July 22, 2018

Soil properties explain diversity of moisture-driven microbial respiration response

The macroscopic moisture function, fm, and its links to microscale processes controlling heterotrophic respiration (HR) in soils. The red curve qualitatively describes the soil HR–moisture relationship, fm, in soils. The inset conceptual figures depict the microscale processes controlling soil HR under dry conditions (a), in which HR rate is limited by the bioavailability of organic carbon (C), and under wet conditions (b), in which HR rate is limited by O2 supply, respectively. The processes controlling th

A moisture function of soil heterotrophic respiration that incorporates microscale processes.

The Science

Researchers coupled fundamental soil properties with microbial physiology in a pore-scale simulation to predict how microbial respiration will vary under different moisture conditions.

The Impact

By modeling soil microbial respiration response to moisture using a more fundamental understanding of the system, we can improve our predictions of how different soils will respond biogeochemically to drought and inundation events like floods and extreme weather.


Researchers have observed for a long time a “sweet spot” where soils respire the most carbon dioxide when they aren’t too wet or too dry. However, the location of this zone seemed to vary across different soil types and it was difficult to predict. 

In this study, scientists captured the underlying physical controls and microbial physiology in a computer simulation and generated a range of different respiration-moisture curves across different soil types. This demonstrated the distribution of these different moisture responses across soils and how those differences can be explained by specific soil properties. The findings will help us develop better models for soil biogeochemistry.


Z. Yan, B. Bond-Lamberty, K. Todd-Brown, V. Bailey, S. Li, C. Liu, C Liu, “A moisture function of soil heterorophic respiration incorporating microscale processes.” Nature Communications volume 9, Article number: 2562 (2018)

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Published: July 22, 2018