吉林敦化臌囊薹草泥炭沼泽土壤甲烷产生速率和氧化速率

Production and Oxidation Rates of Methane from Soils in Carex schmidtii Peat Mire in Dunhua,Jilin

以地处长白山区的吉林省敦化市大石头镇东明林场臌囊薹草(Carex schmidtii)泥炭沼泽为研究对象,于2019年7月15日,采集臌囊薹草草丘、丘下和丘间0~10 cm、10~20 cm和20~30 cm深度的土壤样品,采用室内培养法,培养土壤样品,在连续培养的24 d中,从培养土壤样品的培养瓶中抽取气体样品,测定土壤甲烷的产生速率和氧化速率。研究结果表明,在实验的第24天,臌囊薹草草丘0~30 cm深度土壤的甲烷产生速率最大,为(156.55±83.37)μg/(g·d),在实验的第6小时,土壤甲烷氧化速率最大,为(1.38±0.11)μg/(g·d),二者显著高于丘下和丘间土壤,丘下和丘间土壤甲烷产生速率和氧化速率无显著差异;在垂直方向上,在实验的第24天,草丘10~20 cm深度土壤甲烷产生速率最大;在实验的第16天,丘间10~20 cm深度土壤甲烷产生速率最大;在实验的第12天,丘下0~10 cm深度土壤甲烷产生速率最大;草丘对土壤甲烷的氧化作用在甲烷释放过程中占主导地位,可以有效减少甲烷的排放量,对沼泽碳输出具有重要的调控作用。

The Carex schmidtii peat mire in Dongming forest farm in Dashitou town of Dunhua City in Changbai Mountain was selected as study object,and soil samples at 0-10 cm,10-20 cm and 20-30 cm depth were collected from three distinct microtopographical positions(hummock,under-hummock and hollow).The laboratory simulation method was used to cultivate the soil samples.In the incubation period of 24 d,gas samples were collected from the bottles.The rates of methane production and oxidation of the soils were determined.The results showed that the maximum production rates of methane of the soils at 0-30 cm depth was(156.55±83.37)μg/(g·d)in the hummock of Carex schmidtii on the 24 th day,and oxidation rates was(1.38±0.11)μg/(g·d)on the 6 th hour,respectively,which were significantly higher than those in the hollow and under-hummock.However,there was no significant difference between the rates of methane production and oxidation of soils between positions under-hummock and in the hollow.Within the 0-30 cm soil depth,the highest rate of methane production of soils occurred at 10-20 cm depth in the hummock on the 24 th day,whereas in the hollow on the 16 th day.The highest rate of methane production of soils occurred at 0-10 cm depth in under-hummock on the 12 th day.There was no significant difference between the rates of soil methane oxidation among all soil depths.In the Carex schmidtii peat mire,hummocks have the ecological function of oxidating methane,which could effectively regulate the emission of carbon gas in peat mire and thus has great significance for global climate change.