Factors affecting the success of early salt-marsh colonizers: seed availability rather than site suitability and dispersal traits

We evaluated the process of salt-marsh colonization in early successional stages of salt-marsh restoration and investigated how the sequence of species establishment related to different success factors. Vegetation data were collected by permanent plots from the restoration site and adjacent, reference salt marshes during three consecutive periods. Seed length, width and mass were used as dispersal traits, and Ellenberg moisture, salinity and nutrient indices as indicators of site suitability. Seed production in the reference site and seed bank in the restoration site were also investigated. The establishment of salt-marsh species within the restoration site was rapid (less than 5 years). The cover of plant species was not correlated between the restored and the reference sites at the first year of restoration, but this correlation was significant during the following years. Seed availability was more important in explaining the sequence of species establishment than salt and nutrient-limitation tolerance. The first colonizers are known as massive seed producers, with shorter seed length and lower seed mass, which probably increased buoyancy. Among dispersal and site traits, seed length and mass, and in a less extent salinity and nutrients, indicated a relationship with new colonizers. Despite few species have not (yet) appeared in vegetation and seed bank in the restoration site, the existence of an existing salt marsh adjacent to the restoration site is shown to be vital for fast colonization of newly created intertidal areas

Restauration à l'échelle du paysage : le salut de la biodiversité des pelouses sèches européennes ?

International audienceSpecies-rich dry grasslands in Europe have suffered losses in extent and diversity in the last 50 years. Their conservation requires maintenance of remaining grasslands and restoration of lost or damaged grasslands. We report on landscape-level restoration studies and case studies from dry grasslands in contrasting regions of Europe to discuss the strengths and weaknesses of the approaches, the results achieved and the costs and benefits. We conclude that landscape-level restoration offers exciting new opportunities to restore biodiversity and landscape connectivity in Europe’s dry grasslands. There are now drivers for large-scale restoration written into the 2020 targets of the Convention on Biological Diversity and the European Biodiversity Strategy. However, a more integrated approach to large-scale ecological restoration is needed for the development of policy tools to achieve the greatest benefits from restoration at the landscape scale

Restauration à l'échelle du paysage : le salut de la biodiversité des pelouses sèches européennes ?

International audienceSpecies-rich dry grasslands in Europe have suffered losses in extent and diversity in the last 50 years. Their conservation requires maintenance of remaining grasslands and restoration of lost or damaged grasslands. We report on landscape-level restoration studies and case studies from dry grasslands in contrasting regions of Europe to discuss the strengths and weaknesses of the approaches, the results achieved and the costs and benefits. We conclude that landscape-level restoration offers exciting new opportunities to restore biodiversity and landscape connectivity in Europe’s dry grasslands. There are now drivers for large-scale restoration written into the 2020 targets of the Convention on Biological Diversity and the European Biodiversity Strategy. However, a more integrated approach to large-scale ecological restoration is needed for the development of policy tools to achieve the greatest benefits from restoration at the landscape scale