Latitude distribution characteristics of soil microbial communities in the

Introduction: Investigating soil microbial spatial distribution is essential for understanding ecosystem responses to climate change. Studies on single vegetation types and their influencing factors are limited. Methods: We focused on soil samples from Results: The results showed that dominant bacterial and fungal groups generally exhibited a "unimodal" or "U-shaped" distribution pattern along the latitudinal gradient, with both the highest and lowest values occurring in the mid-section of the study area. Bacterial alpha diversity was higher than fungal alpha diversity. Along the latitudinal gradient, bacterial alpha diversity followed a nonlinear cubic trend, peaking in the southern section and reaching a minimum in the northern section. For fungi, richness displayed a U-shaped pattern, Shannon and evenness indices increased linearly, and the Simpson index decreased linearly. Pearson correlation and redundancy analyses indicated that soil total nitrogen, sand content, total carbon, total phosphorus, litter carbon, and leaf water content influenced bacterial community composition. Fungal communities were primarily affected by mean annual precipitation, soil total nitrogen, nitrate nitrogen, silt content, leaf water content, and litter nitrogen. Discussion: These findings highlight the complex spatial patterns of soil microbial communities in shrublands and reveal key environmental drivers shaping their distribution. Understanding these patterns provides a critical basis for predicting how soil microbial diversity and composition may respond to environmental changes along latitudinal gradients.