# Coniferous-broadleaf mixed plantations reshape phosphorus-solubilizing bacterial communities and enhance soil phosphorus bioavailability in subtropical forests

## TL;DR

Mixed plantations of coniferous and broadleaf trees improve soil phosphorus availability by changing bacterial communities in subtropical forests.

## Contribution

The study reveals how mixed plantations reshape phosphorus-solubilizing bacterial communities and enhance soil phosphorus bioavailability.

## Key findings

- Mixed plantations increased labile phosphorus pools, especially in rhizosphere soils.
- Bacterial communities harboring pqqC genes were closely linked to phosphorus fractions.
- Soil properties had a stronger influence on rhizosphere phosphorus availability than plant properties.

## Abstract

Mixed-species plantations are proven to enhance phosphorus (P) availability in subtropical forest ecosystems. However, the effect of coniferous-broadleaf mixed plantations on soil P cycling dynamics remains poorly understood. Through a long-term field experiment, the study investigated how mixed plantations influence soil P fractions, phoD and pqqC genes, and associated bacterial communities in bulk and rhizosphere soils. Results showed that compared to monocultures, the introduction of broad-leaved trees significantly increased labile P pools, particularly in the rhizosphere. Amplicon-based community profiling of phoD/pqqC genes demonstrated distinct compositional shifts in P-solubilizing bacterial communities across forest types and soil compartments. The pqqC-harboring bacterial communities were more closely related to the P fractions. More importantly, plant properties were important in explaining bulk soil labile P responses, while in rhizosphere soil, labile P was more strongly associated with soil properties, positively affecting labile P. These findings elucidate the complex interplay between tree diversity, microbial functional traits, and soil P transformations. This study underscores the critical role of mixed plantations in promoting microbial-mediated P mobilization and provides valuable insights for designing sustainable forest management strategies to optimize P utilization in subtropical ecosystems.