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Diurnal patterns of methane flux from a seasonal wetland: mechanisms and methodology

Wetlands

By:
ORCID iD , ORCID iD , and ORCID iD
https://doi.org/10.1007/s13157-018-1042-5

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Abstract

Methane emissions from wetlands are temporally dynamic. Few chamber-based studies have explored diurnal variation in methane flux with high temporal replication. Using an automated sampling system, we measured methane flux every 2.5 to 4 h for 205 diel cycles during three growing seasons (2013–2015) from a seasonal wetland in the Prairie Pothole Region of North America. During ponded conditions, fluxes were generally positive (i.e., methanogenesis dominant, 10.1 ± 0.8 mg m−2 h−1), had extreme range of variation (from −1 to 70 mg m−2 h−1), and were highest during late day. In contrast, during dry conditions fluxes were very low and primarily negative (i.e., oxidation dominant, −0.05 ± 0.002 mg m−2 h−1), with the highest (least negative) fluxes occurring at pre-dawn. During semi-saturated conditions, methane fluxes also were very low, oscillated between positive and negative values (i.e., balanced between methanogenesis and methane oxidation), and exhibited no diel pattern. Methane flux was positively correlated with air temperature during ponded conditions (r = 0.57) and negatively during dry conditions (r = −0.42). Multiple regression analyses showed that temperature, light and water-filled pore space explained 72% of variation in methane flux. Methane fluxes are highly temporally dynamic and follow contrasting diel patterns that are dependent on dominant microbial processes influenced by saturation state.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Diurnal patterns of methane flux from a seasonal wetland: mechanisms and methodology
Series title:
Wetlands
DOI:
10.1007/s13157-018-1042-5
Volume:
45
Issue:
10
Year Published:
2018
Language:
English
Publisher:
Springer
Contributing office(s):
Northern Prairie Wildlife Research Center
Description:
11 p.
First page:
4933
Last page:
4943