Abstract:To elucidate the structure and functional characteristics of soil fungal communities in extreme arid desert environments and their driving factors, this study was designed to investigate the desert aeolian soils from Bachu, Pishan, Hotan, Minfeng, and Qiemo counties in the Tarim Basin. Illumina MiSeq high-throughput sequencing and FUNGuild platform analysis were employed to characterize the soil fungal communities. The findings revealed: (1) A total of 1,719 soil fungal OTUs were obtained from the desert soil of the Tarim Basin, belonging to 11 phyla, 40 classes, 100 orders, 206 families, 375 genera, and 558 species. Among them, the phylum Ascomycota dominated absolutely, and contained a large number of unidentified genera (with a relative abundance exceeding 30%). The soil fungal α-diversity index in Bachu County was significantly lower than that in other regions (P<0.05). Significant β-diversity differences were observed, with geographically proximate areas harboring more similar fungal community structures. (2) Saprotrophic and "other" trophic modes predominated across the study area, whereas pathotrophic fungi showed relatively low abundance. Notably, Qiemo County exhibited a more balanced distribution of fungal trophic guilds. (3) The soil fungal α diversity exhibited a highly significant positive correlation with soil pH (P<0.01). The distribution of dominant fungal genera is driven by key environmental factors, including soil properties (TN, TP, EC, pH) and climate parameters (temperature, precipitation, sunshine duration). Geographic location, climatic factors, and soil physicochemical properties collectively explained 33.03% of the variance in desert soil fungal community composition. The relative abundance of symbiotrophic fungi showed highly significant positive correlations with all climatic factors (P<0.01) and a significant negative correlation with soil electrical conductivity (P<0.05). Saprotrophic fungi demonstrated a highly significant positive correlation with soil pH (P<0.01) and a significant positive correlation with annual mean sunshine duration (P<0.05). Pathotrophic fungi exhibited a significant negative correlation with annual mean precipitation (P<0.05). These findings provide critical insights into the structural and functional characteristics of fungal communities in the desert soils of Tarim Basin, and further offering a scientific foundation for biodiversity conservation and functional microbial resource utilization in arid ecosystems.