Iris Lang, PhD

Testé dans neuf pays sur six continents différents, nous montrons que le suivi de la diversité génétique - principal facteur de la capacité d'adaptation des espèces et donc des écosystèmes au changement climatique - pour le Cadre mondial pour la diversité biologique de la Convention sur la diversité biologique est réalisable !

Under the recently adopted Kunming-Montreal Global Biodiversity Framework, 196 Parties committed to reporting the status of genetic diversity for all species. To… Voir plus

Testé dans neuf pays sur six continents différents, nous montrons que le suivi de la diversité génétique - principal facteur de la capacité d'adaptation des espèces et donc des écosystèmes au changement climatique - pour le Cadre mondial pour la diversité biologique de la Convention sur la diversité biologique est réalisable !

Under the recently adopted Kunming-Montreal Global Biodiversity Framework, 196 Parties committed to reporting the status of genetic diversity for all species. To facilitate reporting, three genetic diversity indicators were developed, two of which focus on processes contributing to genetic diversity conservation: maintaining genetically distinct populations and ensuring populations are large enough to maintain genetic diversity. The major advantage of these indicators is that they can be estimated with or without DNA-based data. However, demonstrating their feasibility requires addressing the methodological challenges of using data gathered from diverse sources, across diverse taxonomic groups, and for countries of varying socio-economic status and biodiversity levels. Here, we assess the genetic indicators for 919 taxa, representing 5271 populations across nine countries, including megadiverse countries and developing economies. Eighty-three percent of the taxa assessed had data available to calculate at least one indicator. Our results show that although the majority of species maintain most populations, 58% of species have populations too small to maintain genetic diversity. Moreover, genetic indicator values suggest that IUCN Red List status and other initiatives fail to assess genetic status, highlighting the critical importance of genetic indicators. Voir moins

Les invasions biologiques sont l'une des causes majeures de l'érosion de la biodiversité actuellement. La résilience et la résistance des aires protégées face aux EEE ont été montrées mais restent incomprises à ce jour.
Un inventaire des actions de gestion des espèces animales exotiques envahissantes potentielles et avérées (EEE Faune) au sein des aires protégées de la région Occitanie a été réalisé via un questionnaire. Il a permis de montrer que la perception de plus d'impacts… Voir plus

Les invasions biologiques sont l'une des causes majeures de l'érosion de la biodiversité actuellement. La résilience et la résistance des aires protégées face aux EEE ont été montrées mais restent incomprises à ce jour.
Un inventaire des actions de gestion des espèces animales exotiques envahissantes potentielles et avérées (EEE Faune) au sein des aires protégées de la région Occitanie a été réalisé via un questionnaire. Il a permis de montrer que la perception de plus d'impacts (écologiques, socioéconomiques et sanitaires) des espèces exotiques par le gestionnaire expliquaient la mise en place d'actions sur ces dernières, mais cela ne dépendait pas du type d'aire protégée (protection règlementaire, foncière ou contractuelle). De plus, les espèces déjà largement répandues dans la région et à forts impacts faisaient l'objet de plus d'actions (prévention, gestion, sensibilisation, amélioration de connaissances), et en particulier ce sont ces espèces (appartenant aux catégories Majeure et Modérée de la liste scientifique catégorisée des EEE Faune d'Occitanie) qui faisaient l'objet de plus d'actions de gestion des populations.
Ces résultats montrent l'importance pour les gestionnaires de s'approprier la liste scientifique catégorisée des EEE Faune d'Occitanie pour prioriser certaines actions afin de maximiser leur efficacité. Il est pertinent de gérer en priorité les espèces nouvellement introduites et émergentes. Ponctuellement, la gestion de populations d'espèces de la catégorie Majeure peut être envisagée si un enjeu patrimonial local est à préserver, mais l'éradication est illusoire. La prévention de l'introduction et de la dispersion d'espèces exotiques ainsi que la sensibilisation sont les actions les plus efficaces pour éviter et limiter les invasions biologiques. Voir moins

Les espèces exotiques envahissantes (EEE) constituent une des 5 causes majeures d’érosion de la biodiversité à l’échelle mondiale. Devant leur diversité et leur abondance, il est impossible d’agir sur toutes les EEE. Le règlement UE 1143/2014 et la stratégie nationale relative aux EEE de 2017 offrent un cadre pour la prévention de l’introduction et de la propagation des EEE et leur gestion. Le CEN Occitanie a élaboré et anime actuellement la stratégie régionale relative aux EEE Faune… Voir plus

Les espèces exotiques envahissantes (EEE) constituent une des 5 causes majeures d’érosion de la biodiversité à l’échelle mondiale. Devant leur diversité et leur abondance, il est impossible d’agir sur toutes les EEE. Le règlement UE 1143/2014 et la stratégie nationale relative aux EEE de 2017 offrent un cadre pour la prévention de l’introduction et de la propagation des EEE et leur gestion. Le CEN Occitanie a élaboré et anime actuellement la stratégie régionale relative aux EEE Faune d’Occitanie, dont l’objectif est d’orienter et de coordonner les actions menées vis-à-vis de ces espèces. Un état des lieux des connaissances des EEE Faune présentes ou susceptibles d’être introduites en Occitanie a d’abord été réalisé. Il n’existe pas, à l’heure actuelle, de méthode standardisée partagée par tous les acteur·rice·s pour classer ces espèces selon la menace qu’elles représentent. Une méthode intégrative a donc été développée à partir de 4 méthodes standardisées internationales et régionales (EICAT, SEICAT, ISEIA, ISSIA) afin de catégoriser les espèces exotiques en Occitanie selon leur potentiel d’invasion et leurs impacts écologiques, socio-économiques et sanitaires. L’objectif de cet article est de partager notre retour d’expérience sur le développement de la méthode pour l’élaboration de la liste catégorisée, et sur les utilisations possibles de cette dernière. Nous montrons notamment comment les acteur·rice·s régionaux, peuvent s’approprier la liste catégorisée, qui constitue le premier outil de connaissance sur les EEE Faune en Occitanie. Les catégories ainsi définies, associées au regard de l’expert·e selon le contexte, permettent d’identifier les grands types d’actions à mener sur ces espèces (prévention, gestion, amélioration des connaissances, communication). Ce travail, qui peut servir aux autres régions déclinant la stratégie nationale, offre un cadre pour l’articulation des stratégies régionales et l’amélioration des modes d’organisation au niveau national. Voir moins

The efficient management of invasive alien species (IAS) requires the identification of their introduction pathways. Genetic assessments have proven useful to inform invasion pathways at large (national to worldwide) scales, but studies at local scales are still rare, despite their importance for guiding management.
In this study, genetic analyses were used to identify local invasion pathways of two invasive crayfish species (the spiny-cheek crayfish Faxonius limosus and the red swamp… Voir plus

The efficient management of invasive alien species (IAS) requires the identification of their introduction pathways. Genetic assessments have proven useful to inform invasion pathways at large (national to worldwide) scales, but studies at local scales are still rare, despite their importance for guiding management.
In this study, genetic analyses were used to identify local invasion pathways of two invasive crayfish species (the spiny-cheek crayfish Faxonius limosus and the red swamp crayfish Procambarus clarkii) in a dense network of artificial lakes. We first characterized the spatial patterns of genetic variability, effective population sizes (Ne) and among-lakes recent migration events for each species using neutral microsatellite markers. We then identified the environmental factors affecting genetic variability and inferred the potential local invasion pathways.
Results revealed different patterns of genetic variability between the two species: F. limosus displayed very low levels of genetic diversity, Ne and spatial structuring compared to P. clarkii, which displayed high genetic diversity, Ne and spatial genetic structuring. We also demonstrated context-dependent effects of different environmental factors (fishery management, spatial distribution and lake size) on genetic variability indices.
We did not identify local invasion pathways for F. limosus due to limited genetic variability, likely caused by a strong founder effect and potential parthenogenetic reproduction. Contrastingly, multiple invasion pathways (release, contaminant, unaided/corridor spread and stowaway) were identified for P. clarkii. Voir moins

Knowledge on the ecological determinants and evolutionary processes shaping intraspecific variability in the wild remains scarce. It is particularly needed in the context of biological invasions to fully understand the consequences of invasive species on the functioning of recipient ecosystems.
Using geometric morphometrics, stable isotopes, and elemental composition analyses, we quantified phenotypic variability (morphological, trophic, and stoichiometric traits) within and among… Voir plus

Knowledge on the ecological determinants and evolutionary processes shaping intraspecific variability in the wild remains scarce. It is particularly needed in the context of biological invasions to fully understand the consequences of invasive species on the functioning of recipient ecosystems.
Using geometric morphometrics, stable isotopes, and elemental composition analyses, we quantified phenotypic variability (morphological, trophic, and stoichiometric traits) within and among invasive populations of two crayfish species with distinct invasion histories over 23 gravel pit lakes in southwest France. We sampled 12 populations of the red swamp crayfish (Procambarus clarkii Girard, 1852) and 11 populations of the spiny-cheek crayfish (Faxonius limosus Rafinesque, 1817). We aimed at unravelling the ecological determinants and the mechanisms (neutral or adaptive) underlying the phenotypic variability among invasive populations.
Overall, our results indicate that F. limosus has already gone through local adaptation in the meta-population while this has not yet occurred for P. clarkii, which was introduced later. This highlights that these two invasive species might have contrasting effects across ecological scales.
Our study emphasises that studying invasive species can provide great knowledge on intraspecific variability and its ecological determinants and evolutionary processes in the wild. Our results also stress the need to focus on intraspecific variability in the context of biological invasions as it can be substantial across wide geographic areas. Voir moins

Intraspecific variability is now recognized for its importance on ecosystem functioning. In the context of biological invasions, which can strongly impact ecological processes, it is of high importance to understand the determinants and the patterns of genetic and phenotypic variability to fully apprehend the consequences of invasive individuals on recipient ecosystems. We demonstrated a high variability among and within populations of two crayfish species, Procambarus clarkii and Faxonius… Voir plus

Intraspecific variability is now recognized for its importance on ecosystem functioning. In the context of biological invasions, which can strongly impact ecological processes, it is of high importance to understand the determinants and the patterns of genetic and phenotypic variability to fully apprehend the consequences of invasive individuals on recipient ecosystems. We demonstrated a high variability among and within populations of two crayfish species, Procambarus clarkii and Faxonius limosus, with distinct life-history traits and colonization histories in a narrow-invaded area. We highlighted that colonization history and environmental conditions were the main drivers of the contrasting patterns of genetic and phenotypic variability between the two species. Genetic analyses provided a great inference of local invasion pathways for P. clarkii, which had a great genetic variability, compared to F. limosus for which the local invasion pathways were more cryptic. We found that neutral and adaptive processes shaped the phenotypic variability of the two species in differing proportions. Then, we demonstrated the existence of a stable resource polymorphism along the benthic littoral-pelagic axis within populations of P. clarkii, suggesting that invaders could have contrasting impacts on ecosystem functioning between littoral and pelagic trophic chains. Finally, in an experiment context using a multi-traits approach, we demonstrated that the structure of trait covariations differed between species in a sympatric population, suggesting that P. clarkii impacts would be more predictable than F. limosus, and that P. clarkii could affect a higher range of ecological processes or impact the ecosystem functioning with a greater intensity than F. limosus. Overall, our findings stress the need to integrate intraspecific variability in the context of biological invasions to better understand their impacts on ecosystem functioning. Voir moins

Although intraspecific variability is now widely recognized as affecting evolutionary and ecological processes, our knowledge on the importance of intraspecific variability within invasive species is still limited. This is despite the fact that understanding the linkage between within‐population morphological divergences and the use of different trophic or spatial resources (i.e., resource polymorphism) can help to better predict their ecological impacts on recipient ecosystems. Here, we… Voir plus

Although intraspecific variability is now widely recognized as affecting evolutionary and ecological processes, our knowledge on the importance of intraspecific variability within invasive species is still limited. This is despite the fact that understanding the linkage between within‐population morphological divergences and the use of different trophic or spatial resources (i.e., resource polymorphism) can help to better predict their ecological impacts on recipient ecosystems. Here, we quantified the extent of resource polymorphism within populations of a worldwide invasive crayfish species, Procambarus clarkii, in 16 lake populations by comparing their trophic (estimated using stable isotope analyses) and morphological characteristics between individuals from the littoral and pelagic habitats. Our results first demonstrated that crayfish occured in both littoral and pelagic habitats of seven lakes and that the use of pelagic habitat was associated with increased abundance of littoral crayfish. We then found morphological (i.e., body and chelae shapes) and trophic divergence (i.e., reliance on littoral carbon) among individuals from littoral and pelagic habitats, highlighting the existence of resource polymorphism in invasive populations. There was no genetic differentiation between individuals from the two habitats, implying that this resource polymorphism was stable (i.e., high gene flow between individuals). Finally, we demonstrated that a divergent adaptive process was responsible for the morphological divergence in body and chela shapes between habitats while difference in littoral reliance neutrally evolved under genetic drift. These findings demonstrated that invasive P. clarkii can display strong within‐population phenotypic variability in recent populations, and this could lead to contrasting ecological impacts between littoral and pelagic individuals. Voir moins

Functional traits can be valuable pieces of information for aquaculture research and management. Although fish traits have been the focus of an abundant research, trait datasets for these organisms are difficult to access and often unpractical to achieve meta-analyses without a time-consuming extensive review. Already available large-scale compilations include trait information for many fish species but not as detailed as required for aquaculture purpose. Here, we introduce the TOFF (i.e… Voir plus

Functional traits can be valuable pieces of information for aquaculture research and management. Although fish traits have been the focus of an abundant research, trait datasets for these organisms are difficult to access and often unpractical to achieve meta-analyses without a time-consuming extensive review. Already available large-scale compilations include trait information for many fish species but not as detailed as required for aquaculture purpose. Here, we introduce the TOFF (i.e. Traits OF Fish), a database focusing on fish functional traits that aims at bringing together behavioral, morphological, phenological, and physiological traits always coupled to environmental measurement context into a single open-source access repository. TOFF hosts data from published field and experimental studies. Here, we release data for 228 traits for 174 species extracted from 165 publications and present a collaborative platform. We ultimately aim at providing an inclusive and accessible data resource to facilitate advances in aquaculture development. Voir moins