摘要
采用野外静态箱—气相色谱法,对三江平原沼泽湿地6—9月不同水层下CH4、N2O的排放进行了同步对比研究,并探讨了影响气体排放的主要影响因子。结果表明,不同水层下的CH4和N2O排放具有明显的时空变化特征。CH4排放高峰期在7、8月,N2O主要排放期在6、7月。40 cm水层下的CH4排放强度最高,平均为34.54mg.m-2.h-1;20、60 cm水层下的CH4排放强度居中,平均分别为17.18、13.02 mg.m-2.h-1;0 cm水层下的CH4排放强度最低,平均7.69 mg.m-2.h-1,N2O排放强度最高,为0.072 mg.m-2.h-1;20、40 cm水层下的N2O排放强度相似,平均分别为0.053、0.050 mg.m-2.h-1;60 cm水层下的排放强度最小,平均为0.026 mg.m-2.h-1。相关分析表明,CH4的排放通量与40 cm水深及5 cm地温呈显著或极显著正相关,与其它各土壤温度之间的相关性因水层不同有所差异;N2O排放通量与地表0、40 cm水深呈显著负相关,20 cm水层下的N2O排放通量与5 cm地温呈显著正相关。CH4、N2O的排放通量与大气温度及地表温度均不相关。
Static opaque chamber-GC technique was applied to study the seasonal variation and influence factors of emission of greenhouse gases （ CH4 and N2O） from a marsh wetland at different water depths （0, 20, 40 and 60 cm） in Sanjiang Plain during the growing season. The emissions of CH4 and N20 showed clear temporal and spatial variations. The emission rate of （CH4 was higher in July and August, while that of N20 was higher in June and July. The highest emission flux of CH4 among the four sites was at the water depth of 40 cm, with an average of 34.54 mg·-m2·h-1, followed by 20 em （17.18） , 60 cm （13.02） , and 0 cm （ 7.69 ）. However, the highest emission flux of N20 was at the water depth of 0 cm, with an average of 0.072 mg·m-2·h-1, followed by 20 cm （ 0.053 ） , 40 cm （0.050） , and 60 em （ 0.026 ）. There were significant or highly significant positive correlations between the emission flux of CH4 and water depth of 40 em and soil temperature at 5 em depth. The emission flux of N20 was signlfieantly negatively correlated with water depths of 0 and 40 em, and the emi- ssion flux of N20 at the water depth of 20 cm was significantly positively correlated with soil temperature at 5 em depth. Soil temperature at 5 cm was the main factor affecting water depth at 20 cm. Air temperature and surface soil temperature were not the main factors affecting CH~ and N~ O emissions.
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2012年第5期102-106,共5页
Journal of Northeast Forestry University
基金
国家科技支撑计划项目(2008BAD95B06)
