Background Desert soils are vulnerable and susceptible to environmental changes and human activities. However, the mechanisms by which soil microorganisms respond to increasing human disturbances remain unclear. In particular, the construction of transmission lines in desert areas introduces a complex array of disturbances, physical disruption of soil structure, alterations in soil chemistry, and changes in local hydrology, that can significantly affect microbial communities.

Methods This study selected five 2-year-old transmission tower bases in the northwest of Yanchi County, Ningxia Province. Sites were chosen based on uniform soil and vegetation characteristics, minimizing variability unrelated to disturbance. Systematic field sampling was conducted at multiple depths and distances from each tower, along with parallel sampling in nearby undisturbed land as controls. Collected soils underwent standard physicochemical measurements to contextualize microbial findings. High-throughput 16S rRNA gene sequencing characterized bacterial communities, and bioinformatics workflows, including sequence quality control, clustering, taxonomic assignment, and statistical analyses, were applied to assess changes in soil bacterial community compositions, diversity, and structure between disturbed and undisturbed sites.

Results The results revealed that the α-diversity of bacteria in the surface soil in the disturbed land was significantly higher than that in the undisturbed land, while the β-diversity was markedly lower. The bacterial communities in the disturbed land were predominantly composed of Cyanobacteria and Actinobacteria, with major families including Phormidiaceae, Chroococcidiopsaceae, and Trueperaceae. In contrast, the dominant bacterial phylum in the undisturbed land was Proteobacteria, and key families were Sphingomonadaceae, Beijerinckiaceae, and Rhodobacteraceae. NMDS analysis indicated that a significant difference in the bacterial community structure between the disturbed and un-disturbed land (P = 0.009). Compared to the undisturbed land, the bacterial co-occurrence network in the disturbed land exhibited simpler and more unstable characteristics, suggesting greater sensitivity of the bacterial communities under the tower to environmental changes. Mantel test further demonstrated that pH, available potassium, soil organic carbon, and total nitrogen were the main factors contributing to the differences in bacterial community structures between the disturbed and undisturbed land.

Conclusions The findings indicate that the construction of transmission towers significantly disruptes the soil environment, resulting in alterations to the composition and structure of bacterial communities. This disturbance heightens competition among bacterial species and reduced the stability of the community structure, making it more vulnerable to environmental fluctuations. This study provides theoretical insights and technical supports for soil ecological restoration and management in the context of transmission tower construction.