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Methane and nitrous oxide flux in a Wyoming subalpine meadow
Author(s) -
Mosier A. R.,
Klemedtsson L. K.,
Sommerfeld R. A.,
Musselman R. C.
Publication year - 1993
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/93gb02561
Subject(s) - snow , nitrous oxide , sink (geography) , environmental science , subalpine forest , methane , flux (metallurgy) , snowmelt , transect , hydrology (agriculture) , montane ecology , atmospheric sciences , soil water , water content , soil science , ecology , chemistry , geology , geography , meteorology , cartography , organic chemistry , geotechnical engineering , biology
The atmospheric concentrations of the greenhouse gases nitrous oxide and methane continue to increase. Since both gases are derived primarily from the soil, soil source/sink relationships in a variety of ecosystems must be understood before complete global source/sink budgets can be accurately made. Little information exists about soil/atmosphere exchange of nitrous oxide and methane from subalpine forests and forest meadows. A transect of flux measurement sites was established across a subalpine meadow and adjacent forest in southeastern Wyoming, and CH 4 and N 2 O fluxes were measured at least weekly from snow melt in June until the winter snow covered the meadow in October during 1991 and 1992. Nitrous oxide emissions from the meadow were small both years, averaging only 2.5 and 1.3 ug N m −2 h −1 in 1991 and 1992, respectively. Fluxes were larger during the wetter year and varied from point to point, generally in response to soil moisture conditions. Methane flux varied across the meadow and over the season, also in response to changing soil moisture conditions. During the time of rapid snow melt when water was flowing freely across the meadow, the meadow acted as a net source of CH 4 .After snow melt was completed and the soil dried, the entire meadow became a sink for CH 4 .The mean snow‐free seasonal CH 4 flux for the meadow was −3.5 and −21.4 ug C m −2 h −1 during 1991 and 1992, respectively. As a whole, the meadow served as a sink for atmospheric methane, but sites within the meadow served as a net source of CH 4 during the snow‐free part of the year.