Abstract: Bdelloid rotifers constitute a significant microfaunal taxon in soils. In this study, we investigated the effects of climate and soil physicochemical factors on the bdelloid rotifer community structures, with soil samples being collected from 18 sites in Northeast China (August 2024) and 19 sites in Xinjiang (September 2024). The differences in the bdelloid rotifer community structures and their relationships with environmental factors were compared between the two regions. The results showed that the species richness (36 species) and average abundance (1.15×10⁵ ind·m^-3) of bdelloid rotifers in the soil of Northeast China were significantly higher (P<0.05) than those of Xinjiang (24 species, 0.19×10⁵ ind·m^-3). A total of 21 species were identified in both regions, and the distribution of endemic species exhibited a significant ecological differentiation (15 species in Northeast China and 3 species in Xinjiang). The α diversity indices (Margalef, Shannon, Brillouin, and Simpson) exhibited significantly higher values in Northeast China than that in the Xinjiang (P<0.05). The dominant species were Rotaria sordida and Macrotrachela multispinosa brevispinosa, with dominance values of 0.26 and 0.22, respectively. The soil bdelloid rotifer community structure in Northeast China was driven by mean annual precipitation (15.3% explained) and hydrogen (10.8%). In contrast, in Xinjiang, it was driven by phosphorus (17.8%), sulfur (14%), and chromium (12.4%). Soil water content, titanium, and mean monthly precipitation were key regulators of bdelloid rotifer communities in both regions. These findings suggest that climatic conditions and soil physicochemical factors play a pivotal role in shaping the community structure of bdelloid rotifers in soils across diverse geographic regions.

Key words: bdelloid rotifer, biodiversity, soil fauna, climate change