title: TCMGIS-II based prediction of medicinal plant distribution for conservation planning: a case study of Rheum tanguticum.
abstract: BACKGROUND
  Many medicinal plants are increasingly endangered due to overexploitation and habitat destruction. To provide reliable references for conservation planning and regional management, this study focuses on large-scale distribution prediction of Rheum tanguticum Maxim. ex Balf (Dahuang).
  
  
  METHODS
  Native habitats were determined by specimen examination. An improved version of GIS-based program for the distribution prediction of traditional Chinese medicine (TCMGIS-II) was employed to integrate national geographic, climate and soil type databases of China. Grid-based distance analysis of climate factors was based on the Mikowski distance and the analysis of soil types was based on grade division. The database of resource survey was employed to assess the reliability of prediction result.
  
  
  RESULTS
  A total of 660 counties of 17 provinces in China, covering a land area of 3.63 × 106 km2, shared similar ecological factors with those of native habitats appropriate for R. tanguticum growth.
  
  
  CONCLUSIONS
  TCMGIS-II modeling found the potential habitats of target medicinal plants for their conservation planning. This technology is useful in conservation planning and regional management of medicinal plant resources.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yu
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China.
authors.forename: Caixiang
authors.initials: C
authors.lastname: Xie
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China.
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Song
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China.|Technology Development Centre, China National Group Corporation of Traditional and Herbal Medicine, Beijing 100094, China.
authors.forename: Yingqun
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China.|Hubei University of Chinese Medicine, Wuhan 430065, China.
authors.forename: Shilin
authors.initials: S
authors.lastname: Chen