Methane flux and stable hydrogen and carbon isotope composition of sedimentary methane from the Florida Everglades
- Univ. of South Florida, St. Petersburg (USA)
Methane flux and the stable isotopic composition of sedimentary methane were measured at four locations in the Florida Everglades system. Individual estimates of methane flux ranged over more than 3 orders of magnitude, from about 0.001 to 2.6 g CH{sub 4}/sq m/day. Significant interstation differences in total methane flux were also observed and are judged most likely attributable to differences in the size and spacing of emergent aquatic vegetation, and possibly differences in the type of organic matter incorporated into the sediments. On the basis of measurements presented here and by other investigators, the Everglades system appears to be a relatively weak source of atmospheric methane, probably contributing less than 0.5 Tg CH{sub 4}/yr. Emergent aquatic plants appear to be capable of indirectly affecting the stable isotopic composition of sedimentary methane by stimulating methane oxidation via root aeration. A significant positive correlation between delta D-CH4 and delta C{sup 13}-CH{sub 4} was observed for samples collected from sediments covered by tall, dense stands of emergent plants. In contrast, a significant negative correlation between the delta D and delta C{sup 13} of sedimentary methane was observed for samples collected at an open water site where ebullition dominated methane transfer to the atmosphere. 63 refs., 8 figs., 3 tabs.
- OSTI ID:
- 6657205
- Journal Information:
- Global Biogeochemical Cycles; (USA), Vol. 2:4; ISSN 0886-6236
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
FLORIDA
AIR POLLUTION
METHANE
ECOLOGICAL CONCENTRATION
AQUATIC ORGANISMS
CARBON 13
DIFFUSION
ORGANIC MATTER
OXIDATION
PLANTS
SEDIMENTS
WETLANDS
ALKANES
AQUATIC ECOSYSTEMS
CARBON ISOTOPES
CHEMICAL REACTIONS
ECOSYSTEMS
EVEN-ODD NUCLEI
FEDERAL REGION IV
HYDROCARBONS
ISOTOPES
LIGHT NUCLEI
NORTH AMERICA
NUCLEI
ORGANIC COMPOUNDS
POLLUTION
STABLE ISOTOPES
USA
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)