© IAVS; Opulus Press Uppsala. The natural regeneration of salt marsh on formerly reclaimed land

Question: Does the vegetation of restored salt marshes increas-ingly resemble natural reference communities over time? Location: The Essex estuaries, southeast England. Methods: Abandoned reclamations, where coastal defences had been breached in storm events, and current salt marsh recreation schemes were surveyed giving a chronosequence of salt marsh regeneration from 2 to 107 years. The presence, abundance and height of plant species were recorded and comparisons were made with adjacent reference salt marsh communities at equivalent elevations. Results: Of the 18 paired sites surveyed, 13 regenerated marshes had fewer species than their adjacent reference marsh, three had an equal number and two had more. The plant com-munities of only two de-embankment sites matched that of the reference community. 0-50 year old sites and 51-100 year old sites had fewer species per quadrat than the 101+ year sites and the reference salt marshes. There was a weak relationship between differences in species richness for regenerated and reference marshes and the time since sites were first re-exposed to tidal inundation. Cover values for the invasive and recently evolved Spartina anglica were greater within regenerated than reference marshes. Conclusions: Salt marsh plants will colonise formerly re-claimed land relatively quickly on resumption of tidal flooding. However, even after 100 years regenerated salt marshes differ in species richness, composition and structure from reference communities