Premium
Pulse‐labeling studies of carbon cycling in Arctic tundra ecosystems: The contribution of photosynthates to methane emission
Author(s) -
King J. Y.,
Reeburgh W. S.,
Thieler K. K.,
Kling G. W.,
Loya W. M.,
Johnson L. C.,
Nadelhoffer K. J.
Publication year - 2002
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 - 10.1029/2001gb001456
Subject(s) - tundra , methane , carbon cycle , carbon fibers , environmental science , tussock , carbon dioxide , atmospheric carbon cycle , carbon respiration , photosynthesis , environmental chemistry , ecosystem , chemistry , carbon sequestration , ecology , negative carbon dioxide emission , materials science , biology , biochemistry , organic chemistry , composite number , composite material
We investigated a possible mechanism underlying observed correlations between net ecosystem carbon dioxide exchange and methane emission. Using the technique of 14 C pulse‐labeling, we traced the movement of carbon fixed by photosynthesis as it moved through wet sedge and moist tussock tundra plant‐soil mesocosms and was emitted as methane to the atmosphere. The 14 C tracer provided a definitive way of quantifying the fate of recently fixed carbon. Carbon fixed by photosynthesis was measured as emitted methane from both moist tussock and wet sedge tundra mesocosms within 2 hours after labeling. Integration of time series measurements of methane emission showed that recent photosynthates are an important source of carbon for methane production. Approximately 2% of carbon fixed by photosynthesis at peak growing season was subsequently emitted as methane from moist tussock tundra, and approximately 3% was emitted as methane from wet sedge tundra. Measurements of soil pore water carbon pools demonstrate rapid transfer of 14 C from plant carbon to dissolved forms and subsequently to the atmosphere as carbon dioxide or methane.