Our main objective was to elucidate how snow cover and soil frost influenced CO2dynamics over agricultural land. We observed the CO2flux above the soil or snow surface continuously using the commonly used static-chamber method and the CO2concentration in the soil on snow-removal plot and untreated control plot over agricultural land in northern Japan from September 25, 2009, to May 31, 2010. The recorded largest CO2flux was 3.9 μmol m-2 s-1and CO2concentration in soil was 390-5000 ppm. Little CO2flux was observed during the soil-freezing and snow-covered periods. The CO2concentration had been increasing about 10 ppm day-1during the soil-freezing period at the snow-removal plot. At the beginning of April, the CO2flux increased temporarily up to 0.19 μmol m-2 s-1after the snow melted entirely at the untreated control plot and up to 0.52 μmol m-2 s-1after the soil had thawed at the snow-removal plot. Snow-melting and soil-thawing largely influenced on CO2flux, irrespective of soil temperature. The data were not explained by conventionally used temperature response functions for CO2fluxes in these periods.
All Science Journal Classification (ASJC) codes
- Agronomy and Crop Science
- Atmospheric Science