Abstract
Soil microbes play a crucial role in the carbon (C) cycle; however, they have been overlooked in predicting the terrestrial C cycle. We applied a microbial-explicit Earth system model - the Community Land Model-Microbe (CLM-Microbe) - to investigate the dynamics of soil microbes during 1901 to 2016. The CLM-Microbe model was able to reproduce the variations of gross (GPP) and net (NPP) primary productivity, heterotrophic (HR) and soil (SR) respiration, microbial (MBC) biomass C in fungi (FBC) and bacteria (BBC) in the top 30 cm and 1 m, and dissolved (DOC) and soil organic C (SOC) in the top 30 cm and 1 m during 1901-2016. During the study period, simulated C variables increased by approximately 12 PgC yr-1 for HR, 25 PgC yr-1 for SR, 1.0 PgC for FBC and 0.4 PgC for BBC in 0-30 cm, and 1.2 PgC for FBC and 0.7 PgC for BBC in 0-1 m. Increases in microbial C fluxes and pools were widely found, particularly at high latitudes and in equatorial regions, but we also observed their decreases in some grids. Overall, the area-weighted averages of HR, SR, FBC, and BBC in the top 1 m were significantly correlated with those of soil moisture and soil temperature in the top 1 m. These results suggested that microbial C fluxes and pools were jointly governed by vegetation C input and soil temperature and moisture. Our simulations revealed the spatial and temporal patterns of microbial C fluxes and pools in response to environmental change, laying the foundation for an improved understanding of soil microbial roles in the global terrestrial C cycle.
| Original language | English |
|---|---|
| Pages (from-to) | 2313-2333 |
| Number of pages | 21 |
| Journal | Biogeosciences |
| Volume | 21 |
| Issue number | 9 |
| DOIs | |
| State | Published - May 14 2024 |
Funding
This study has been supported by an NSF CAREER project (2145130), an NSF RAPID award (2154746), and the CSU Program for Education and Research in Biotechnology. Support for this work for Melanie A. Mayes was provided by an Early Career Award through the U.S. Department of Energy (DOE) Biological and Environmental Research Program. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the U.S. DOE. This research has been supported by the Directorate for Biological Sciences (grant nos. 2145130 and 2154746) and the Biological and Environmental Research (grant no. DE-AC05-00OR22725). This article has been authored by UT-Battelle, LLC, under contract no. DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( https://www.energy.gov/doe-public-access-plan , last access: 9 March 2022).