Research On Plant Growth Characteristics And Heavy Metal Interaction Mechanism In Three Gorges Reservoir Riparian Zone

The rule of anti-seasonal flooding in the Three Gorges Reservoir area caused a large number of deaths of primary plants on both sides of the slope,and the exposed soil mass formed a special area with a drop of 30m on both sides of the reservoir area,namely,the riparian zone.Riparian zone has caused serious soil erosion,environmental pollution of the slopes on both sides and serious damage to the ecosystem.In this paper,plant remediation technology is used to control the riparian zone in the Three Gorges Reservoir area.Indoor simulation and outdoor model test methods are used to introduce dominant species that can adapt to the rule of anti-seasonal flooding and harsh environment in the reservoir area,study their physiological characteristics,study the tolerance and absorption capacity of dominant species to heavy metals,so as to improve the ability of dominant species to better adapt to the environment in the reservoir area.The conclusions are as follows:?1?The plant species distribution in the reservoir area investigated on the spot is related to the regional soil fertility and the elevation difference of plant growth.In areas with frequent human and animal activities,there are many kinds of plants;in areas with low elevation,there are many kinds of herbaceous plants;in areas with high elevation,in addition to the rich varieties of herbaceous plants,some arbor plants can also survive and have different kinds.?2?Indoor and outdoor simulation experiments explore the influencing factors of C.dactylon growth status by simulating the anti-seasonal flooding law in the reservoir area.The results show that the important factor affecting the growth status of the dominant species of C.dactylon in the reservoir area is the elevation difference.The higher the height,the greater the number of C.dactylon,the higher the average height and greening rate,and the better the growth state.On the contrary,the fewer C.dactylon,the lower the average height and greening rate,the worse the growth state;by comparing the state of C.dactylon before and after the flooding test,it was found that the growth state of C.dactylon decreased every time it experienced periodic flooding in the reservoir area compared with the previous year.Growth advantage is reduced.?3?There are differences in the treatment ability of the dominant species of C.dactylon and Abutilon theophrasti Medicus to heavy metal contaminated soil:the tolerance and absorption ability of C.dactylon to Cu²⁺and Zn²⁺were stronger than that of Abutilon theophrasti Medicus,the tolerance of Zn²⁺is higher than that of Cu²⁺,and the absorption of Cu²⁺is higher than that of Zn²⁺;the tolerance of Abutilon theophrasti Medicus to Zn²⁺was stronger than Cu²⁺,and the absorption of Cu²⁺was higher than Zn²⁺.