[Planning of ecologically suitable areas for Ligusticum chuanxiong under background of soil cadmium pollution].

Chuanxiong Rhizoma is a traditional Chinese medicinal material mainly produced in Sichuan and Chongqing of China. In recent years, the cadmium content in Chuanxiong Rhizoma produced in most of the genuine producing areas has exceeded the standard, which makes Chuanxiong Rhizoma difficult to be exported. To solve the problem of excessive cadmium content in soil, this study employed the MaxEnt model to simulate the potential geographic distribution of Ligusticum chuanxiong and evaluate important environmental factors, and re-plan its ecologically suitable areas based on the mineral distribution characteristics and soil cadmium pollution status. The results showed that the places suitable for L. chuanxiong growing covered an area of 335 523.69 km2, mainly in central and eastern Sichuan, southern Shaanxi and most parts of Chongqing. Among them, the highly suitable areas of L. chuanxiong were mainly concentrated in Chengdu, Ya'an, Deyang, and Mianyang. Solar radiation, annual precipitation, and annual range of temperature were evaluated as important variables affecting the distribution of L. chuanxiong, with the contribution rates of 62.3%, 13.3%, and 6.8%, respectively. In addition, Qionglai county, Chongqing county, Mianyang city(Youxian district and Fucheng district), Qingchuan county, and Xinjin county were classified into the first-class ecologically suitable zone, covering a total area of 2 768.87 km2. The se-cond-class ecologically suitable zone was even wider, involving such counties as Tongjiang county, Renshou county, Jianyang county, and Nanjiang county, and the total area reached 43 616.92 km~2. The re-planning of the ecologically suitable areas for L. chuanxiong has provided strong data support for the cultivation and resource development of L. chuanxiong and also new ideas for solving the problem of excessive cadmium content in L. chuanxiong.