Acknowledgments
This work was supported by the Public Welfare Project of the National Scientific Research Institution (No.CAFRIFEEP201101), China, and the National Biological Specimens and Resources Sharing Platform in Nature Reserve (No. 2005DKA21404). We also gratefully acknowledge Dr. Ye Deng, Dr. Yunfeng Yang, Mr. Jingyuan Yang, Mr. Kun Liu, Mr. Min Wang and Dr. Yadong Xue for helping data analysis and survey the field plant plots.