Unraveling the Role of Ectomycorrhizal Fungi in Soil Decomposition and Carbon Accumulation

Litter, fungal type, and climate are key factors shaping the ectomycorrhizal effects.

Image is described in caption.

Results of ectomycorrhizal (ECM) fungi functional trait experiments: (a) relative changes (%) in saprotrophic biomass, (b) unprotected soil organic carbon accumulation, and (c) ECM competition effects induced by different nitrogen acquisition strategies of ectomycorrhizae.

[Reprinted with permission from Shao, S., et al. "Ectomycorrhizal Effects on Decomposition Are Highly Dependent on Fungal Traits, Climate, and Litter Properties: A Model-Based Assessment." Soil Biology and Biochemistry 184 109073 (2023). DOI:10.1016/j.soilbio.2023.109073.]

The Science

This study examined ectomycorrhizal (ECM) fungi and their impact on decomposition and carbon storage in forests. Using computer models, researchers explored how ECM fungi compete with other microbes for nutrients, like nitrogen, and affect the breakdown of dead materials in the soil. Findings show that the influence of ECM fungi depends on factors like climate, litter quality, and the type of fungi present. Understanding these interactions is crucial for managing and protecting forests. This research sheds light on how ECM fungi shape soil processes and carbon storage, providing important insights into forest ecology.

The Impact

This research deepens science’s understanding of how ECM fungi influence the decomposition of dead material in forests. This knowledge can help scientists better manage forest ecosystems and improve understanding of the carbon storage processes that are essential for Earth’s health. Studying ECM fungi and their effects on the soil provides valuable insights into how forests work and how they play a crucial role in regulating Earth’s climate.

Summary

In this study, researchers investigated the interactions between ECM fungi and saprotrophic soil microbes, focusing on their competition for nitrogen resources and their effect on forest soil carbon storage. By incorporating mycorrhizal processes into the Carbon, Organisms, Rhizosphere, and Protection in the Soil Environment (CORPSE) model, researchers simulated various scenarios to explore how ECM fungi influence decomposition and carbon accumulation in the soil. The competition effect of ECM fungi was found to be context-dependent, being more pronounced when litter inputs lacked nitrogen and were relatively recalcitrant. Furthermore, their capacity to extract nitrogen from recalcitrant soil organic matter and microbial necromass contributed to their impact. Climate and seasonality also played a role, with the competition effect being most significant in cooler climates and during peak litterfall. However, despite a substantial competition effect, the increase in soil organic carbon accumulation was relatively modest, around 10%. These findings offer important insights into the intricate mechanisms governing carbon dynamics in forest ecosystems, providing valuable knowledge for better forest management and conservation.

Principal Investigator

Caitlin Hicks Pries
Dartmouth College
[email protected]

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
[email protected]

Funding

This research was supported by the Biological and Environmental Research (BER) Program within the U.S. Department of Energy’s (DOE) Office of Science under Grant/Award Number DE-SC0020228.

References

Shao, S., et al. "Ectomycorrhizal Effects on Decomposition Are Highly Dependent on Fungal Traits, Climate, and Litter Properties: A Model-Based Assessment." Soil Biology and Biochemistry 184 109073  (2023). https://doi.org/10.1016/j.soilbio.2023.109073.