Net ecosystem methane and carbon dioxide exchanges in a Lake Erie coastal marsh and a nearby cropland
Document Type
Article
Publication Date
1-1-2014
Publication Title
Journal of Geophysical Research Biogeosciences
Keywords
carbon, cropland, eddy covariance, freshwater marsh, greenhouse gas, methane
Abstract
Net ecosystem carbon dioxide (FCO2) and methane (F CH4) exchanges were measured by using the eddy covariance method to quantify the atmospheric carbon budget at a Typha- and Nymphaea-dominated freshwater marsh (March 2011 to March 2013) and a soybean cropland (May 2011 to May 2012) in northwestern Ohio, USA. Two year average annual FCH4 (49.7 g C-CH4 m-2 yr-1) from the marsh was high and compatible with its net annual CO2 uptake (FCO2: -21.0 g C-CO2 m-2 yr-1). In contrast, F CH4 was small (2.3 g C-CH4 m-2 yr-1) and accounted for a minor portion of the atmospheric carbon budget (F CO2: -151.8 g C-CO2 m-2 yr-1) at the cropland. At the seasonal scale, soil temperature associated with methane (CH4) production provided the dominant regulator of FCH4 at the marsh (R2 = 0.86). At the diurnal scale, plant-modulated gas flow was the major pathway for CH4 outgassing in the growing season at the marsh. Diffusion and ebullition became the major pathways in the nongrowing season and were regulated by friction velocity. Our findings highlight the importance of freshwater marshes for their efficiency in turning over and releasing newly fixed carbon as CH4. Despite marshes accounting for only ~4% of area in the agriculture-dominated landscape, their high FCH4 should be carefully addressed in the regional carbon budget. Key Points Two year average CH4 flux from a marsh was compatible with its net CO2 uptake CH4 flux was regulated by different factors at diurnal and seasonal scales Plant-modulated gas flow and inundation led to high CH4 flux from the marsh ©2014. American Geophysical Union. All Rights Reserved.
Volume
119
Issue
5
First Page
722
Last Page
740
E-ISSN
21698961
DOI
10.1002/2013JG002520
Recommended Citation
Chu, Housen; Chen, Jiquan; Gottgens, Johan F.; Ouyang, Zutao; John, Ranjeet; Czajkowski, Kevin; and Becker, Richard, "Net ecosystem methane and carbon dioxide exchanges in a Lake Erie coastal marsh and a nearby cropland" (2014). Faculty Publications. 156.
https://red.library.usd.edu/sustainability-fp/156