Fragmented populations and dispersal syndromes: from genes to metapopulations dynamic

Informations

Funding country

France

Acronym

FRADISYN

URL

-

Start date

3/1/2013

End date

-

Budget

239,995 EUR

Fundings

Abstract

Habitat loss and fragmentation are major threats affecting more than 85% of terrestrial threatened species and thus menacing biodiversity. For instance, 40% of original forest cover has been lost through human activity. The problem of habitat loss is made worse by the fragmentation of natural habitats, which results in smaller, more isolated sub-populations with reduced possibilities for dispersal. Fragmented populations follow a metapopulation dynamic dependent on local extinction, dispersal into locally extinct patches (colonization) and into extant patches (reinforcement). Reduced dispersal can hinder the recolonization of patches where sub-populations have become extinct, leading to stochastic local and ultimately global extinctions. Therefore, habitat fragmentation affects species occurrence through patch isolation. In FRADISYN, we study dispersal processes, the adaptive mechanisms allowing connectivity between patches and thus species to overcome this spatial isolation. We aim to integrate inter-individual variability in dispersal decisions, a recent advance in dispersal theory, into the dynamic of fragmented populations. Such inter-individual variability arises from the variability in phenotypic traits that shapes individual success in diverse ecological conditions and, in turn, should produce inter-individual differences in habitat selection. Those various associations between phenotypic traits and habitat preferences, named dispersal syndromes, should affect metapopulations dynamics. We predict that colonization and reinforcement involve individuals of different syndromes. Here, we aim to experimentally study, for the first time, the heterogeneity in dispersal syndromes, by exploring the relations between phenotypic traits and habitat preferences, the relationship between habitat preferences and fitness outcomes and the mechanisms producing and maintaining the heterogeneity in dispersal syndromes. Our project will use an integrative approach blending molecular, behavioral and modeling analyses. We will first quantify the relations between habitat preferences and behavioral types that are phenotypic traits likely to drive dispersal decisions. We will then study 1) the role of sequence polymorphism and expression of genes involved in neurochemicals in the production of those relations and 2) the heritability, consistency and effects on performance of established dispersal syndromes explaining their maintenance. Finally, we will integrate results from those tasks into metapopulation dynamic with experimental and modeling approaches. The success of FRADISYN requires a variety of knowledge brought by a team of young researchers from two labs (EDB and SEEM) and a unique and innovating experimental system of metapopulations available at SEEM. This project will merge the knowledge and skills from these two labs to develop the link between population, behavioral and evolutionary ecology. Given the importance of dispersal for species adaptability to changing environments, we need a more integrative comprehension of dispersal processes to understand how, after fragmentation, species can overcome isolation between patches to increase connectivity within the landscape. FRADISYN proposes a highly innovative approach that integrates explicitly within-species phenotypic variation into fragmented population dynamic models. We believe our results will be of wide interest for scientific communities and thus will be published in high ranking journals.