title: The influence of plants on atmospheric methane in an agriculture-dominated landscape.
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.
authors.affiliation: School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA, xin.zhang@yale.edu.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Xuhui
authors.initials: X
authors.lastname: Lee
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Griffis
authors.forename: John M
authors.initials: JM
authors.lastname: Baker
authors.forename: Matt D
authors.initials: MD
authors.lastname: Erickson
authors.forename: Ning
authors.initials: N
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Xiao
mesh_terms: D000383:Agriculture; D000393:Air Pollutants / Q000378:metabolism*; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism; D005308:Fertilizers; D008697:Methane / Q000378:metabolism*; D009584:Nitrogen / Q000494:pharmacology; D010507:Periodicity; D010758:Phosphorus / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D013025:Glycine max / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D014481:United States; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000393:Air Pollutants; D005308:Fertilizers; D002245:Carbon Dioxide; D010758:Phosphorus; D009584:Nitrogen; D008697:Methane; D011188:Potassium