Soil gas CO and its carbon isotope analyses in the semi-natural woods on the campus of Hokkaido University

Fujiyoshi, Ryoko*; Haraki, Yukihide*; Sumiyoshi, Takashi*; Amano, Hikaru

Carbon dioxide in soil air has been monitored in the holes at 30 and 100 cm in depth under a cool-temperate deciduous stand on the campus of Hokkaido University since June in 2007. Air samples were collected periodically from the holes, and also from the atmosphere in the woods (2 m in height from the soil surface). Carbon isotopic analyses of the CO samples were performed by AMS at the Mutsu Facility of the Japan Atomic Energy Agency (JAEA-AMS-MUTSU). Preliminary results show that CO in the woods including the air at 2 m in height may result from mixing of atmospheric air and soil components of various sources, such as CO from contemporary soil organic matter and old carbon of deep source to a varying degree depending on meteorological and biological conditions.