Contexte

In fragmented landscapes, functional connectivity plays a key role for long-term population viability by allowing the recolonization of habitats which have been emptied by local extinction, augmenting population sizes, reducing inbreeding depression and negative effects of genetic drift. Enhancing structural connectivity through the preservation or restoration of migration corridors is therefore a primary objective in species conservation to maintain functional connectivity of populations. However, the impact of landscape fragmentation on dispersal and gene flow is challenging since it depends on both species- and landscape- specific effects.

Objectif

This M2 project is part of a multispecies project ($) which targets European temperate forests. It aims at exploring the relationship between structural and functional connectivity and focuses especially on the carabid forest specialist Abax parallelepipedus, a species of interest for biocontrol in agricultural landscape. Genetic analyses will be conducted across heterogeneous landscapes in time and space.  Three hypotheses will be tested – all consider dispersal as a trait coevolving with ecological specialization:

1. 1. generalists are more dispersive than specialists;
   2. whatever the dispersal capacity, dispersal is counter-selected in specialists characterized by high movement cost;
   3. whatever the dispersal capacity, dispersal is advantaged(?) in specialists characterized by low movement cost.

Populations of A. parallelepipedus will be sampled in Picardy (Thierache) and in Brittany (ZAA) linearly along hedgerows (potential corridor) and in forest patches (habitat). Next, the analysis of mitochondrial sequences and microsatellite multilocus genotypes will permit to assess the historical component of total genetic variation and quantify dispersal through measures of gene flow between populations. Finally, (i) multivariate and Bayesian clustering methods will be used to detect population genetic structure and potential immigrants between favorable habitats, and (ii) correlative analyses and graph theoretic approaches will be performed to understand genetic connectivity between populations and to investigate the relationship between of landscape quality and genetic structuring.

UPJV, UMR7058 EDYSAN

Encadrement

Annie Guiller (PR) annie.guiller@u-picardie.fr
Vincent Le Roux (MCF) vincent.Leroux@u-picardie.fr
Ronan Marrec (MCF) ronan.marrec@u-picardie.fr

Financement

This M2 project is part of the EU (BiodivERsA) project Woodnet (https://woodnetweb.wordpress.com/project/) and the regional (Hauts-de-France) project Pegase (https://www.u-picardie.fr/edysan/pegase/).

Durée et indemnités de stage
Durée du stage: 6 mois
Indemnisation de stage en fonction des dispositions légales en vigueur

Le dossier de candidature, constitué d’un CV et d’une lettre de motivation (français ou anglais), est à envoyer par email aux trois responsables de stage. N’hésitez pas à contacter les responsables de stage pour tout renseignement supplémentaire.