Investigating mortality caused by environmental doses of urban pollutants, the phthalates DnBP and DEHP, on the urban pollinator Bombus terrestris

Cities are environments with severe environmental constraints (e.g. fragmented habitats, urban heat islands, air and soil pollutants) which can be detrimental to wildlife development. We focus our research on the impact of urban pollutant chronic exposure, such as phthalates, on pollinators. These ubiquitous emerging pollutants are endocrine disruptors known to affect invertebrates through immune stress, reproductive impairments, and developmental issues. In this study, we first evaluated phthalates exposure at atmospheric and cuticular levels on city-caught Bombus terrestris. Then, we tested under laboratory conditions the effects of two commonly found phthalates, DEHP (Di(2-ethylhexyl) phthalate) and DnBP (Di-n-butyl phthalate), on the individual and colonial health of Bombus terrestris. Our first results suggest that environmental level exposure to those chemicals can lead to mortality in Bombus terrestris. Faced with these results, it appears that there is a need for deeper investigations of the role of endocrine disruptors, such as phthalates, in the current global decline of insects, and particularly, pollinator populations.5438 - ASPI - Michez - Abeilles sauvages en ville : effets des polluants urbains sur la santé des insectes et sur les interactions plantes-pollinisateurs - Sources privée

Status and trends of wild pollinators in Belgium and north of France

Status and trends of wild pollinators in Belgium and North of France Morgane Folschweiller1, Floriane Jacquemin2, Maxime Drossart1, Marc Dufrêne2, Pierre Rasmont1 Folschweiller M. 1, Jacquemin F.2, Drossart M.1, Dufrêne M.2, Michez D. 1, Rasmont P.1 1Laboratoire de Zoologie, Université de Mons, Mons, Belgium 2UR Biodiversité et Payasage, Université de Liège - Gembloux AgroBioTech, Gembloux, Belgium Pollinators play a very important role in terrestrial ecosystems. Indeed, by contributing to the pollination of most of our wild and cultivated flowering plants, they provide an essential ecosystem service. The main goal of the SAPOLL project is to elaborate an action plan for the conservation of wild pollinators in Belgium and north of France. In order to do so, prior assessments are needed. Here we present our first review of wild pollinators situation at global and regional level. This report, made by regional experts, addresses the decline of wild pollinators, the associated factors and also the consequences of this decline

Plan d'action transfrontalier en faveur des pollinisateurs sauvages

Sauvons nos pollinisateurs - Plan d'action transfrontalier pour les pollinisateurs sauvages - Région wallonn

Prise en compte de l'adaptation locale et de la dépression hybride en biologie de la conservation (exemple de Biscutella neustriaca, endémique de Haute Normandie)

Pour éviter la disparition d'une espèce menacée, l'augmentation des effectifs par transfert d'individus d une population source à la population cible (renforcement) et la création de populations nouvelles (réintroduction), constituent des instruments clés des stratégies de conservation. Cependant le transfert d individus dans un contexte d adaptation locale peut aboutir à une mal-adaptation des individus transférés dans leur environnement d introduction. Par ailleurs les descendants des croisements entre individus natifs et individus transplantés peuvent présenter une valeur sélective réduite consécutive à la dépression hybride. Intégrer les notions d adaptation locale et de dépression hybride en biologie de la conservation suscite de nombreuses interrogations, quant à la mise en évidence des adaptations locales, les mesures de distances entre populations, le choix des populations cibles dans un protocole de renforcement ou de réintroduction.La présente thèse s inscrit dans un projet de conservation d une espèce micro-endémique menacée, la Biscutelle de Neustrie. Elle s attache à prendre en compte l adaptation locale et ses conséquences dans les protocoles de renforcement de l espèce. Cette thèse comporte trois volets : (1) l étude de la dépression hybride en lien avec la distribution géographique de l espèce, en conditions environnementales contrôlées et en sites d introductions (2) l étude de la différenciation écologique des populations en termes d habitats et de traits d histoire de vie ainsi que le patron d adaptation locale des plantes à leur environnement naturel (3) la comparaison de deux stratégies conservatrices de renforcement : l auto- et l allo-renforcement. La synthèse de ces trois volets a permis d élaborer un protocole de conservation pour l espèce et plus largement d identifier les paramètres à intégrer pour réussir un transfert d individus chez les espèces menacées ou d en comprendre les échecs.LILLE1-Bib. Electronique (590099901) / SudocSudocFranceF

Uncertainties in the projection of species distributions related to general circulation models

International audienceEcological Niche Models (ENMs) are increasingly used by ecologists to project species potential future distribution. However, the application of such models may be challenging, and some caveats have already been identified. While studies have generally shown that projections may be sensitive to the ENM applied or the emission scenario, to name just a few, the sensitivity of ENM-based scenarios to General Circulation Models (GCMs) has been often underappreciated. Here, using a multi-GCM and multi-emission scenario approach, we evaluated the variability in projected distributions under future climate conditions. We modeled the ecological realized niche (sensu Hutchinson) and predicted the baseline distribution of species with contrasting spatial patterns and representative of two major functional groups of European trees: the dwarf birch and the sweet chestnut. Their future distributions were then projected onto future climatic conditions derived from seven GCMs and four emissions scenarios using the new Representative Concentration Pathways (RCPs) developed for the Intergovernmental Panel on Climate Change (IPCC) AR5 report. Uncertainties arising from GCMs and those resulting from emissions scenarios were quantified and compared. Our study reveals that scenarios of future species distribution exhibit broad differences, depending not only on emissions scenarios but also on GCMs. We found that the between-GCM variability was greater than the between-RCP variability for the next decades and both types of variability reached a similar level at the end of this century. Our result highlights that a combined multi-GCM and multi-RCP approach is needed to better consider potential trajectories and uncertainties in future species distributions. In all cases, between-GCM variability increases with the level of warming, and if nothing is done to alleviate global warming, future species spatial distribution may become more and more difficult to anticipate. When future species spatial distributions are examined, we propose to use a large number of GCMs and RCPs to better anticipate potential trajectories and quantify uncertainties

Genetic diversity and ecological differentiation in the endangered fen orchid (Liparis loeselii)

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Climate change and the ash dieback crisis

International audienceBeyond the direct influence of climate change on species distribution and phenology, indirect effects may also arise from perturbations in species interactions. Infectious diseases are strong biotic forces that can precipitate population declines and lead to biodiversity loss. It has been shown in forest ecosystems worldwide that at least 10% of trees are vulnerable to extinction and pathogens are increasingly implicated. In Europe, the emerging ash dieback disease caused by the fungus Hymenoscyphus fraxineus, commonly called Chalara fraxinea, is causing a severe mortality of common ash trees (Fraxinus excelsior); this is raising concerns for the persistence of this widespread tree, which is both a key component of forest ecosystems and economically important for timber production. Here, we show how the pathogen and climate change may interact to affect the future spatial distribution of the common ash. Using two presence-only models, seven General Circulation Models and four emission scenarios, we show that climate change, by affecting the host and the pathogen separately, may uncouple their spatial distribution to create a mismatch in species interaction and so a lowering of disease transmission. Consequently, as climate change expands the ranges of both species polewards it may alleviate the ash dieback crisis in southern and occidental regions at the same time

Does phenology explain plant–pollinator interactions at different latitudes? An assessment of its explanatory power in plant–hoverfly networks in French calcareous grasslands

International audienceFor plant–pollinator interactions to occur, the flowering of plants and the flying period of pollinators (i.e. their phenologies) have to overlap. Yet, few models make use of this principle to predict interactions and fewer still are able to compare interaction networks of different sizes. Here, we tackled both challenges using Bayesian structural equation models (SEM), incorporating the effect of phenological overlap in six plant–hoverfly networks. Insect and plant abundances were strong determinants of the number of visits, while phenology overlap alone was not sufficient, but significantly improved model fit. Phenology overlap was a stronger determinant of plant–pollinator interactions in sites where the average overlap was longer and network compartmentalization was weaker, i.e. at higher latitudes. Our approach highlights the advantages of using Bayesian SEMs to compare interaction networks of different sizes along environmental gradients and articulates the various steps needed to do so

Le voyage de la biodiversité en ville : Focus sur le voyage des insectes pollinisateurs et leur rôle dans les continuités écologiques entre les espaces de nature urbains

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Réseaux d’interactions, état de santé et connectivités des pollinisateurs sauvages en milieu urbain : effets d’un gradient d’urbanisation.

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