Effects of single and mixed grazing of yak and Tibetan sheep on the balance between vegetative and reproductive growth of Potentilla acaulis in alpine grassland

• WANG Fangcao, 
• DONG Quanmin, 
• FENG Bin, 
• LIU Yuzhen, 
• YU Yang, 
• YANG Xiaoxia, 
• ZHANG Chunping, 
• CAO Quan, 
• LIU Wenting