3.4. Factors affecting the distribution of the Bathyarchaeial community
Our findings revealed that deterministic processes played a substantial role in the assembly of highly prevalent Bathyarchaeia , particularly the Bathy-6 subgroup. This suggests that environmental filtering is a pivotal factor influencing their community structure. Consequently, we conducted an in-depth exploration of the relationship between environmental parameters and the distribution ofBathyarchaeia and Bathy-6 .
The statistical analysis demonstrated that the relative abundance ofBathyarchaeia exhibited a significant negative correlation with soil C/N and a positive correlation with the mean annual temperature (MAT) (as portrayed in Fig. 4a, p < 0.01). In the case of the Bathyarchaeial community, soil pH and C/N emerged as the two principal factors shaping the communities of Bathyarchaeia andBathy-6 . This observation was reinforced by the results of structural equation modeling (SEM), which assessed the direct and indirect impacts of environmental parameters on the Bathyarchaeial community and Bathy-6 (Fig. 4b). SEM outcomes indicated that theBathy-6 community could be directly influenced by soil pH and the Bathyarchaeial community. Moreover, the relative abundance ofBathy-6 was positively affected by MAT and indirectly influenced by soil C/N and pH.
Furthermore, we performed Pearson’s analysis to assess the influence of environmental parameters on the abundance of Bathyarchaeial subgroups detected in this study. The results indicated that soil EC, SOM, NH4+, NO3, Fe, TN, and TC exhibited predominantly positive correlations with Bath-5bb ,Bathy-15 , Bthy-11 , and negative correlations withBathy-17 . The relative abundance of Bathy-6 displayed significant negative correlations with pH and C/N and positive correlations with MAT (Fig. 4c).
Moreover, Random Forest analysis provided further insights, indicating that MAT, C/N, and pH are the primary factors driving the distribution of Bathy-6 (Fig. 5). These results underscore that Bathy-6tends to have a higher abundance in environments characterized by higher temperatures, lower C/N ratios, and slightly acidic conditions (Fig. 5).