青海湖流域两种不同高寒湿地类型CO_(2)、CH_(4)和N_(2)O排放通量对模拟降水的响应

Response of CO_(2),CH_(4) and N_(2)O fluxes of two different alpine wetland types in Qinghai Lake basin to simulated precipitation

以青海湖流域两种不同类型高寒湿地(鸟岛湖滨湿地、瓦颜山河源湿地)为研究对象,探究模拟降水(增雨50%处理、减雨50%处理以及自然处理)对高寒湿地温室气体(CO_(2)、CH_(4)、N_(2)O)排放通量的影响。于2019年8月,使用静态箱–气相色谱法对两地温室气体进行观测。结果表明:(1)模拟降水对鸟岛湖滨湿地、瓦颜山河源湿地CO_(2)排放通量作用明显,鸟岛减雨、增雨处理下平均排放通量为105.176、128.984 mg·m^(-2)·h^(-1),瓦颜山减雨、增雨处理下平均排放通量为201.761、174.000 mg·m^(-2)·h^(-1)。(2)模拟降水装置对鸟岛湖滨湿地CH_(4)排放通量作用明显,减雨、增雨处理下平均排放通量为1.014、3.840μg·m^(-2)·h^(-1),对瓦颜山河源湿地CH_(4)排放通量影响不明显,减雨、增雨处理下平均排放通量为–5.261、–5.485μg·m^(-2)·h^(-1)。(3)增雨处理对鸟岛湖滨湿地N_(2)O排放通量有抑制作用,减雨、增雨处理下平均排放通量为0.382、–1.216μg·m^(-2)·h^(-1),增雨处理下瓦颜山河源湿地N_(2)O排放通量反而增加,减雨、增雨处理下平均排放通量为–0.893、1.725μg·m^(-2)·h^(-1)。(4)鸟岛湖滨湿地10 cm土壤温度和温室气体排放通量呈不相关,瓦颜山河源湿地10 cm土壤温度与CO_(2)排放通量呈显著相关,与其余气体排放通量无显著相关性。(5)高寒湿地模拟降水对鸟岛湖滨湿地铵态氮(NH_(4)^(+)-N)以及硝态氮(NO_(3)^(-)-N)含量都有较明显的增加。瓦颜山河源湿地的铵态氮(NH_(4)^(+)-N)含量有降低趋势,硝态氮(NO_(3)^(-)-N)含量呈增长趋势。

Taking two different types of alpine wetlands in Qinghai Lake Basin(Bird Island Lakeside Wetland,Wayanshan River Source Wetland)as the research objects,the simulated precipitation(50%increase in rain treatment,50%reduction in rain treatment and natural treatment)on greenhouse gases in alpine wetland was explored(CO_(2),CH_(4),N_(2)O)influence of emission flux.In August 2019,static chamber-gas chromatography was used to observe the greenhouse gases in the two places.The results showed that:(1)Simulated precipitation had a significant effect on the CO_(2)emission flux of the Bird Island Lakeside Wetland and Wayanshan River Source Wetland.The average emission flux of Bird Island during the rain reduction and rain enhancement treatments was 105.176,128.984 mg·m^(-2)·h^(-1).The average emission flux of Wayanshan under rain reduction and rain enhancement treatment was 201.761,174.000 mg·m^(-2)·h^(-1).(2)The simulated precipitation device had a significant effect on the CH_(4)emission flux of Bird Island Lakeside Wetland.The average emission flux under the rain enhancement treatment was 1.014 and 3.840μg·m^(-2)·h^(-1),which had little effect on the CH_(4)emission flux of Wayanshan River Source Wetland.The average emission flux under the rain reduction and rain enhancement treatment was-5.261,-5.485μg·m^(-2)·h^(-1).(3)Rain enhancement treatment could suppress the N_(2)O emission flux of Bird Island Lakeside Wetland.The average emission flux under rain reduction and rain enhancement treatment was 0.382,^(-1).216μg·m^(-2)·h^(-1),the N_(2)O emission flux from the Wayanshan River Source Wetland increased under rain enhancement treatment,the average emission flux under rain reduction and rain enhancement treatment was-0.893,1.725μg·m^(-2)·h^(-1).(4)The 10 cm soil temperature at Bird Island Lakeside Wetland was not related to the greenhouse gas emission flux,and the 10 cm soil temperature at the Wayanshan River Source Wetland was significantly correlated with the CO_(2)emission flux,but was not significant correlated with other gas fluxes.(5)Simulated precipitation in alpine wetlands significantly increased the content of ammonium nitrogen(NH_(4)^(+)-N)and nitrate nitrogen(NO_(3)^(-)-N)in the Bird Island Lakeside Wetland.But the content of ammonium nitrogen(NH_(4)^(+)-N)in the Wayanshan River Source Wetland had a tendency to decrease,and the content of nitrate nitrogen(NO_(3)^(-)-N)showed an increasing trend.