Populus × euramericana Accumulates More Organic Pollutants (PAHs and PCBs), While P. nigra ‘Italica’ Absorbs More Heavy Metals

Abstract

The phytoremediation capacity of three common poplar species, white poplar (Populus alba L.), Lombardy poplar (Populus nigra ’Italica’), and Euro-American hybrid poplar (Populus × euramericana (Dode) Guinier cl. I-214), grown in a middle-sized city with a continental climate in Serbia was analyzed. For this purpose, 15 polycyclic aromatic hydrocarbons (PAHs), 10 polychlorinated biphenyls (PCBs), and 6 heavy metals (HMs) were tracked in leaves and one-year-old branches. P. × euramericana showed the highest PAH uptake capacity, with concentrations of 821.40 ng g−1 dry weight (DW) and 453.64 ng g−1 DW in leaves and branches, respectively. Likewise, P. euramericana accumulated the highest levels of PCBs in leaves (364.53 ng g−1 DW). Additionally, P. nigra ‘Italica’ demonstrated the greatest accumulation potential for HMs, particularly zinc, with 310.10 µg g−1 DW in leaves. Leaves accumulated ~30% more pollutants compared with branches. Significant differences in pollutant uptake capacities were found among species and plant organs. These findings highlight the importance of species selection in phytoremediation and clarify the role of poplar species in accumulating pollutants to mitigate urban pollution. Finally, this study provides valuable insights for future phytoremediation strategies using poplars, especially in urban environments with similar conditions.