Abstract Aims This study aimed to examine the relationships between rhizosphere (RS) microorganisms of the desert pioneer plant Psammochloa villosa and soil nutrient availability, with the goal of clarifying microbial mechanisms supporting its persistence in desertified regions and identifying potential targets for microbiome-based management. Methods and Results Using absolute quantification of 16S rRNA gene and ITS sequencing, microbial communities in the RS of P. villosa were compared with those in bulk soil (BS). The results showed that the rhizosphere of P. villosa had significantly lower total phosphorus (TP) but higher carbon-to-phosphorus (C/P) and nitrogen-to-phosphorus (N/P) ratios than BS, while the available nitrogen-to-available phosphorus ratio (AN/AP) was 4–5 times higher than N/P. This pattern suggests that the RS experiences stronger phosphorus limitation than BS. A lower fungi-to-bacteria (F/B) ratio in the RS relative to BS was positively associated with TP and negatively associated with soil C/P and N/P ratios, indicating a bacterial-dominated community under phosphorus-limited conditions. Structural equation modeling further indicated that rhizobacterial diversity strongly promoted the acquisition of available nutrients by significantly affecting soil organic carbon (SOC), TP, and stoichiometric balance. Conclusions These results indicate that bacterial diversity is tightly linked to the regulation of ecological stoichiometry and nutrient availability under P-limited conditions in the rhizosphere of P. villosa.
Guo et al. (Fri,) studied this question.