How fungi control the soil carbon storage
2026-06-30
New studies by the Agroecology Research Group, in collaboration with the Soil Ecology Research Group, show that fungi play a key role in carbon storage and dynamics in soils – and that their impact depends heavily on the ecosystem and soil properties.
In forests, mycorrhizal types play a decisive role in determining the composition of organic matter: whilst plant residues dominate the particulate organic matter, the more stable mineral-bound fraction originates primarily from fungal residues. There are clear differences between the fungal groups: in systems with arbuscular mycorrhiza, saprotrophic fungi are the main contributors to stabilisation, whereas symbiotic fungi themselves dominate stabilisation in forests with ectomycorrhiza (Vasilica et al. 2026).
At the same time, a second study shows that dead fungal biomass (necromass) is a highly dynamic component of this process: it is rapidly broken down by microbes, partly released as CO₂, but also quickly incorporated into more stable soil fractions. This stabilisation is highly dependent on soil properties – such as texture. Surprisingly, in clay-rich soils, less necromass was initially stabilised, but it remains preserved for a longer period (Kurbel et al. 2026). Another novel aspect of this study was its focus on necromass from arbuscular mycorrhizal fungi.
Conclusion: Fungi are key players in the soil carbon cycle – they determine both the formation of stable organic matter and its decomposition. The interplay between tree species, mycorrhizal types and soil conditions is therefore crucial for future carbon storage in terrestrial ecosystems.