Background Soil microbiomes play a crucial role in the overall health and stability of the desert ecosystem. Understanding how engineering construction influences the soil microbial communities is crucial for effective land management and sustainable development in desert regions.However, the mechanismunderlying thisinfluence remains unclear.

Methods We investigated deep soil bacterial communities (60-80 cm) beneath the transmission tower base, which has been built for two years, in the western Gonghe Basin of Qinghai province. High-throughput amplicon sequencingwas performed to explore bacterial communities (16S rRNA). Bioinformatics analyses were also deployed, including Principal Coordinates Analysis (PCoA), Mantel, and null model analysis.

Results The results revealed a significanteffect of tower base construction on the deep soil ecosystem. Chemical properties (soil microbial carbon, microbial nitrogen, organic carbon, total nitrogen, total phosphorus, total potassium, available phosphorus, available potassium) and α-diversity (Chao1 and phylogenetic diversity) significantly decreased after the tower base construction. Actinobacteria, Acidobacteria, and Proteobacteria dominated in deep soils, accounting for 50.08% of the total abundance. In particular, beneathtransmission tower, the abundance of anaerobic bacterial phyla such as Actinobacteria, Firmicutes, and Chloroflexi decreased significantly. Moreover, PCoAanalysis revealed that the bacterial community structure beneath the transmission towers had a dramatic difference from that in adjacent undisturbed lands. Null model analysisshowed that stochastic processes primarily influenced the assembly of bacterial communities in deep soils, bacterial communities beneath transmission towers demonstrated a notable increase in the randomness (|βNTI| > 2: 21.1%). Mantel test indicated thatkey driving factors of bacterial diversity and community structure in the deep soils were identified as pH, total nitrogen, and available phosphorus. The construction of tower bases disrupted the soil's physical structure, resulting in changes in soil chemical properties, which in turn impacted the composition and structure of the soil bacterial community.

Conclusions This study increases our understanding of the ramifications of human activities, particularly engineering construction and production, on the biotic environment of deep soil. The findings highlight the importance of sustainable practices in construction and land management. Furthermore, the study provides valuable theoretical support for soil and water conservation and ecological restoration of desert ecosystems.