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With warming, the wetlands of Interior Alaska may experience more frequent or extensive stand-replacing fires and permafrost degradation, and thus change the primary factors controlling carbon emissions. I measured carbon exchange along a moisture transect from the center of a Sphagnum-dominated bog...

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Bibliographic Details
Main Author: Isla Heather Myers-smith
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
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Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.357.1797
http://www.lter.uaf.edu/pdf/1017_Meyers-Smith_2005.pdf
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Summary:With warming, the wetlands of Interior Alaska may experience more frequent or extensive stand-replacing fires and permafrost degradation, and thus change the primary factors controlling carbon emissions. I measured carbon exchange along a moisture transect from the center of a Sphagnum-dominated bog into the surrounding burn scar (2001 Survey Line Fire) during the growing season of 2004. Both the bog and the surrounding burn were sinks for CO2, and the bog was a CH4 source in the abnormally dry summer of 2004. Thermokarst and subsiding soils were observed on the margin of the Sphagnum bog in the three years since the fire, increasing the anaerobic portion of the soil landscape. It was in this portion of the transect where I observed the greatest variation in carbon fluxes, indicating that permafrost collapse is altering the pattern of emissions from this landscape. I tracked historic changes in vegetation, hydrology and fire at this site through macrofossil, charcoal and diatom analysis of peat cores. The paleoecological record suggests that fire mediates collapse in this system. This study suggests that future changes in temperature and precipitation will likely change carbon