Microorganisms play a key role in soil carbon storage, as shown by an international collaborative study involving researchers from the Department of Geography. Microbial carbon use efficiency is at least four times more influential than other biological or environmental factors when it comes to global soil carbon storage and distribution. The results have implications for improving soil health and mitigating climate change.
Soils serve as crucial carbon sinks in the battle against climate change, storing more carbon than any other terrestrial ecosystem and three times more than the atmosphere. However, the processes involved in soil carbon storage have not been well understood. While microorganisms have long been recognized as important contributors to the accumulation and loss of soil organic carbon (SOC), the specific contributions of different biological and environmental processes have remained largely unknown.
The study, titled "Microbial Carbon Use Efficiency Promotes Global Soil Carbon Storage" and published on May 24 in Nature, employed a novel approach to quantifying the processes that determine soil carbon dynamics. The international research team comprehensively explored the relationship between carbon use efficiency, SOC preservation, and various factors such as climate, vegetation, and soil properties. The study represents the first successful integration of global-scale datasets, a microbial-process explicit model, data assimilation, deep learning, and meta-analysis to examine this relationship.
Microbial carbon use efficiency (CUE) measures the proportion of carbon used by microbes for growth versus metabolism. When carbon is used for microbial growth, it becomes incorporated into microbial cells, which supports its storage in the soil. Conversely, when carbon is used for metabolism, it is released into the air as carbon dioxide, acting as a greenhouse gas. The study emphasizes that microbial growth is more crucial than metabolism in determining the amount of carbon stored in the soil.
Feng Tao, Yuanyuan Huang, Bruce A. Hungate, Stefano Manzoni, Serita D. Frey, Michael W. I. Schmidt, Markus Reichstein, Nuno Carvalhais, Philippe Ciais, Lifen Jiang, Johannes Lehmann, Ying-Ping Wang, Benjamin Z. Houlton, Bernhard Ahrens, Umakant Mishra, Gustaf Hugelius, Toby D. Hocking, Xingjie Lu, Zheng Shi, Kostiantyn Viatkin, Ronald Vargas, Yusuf Yigini, Christian Omuto, Ashish A. Malik, … Yiqi Luo Microbial carbon use efficiency promotes global soil carbon storage. Nature (2023). https://doi.org/10.1038/s41586-023-06042-3
Informationsdienst Wissenschaft: Press Release, 26.05.2023
Image: Agricultural soils in southern Europe (Antonio Jordán, imaggeo.egu.eu)