Soil Properties Explain Diversity of Moisture-Driven Microbial Respiration Response

Linking microscale processes and macroscale fluxes using soil properties in a process-rich simulation.

The Science

Researchers from Pacific Northwest National Laboratory (PNNL) 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, scientists from PNNL can improve predictions of how different soils will respond biogeochemically to drought and inundation events like floods and extreme weather.

Summary

PNNL researchers have observed for a long time a “sweet spot” where soils respire the most carbon dioxide when they are not too wet or too dry. However, the location of this zone seemed to vary across different soil types and 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 aid development of better models for soil biogeochemistry.

Principal Investigator

Vanessa Bailey
Pacific Northwest National Laboratory
Vanessa.Bailey@pnnl.gov

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
daniel.stover@science.doe.gov

Funding

This research was supported by the National Key R&D Program of China and the Terrestrial Ecosystem Science (TES) program of the Office of Biological and Environmental Research (BER) within the U.S. Department of Energy (DOE) Office of Science.

References

Yan, Z., B. Bond-Lamberty, K. E. Todd-Brown, and V. L. Bailey, et al. "A moisture function of soil heterorophic respiration incorporating microscale processes". Nature Communications 9 2562  ((2018)). http://dx.doi.org/10.1038/s41467-018-04971-6.