Effects of Heavy Grazing on Interspecific Relationships at Different Spatial Scales in Desert Steppe of China

This study investigates the effects of grazing intensity and spatial scale on the important values, interspecific relationships, and community stability of desert steppe plant communities in Siziwang Banner, Inner Mongolia, China. Using vegetation data collected at three spatial scales (50 m × 50 m, 25 m × 25 m, and 2.5 m × 2.5 m) under two grazing conditions (no grazing and heavy grazing), we employed ecological statistics, including variance ratio analysis, χ 2 tests, and the Jaccard index, to analyze species interactions and community structure. The results indicated that the important values of species vary with both spatial scale and grazing intensity; for example, Stipa breviflori and Chenopodium aristatum exhibited significantly higher important values in heavily grazed areas. Larger spatial scales enhanced the dominance of Cleistogenes songorica and Chenopodium aristatum , while smaller scales favored Stipa breviflori and Caragana stenophylla . Furthermore, interspecific associations were stronger in heavy grazing conditions. The community demonstrated consistent instability; however, no grazing areas were more stable than heavily grazed ones. These findings highlight that species importance, interspecific relationships, and community stability are closely linked to grazing intensity and spatial scale, emphasizing the critical role of sustainable grazing management in maintaining the long-term stability and resilience of desert steppe ecosystems. By emphasizing the need for targeted and sustainable management strategies, this study aims to contribute to the restoration and preservation of these vital ecosystems.