若尔盖高原沼泽湿地CH4排放研究

若尔盖高原沼泽湿地海拔 3400 m，面积 4038km²，是我国面积最大的高原沼泽湿地分布区。2001年 5～9月的非冰冻期，其主要沼泽类型木里苔草沼泽的CH₄排放通量范围是 0.51～ 8.20 m g/（m ²· h），平均值为 2.87 m g/（m ²· h）；乌拉苔草沼泽CH₄排放通量范围是 0.36～10.04 m g/（m ²· h），平均值为 4.51 m g/（m ²· h）。在空间分布上，不同沼泽类型之间CH₄排放通量具有一定的差异。在季节变化上，没有明显的排放高峰。根据代表性观测点的CH₄平均排放量、日数和沼泽总面积推算，非冰冻期若尔盖高原沼泽湿地CH₄的排放量为 0.052Tg/a。

METHANE EMISSION FROM MARSHES IN ZOIGE PLATEAU

Now the global climate change is the grandest environmental problem in the world. Methane as an important green house gas, its concentration in the global troposphere is increasing. Based on IPCC, atmospheric concentration of methane has increased to 1.745 ppm in 1998. Marsh is a major source of methane emission. China is one of the countries in which there are more marshes. In addition, of all the countries with marshes in the world, only China has plateau marsh, so studying methane emission from China’s plateau marsh is of great importance to estimating the global gross of methane emission. With an area of about 4 038 km², Zoige plateau is the largest  plateau marsh in China. The carex muliejsis marsh and the carex Meyeriana marsh are the typical marshes in the area. Methane emission flux from the two typical marshes was first monitored twice a week from May to September in 2001. Methane flux measurements were made with the use of a closed-chamber. Methane concentration was determined using a gas chromatograph called Shimadzu GC-12A made in Japan and equipped with a flame ionization detector and a 2-m Poropak Q (80/100 mesh) column. Methane emission flux from the the carex Muliejsis marsh was 0.51~8.20 mg/(m²·h), with an average of 2.87 mg/(m²·h), and from the carex meyeriana marsh was 0.36~10.04 mg/(m²·h), with an average of 4.51 mg/(m²·h). As Zoige plateau with a special climate, a 3~5℃ low temperature even occurred in July and August, which causes no more methane to be emitted from the marshes in the two months than in the other months of the year and there was not obvious high value of CH₄ emission in the period of monitoring. According to the CH₄ average emission quantity, count of days and area of the marshes, the CH₄ emission quantity is about 0.052 Tg/a in Zoige marshes.  