Amazon capims (floating grassmats): A source of sup 13 C enriched methane to the troposphere

Journal Article · Tue Aug 01 04:00:00 EDT 1989 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/GL016i008p00799· OSTI ID:5608945

Chanton, J ^[1]; Crill, P ^[2]; Martens, C ^[3]; Bartlett, K

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1. Florida State Univ., Tallahassee (USA)
2. Univ. of New Hampshire, Durham (USA)
3. Univ. of North Carolina, Chapel Hill (USA)

The {sup 13}C isotope composition of methane emitted to the troposphere from Amazon capims (floating grassmats) ranged from {minus}36.9 to {minus}48.0{per thousand} averaging {minus}44.4 {plus minus} 4.2{per thousand}. All pools of methane associated with the grassmats were {sup 13}C enriched; methane withdrawn from plant stems ranged from {minus}39 to {minus}49{per thousand} while bubbles stirred from the root mat averaged {minus}41.4{per thousand}. As the CH{sub 4} flux from these habitats makes up some 40% of the total flux from the Amazon flooplain, CH{sub 4} emissions form the region as a whole must be enriched in the heavy carbon isotope. Methane withdrawn from the stems of five genera of rooted macrophysics ranging in latitude from the Florida Everglades to the Alaskan Arctic exhibited {sup 13}C enrichment relative to the sedimentary methane bubble reservoir. Several hypotheses based upon isotopic fractionation by methane transport, oxidation and production processes are proposed to explain this phenomenon.

• OSTI ID: 5608945
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 16:8; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ALKANES
AMAZON RIVER
AQUATIC ECOSYSTEMS
AQUATIC ORGANISMS
ATMOSPHERIC CHEMISTRY
BIODEGRADATION
BIOSYNTHESIS
BRAZIL
CARBON 13
CARBON ISOTOPES
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
DEVELOPING COUNTRIES
EARTH ATMOSPHERE
ECOSYSTEMS
EMISSION
ENRICHMENT
EVEN-ODD NUCLEI
GRAMINEAE
HYDROCARBONS
ISOTOPE RATIO
ISOTOPES
LATIN AMERICA
LIGHT NUCLEI
LILIOPSIDA
MAGNOLIOPHYTA
METHANE
NUCLEI
ORGANIC COMPOUNDS
PLANTS
POLLUTION SOURCES
RIVERS
SOUTH AMERICA
STABLE ISOTOPES
STREAMS
SURFACE WATERS
SYNTHESIS
TROPOSPHERE
WETLANDS