The influence of plants on atmospheric methane in an agriculture-dominated landscape

Authors

Xin Zhang, Yale UniversityFollow
Xuhui Lee, Yale UniversityFollow
Timothy J. Griffis, University of MinnesotaFollow
John M. Baker, USDA-ARSFollow
Matt D. Erickson, University of MinnesotaFollow
Ning Hu, Nanjing University of Information Science and Technology
Wei Xiao, Nanjing University of Information Science and Technology

Document Type

Article

Date of this Version

2013

Citation

Int J Biometeorol; DOI 10.1007/s00484-013-0662-y

Abstract

The primary objective of this study was to clarify the influence of crop plants on atmospheric methane (CH₄) in an agriculture-dominated landscape in the Upper Midwest of the United States. Measurements were carried out at two contrasting scales. At the plant scale, CH₄ fluxes from soybean and corn plants were measured with a laser-based plant chamber system. At the landscape scale, the land surface flux was estimated with a modified Bowen ratio technique using measurements made on a tall tower. The chamber data revealed a diurnal pattern for the plant CH₄ flux: it was positive (an emission rate of 0.4 ± 0.1 nmol m⁻² s⁻¹, average of soybean and corn, in reference to the unit ground area) during the day, and negative (an uptake rate of −0.8±0.8 nmol m⁻² s⁻¹) during the night. At the landscape scale, the flux was estimated to be 14.8 nmol m⁻² s⁻¹ at night and highly uncertain during the day, but the available references and the flux estimates from the equilibrium methods suggested that the CH₄ flux during the entire observation period was similar to the estimated nighttime flux. Thus, soybean and corn plants have a negligible role in the landscape-scale CH₄ budget.