogamy, the production of closed flowers providing obligatory selfed seeds, has evolved repeatedly in more than 50 botanical families. Usually associated with chasmogamy, open flowers producing potentially outcrossed seeds in various proportion is an iconic example of mixed self-fertilization.Here, I develop an analytical Evolutionarily Stable Strategies (ESS) model for the evolution of cleistogamy. The model considers the role of inbreeding depression and the dependence of pollen export to chasmogamous flowers. Three generic functional relationships between pollen export and cleistogamy are considered. The model reveals that the classical inbreeding depression threshold of 0.5 no longer applies in the evolution of cleistogamy. Evolutionarily stable mixed cleistogamy is possible when inbreeding depression is low (below 0.5) and when pollen export per flower decreases with the rate of chasmogamy, consistent with the higher physiological cost of open flowers relative to closed flowers. Beyond the cost of flower types, the model points out the major impact of cleistogamy rate on gene transmission through pollen in the evolution of cleistogamy
Circumpolar spread of avian influenza H5N1 to southern Indian Ocean islands
No full textInternational audienceSince 2020, the outbreak of high pathogenicity avian influenza (HPAI) H5N1 virus clade 2.3.4.4b has turned into the largest documented panzootic 1,3 . Here, we describe its arrival into the Indian Ocean sub-Antarctic archipelagos of Crozet and Kerguelen, where we first detected the virus in October 2024 in dead southern elephant seals. While the panzootic is ongoing, it has already caused unprecedented mortalities of marine mammals and seabirds. We collected brain swabs from seal and seabird carcasses and obtained 25 novel HPAI H5N1 2.3.4.4b sequences. Using phylogeographic analyses, we show that there have been independent introductions of the virus to Crozet and Kerguelen islands, most likely from the distant South Georgia islands in the Southern Atlantic, and not from the more nearby coasts of South Africa. Our results point to a year-long gap in genomic surveillance in the sub-Antarctic region. Locally, our analyses show that the virus is transmitted between different species. Our serological analyses show that some southern elephant seal had mounted an anti-H5 antibody response. Through its circumpolar spread to the Indian Ocean, HPAI H5N1 2.3.4.4b moves closer to Australia, which remains free from infections with this strain, and represents a major threat to the sub-Antarctic wildlife.The ongoing outbreak of clade 2.3.4.4b of high pathogenicity avian influenza (HPAI) H5N1 virus has been unique not only in the large number of host species affected, with a wide range of both birds and mammals reported dead 1-3 , but also in the scale of the panzootic, with all continents except Oceania affected 4 . Originating in Asia in 1996 5,6 , the A/Goose/Guangdong/1/1996 lineage HPAIV spread across the world in different waves, recombined and diversified into different clades of various H5Nx viruses. Clade 2.3.4.4b started to become a worldwide preoccupation in 2014, and in the large outbreak of 2016-2017, HPAI H5N8 viruses of clade 2.3.4.4b reached South Africa 7,8 . Since 2021, HPAI H5N1 viruses of clade 2.3.4.4b severely impacted wild bird species and poultry across Europe 9-11 , southern Africa 12-14 , North America 15 , and South America where it resulted in die-offs of tens of thousands of seabirds 16 and marine mammals 17,18 . At the time of writing, HPAIV H5N1 clade 2.3.4.4b has not been detected in any birds or other animals in Australia and the southern Pacific region 19 . While there were no incursions into the Antarctic region during the summer season 2022/2023 20 , HPAIV H5N1 clade 2.3.4.4b was detected for the first time</div
FAIRTraits: an enriched, FAIR‐compliant database of plant traits from Mediterranean populations of 240 species
No full textInternational audienceMany existing datasets also lack the environmental details necessary to investigate trait–environment relationships at local scales. Here, we present FAIRTraits, a comprehensive dataset that addresses these limitations by compiling 189,452 records of quantitative trait measurements collected between 1997 and 2023 from 1955 populations of 240 vascular plant species in the Northern Mediterranean Basin, a region known both for its exceptional biodiversity and as a climate change hotspot. All data were collected by a single research group using consistent and well-documented field and laboratory protocols, ensuring internal consistency across traits, species, sites, and years. FAIRTraits includes 180 traits measured at the individual or replicate level, with no aggregation. It features an unprecedented diversity of traits spanning all major plant organs—leaves, stems, roots, and reproductive parts. These include widely used traits such as specific leaf area and plant height, but also traits that are rarely reported, especially below-ground traits related to root morphology, as well as mechanical properties, phenology, and microbial associations. In addition to raw measurements, species are annotated with categorical descriptors (e.g., life form, photosynthetic pathway, and successional status), and species-level values taken from a Mediterranean flora, for key traits such as reproductive phenology and maximum height. To support analyses that account for environmental variability, each observation is linked to detailed descriptors of the plot where the individual was sampled, including climate data, soil physicochemical properties, and disturbance regime. Full metadata on sampling protocols and measurement methods are provided for every trait and environmental variable. FAIRTraits was built in compliance with the FAIR principles of data management (Findable, Accessible, Interoperable, and Reusable). Metadata are described using the Ecological Metadata Language (EML); trait definitions are standardized using community-endorsed semantic resources. The data are archived across two interoperable repositories: GBIF (via Darwin Core and trait-specific extensions) for taxon–trait associations and InDoRES for environmental and contextual data. These efforts ensure long-term preservation, data traceability, and seamless integration with plant trait databases such as BROT or TRY, and cross-organism initiatives such as the Open Traits Network or the Encyclopedia of Life. FAIRTraits offers a robust, richly documented, and reusable resource for investigating plant functional strategies, trait–environment relationships, and scaling from individuals to communities and ecosystems. It also provides a concrete example of how trait datasets can meet the highest standards of data quality and interoperability—serving as a model for future community-led initiatives in functional ecology. The FAIRTraits database is released under the CC-BY Attribution 4.0 International license
Global patterns of colouration complexity in the Paridae: effects of climate and species characteristics across body regions
No full textInternational audienceAvian plumage colouration is an iconic example of trait variability among species. Sexual, social and natural selection, and the environmental variables modulating them are the main drivers of this variability.So far, most research exploring environmental effects on the variability of plumage colouration has focused on the variation in overall plumage darkness. Research on other aspects of colour variation, such as the diversity of colours exhibited by a species (i.e. colour complexity), is limited and has produced inconsistent results. Furthermore, colour complexity has mostly been analysed at the whole-plumage level, despite the possibility that the colour complexity of different plumage patches may be sensitive to different environmental factors.Here, we quantify male and female colouration in 58 species of the family Paridae, and use multi-predictor Bayesian phylogenetic mixed models to estimate the relationship of colouration with biotic and climatic variables that quantify environment, and with several species-specific characteristics. We consider both the colouration of the whole plumage and the colouration of four separate colour patches (head, chest, back and wing).We find that Paridae species in climates with intermediate temperatures present more complex colouration than do species in warmer/colder climates. In addition, males, relatively small species, and species with relatively greater sexual dichromatism have more complex plumage colouration. We find that the numbers of predators and sympatric conspecifics are more associated with female colouration than with male colouration. Finally, the strength of the associations with colour complexity is specific to each plumage region: species recognition, beak size and climate variables related to competition for reproductive resources (i.e. precipitation seasonality) are more strongly associated with colouration complexity of the head and breast than with that of the back and wing.Overall, our results illustrate the importance of climatic and social variables, the link between colour complexity and dichromatism in both sexes, and the analysis of distinct plumage areas for understanding global patterns of colouration complexity and the processes that promote them
Colony size as the main driver of the evolution of song diversity and composition in weaverbirds
No full textOSF Preprints, version 3 : https://doi.org/10.31219/osf.io/z5bgy_v3International audienceBirdsong is a complex signal shaped by multiple factors and has been explored most widely through the lens of sexual selection, but with mixed results. Here, we focus on the evolution of two song parameters: diversity, which is widely studied, and composition, which is poorly understood. We assessed the potential role of mating system as a proxy for sexual selection, but in addition, investigated whether colony size, a proxy for sociality, and phylogenetic history influence the evolution of these parameters in weaverbirds family (Aves: Ploceidae). Using comparative and path analyses we find that, as expected, species living in larger colonies present greater song diversity and had similar song composition. However, contrary to expectations, polygamous species do not present higher song diversity, nor more similar acoustic composition than monogamous species. A relatively high effect of phylogeny was detected on both song variables. Our results thus suggest that, in this family, sociality is a stronger driver of song diversity and composition than sexual selection. These findings highlight the importance of testing multiple factors when studying bird song evolution and the relevance of sociality
Deep learning approach to detect and visualize sexual dimorphism in monomorphic species
No full textInternational audienceSex recognition is facilitated by dimorphism in some traits. However, humans often fail to find the traits that allow distinction between sexes in other species. Deep learning has shown great application potential in identifying cryptic differences between sexes, but it has rarely been used to assess sexual dimorphism. In this study, the ability of a fine-tuned classification neural network, which is known as EfficientNet, to find differences between sexes in a species that appears monomorphic to humans, such as the sociable weaver, Philetairus socius, was evaluated. In addition, the benefits of the Grad-CAM visualization technique were assessed to understand which parts of the head of the individuals are used by the network to differentiate the sexes. We trained 10-fold cross-validation models on more than 4500 pictures of the head from more than 1300 individuals. Results show that the network can predict the sex of sociable weavers with an accuracy of 76%, which is considerably higher than humans' performance (56%). Moreover, the model was similarly good at predicting females and males. When interpreting the probability of being classified to one sex, our results further reveal the effect of theinteraction of sex with age on the confidence score of the models, which shows that younger males are less masculine than older ones, and older females are more masculine than younger ones. Finally, using Grad-CAM, we found that the model mostly used the bill region to predict the sex of individuals. Overall, this work shows the potential application of artificial intelligence as a noninvasive sexing tool, surpassing human capabilities and aiding in pinpointing potential cryptic dimorphic body parts that have yet to be identified. Half of the world’s bird species appear sexually monomorphic to humans, and re-evaluation of species dimorphism with this type of methods could deepen our understanding of topics such as sex-specific selection on animal traits, behavioural differences and sex ratio variation across tim
Partnerships for sustainable food and bioeconomy systems in Europe: exploring the role of intermediaries
No full textInternational audiencePartnerships have their own vision of sustainability, from formal broad concepts such as bioeconomy or blue economy to grounded-specific objectives. As highlighted in numerous studies, managing diverse visions towards a common goal can be challenging. This article seeks to explore the factors influencing sustainable value co-creation through a novel lens: the intermediaries operating at the partnership level. These intermediaries are potential key players in the success of partnerships focused on sustainable food and bioeconomy systems in Europe. To identify their roles and positions, three in-depth case studies were conducted on partnerships (Pôle Mer Mediterranée, Foodwest, and BIOEAST) operating at regional, national and cross-countries scales. The findings contribute to the existing literature by clarifying the role of intermediaries in sustainable value co-creation processes and by classifying the positioning of intermediaries within partnerships. Here, we have described intermediaries as the actors within a partnership who facilitate interactions between partners and/or partners’ connections with the outside. Two different types of intermediaries emerged (i) a part-time facilitating group of intermediaries loosely bound together and (ii) a full-time management team of intermediaries coherently intervening. The study demonstrates that both categories have a major influence in shaping the sustainable co-creation process even though they employ different approaches using a unique mix of tools: animation, communication (internal), promotion of the partnership (outside) and coordination. These are further influenced by factors such as the level of formality or informality in communication between intermediaries and partners as well as their specific geographic and thematic contexts
Agroecology Living Labs to transform food systems: a critical review at the science-policy-society nexus in Europe
No full textInternational audienceAgroecology Living Labs (ALL) are a promising approach to support food system transformation toward sustainability. Amid rapid uptake in Europe, we critically review the foundational literature supporting ALL: sustainable transition and innovation theories and the literature on agricultural knowledge and innovation systems to highlight transformative potential. To conduct this review, a diverse team of both social and natural scientists engaged in a co-creation process. We found that transformative ALL: 1) align methods with agroecology principles, 2) utilize place-based transformation approaches, and 3) foster a paradigm shift to participatory knowledge production. We identify seeds of transformation or cross-cutting characteristics across dominant theories and research approaches to fill political space and support transformative ALL. The first seed emphasizes moving beyond technical innovation toward socioecological system governance. The second seed promotes developing ALL at the territory/landscape scale as a mediator for open innovation across the science-policy-society nexus. The third seed highlights the transformative potential of inclusive and participatory knowledge production within structures that scale via networks. ALL, if methodically facilitated and supported across decision-making scales, have the potential to usher in a new transformative participatory paradigm in Europe toward more agroecological sustainable food systems at the science-policy-society nexus.</div
DNA methylation: a way for fast-renewed inbreeding depression in animals? An example with the mollusc species Physa acuta
No full textInternational audienc
Pathology 1950-1974
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/614680/)International audienc