【摘要】 随着全球气候变化,降水量和降水强度的变化成为热点议题。以青海湖流域瓦颜山和鸟岛湿地为研究对象,设降水梯度为减雨50%（P_-）、自然对照（P₀）、增雨50%（P₊）,采用静态箱—气相色谱法研究不同降水对两种湿地CO₂、CH₄、N₂O通量的影响,并分析其作用因子。结果表明:1)生长季两种湿地均为CO₂和N₂O排放源,其月均排放量瓦颜山为132.82 mg·m^–2·h^–1和0.38μg·m^–2·h^–1,鸟岛为90.79 mg·m^–2·h^–1和0.79μg·m^–2·h^–1,瓦颜山为CH₄的吸收汇,其吸收量为3.21μg·m^–2·h^–1,鸟岛为CH₄的排放源,其排放量为1.84μg·m^–2·h^–1;2)不同降水处理对两种湿地的CO₂和N₂O排放均无显著影响,对CH₄交换量影响显著（P<0.05）,瓦颜山CH₄吸收量为:8月>9月>5>月6月>7月,P-较P₀减少41.34%,P_-促进CH₄排放,P₊较P₀减少85.91%,P₊促进CH₄吸收,鸟岛生长季CH₄排放通量:9月>8月>7>月6月>5月,P_-较P₀减少57.40%,P₊较P₀增加72.51%。3)不同降水处理对两种湿地的生物量影响均不显著（P>0.05）且呈现一致的影响结果,增雨会增加地上、地下生物量,同时会减少凋落物含量,减雨处理反之。4)不同降水处理对两种湿地的土壤因子的影响均不显著（P>0.05）,表现在:增雨会增加土壤湿度,较小尺度降低土壤温度,减雨处理反之;增减雨处理均会降低土壤的全氮、全碳含量;生长季两种湿地净氨化速率均为正值,即铵态氮含量在生长季节呈现增加的趋势,而净硝化速率为负值,则硝态氮含量呈减少趋势。5)高寒湿地温室气体交换的影响因子和交换机理因湿地类型而异。更多还原

【Abstract】 Along with the global climate change,precipitation and precipitation intensity have become hot topics.In this study,the wetland at the source of the Wayanshan in the Qinghai Lake Basin,the Bird Island Wetland between Buha Estuary Wetland and Lakeside Wetland were used as research objects from May to September 2019.The precipitation gradient was set to 50%rain reduction （P_-）,natural control （P₀）,50%rain increase （P₊）,and static box-gas chromatography was used to study the CO₂,CH₄,and N₂O fluxes of two types of wetlands with different precipitation and their contributing factors.The results showed that:1)Both types of wetlands in the growing season were emission sources of CO₂ and N₂O,the average monthly emission in Wayanshan was 132.82 mg·m^–2·h^–1 and 0.38μg·m^–2·h^–1,the Bird Island was 90.79 mg·m^–2·h^–1 and 0.79μg·m^–2·h^–1,the Wayanshan was an absorption sink for CH₄,and its absorption was 3.21μg·m^–2·h^–1.The Bird Island was the source of CH₄ emissions with value of 1.84μg·m^–2·h^–1.2) Different precipitation treatments had no significant impact on emission of CO₂ and N₂O in the two wetlands,but significantly affected the amount of CH₄ exchange （P<0.05）.The amount of CH₄ absorbed in Wayanshan was:August>September>May>June>July.P-was 41.34%lower than that of P₀,and P_-promoted emission of CH₄.P₊was 85.91%lower than that of P₀,and P₊promoted absorption of CH₄.Emission flux of CH₄in the Bird Island during the growing season was as follows:September>August>July>June>May.P-was 57.40%lower than that of P₀,and P₊was 72.51%higher than that of P₀.3) The effects of different precipitation treatments on the biomass of the two wetlands were not significant （P>0.05） and showed consistent results.Increased rain would increase aboveground and underground biomass.At the same time,it would reduce the litter content,and the rain reduction treatment was reversed.4)The effects of different precipitation treatments on the soil factors of the two wetlands were not significant （P>0.05）.Increased rain would increase soil moisture,and reduce soil temperature on a smaller scale;the rain reduction treatment was reversed.Increasing or decreasing rain treatment would reduce the total nitrogen and total carbon content of the soil.The net ammoniation rates of two wetlands were positive value in the growing season.The ammonium nitrogen content showed an increasing trend during the growing season.The net nitrification rate was negative value,then the nitrate nitrogen content showed a decreasing trend.5)The influence factors and exchange mechanism of greenhouse gas exchange in alpine wetland were type of wetland dependently.更多还原