Soil CO2 Efflux in the High Arctic in Ny-？lesund, Svalbard During Summer

Abstract

To evaluate the role of soil carbon to the net ecosystem exchange of CO2 in summer season, quantifying of CO2 efflux from soil surface to atmosphere and its controlling factors were investigated in the Korean Dasan station (78° 55´ N, 11° 55´E), Ny-&Aring

lesund in Svalbard, Norway. Soil CO2 efflux measurement were conducted within the major footprint area of the tower CO2 flux measurements in the plot (30 m x 30 m) using a closed-dynamic chamber system for July 2007, 2008 and 2009. Spatially averaged soil CO2 efflux for 16 sampling locations ranged from 0.3 to 0.7 &#61549

mol m-2 s-1 and means of that were 0.56(&#61617

0.07) &#61549

mol m-2 s-1 (2007), 0.54(&#61617

0.13) &#61549

mol m-2 s-1 (2008) and 0.51(&#61617

0.09). Spatially averaged soil temperature ranged from 6 to 12 &#61616

C and soil water content ranged from 13 to 27% during measuring soil CO2 efflux. The patterns of soil CO2 efflux for study periods generally followed those of soil temperature. But, patterns of soil CO2 efflux did not show clear relationship against the soil water content. Coefficient of variation of soil CO2 efflux for 16 locations ranged from 21 to 27% which is normal range for various ecosystems. Based on the preliminary results on CO2 exchange, the tundra ecosystem plays a role as a week sink for the atmospheric CO2 in summer season. This study was supported by 'Integrated research on the COMposition of Polar Atmosphere and Climate Change (COMPAC)' of Korea Polar Research Institute.