Linking Ecosystem CH4 Fluxes to Soil Profile CH4 Concentrations and Oxidation Rates : Year-Round Measurements and Drought Effects in a Danish Farmland
Wang, Peiyan ; Zhao, Bingqian LU ; Hansen, Line Vinther ; Zhang, Wenxin LU
; Mortensen, Louise H.
; Brændholt, Andreas
; Bruun, Sander
; Ambus, Per
and Elberling, Bo
(2025)
In Journal of Geophysical Research: Biogeosciences
130(8).
- Abstract
Methane (CH4) oxidation in well-drained soils is a key process contributing to the global CH4 sink. Yet, temporal and depth-specific CH4 oxidation is rarely described despite being critical for the surface net CH4 uptake. Here, we linked year-round field observations of CH4 fluxes in well-drained cultivated soils with subsurface CH4 concentrations, laboratory incubations, and process-based modeling to uncover these mechanisms. Field observed CH4 fluxes ranged from −0.43 to 0.19 mg CH4 m−2 day−1 with an average of −0.15 ± 0.01 mg CH4 m−2 day−1 over the year-round study period. Much higher... (More)
Methane (CH4) oxidation in well-drained soils is a key process contributing to the global CH4 sink. Yet, temporal and depth-specific CH4 oxidation is rarely described despite being critical for the surface net CH4 uptake. Here, we linked year-round field observations of CH4 fluxes in well-drained cultivated soils with subsurface CH4 concentrations, laboratory incubations, and process-based modeling to uncover these mechanisms. Field observed CH4 fluxes ranged from −0.43 to 0.19 mg CH4 m−2 day−1 with an average of −0.15 ± 0.01 mg CH4 m−2 day−1 over the year-round study period. Much higher CH4 uptakes were observed in summer than in winter, indicating marked seasonal variations. Modeling using the CoupModel to simulate soil temperatures and water content as drivers, along with an analytic reaction-based model to simulate CH4 fluxes, shows that the depth infiltration of atmospheric CH4 is a critical parameter for defining a CH4 oxidation reaction zone below the surface. The thickness of the reaction zone varied seasonally. Sensitivity tests of CH4 concentrations and oxidation profiles in response to contrasting precipitation scenarios reveal that CH4 oxidation during drought scenarios is increased at deeper depths due to higher CH4 availability. However, CH4 oxidation in near-surface layers decreased due to low soil water content, resulting in a significantly lower net surface CH4 uptake. Our findings suggest that both the depth-specific CH4 oxidation profile and net surface CH4 fluxes will likely change under future warmer and drier periods.
(Less)
- author
- Wang, Peiyan
; Zhao, Bingqian
LU
; Hansen, Line Vinther
; Zhang, Wenxin
LU
; Mortensen, Louise H.
; Brændholt, Andreas
; Bruun, Sander
; Ambus, Per
and Elberling, Bo
- organization
- publishing date
- 2025-08
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- CH uptake, cropland, drought, modeling, reaction zone, soil CH profile
- in
- Journal of Geophysical Research: Biogeosciences
- volume
- 130
- issue
- 8
- article number
- e2025JG008829
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:105011945246
- ISSN
- 2169-8953
- DOI
- 10.1029/2025JG008829
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2025. The Author(s).
- id
- ff2ea5ee-ab4d-4731-ab73-07001ca8c4a8
- date added to LUP
- 2025-08-13 12:31:13
- date last changed
- 2025-08-13 16:49:16
@article{ff2ea5ee-ab4d-4731-ab73-07001ca8c4a8,
abstract = {{<p>Methane (CH<sub>4</sub>) oxidation in well-drained soils is a key process contributing to the global CH<sub>4</sub> sink. Yet, temporal and depth-specific CH<sub>4</sub> oxidation is rarely described despite being critical for the surface net CH<sub>4</sub> uptake. Here, we linked year-round field observations of CH<sub>4</sub> fluxes in well-drained cultivated soils with subsurface CH<sub>4</sub> concentrations, laboratory incubations, and process-based modeling to uncover these mechanisms. Field observed CH<sub>4</sub> fluxes ranged from −0.43 to 0.19 mg CH<sub>4</sub> m<sup>−2</sup> day<sup>−1</sup> with an average of −0.15 ± 0.01 mg CH<sub>4</sub> m<sup>−2</sup> day<sup>−1</sup> over the year-round study period. Much higher CH<sub>4</sub> uptakes were observed in summer than in winter, indicating marked seasonal variations. Modeling using the CoupModel to simulate soil temperatures and water content as drivers, along with an analytic reaction-based model to simulate CH<sub>4</sub> fluxes, shows that the depth infiltration of atmospheric CH<sub>4</sub> is a critical parameter for defining a CH<sub>4</sub> oxidation reaction zone below the surface. The thickness of the reaction zone varied seasonally. Sensitivity tests of CH<sub>4</sub> concentrations and oxidation profiles in response to contrasting precipitation scenarios reveal that CH<sub>4</sub> oxidation during drought scenarios is increased at deeper depths due to higher CH<sub>4</sub> availability. However, CH<sub>4</sub> oxidation in near-surface layers decreased due to low soil water content, resulting in a significantly lower net surface CH<sub>4</sub> uptake. Our findings suggest that both the depth-specific CH<sub>4</sub> oxidation profile and net surface CH<sub>4</sub> fluxes will likely change under future warmer and drier periods.</p>}},
author = {{Wang, Peiyan and Zhao, Bingqian and Hansen, Line Vinther and Zhang, Wenxin and Mortensen, Louise H. and Brændholt, Andreas and Bruun, Sander and Ambus, Per and Elberling, Bo}},
issn = {{2169-8953}},
keywords = {{CH uptake; cropland; drought; modeling; reaction zone; soil CH profile}},
language = {{eng}},
number = {{8}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Journal of Geophysical Research: Biogeosciences}},
title = {{Linking Ecosystem CH<sub>4</sub> Fluxes to Soil Profile CH<sub>4</sub> Concentrations and Oxidation Rates : Year-Round Measurements and Drought Effects in a Danish Farmland}},
url = {{http://dx.doi.org/10.1029/2025JG008829}},
doi = {{10.1029/2025JG008829}},
volume = {{130}},
year = {{2025}},
}