A research team led by Prof. BAI Yongfei from the Institute of Botany of the Chinese Academy of Sciences (CAS), in collaboration with partners, has highlighted the critical role of mycorrhizal symbiosis in enhancing soil organic carbon (SOC) storage in grassland ecosystems across China. 

The findings, published in PNAS, reveal how a hidden partnership between plants and mycorrhizal fungi plays a vital role in helping grasslands store more carbon - a key factor in combating climate change. 

In this study, the researchers combined extensive field survey data with the FungalROOT mycorrhizal plant database to investigate the mycorrhizal status of plants across diverse grassland communities. They found that mycorrhizal fungi - tiny helpers in the soil - play a big role in helping grasslands store more carbon, both near the surface and deeper soil layers by promoting plant diversity and increasing the amount of biomass allocated to roots. 

Grasslands dominated by plants that depend on mycorrhizal fungi stored notably more carbon than those with plants that don't depend on them as much. Additionally, as temperatures and rainfall increase, grassland communities tend to shift toward having more mycorrhizal-dependent plants, while the abundance of plants that can thrive without these fungi diminishes.

This study sheds light on how mycorrhizal fungi in maintaining both plant diversity and SOC storage in grasslands, especially in the face of changing global environmental conditions. 

The findings suggest that strategies aimed at supporting mycorrhizal relationships in grasslands could be a powerful tool for improving carbon sequestration and mitigating the effects of climate change.

Typical steppe ecosystem dominated by Stipa grandis and Leymus chinensis in the Xilin River basin, Inner Mongolia, China (Image by BAI Yongfei)