## 3 Results
### Bacterial Communities and Diversity  
Relative bacterial OTU richness was present in four different soil samples across phylum, class, order, family, and genus (Figure 3). The dataset for phylogenetic analyses comprised 1 kingdom, 3 phyla, 7 classes, 7 orders, 16 families and 40 genera. The heatmap plot depicted the relative abundance of each dominant genera (variables clustering on the \(Y\)-axis) within soil samples (\(X\)-axis clustering) (Figure 4). As shown in Figure 4, four samples from CK grouped together; Cn-R2, Cn-R1, Er-R3, Er-R2 grouped together; and Py-R2 and Py-R3 grouped together. The 50 most abundant genera were depicted. The results show that the majority of sequences belonging to _Asteroleplasma_, _Enterococcus_, _Opittuus_, and _Alkalophilus_ were presented in soil from the CK group. _Dokdonella_, _Pseudomonas_, _Snaeromyxobacter_, and _Hyphomicrobium_ were presented in soil from the Er-R and Cn-R groups. _Candidatus Xiphinematobacter_, _Mycobacterium_, _Bradyrhizobium_, and _Nostocoida_ were presented in soil from the Py-R groups. We observed that the class _Proteobacteria_ had the highest abundance (24.43%) in the rhizosphere soils of the three plants and soil samples from grassland plots, followed by _Acidobacteria_ (21.09%), _Verrucomicrobia_ (19.48%), _Planctomycetes_ (9.20%), and _Anctinobacteria_ (5.53%) (Figure 5).  
A Venn diagram (Figure 6) illustrates that the bacterial communities of _E. rufipilus_ (Er) shared 4095 OTUs between bulk (Er-B) and rhizosphere soils (Er-R) (Figure 6a); the bacterial communities of _C. nepalensis_ (Cn) shared 3824 OTUs between bulk (Cn-B) and rhizosphere soils (Cn-R) (Figure 6b); the bacterial communities of _P. yunnanensis_ (Py) shared 2817 OTUs between bulk (Py-B) and rhizosphere soils (Py-R) (Figure 6c); and the bacterial communities among the four groups (Er-R, Cn-R, Py-R, and CK) shared 2516 OTUs (Figure 6d). The OTUs derived from the soil associated with the three plant species showed that rhizosphere soils had more OTUs than bulk soils (Figure 6a-c).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Soil Sample** & **Chao1** & **ACE** & **Simpson** & **Shannon** \\ \hline Er-R & 1868(1748,1953) & 2302(2135,2478) & 0.99151443 & 8.93(8.85,9.02) \\ \hline Cn-R & 1817(1668,2068) & 2209(2010,2503) & 0.989189011 & 8.78(8.72,8.82) \\ \hline Py-R & 1595(1428,1745) & 2036(1736,2193) & 0.981008466 & 8.11(7.72,8.36) \\ \hline CK & 2012(1682,2333) & 2511(1682,3530) & 0.990400468 & 8.91(8.42,9.24) \\ \hline \hline \end{tabular} Notes: The values in parentheses show the upper and lower limits; Er-R, rhizosphere soil of _Erianthus rufipilus_; Cn-R, rhizosphere soil of _Coriaria nepalensis_; Py-R, rhizosphere soil of _Pinus yunnanensis_; CK, soil from grassland plots.  
\end{table}
Table 3: Comparison of richness and diversity indices among the rhizosphere soils and grassland plots.  
Figure 3: The phylogenetic tree of partial 16S rRNA gene read information based on NCBI Taxonomy by MEGAN. Notes: Er-R, rhizosphere soil of _Erianthus rufipilus_; Cn-R, rhizosphere soil of _Coriaria nepalensis_; Py-R, rhizosphere soil of _Pinus yunnanensis_; CK, soil from grassland plots.  
Figure 4: Hierarchically clustered heatmap of rhizosphere bacterial communities of dominant plants at the genus level. Soil samples are clustered laterally based on their bacterial similarity and bacterial taxa are clustered vertically. The red color represents the genus with higher abundance and green color represents the genus with lower abundance. Notes: Er-R, rhizosphere soil of _Erianthus rufipilus_; Cn-R, rhizosphere soil of _Coriaria nealensis_; Py-R, rhizosphere soil of _Pitus yunnensis_; CK, soil from grassland plots.  
Figure 5: Hierarchical tree of dominant bacterial groups at classification level based on GraPhlAn software, it shows units of classification from phyla to genus (inner to outer rings). Size of nodes indicated the abundance.