Assessment of Soil Heavy Metal Pollution and Phytoremediation Potential of Dominant Species in Water-Level-Fluctuation Zone of Large Reservoir

The water-level-fluctuation zone of a reservoir is an important connection between land and water; due to counter-seasonal rhythmic water level changes, this area is more sensitive and vulnerable, whereas the assessment and management of heavy metal pollution are still elusive. This study selected the water-level-fluctuation zone in the hinterland of the Three Gorges Reservoir. Through a quadrats investigation, the soil pollution status of seven heavy metals and the composition of herbaceous plants were identified, and the potential of the dominant species for phytoremediation was assessed. The results showed that the overall pollution was at the alert level (PN = 0.97) and a low ecological risk level (RI = 123.12). And the study area was primarily contaminated by a mixed source of traffic, agriculture, and industry. A total of 17 dominant species were calculated using importance values. Most dominant species had better phytoremediation potential for Cd and Cu. None of the 17 dominant species were hyperaccumulators, but they could still play an important role in phytoremediation due to their high adaptability to specific environments. The results have guiding significance for the management and remediation of soil heavy metal pollution in global reservoir areas, further promoting global ecological security and sustainable development.