Effectiveness of the Aquatic Halophyte Sarcocornia perennis spp. perennis as a Biotool for Ecological Restoration of Salt Marshes

Ecological restoration and creation of salt marshes is needed to compensate for their degradation and loss, but little is known about halophytes as plant biotools in restoration projects. The aim of this study was to evaluate Sarcocornia perennis spp. perennis , a common halophyte in European, Southern Africa and South America salt marshes, as a restoration biotool. We analysed S. perennis sedimentary habitat and quantified its biomass production and the concentration and stock of carbon, nitrogen and nine metals (Al, As, Cd, Cr, Cu, Fe, Ni, Pb and Zn) in the tissues of S. perennis , 28 months after plantation in an innovative restoration project in the Odiel Marshes. S. perennis had accumulated above-ground biomass values (ca. 1,600 g dry weight (DW) m −2 ) within the range recorded previously for natural populations, but root biomass was lower than for mature natural populations. S. perennis prairies accumulated 299 g C m −2 year −1 and 25 g N m −2 year −1 . With the exception of Pb and As, plant transfer coefficient results document the ability of transplanted S. perennis to hyperaccumulate nearly every metal we measured. The highest metal concentrations were recorded in S. perennis ssp. perennis roots (translocation coefficient lower than 1.0 for every metal). Our results provide strong support for the use of S. perennis ssp. perennis transplants as a biotool for salt marsh restoration at low–medium elevations in the tidal gradient. Use of live vegetation for metal extraction may enhance other restoration functions including phytostabilization, reduced eutrophication and negative effects of climate change.