Close-to-Nature management shifts soil phosphorus availability and P-cycling genes in Chinese fir systems

期刊论文
发表日期：

2024年3月18日

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Xiangteng Chen,
Guangyu Zhao,
Yanglong Li,
Shumeng Wei,
Yuhong Dong,
Ruzhen Jiao

摘要

Background and Aims

Phosphorus (P) plays a vital role in plant physiology, and the soils of Chinese fir-producing areas are rich in aluminum and iron ions, making phosphorus highly susceptible to fixation. Insufficient phosphorus nutrient supply is a main constraint to the sustainability of Chinese fir plantations. The aim of this study is to ameliorate the problem of soil available phosphorus deficiency in Chinese fir plantations by changing the management mode, introducing local broad-leaved tree species to form multiple layers of different ages, thereby enhancing soil productivity.

Methods

The properties and phosphorus fractions of the surface soils (0-20 cm), litter and leaf nutrients were determined, and macro-genomic technique was used to explore changes of soil phosphorus cycling (P-cycling) genes.

Results

(1) The close-to-nature management (CNM) significantly increased soil organic carbon (SOC) and available phosphorus (AP) content and affected litter and plant nutrients. (2) The CNM affected the availability of soil phosphorus. The labile phosphorus (resin-P, NaHCO₃-Pi) and moderately labile phosphorus (NaOH-Pi) were significantly higher in CNM forests than in Chinese fir plantation. (3) The relative abundances of most of the P-cycling genes differed between the forests, with higher abundances of P-solubilization (ppa), P-mineralization (phnL and opd) and P-regulatory (phoB) genes in CNM forests. Moreover, MBC (microbial biomass carbon), SOC, total nitrogen (TN) and LTP (litter total phosphorus) were the main factors affecting the composition of soil P-cycling genes.

Conclusions

The CNM affected properties (soil, litter and plant) and improved soil phosphorus availability and the relative abundance of P-cycling genes. This study revealed the regulation mechanism of P-cycling in the CNM of Chinese fir plantation from microbial P-cycling genes perspective, which highlights the importance of P supply and microbial metabolic strategy by CNM of Chinese fir plantation.