Metal extraction of some native plant species in a contaminated sites of Iran

ABSTRACT: Some higher plant species develop tolerance strategies to enable surviving and reproducing in highly metal contaminated soils. In order to study the potential of metal accumulation of some native plant species, three natural heavily contaminated sites including Anguran mine in Northwest, Bama mine in central and Sormeh mine in South of Iran were selected. In each site three composite soil samples and dominant native plant species were collected. Soil (total and DTPA extractable) and plant tissues (root and shoot) were analyzed for Zn, Pb and Cd. The average total concentration were 6099.3 mgkg-1for Zn, 5369.6 mgkg-1 for Pb and 25.9mgkg-1 for Cd. Whereas DTPA extractable concentration were 60.5 mgkg-1 for Zn, 32.5 mgkg-1 for Pb and 2.34 mgkg-1 for Cd in study soils. Based on metal concentration and biomass production, eleven native plant species were found to be able to accumulate more metals than the others. The maximum shoot concentration were found in Stipa barbata for Zn (4325.0 mgkg-1), in Kochia chenopodiaceae for Pb (1820.0 mgkg-1) and in Stipa barbata for Cd (28.4 mgkg-1). The maximum root concentration were 2762.0mgkg-1 for Zn in Stipa barbata, 1927.0mgkg-1 for Pb in Kochia chenopodiaceae and 34.5 mgkg-1 for Cd in Stipa Barbata. According to uptake index and shoot root ratio Stipa barbata accumulated more Zn and Cd in aboveground tissues, while Kochia chenopodiaceae accumulated more Pb in root and shoot