Date: 04.07.2025
Plant diversity helps store carbon in soil – but not everywhere equally
Soil can play a vital role in the fight against climate change – it is capable of storing vast amounts of carbon. However, soil processes differ across ecosystems such as forests, grasslands or agricultural fields, and many factors come into play. Scientists from the Biology Centre of the Czech Academy of Sciences, together with colleagues from Germany and the USA, have now focused on how plant diversity affects carbon storage in soil.
In their review study, published in early July in the prestigious journal Nature Communications, they explore why plant diversity sometimes significantly increases soil carbon storage – and sometimes barely at all.
Plant diversity supports soil carbon storage – but not everywhere and not under all conditions. “Put simply, the benefit of plant diversity for carbon storage depends on how much carbon is already present in the soil, and in what form,” explains Šárka Angst, lead author of the study from the Biology Centre CAS. “Soils in mature forests or some grasslands are already saturated with stable carbon, so increasing plant diversity has less impact there than, for example, in intensively used agricultural land or in deeper soil layers poor in carbon. In those environments, biodiversity can have a much stronger positive effect and significantly contribute to carbon sequestration – and thus climate protection,” she says.
Carbon in soil exists in forms with different stability. The authors distinguish between two main types:
• Carbon stored in particulate organic matter (POM), which consists of relatively fresh, partially decomposed plant residues (such as leaves, roots and stems) and remains in the soil for only days to a few years.
• Mineral-associated organic matter (MAOM), which can persist in mineral soil particles for centuries.
Plant diversity influences these two types in different ways and depending on the ecosystem. In some cases, its effect is seen mainly in the formation of labile organic matter (POM), while in others, it supports the storage of stable carbon (MAOM). “Our study shows that we should not expect a universal benefit of biodiversity for soil carbon under all conditions,” says co-author Gerrit Angst from the Biology Centre CAS. “Instead, it is essential to consider soil type, land use, climate, and plant community composition. Only then can we make effective use of biodiversity to improve soil quality and enhance carbon storage.”
Experimental fields. Credit: The Jena Experiment
The study was carried out in collaboration with researchers from the German Centre for Integrative Biodiversity Research (iDiv), Leipzig University, Cleveland State University, and the Max Planck Institute for Biogeochemistry. The scientists also call for further research – especially long-term experiments across different climatic and soil types – to better understand how biodiversity influences carbon sequestration. According to the authors, understanding these interactions is key to protecting soil, managing landscapes sustainably, and ultimately addressing climate change.
Review study:
Angst, Š., Angst, G., Mueller, K.E. et al. Un(der)explored links between plant diversity and particulate and mineral-associated organic matter in soil. Nat Commun 16, 5548 (2025). https://doi.org/10.1038/s41467-025-60712-6
