[1] Sichuan Acad Agr Sci, Soil & Fertilizer Inst, Chengdu 610066, Sichuan, Peoples R China
[2] Kadoorie Conservat China, Kadoorie Farm & Bot Garden, Tai Po, Lam Kam Rd, Hong Kong 999077, Peoples R China
[3] Cornell Univ, SRI Int Network & Resource Ctr, Ithaca, NY 14853 USA