Modeling methane dynamics in three wetlands in Northeastern China by using the CLM-Microbe model

ABSTRACT

Wetlands account for up to 70% of the natural source of methane (CH₄) in terrestrial ecosystems on a global scale. Soil microbes are the ultimate producers and biological consumers of CH₄ in wetlands. Therefore, simulating microbial mechanisms of CH₄ production and consumptionwould improve the predictability of CH₄ flux in wetland ecosystems. In this study, we applied a microbial-explicit model, the CLM-Microbe, to simulate CH₄ flux in three major natural wetlands in northeastern China. The CLM-Microbe model was able to capture the seasonal variation of gross primary productivity (GPP), dissolved organic carbon (DOC), and CH₄ flux. The CLM-Microbe model explained more than 40% of the variation in GPP and CH₄ flux across sites. Marsh wetlands had higher CH₄ flux than mountain peatlands. Ebullition dominated the CH₄ transport pathway in all three wetlands. The methanogenesis dominates while methanotroph makes a minor contribution to the CH₄ flux, making all wetlands a CH₄ source. Sensitivity analysis indicated that microbial growth and death rates are the key factors governing CH₄ emission and vegetation physiological properties (flnr) and maintenance respiration predominate GPP variation. Explicitly simulating microbial processes allows genomic information to be incorporated, laying a foundation for better predicting CH₄ dynamics under the changing environment.

KEYWORDS:

• CH₄ flux
• microbe
• CLM-Microbe model
• wetlands

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was partially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA28020502), the National Natural Science Foundation (No. 41771102, 41730643, 32171873, 41701198) of China, and Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. F.H., Y.W., and X.X. are grateful for the financial and facility support from the U.S. Department of Energy and National Science Foundation (2145130) that has partially funded the development of the CLM-Microbe model.