A first step in analysing restoration achievements is a clear definition of the target species. Successful restoration of plant communities depends on the availability of target species and the presence of favourable environmental conditions that allow the species to germinate and establish. Proper elevation in relation to tidal inundation is therefore a prerequisite for the successful restoration of salt-marsh vegetation after de-embankment. The rate of salt-marsh development and species diversity appears to be affected mainly by surface elevation. Because most salt-marsh species are dispersed over short distances, it is important that a well-developed salt marsh is adjacent to the restoration site. The prospect of salt-marsh restoration after de-embankment is good, with target species establishing spontaneously and vegetation succession taking place.

Salt tolerance appeared to be much more important in explaining the sequence of species establishment than the availability of the species in the local or regional species pools or dispersal traits. After 8 years, the lower elevations were still covered by annual Salicornia salt marsh despite the potential for the development of a Puccinellia community. Plant composition at the highest elevation of the restoration site developed from an annual Salicornia community into a Puccinellia maritima salt marsh, which was similar to the local reference marsh. Perennial species ( Puccinellia maritima, Aster tripolium, Spartina anglica, Spergularia media, Atriplex portulacoides and Limonium vulgare) only started to colonize or increase notably in abundance after 3 years of restoration.

and Suaeda maritima colonized and reached maximum abundance first. It took approximately 5 years for species diversity in the restoration site to become similar to a local reference marsh. We evaluated the process of salt-marsh restoration at a species- and plant-community level and investigated how the sequence of species establishment is related to site suitability, availability of the target species in the local and regional species pools and dispersal traits. Insight into the process of salt-marsh development can guide the design, implementation and evaluation of salt-marsh restoration schemes and help determine appropriate management strategies. Restoration of salt marshes on previously reclaimed land provides an excellent opportunity to study plant colonization and subsequent development of salt-marsh vegetation.

Importance of tidal pools in evolution