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Title: Methane transport mechanisms and isotopic fractionation in emergent macrophytes of an Alaskan tundra lake

Journal Article · · Journal of Geophysical Research; (United States)
DOI:https://doi.org/10.1029/90JD01542· OSTI ID:6764743
; ; ; ;  [1]
  1. Florida State Univ., Tallahassee (United States) North Carolina Univ., Chapel Hill (United States) New Hampshire Univ., Durham (United States) North Carolina State Univ., Raleigh (United States)

The stable carbon isotopic composition of methane associated with and emitted by the two dominant emergent macrophytes abundant in the many Alaskan tundra lakes, Carex rostrata and Arctophila fulva, is determined. The carbon isotopic composition of the methane was -58.6 +/- 0.5 (n=2) for Arctophila and -66.6 +/- 2.5 (n=6) for Carex. The methane emitted by these species is depleted in C-13 by 12 per mil for Arctophila and 18 per mil for Carex relative to methane withdrawn from plant stems 1-2 cm below the waterline. The results suggest more rapid transport of (C-12)H4 relative to (C-13)H4 through plants to the atmosphere. Plant stem methane concentrations ranged from 0.2 to 4.0 percent in Arctophila, with an isotopic composition of -46.1 +/- 4.3 percent (n=8). Carex stem methane concentrations ranged from 150 to 1200 ppm, with an isotopic composition of -48.3 +/- 1.4 per mil (n=3). 60 refs.

OSTI ID:
6764743
Journal Information:
Journal of Geophysical Research; (United States), Vol. 97; ISSN 0148-0227
Country of Publication:
United States
Language:
English