罗汉果主产区土壤重金属潜在生态危害评价

Evaluation of potential ecological risk from heavy metals in soil of main producing Siraitia grosvenorii areas

对桂北罗汉果主产区8套地层上A层土壤及罗汉果的果实中5种重金属元素(As、Cd、Pb、Hg、Cr)含量进行测试分析,利用区域土壤背景值分析了不同地层上A层土壤的质量,并采用Hakanson潜在生态危害指数法分析了土壤重金属元素的潜在生态危害程度。研究结果表明:罗汉果主产区8个地层上的A层土壤污染程度属于中度及中度以上,其中K层为中度污染区,-Cq、Pt21地层区则为重度污染区,产生污染的重金属元素主要为Pb、Cr、As;8个地层土壤上生长的罗汉果的果实中5种重金属元素的含量远低于国家绿色行业标准值,表明罗汉果在桂北喀斯特生态区具有抗土壤污染和果实优质的特征,应加大对该资源植物的开发力度,促进区域经济发展和生态环境的建设。

This paper tests and analyses the contents of 5 heavy metal elements （As, Cd, Pb, Hg, Cr） in the Siraitia grosvenorii and the A layer soil on 8 different formations in the north region of Guilin City. The authors analyze the quality of the soil and study potential ecological harm degree of the heavy metal elements in the soil by use of the Hakanson potential ecological risk index. The results are as follows. The pollution level of the A layer of soil shows medium or above. For example, K formation is a moderate pollution area and ￠q and Pt1^2 formations are strength contamination zones. The main pollution elements are Pb, Cr, and As. The content of 5 heavy metal elements in the Siraitia grosvenorii are far lower than the national green industry standard value, indicating that the Siraitia grosvenorii is characterized by anti-pollution and high quality in the karst-ecological region. Thus, the development of resource plant Siraitia grosvenorii should be strengthened.