Interclonal Variation in Heavy Metal Accumulation Among Poplar and Willow Clones: Implications for Phytoremediation of Contaminated Landfill Soils

In this study, five poplar clones (<i>Populus deltoides</i> cl. PE19/66, cl. S1-8, cl. 135/81, and <i>Populus × euramericana</i> cl. I-214, cl. Pannonia) and two white willow clones (<i>Salix alba</i> cl. 380, cl. 107/65-9) were tested in pot trials. The aim was to evaluate their potential for phytoextraction of nine heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in three substrates, two based on soil from landfills near Belgrade and Novi Sad, and one control treatment based on nursery soil. The shoot content of all analyzed heavy metals was the highest in the BG substrate with the highest content of heavy metals and the lowest in the control substrate. White willow clone 107/65-9 achieved the highest accumulation of Cd, Cr, Fe, Ni and Pb and along with another willow clone 380 is found to act as generalists. Poplar clones performed more as specialists: I-214 and Pannonia for copper, PE 19/66 for manganese and S1-8 for nickel and zinc. Considerable differences among examined clones in heavy metal accumulation and reaction to substrates should be taken into consideration in further pot and field trials as well as in phytoremediation projects on landfills.