Bacterial richness enhances the thermostability of soil organic matter via a long-term trade-off between molecular diversity and thermodynamic stability

The persistence of soil organic matter (SOM) is shaped by its molecular features and stability, but the temporal dynamics of these features remain unclear. Here we investigate the molecular diversity (the number of molecules) and molecular thermodynamic stability (the theoretical Gibbs free energy for the half reaction of carbon oxidation) of SOM in soils from long-term (>30 years) paddy and upland experimental fields. Thermogravimetric analysis shows that enhanced SOM thermostability aligns with the temporal variation of molecular thermodynamic stability in these soils. Increased SOM molecular thermodynamic stability occurs alongside decreased molecular diversity over decades, and this temporal trade-off (negative relationship) is modulated by increased bacterial richness. These findings highlight the role of microbial diversity in enhancing SOM thermostability and support strategies that promote bacterial richness for improved SOM persistence in agriculture.

WU Meng;  LUGATO Emanuele;  LI Pengfa;  LIU Jia;  QIU Cunpu;  WANG Shuang;  MA Xingzhu;  HAO Xiaoyu;  LIU Ming;  SHAN Jun;  YAN Xiaoyuan;  LI Zhongpei; 

2025-11-21

NATURE PORTFOLIO

JRC135471

2662-1355 (online),   

https://www.nature.com/articles/s43016-025-01253-5,    https://doi.org/10.1038/s43016-025-01253-5,    https://publications.jrc.ec.europa.eu/repository/handle/JRC135471,   

10.1038/s43016-025-01253-5 (online),