Effects of grazing intensity on dominant populations and species diversity in a Stipa breviflora desert steppe

In thus study, we sought to determine the effects of grazing intensity on the dominant populations, species diversity, and their interrelationships in a Stipa breviflora desert steppe region of Sunite Right Banner, Xilin Gol League, Inner Mongolia. Using a single-factor randomized block design, we assessed the effects of three experimental grazing treatments, namely, no grazing (as a control), moderate grazing, and heavy grazing, which were assessed using a combination of comparative and advantage analyses. The results revealed that there were no significant differences in the importance value of the different dominant populations and species diversity indices in plots grazed at different intensities (P > 0.05). On the basis of the absolute quantitative relationship, the richness and diversity indices in plants the S. breviflora desert steppe were found to be particularly sensitive to the intensity of grazing, whereas on the basis of the relative and comprehensive quantitative relationships, we detected considerable changes in diversity and dominance indices in response to moderate grazing, and a pronounced change in the evenness index under heavy grazing. In terms of the relative and absolute quantitative relationships, we detected no significant changes in the dominance order of dominant populations in response to different grazing treatments, whereas in contrast, the dominance order of species diversity was considerably affected by these relationships. These findings indicate that the dominant populations and species diversity indices of desert steppe plant communities can adapt to the influence of grazing intensity by adjusting their correlation intensity.