关键词: 迁移特征, 重金属, 土壤-根系界面

Abstract: Taking ligustrum lucidum in the coal mine reclamation area at Huainan，Anhui，China as an example，the Paper，based on the characteristics of adsorption of heavy metals in soil by woody plants，comes up with a new sampling scheme and lays out sampling points. Meanwhile，it determines the concentrations of heavy metals Cu，Zn，Cd，Cr and Pb in samples by using graphite furnace method. Through the analysis of the trend of multi-parameter statistical regression，the thesis explores migration characteristics of heavy metals in the soil - root interface system. The results are as follows：firstly，in the system of soil and ligustrum lucidum，along the root system，the migration ability of some heavy metals，such as Cu，Zn and Cd，becomes strong gradually. It mainly ranges from 60cm to 90 cm. The content variation of these three heavy metals fluctuates greatly. The migration ability of heavy metals，such as Cr and Pb，is relatively weak，and the content variation of these metals is relatively stable. Secondly，the space migration characteristics of heavy metals in the system of soil and ligustrum lucidum are related to the ability of plants to absorb and accumulate these heavy metals. That is，the roots of woody plants have strong ability to absorb and accumulate these heavy metals，and thus their migration ability is relatively strong while the content variation fluctuates greatly along the root system. The migration characteristics follow a cubic curve model along the root. The model can be expressed as y=ax³+bx²+cx+d. Also，the content variation of these metals has a main accumulation range. Therefore，the research shows that，in the coal mine reclamation area in Huainan，the weaker the ability of ligustrum lucidum to absorb and accumulate heavy metals is，the weaker its migration ability is. Meanwhile，the research reveals that the accumulation characteristics follow a linear model. When researching into the migration characteristics of heavy metals in the system of soil and ligustrum lucidum，many factors should be taken into consideration，such as existing forms of heavy metals，the interaction between them，and the varieties and ages of woody plants. Therefore，the research direction in the future should focus on different existing forms of heavy metals and influence of interaction between them on migration characteristics. Hence，the research provides scientific evidence to the promotion and application of phytoremediation technology. The study of spatial distribution characteristics of heavy metals in soil-root system has important theoretical and realistic significance for the research of soil pollution risk assessment and phytoremediation effect on soil in the coal mine reclamation area.

Key words: migration characteristics, heavy metal, soil-root interface