1. Institute of Mountain Hazards and Environment; Chinese Academy of Sciences; Chengdu 610041 China
2. Univ. of Chinese Academy of Sciences; Beijing 100049 China
3. College of Tourism and Land Resource, Chongqing Technology and Business Univ.; Chongqing 400067 China
4. Dep. of Soil Science; Univ. of Trier; 54286 Trier Germany
5. College of Material and Chemical Engineering, Hainan Univ.; Haikou 570228 China