High-intensity versus low-intensity restoration alternatives of a tidal marsh in Guadalquivir estuary, SW Spain

摘要: Abstract Dredged sediments from Guadalquivir River estuary were deposited on Algaida Marsh in the 1980s. Ecological restoration of 52 ha was started 2000. Intervention included removal dredged material, geomorphological reconstruction surfaces, diversification substrates and tidal flow. Biological colonization achieved by natural mechanisms (water flow, active dispersal fish, birds, flying insects). Two intensities intervention have been applied to adjacent sectors, their effects vegetation monitored for 5 years. The high-intensity sector immediately colonised fish (24 species, 30% estuarine species) serving as a hatchery estuary. Both high- low-intensity sectors attracted birds. Ninety-one species recorded, representing large proportion species. Within 3 years, mudflats covered with marsh dominated Spartina densiflora . limited presents Sarcocornia perennis communities incorporation. Results show comparable succession both proceeding at faster pace where ecosystem connectivity higher. Five years after restoration, composition converging showed only few differences tide marshes. advantages intensive versus extensive ecological are discussed terms community biodiversity, successional changes, costs.