La Trobe
2020 Jin SBB 144, 107780.pdf (1.38 MB)

Long-term CO2 enrichment alters the diversity and function of the microbial community in soils with high organic carbon

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© 2020 Elsevier Ltd The response of soil microorganisms to elevated atmospheric CO2 (eCO2) has the potential to alter the regulation of soil biogeochemical processes including carbon and nutrient cycling. A mechanistic understanding of this microbial response in agricultural systems is essential due to the potential impact on soil quality. This study used an eight-year free-air-CO2 enrichment (SoilFACE) experiment to assess the microbial response to eCO2 in three major agricultural soils (Chromosol, Vertosol, and Calcarosol) planted annually with grain crops. Elevated CO2 increased the number of operational taxonomic unit (OTU) by 14.3%, 13.3% and 4.1% and the Shannon diversity by 3.7%, 4.4%, and 2.6% in the top 5-cm soil layer of the Chromosol, Calcarosol and Vertosol, respectively. The relative abundance of the oligotroph Acidobacteriaceae Subgroup 1 in the top 5-cm soil of the Chromosol and Vertosol was significantly increased by eCO2. Elevated CO2 did not affect community diversity in the 5–10 cm soil layer. The functional attribute analysis of the bacterial communities showed that eCO2 increased pectin and benzene degradation, the pentose phosphate pathway and the production of phytase-6 in the top 5-cm soil of the Chromosol. These results suggest that eCO2 increases the presence of oligotrophs in the bacterial community and overall mineralization of soil organic carbon (SOC) in surface soils with high SOC. Changes in microbial function due to eCO2 likely impact the stability of SOC and, consequently, the quality of farming soils for sustainable crop production.


This research was supported by La Trobe University Research Focus Area project (RFA) (2000002982) and the China Studies Seed-funding Research Grant, Australia. The Australian Grains Free Air CO2 Enrichment program including SoilFACE is jointly run by Agriculture Victoria (Victorian State Department of Jobs, Precincts and Resources) with the University of Melbourne and funding from the Grains Research and Development Corporation (GRDC) and the Australian Government Department of Agriculture and Water Resources. We gratefully acknowledge Mel Munn, Roger Perris, Liana Warren and Russel Argall and team (Agriculture Victoria) for management of the SoilFACE experiment, Mahabubur Mollah (Research Engineer, Agriculture Victoria) for running the FACE technology and Yanhong Wang (Lecture, Guiyang University of Chinese Medicine) for extracting soil DNA.


Publication Date



Soil Biology and Biochemistry



Article Number



9p. (p. 1-9)





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