Flora of heavy metal-rich soils in NW Iran and some potential hyper-accumulator and accumulator species

In the northwestern part of Iran (Azerbaijan province), there are numerous, active mining areas with heavymetal-rich soils. The plant vegetation growing on these soils could represent a specific flora having potential hyperaccumulators, accumulators and excluder species. In this work, soils rich in Ni, Zn, Cu andMn and plants were identified during April to September in 2002–2003. Plant species belonging to 39 families were collected and the heavy metals in the above-ground parts of specimens were analyzed. For the majority of species, though metal concentrations were orders of magnitude higher than plants growing on soils without mineralization, the concentrations were below the threshold defining hyper-accumulation. The Ni, Zn, Cu and Mn excluder species that grow on metal rich soils but restrict metal absorption and/or transport into shoots were also identified. These species are suitable for the rehabilitation and stabilization of contaminated lands around mining areas as well as the remediation of agricultural soils affected by wastewaters of metal smelters in mining sites of NW Iran