Effects Of Different Livestock Combination Grazing On Plant And Soil In Desert Steppe

This experiment was conducted to investigate effects of grazing system（single sheep or cattle grazing,mixed grazing of cattle and sheep）on plant community above-biomass,belowground net primary productivity,root mass fraction and soil-rootδ¹³C in desert steppe of Inner Mongolia Xilamuren grassland from 2014 to2015.The results indicated that grazing system affected the plant community above-biomass,belowground net primary productivity and root mass fraction significantly,but soil-rootδ¹³C.（1）The ground biomass increased rapidly from June to August.In addition to the cattle and sheep mixed grazing,the maximum of other treatments aboveground biomass was in August.Plant community biomass in Sheep grazing was significantly higher than the cattle grazing and cattle with sheep mixed grazing treatment.（p<0.05）.（2）The Belowground Net Primary Productivity of plant community produced greater difference in July.Cattle and sheep mixed grazing was significantly higher than other treatment,the underground net primary productivity were 9.76 g/m2 and9.76 g/m2 in July 2014 and July 2015 respectively.（3）The root mass fraction in 2015 was higher than 2014 with different grazing treatment,which of cattle and sheep mixed grazing changed obviously.（4）Different grazing livestock combination in a short period of time had no obvious effect on plant roots and soilδ¹³C.