Rodent disturbance significantly affected the composition of soil bacterial community in alpine meadow

DongSheng YuZelong ZhangJingru ChenLili Nan^*

• Gansu Agricultural University, Lanzhou, China

Alpine meadows represent one of the predominant ecosystem types on the Tibetan Plateau, comprising 35% of the total area of the plateau. This study aimed to investigate the effects of rodent disturbances-specifically through foraging, burrowing, and mound-building-on the physicochemical properties of alpine meadow soil and the diversity of bacterial communities. Healthy meadows served as the control, while disturbed meadows featuring zokor mounds were utilized as experimental subjects. The study explored the response mechanisms of soil physicochemical factors, enzyme activity, and bacterial community structure to rodent disturbances across two distinct habitat types. Furthermore, it assessed the relationship between bacterial community diversity and soil physicochemical properties and enzyme activity. The results indicated that rodent disturbances led to significant decreases (P<0.05) in several factors, including soil water content, electrical conductivity, alkaline phosphatase, catalase, sucrase, urease, soil organic carbon, carbon-to-nitrogen ratio, microbial biomass carbon, nitrogen, and the alpha diversity indices of the bacterial community (Simpson and Shannon-Wiener indices) in zokor mound patches. The disturbance behavior exhibited a significant effect on soil bacterial community beta diversity (R² =0.377, P<0.001), with soil organic carbon (SOC) identified as the most significant environmental factor influencing beta diversity (P<0.01). Pearson correlation analysis revealed significant correlations between the diversity of various bacterial communities and soil physicochemical properties as well as biological characteristics (P<0.05). The dominant phyla identified were Acidobacteriota (33.43%-32.37%), Verrucomicrobiota (21.04%-26.84%), Proteobacteria (20.46%-16.65%), and Bacteroidota (3.02%-4.02%). Redundancy analysis revealed that the carbon-tonitrogen ratio, with an explanatory rate of up to 64.8%, was the primary factor driving changes in bacterial communities. These findings enhance our understanding of the impacts of rodent bioturbation on the characteristics of bacterial communities within the alpine meadow ecosystems of the Tibetan Plateau. They also provide theoretical support for mechanisms related to degradation, restoration, and the prevention of rodent damage in alpine meadows ecosystems.