Methane flux from coastal salt marshes

Journal Article · Thu Jun 20 04:00:00 EDT 1985 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JD090iD03p05710· OSTI ID:6833799

Bartlett, K B; Harriss, R C; Sebacher, D I

The seasonal flux of methane to the atmosphere from salt marsh soils was examined in three different vegetation zones within a single marsh near Yorktown, Virginia. A total of 100 measurements were made over a 2-year period, with maximum rates occurring during summer and fall. Spatial and temporal variability in fluxes was high; rates ranged from -2.4 to 21.3 x 10/sup -3/ g CH/sub 4//m/sup 2//d. Estimates of annual methane losses to the atmosphere were 0.43 g CH/sub 4//m/sup 2/ for a salt meadow zone, 1.3 g CH/sub 4//m/sup 2/ for short Spartina alterniflora, and 1.2 g CH/sub 4//m/sup 2/ for tall creek-bank S. alterniflora. A total of 63 flux measurements, made in a variety of other coastal salt marshes along the east coast of the US, suggest that the Virginia site may be fairly typical for this region. In addition to diffusional losses across the air-soil interface, methane can be lost from the marsh system to the atmosphere through the lateral movement of pore waters supersaturated with methane into tidal creeks, with subsequent degassing across the water-air interface. Estimates of the magnitude of methane input to the atmosphere by this mechanism indicate it may be as important as diffusional losses across the air-soil interface. These data suggest that salt marshes of this type make only a minor contribution to global atmospheric methane.

• Research Organization: College of William and Mary/Virginia Associated Research Campus, Hampton, VA
• OSTI ID: 6833799
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 90:D3; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
AIR-BIOSPHERE INTERACTIONS
AIR-WATER INTERACTIONS
ALKANES
AQUATIC ECOSYSTEMS
COASTAL REGIONS
DIFFUSION
ECOLOGICAL CONCENTRATION
ECOSYSTEMS
FEDERAL REGION III
GLOBAL ASPECTS
GRASS
HYDROCARBONS
MARSHES
METHANE
NORTH AMERICA
ORGANIC COMPOUNDS
PLANTS
POLLUTION
POLLUTION SOURCES
SEASONAL VARIATIONS
USA
VARIATIONS
VIRGINIA
WETLANDS