Abstract: The soil CO₂ flux of four temperate forest types was studied in Mt.Changbai. The soil CO₂ flux in the four typical forests was significantly different at short time scale. The released CO₂ flux of the four typical forest indicated obvious spatial heterogeneity. The rate of released CO₂ flux was the highest in Populus-Betula mixed forest and the lowest in populus forest. The sequence was: Populus-Betula mixed forest > broad leaved-Korean pine forest > Betula forest > Populus forest. Daily course of soil CO₂ flux was very different in the four forest types. Except for Populus-Betula mixed forest, in which the changes of CO₂ flux exhibited a single peak and showed relative consistency with changes of temperature, there were no regular changes of CO₂ flux in other forest types. The litter influenced the CO₂ flux significantly in each forest type. The CO₂ flux in the forest where soil was covered with litter was higher than that with out litter. The average value was 262.86～556.55 mgC·m^-2·h^-1 in the forests with the litter and 205.85～395.69 mg·m^-2·h^-1 in the forests without litter. The contribution of litter to total soil CO₂ flux was 14 %to 30%.

Key words: Fargesiadenudata, Soil nutrient pool, Available nutrient dynamics, Density