Microbial Parameters Can Be Generalized in Soil Biogeochemical Model

Microbial parameters in a soil carbon cycling model can be generalized across different soil series, potentially simplifying the application for the future.

Graph is described in caption.

Model parameters for simulating heterotrophic respiration (Rh) are equally generalizable across a single soil and cellulose addition treatment, treatments and controls, and all soil series, but not across forest and grassland land covers.

[Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0) from Jian, S., et al. "Generalizing Microbial Parameters in Soil Biogeochemical Models: Insights From a Multi-Site Incubation Experiment." Journal of Geophysical Research: Biogeosciences 129 (4), e2023JG007825 (2024). DOI:10.1029/2023JG007825.‌]

The Science

Incorporating soil microbial processes can improve soil model projections, and achieving a common set of microbial parameters across sites would enable more widespread application. Based on a 2‐year soil incubation data set, this study showed key microbial parameters could be generalized at the soil series level (four distinct soil series from three soil orders) but not land cover type (forest vs. grassland). The common set of parameters includes those processes controlling microbial growth and maintenance as well as extracellular enzyme production and turnover.

The Impact

Future microbial model applications can potentially use the same parameters across different soil series but not across plant functional types when implementing models at various sites. Besides heterotrophic respiration and microbial biomass data, soil extracellular enzyme data sets are particularly needed to achieve reliable microbial‐relevant parameters for large‐scale soil model projections.

Summary

The study used the Microbial ENzyme Decomposition (MEND) model for simulations. MEND is one of the earlier soil process models (2013) that explicitly incorporates microbial biomass and enzyme function to simulate soil carbon and nitrogen cycling. MEND has been applied to incubation studies, long-term field studies, and ecosystem demographic and earth system models. Therefore, the findings that microbial parameters can be generalized across different soil series and orders could enable broader application of explicit microbial activities in earth system models. This approach should be tested with other datasets and microbial soil carbon cycling models.

Principal Investigator

Paul Hanson
Oak Ridge National Laboratory
[email protected]

Program Manager

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

Funding

Support was received from the U.S. National Science Foundation HBCU‐EiR (No. 1900885), the U.S. Department of Energy (DOE) Office of Science Research Development and Partnership Pilot program (DE‐SC0023206), and the U.S. Department of Agriculture’s National Institute of Food and Agriculture Grant (No. 2021‐67020‐34933). Funding was also received from the DOE Biological and Environmental Research program through the Oak Ridge National Laboratory (ORNL) Terrestrial Ecosystem Science Scientific Focus Area and subcontracted to Tennessee State University (No. 4000148926) and DOE’s Genomic Science Program (Award Number DESC0020163 and DE‐SC0023106). Contributions from Wuhan University are supported by National Natural Science Foundation of China (No. 42371032). ORNL is managed by UT‐Battelle, LLC, under contract DE‐AC05‐00OR22725 with DOE.

Related Links

References

Jian, S., et al. "Generalizing Microbial Parameters in Soil Biogeochemical Models: Insights From a Multi-Site Incubation Experiment." Journal of Geophysical Research: Biogeosciences 129 (4), e2023JG007825  (2024). https://doi.org/10.1029/2023JG007825.