A plant-assisted bioremediation strategy was applied in an area located in Southern Italy, close to the city
of Taranto, historically contaminated by polychlorinated biphenyls (PCBs) and heavy metals. A specific
poplar clone (Monviso) was selected for its ability to promote organic pollutant degradation in the
rhizosphere, as demonstrated elsewhere. Chemical and microbiological analyses were performed at the
time of poplar planting in selected plots at different distances from the trunk (0.25–1 m) and at different
soil depths (0–20 and 20–40 cm), at day 420. A significant decrease in PCB congeners and a reduction in
all heavy metals was observed where the poplar trees were present. No evidence of PCB and heavy metal
reduction was observed in the non poplar-vegetated soil. Microbial analyses (dehydrogenase activity, cell
viability, microbial abundance) of the autochthonous microbial community showed an improvement in
soil quality. In particular, microbial activity generally increased in the poplar-rhizosphere and a positive
effect was observed in some cases at up to 1 m distance from the trunk and up to 40 cm depth. The
Monviso clone was effective in promoting both a general decrease in contaminant occurrence and an
increase in microbial activity in the chronically polluted area a little more than one year after planting