Study on Suitability Zoning of Astragalus membranaceus var. mongholicus in Dingxi City Based on MaxEnt and ArcGIS / 中国药房

ABSTRACT

OBJECTIVE：To study the ecological suitability zoning of Astragalus membranaceus var. mongholicus in Dingxi city. METHODS ：Taking 1 001 batches of A. membranaceus var. mongholicus in Dingxi city as the investigation samples （each natural village with A. membranaceus var. mongholicus cultivation as the collection unit ），the longitude and latitude information of them were obtained from Dingxi economic crop technology promotion station ，and 55 environmental ecological factors （including climate，terrain，soil，etc.）were obtained from the Grid Database of Spatial Information of TCM Resources . Combined with the information of longitude ，latitude and environmental ecological factors ，the maximum entropy model （MaxEnt model ） was established with 75％ samples as the training set ，and the main ecological factors were screened out ，and 25％ samples were set as the validation set for model validation. Then the suitable growing areas of A. membranaceus var. mongholicus were divided by using ArcGIS. RESULTS ：Established MaxEnt model had good prediction （the area under the working characteristic curve of subjects in training set and verification set was 0.970 and 0.968）. Eight main ecological factors ，such as altitude ，precipitation and temperature ， were selected （the total contribution rate was 98.90％）. The comprehensive analysis found that the altitude was 1 800 to 2 650 m， the average precipitation in April was 25 to 50 mm，the lowest temperature of the coldest month was －16 to －8 ℃，the wettest monthly precipitation was 95 to 110 mm，and the seasonal variation of temperature was 70 to 80，the average temperature in December was －6 to －3 ℃ ，the average precipitation in October was 30 to 50 mm，and the average precipitation in December was 0 to 10 mm，which was the suitable environmental parameter for the growth of A. membranaceus var. mongholicus in Dingxi city. Based the results of ArcGIS analysis ，in Dingxi city ，A. membranaceus var. mongholicus was generally suitable for growth ；in the northwest of Lintao county ，the north of Anding district ，the south of Tongwei county ，a small area in the south of Longxi county and the south of Minxian county ，the border between Weiyuan county ，Zhangxian county and Minxian county ，A membranaceus var. mongholicus was not suitable for growth. CONCLUSIONS： Ther results of established model is in E-mail：961308817@qq.com line with the actual investigation ， can provide reference for the planting regional planning of A. membranaceus var. mongholicus in Dingxi city.