Soil CO2 along Trans-Alaska Pipeline

3-year winter and spring soil CO2 efflux was conducted in several sites along the trans-Alaska pipeline, Alaska during winter and spring seasons of 2010 to 2012. During the spring, the snow was disappeared mostly fast in the surrounding of tree such as white spruce (Picea glauca) and black spruce (Picea mariana) in boreal forest of Alaska. On the other hand, in tundra, the snow-covered tussock tundra was firstly exposed due to the topography. In white spruce forest, 4-directional soil CO2 efflux is higher east, south, west, and north in turn. Soil temperature is a crucial role in determining soil CO2 efflux, indicating a exponential curve. The CO2 efflux is related to with and without snow cluster that formed by sublimation. However, the efflux has much lower relation to snow depth. In exposed soil in spring of 2011, the CO2 efflux is similar to the growing season CO2 efflux. 3-yr spring CO2 efflux corresponds to 22-46% of annual CO2 efflux along the trans-Alaska pipeline, Alaska during the spring seasons.