Glomalin-related soil proteins (GRSP), key metabolites secreted by arbuscular mycorrhizal fungi (AMF), are renowned as the "super glue" that maintains the stability of soil organic carbon (SOC). However, against the backdrop of global climate change, the dynamic responses of this critical protein have not yet been quantified on a global scale.

To address this knowledge gap, a research team from the South China Botanical Garden of the Chinese Academy of Sciences, has conducted a meta-analysis of 529 studies across global terrestrial ecosystems. Their findings were recently published in Functional Ecology.

The analysis systematically evaluated the effects of several major global change factors—nitrogen (N) addition, phosphorus (P) addition, warming, elevated CO₂, drought, and forest restoration—on GRSP. The results revealed that biological and nutrient factors exert effects far greater than those of climatic factors.

Forest restoration yielded the most significant enhancement, increasing easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP) by 49% and 65%, respectively.

Furthermore, nitrogen addition, phosphorus addition, and combined NP additions alleviated nutrient limitations, stimulating plant carbon inputs and fungal growth, which in turn increased GRSP content by 3.1% to 13.4%. Notably, the impacts of elevated CO₂, warming, and drought on GRSP pools were statistically negligible.

Validated by both machine learning and structural equation modeling, plant carbon input and AMF activity emerged as the core drivers regulating GRSP dynamics. Increased GRSP not only contributes directly to the SOC pool but also indirectly sequesters more carbon by cementing soil particles and improving aggregate stability—indicated by an increase in mean weight diameter.

This study confirms that, amid global environmental change, strengthening "plant-mycorrhiza" interactions through forest restoration and optimized nutrient management to boost GRSP production is an effective pathway for enhancing soil carbon sequestration potential.

This work was funded by the National Natural Science Foundation of China and the Guangdong Provincial Basic and Applied Basic Research Fund.