Native species from contaminated soils: Ecophysiological aspects and their use on phytoremediation

Native plants that evolved to colonize contaminated soils with heavy metals (metallophytes and pseudometallophytes) may use two basic strategies to deal with high metal concentration: (i) exclusion mechanisms by which uptake of roots and root to shoot transport is restricted, (ii) accumulation using several mechanisms to immobilize and compartimentalize metals in vacuoles. Due to their endemism and mining activities special care should be taken to avoid destruction of the metallophyte habitats and the associated loss of species. These plants offer a huge potential for the development of environmental phytotechnologies as revegetation, phytoestabilization and phytoextraction of metal-polluted areas. Finally a study of native plants from metalliferous soils from Northen Spain, with high levels of Zn, Pb and Cd, is presented.