Modeling carbon cycling in boreal soils under climate change

Understanding and accurately representing ecological processes between land reservoirs and the atmosphere is crucial for predicting climate responses. However, the terrestrial carbon cycle in Earth system models remains a source of uncertainty. Particularly boreal soils, which store large amounts of organic matter, are an important player in the global carbon cycle, and are therefore a key component in terrestrial models. 

Recent advancements, such as microbial-explicit models, have improved the modeling of carbon cycling and soil decomposition processes. Further, is the symbiosis between mycorrhizal fungi and vegetation is a critical ecological process influencing climate dynamics. The exchange of nutrients between the symbionts not only affects carbon storage and vegetation growth, it also impacts biogeophysical aspects of the vegetation, such as albedo, surface roughness, and transpiration. Incorporating and refining those biogeochemical processes in the terrestrial carbon cycle in Earth system models is essential for enhancing predictions of soil and vegetation responses to global warming.

Coupling the microbial-explicit soil decomposition model, MIMICS+, into the Earth system model CTSM, and connecting the mycorrhizal component of MIMICS+ to the above-ground vegetation will enable feedback mechanisms between soils and vegetation. This integration aims to improve the representation of ecosystem-climate feedbacks and provide a more robust tool for understanding the impacts of climate change on terrestrial ecosystems.