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bioRxiv2023

Contribution of carbon inputs to soil carbon accumulation cannot be neglected

In a recently published paper (1), the authors report that microbial carbon use efficiency (CUE) is the primary determinant of global soil organic carbon (SOC) storage and that the relative impact of plant carbon inputs on SOC is minor. While soil microbes undoubtedly play an important role in soil organic carbon cycling, we are concerned about the robustness of the approach taken by Tao et al. (1) and highlight potential biases in their analyses that may lead to misleading, model-dependent results.

ecology↗

bioRxiv2019

Microbial evolution reshapes soil carbon feedbacks to climate change

Microbial decomposition of soil organic matter is a key component of the global carbon cycle. As Earths climate changes, the response of microbes and microbial enzymes to rising temperatures will largely determine the soil carbon feedback to atmospheric CO2. However, while increasing attention focuses on physiological and ecological mechanisms of microbial responses, the role of evolutionary adaptation has been little studied. To address this gap, we developed an ecosystem-evolutionary model of a soil microbe-enzyme system under warming. Constraining the model with observations from five contrasting sites reveals evolutionary aggravation of soil carbon loss to be the most likely outcome; however, temperature-dependent increases in mortality could cause an evolutionary buffering effect instead. We generally predict a strong latitudinal pattern, from small evolutionary effects at low latitude to large evolutionary effects at high latitudes. Accounting for evolutionary mechanisms will likely be critical for improving projections of Earth system responses to climate change.

ecology↗