Continuous measurement of CO2 flux through the snowpack in a dwarf bamboo ecosystem on Rishiri Island,Hokkaido, Japan

To investigate the dynamics and environmental drivers of CO₂ flux through the winter snowpack in a dwarf bamboo ecosystem (Hokkaido, northeast Japan), we constructed an automated sampling system to measured CO₂ concentrations at five different levels in the snowpack, from the base to the upper snow surface. Using a gas diffusion approach, we estimated an average apparent soil CO₂ flux of 0.26 μmol m^?2 s^?1 during the snow season (December–April); temporally, the CO₂ flux increased until mid-snow season, but showed no clear trend thereafter; late-season snow-melting events resulted in rapid decreases in apparent CO₂ flux values. Air temperature and subnivean CO₂ flux exhibited a positive linear relationship. After eliminating the effects of wind pumping, we estimated the actual soil CO₂ flux (0.41 μmol m^?2 s^?1) to be 54% larger than the apparent flux. This study provides new constraints on snow-season carbon emissions in a dwarf bamboo ecosystem in northeast Asia.