Effects Of Grazing On Plant Community Characteristics And Belowground Net Primary Productivity 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 characteristics and belowground net primary productivity in desert steppe of Inner Mongolia Xilamuren grassland from 2012 to 2013. The results indicated that grazing system affected the community characteristic and belowground net primary productivity significantly.(1)The community above-ground biomass of cattle grazing, mixed grazing and sheep grazing were 54.99g/m2,57.83g/m2 and 69.64g/m2, respectively in 2012, and 53.12g/m2,59.93g/m2 and 72.31g/m2, respectively in 2013, which decrease under cattle grazing and mixed grazing compared with sheep grazing. There is no significant difference between cattle grazing and mixed grazing.(2)Grazing reduced the height of plant, and the cattle grazing and mixed grazing were the more apparent. The plant community cover under grazing treatments did not differ significantly. The community density increased under grazing treatments, and the mixed grazing was the more apparent. The sheep grazing improved the important value of Stipa krylovii, whereas decreased the important value of legumes and forbs.(3)The mixed grazing improved the plant community diversity under moderate grazing. The sheep grazing decreased plant species richness, Shannon-Wiener index and evenness.(4)The belowground net primary productivity decreased under single grazing, whereas was not affected by mixed grazing.