Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains

Global Biogeochemical Cycles
By: , and 

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Abstract

Methane exchange between the atmosphere and subalpine wetland and unsaturated soils was evaluated over a 15-month period during 1995-1996. Four vegetation community types along a moisture gradient (wetland, moist-grassy, moist-mossy, and dry) were included in a 100 m sampling transect situated at 3200 m elevation in Rocky Mountain National Park, Colorado. Methane fluxes and soil temperature were measured during snow-free and snow-covered periods, and soil moisture content was measured during snow-free periods. The range of mean measured fluxes through all seasons (a positive value represents CH4 efflux to the atmosphere) were: 0.3 to 29.2 mmol CH4 m-2 d-1 wetland area; 0.1 to 1.8 mmol CH4 m-2 d-1, moist-grassy area; -0.04 to 0.7 mmol CH4 m-2 d-1, moist-mossy area; and -0.6 to 0 mmol CH4 m-2 d-1, dry area. Methane efflux was significantly correlated with soil temperature (5 cm) at the continuously saturated wetland area during snow-free periods. Consumption of atmospheric methane was significantly correlated with moisture content in the upper 5 cm of soil at the dry area. A model based on the wetland flux-temperature relationship estimated an annual methane emission of 2.53 mol CH4 m-2 from the wetland. Estimates of annual methane flux based on field measurements at the other sites were 0.12 mol CH4 m-2, moist-grassy area; 0.03 mol CH4 m-2, moist-mossy area; and -0.04 mol CH4 m-2, dry area. Methane fluxes during snow-covered periods were responsible for 25, 73, 23, and 43% of the annual fluxes at the wetland, moist-grassy, moist-mossy, and dry sites, respectively.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains
Series title Global Biogeochemical Cycles
DOI 10.1029/1998GB900003
Volume 13
Issue 1
Year Published 1999
Language English
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Global Biogeochemical Cycles
First page 101
Last page 113