青藏高原花石峡冻土站高寒湿地CH_4排放研究

Study on CH_4 Fluxes from Alpine Wetlands at the Huashixia Permafrost Station, Tibetan Plateau

利用静态箱技术对青藏高原花石峡冻土站附近湿地生态系统ＣＨ４排放的初步调查表明，各个植物群落内部和不同群落之间的ＣＨ４排放量变化都很大．花石峡地区高寒湿地基本可分为潮湿高寒草甸、沼泽化草甸、杉叶藻沼泽和毛柄水毛茛沼泽，其群落夏季ＣＨ４平均排放量分别为４４３１，１００５，４５９４和－０２８ｍｇ·ｍ－２ｄ－１．花石峡融化季节ＣＨ４排放量为４０８ｇ·ｍ－２ａ－１．简单外推表明，青藏高原高寒湿地ＣＨ４年排放量约为１Ｔｇ·ａ－１．

Study of CH_4 fluxes with the static chamber technique in alpine wetlands at the Huashixia Permafrost Station in the Tibetan Plateau in the summer of 1996 indicates that intra-site and inter-ecosytem variations of the CH 4 fluxes were very strong. Ecosystems in the studied region can be roughly divided into four groups, wet alpine meadow (Form. Kobresia humilis and Carex moorcroftii ), Form. Batrachium trichophyllum , Form. Hippuris vulgaris , and secondary Form. Kobresia tibetica. Their average CH 4 fluxes are 44 31, 10 05, -0 28 and 45 94 mg·m -2 d -1 during the observation period, with an weighed average of 43 9 mg·m -2 d -1 based on the wetland areal percentage of the four observed ecosystems at the station. The annual CH 4 emission from alpine wetlands is estimated at 7 862 g·m -2 a -1 . Preliminary extrapolation indicates that the CH 4 fluxes from alpine wetlands on the Tibetan Plateau is about1 Tg·a -1