Multiple environmental stressors interactively affect soil phosphorus cycling microbiomes

Abstract Soil phosphorus (P) cycling microorganisms (PCMs) facilitate organic P mineralization (represented by the phoD gene) and inorganic P dissolution ( pqqC ), driving terrestrial P cycling and enhancing P availability to plants. However, the interactive effects (i.e., additive, synergistic, and antagonistic interactions) of multiple environmental stressors (i.e., acidification, salinization, drought, metal pollution and human disturbance) on PCMs remain unclear. Combining a large-scale survey and controlled experiments, we found that the interactive effects of stressors with significance on PCM abundance and diversity were more ubiquitous than the effects of individual stressors. Specifically, acidification and drought had antagonistic and synergistic effects on the abundances of organic P mineralization microorganisms and inorganic P dissolution microorganisms, respectively, while antagonistic effects between drought and metal pollution were observed on the diversity of these microorganisms. The PCM changes were associated with soil P-related stoichiometric parameters under interactive effects, indicating that interactive stressors strongly influenced microbial-regulated P cycling and P availability in soil. These findings underscore the need to incorporate interactive stressor effects into strategies for sustainable soil P management and ecosystem resilience.