Abstract: Grasshopper abundance was compered between Aneurolepidium chinense and Stipa grandis steppes which were grazed and excluded from livestock. The abundance of Dasyhippus barbipes dominated on Stipa grandis steppe is 4～5 times as high as that of Chorthippus dubius on Aneurolepidium chinense steppe. After exclusion from livestock for 13 years, the total biomass of grasshopper is increased by 24% on Anearolepidium chinense steppe, and is decreased a little on Stipa grandis steppe. The livestock exclusion leads to changes in structure and compeition of grasshoppers. The abundance of Angaracris barabensis, Dasyhippus barbipes, Myrmeleote ttix palpalis and Oedaleus asiaticus is decreased and that of Chorthippus fallax, Mongolotet tix japonicus vittatus and Omocestus haemorrhoidalis is increased. The biomass of Calliptamus abbreviatus and Chorthippus dubius is increased on Aneurolepidium chinense steppe, but decreased on Stipa grandis steppe.

Key words: Livestock exclusion, Grasshopers, Abundance, Aneurolepidium chinense steppes, Stipa grandis steppes, 16S rDNA sequences, catalase, endophytic bacteria, wheat seedling, peroxidase, salt stress