Published In

Geophysical Research Letters

Document Type

Article

Publication Date

2-1-2010

Subjects

Methane, Biogeochemistry

Abstract

Recent studies indicate that plants may be a previously overlooked but significant source of atmospheric CH₄, though there is considerable disagreement on the mechanism of production. Our work sought to verify that woody deciduous trees grown under inundated conditions had the capacity for transporting CH₄ from an anaerobic subsurface to the atmosphere and to consider if such a source could be important globally. Here, we report results from a greenhouse mesocosm study that indicate significant emissions of anaerobically produced CH₄ transmitted to the atmosphere through broadleaf riparian tree species grown under flooded conditions. Using a leaf area normalized mean emission rate (0.7 ± 0.3 μg cm⁻² hr⁻¹), results were scaled globally for flooded forest regions and estimated to be 60 ± 20 Tg year⁻¹, ~10% of the global CH₄ source. The carbon isotopic composition of CH4 emitted was found to be significantly enriched compared with expectations (δ13C ~ −54‰) and provided an important isotopic constraint on the global source which coincides with the mean of the globally scaled greenhouse-based estimate.

Description

Copyright 2010 by the American Geophysical Union

DOI

10.1029/2009GL041565

Persistent Identifier

http://archives.pdx.edu/ds/psu/7560

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