Drought-resistant physiological characteristic of four dominated grass vegetation species during the seedling stage in dry-hot valley of the Jinsha River

• Jian-cha Li, 
• Dong-hong Xiong, 
• Jian-rui Kui, 
• Chun-xue Wang, 
• Bo Fan, 
• Bao-jun Zhang, 
• Ming-zhong Zhang, 
• Min Guo, 
• Liang-tao Shi