Integrating demographic and genetic effects of connections on the viability of an endangered plant in a highly fragmented habitat

► We analysed the role of corridors and the soil seed bank on the viability of a metapopulation of a rare plant species. ► We investigated the impact of connectivity and the synchronisation of the local environments on metapopulation viability. ► We used a demo-genetic model to study how these factors and their interactions affect population viability. ► When a soil seed bank occurs, extinction risk is maximised for intermediate network size. ► The implementation of temporary connections among networks is an efficient management option to maximise viability.