Abstract:

Nitrous oxide (N₂O) is one of the important kinds of greenhouse gases, and it mainly comes from soil ecosystem.The soil N₂O emission flux in the plantation of Acer truncatum and Pinus tabulaeformis woodland was measured in situ using static closed chamber technique at the year of 1997～1998 in Xishan area,Beijing,China.The annual N₂O emission flux ranges from -1.2 to 7.92 μg·m^-2h^-1 with mean of 3.16 μg·m^-2h^-1.It has seasonal variation as the highest flux in summer,the second in spring and autumn,and the lowest in winter.The N₂O emission flux is mainly determined by soil temperature,soil moisture and the precipitation within 5 days before the N₂O emission rate also has undulated diurnal variation that comes the lowest in 6'oclock and the peak in 9 and 18'oclock.

Key words: Forest soils, Greenhouse gases, Nitrous oxide (N₂O), Emission flux