增温对青海湖流域高寒沼泽草甸主要温室气体通量的影响  

Impact of warming on greenhouse gas fluxes fromalpine marsh meadows in the QinghaiLake basin

作　　者：吴恒飞 陈克龙[2] 张乐乐 丁俊霞 WU Heng-fei;CHENG Ke-long;ZHANG Le-le;DING Jun-xia(College of Geographical Sciences,Qinghai Normal University,Xining 810008,China;MOE Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation,Xining 810008)

机构地区：[1]青海师范大学地理科学学院,青海西宁810008 [2]青海师范大学青藏高原地表过程与生态保育教育部重点实验室,青海西宁810008

出　　处：《草原与草坪》2021年第4期1-9,共9页Grassland and Turf

基　　金：国家自然科学基金项目(41661023);国家科技支撑计划项目(2017YFC0403601);青海省科技厅项目(2017-ZJ-720、2018-ZJ-T09)。

摘　　要：全球变暖下的温度升高对陆地生态系统碳循环产生了较大影响,而高寒沼泽草甸生态系统是气候变化的敏感区域。以青海湖流域两种类型高寒沼泽草甸(小泊湖湖滨湿地和瓦颜山河源湿地)为研究对象,利用开顶箱法(OTC)模拟全球变暖,采用静态箱—气相色谱仪法探究了2018年9月两地在增温处理下三种主要温室气体(CH_(4)、CO_(2)和N_(2)O)的日间排放变化特征。研究结果表明:9月中旬日间小泊湖湿地表现为CH_(4)和CO_(2)的源、N_(2)O的汇,增温提高了小泊湖湿地CH_(4)及CO_(2)排放通量的吸收能力,使CH_(4)及CO_(2)排放通量相较于对照分别减少了48.43%和20.65%,对N_(2)O无显著影响;瓦颜山湿地分别表现为CH_(4)的汇及CO_(2)、N_(2)O的源,增温使瓦颜山湿地CH_(4)由弱汇转为弱源,N_(2)O由弱源转为弱汇,并促进了CO_(2)的排放,使CO_(2)排放通量增加了15.79%。两地不同处理下土壤10、20 cm温度及土壤表层含水量与三种温室气体通量相关性分析表明:除小泊湖湿地对照样地CO_(2)通量与土壤10 cm、20 cm温度存在显著的相关性(P<0.05),其他样地相关性均不显著(P>0.05),主要由表土温度及含水量的滞后效应所导致。表明全球变暖对青海湖高寒沼泽草甸温室气体排放通量有一定影响,不同类型高寒沼泽草甸对全球变暖的响应也不尽相同。研究对了解未来青海湖流域乃至青藏高原的碳氮平衡有重要意义。The increasing temperature under global warming has great effects on the carbon cycle of terrestrial ecosystem,and the alpine marsh meadow ecosystem is the sensitive area to climate change.In this paper,two alpine swamp meadows(Xiaopohu Lakeside Wetland and Wayanshan Headwater Wetland)in the Qinghai Lake Basin were taken as the research objects,and Open Top Chamber(OTC)and static box-like gas chromatograph were used to analyze the diurnal variation of three main greenhouse gases(CH_(4),CO_(2)and N 2O)in September 2018.Results showed that Xiaopohu Lakeside Wetland was the source of CH_(4)and CO_(2)while the sink of N 2O.The absorption capacity of CH_(4)and CO_(2)increased in response to warming,which reduced the CH_(4)and CO_(2)fluxes by 48.43%and 20.65%,respectively,while there was no significant effect on N 2O flux.Wayanshan Wetland was the sink of CH_(4)and the source of CO_(2)and N 2O,respectively.Warming at Wayanshan Wetland shifted CH_(4)from weak sink to weak source,and shifted N 2O from weak source to weak sink,and promoted the CO_(2)emission capacity with an increase in CO_(2)emission flux by 15.79%.There was a significant correlation between soil CO_(2)flux and soil temperature at the soil depth of 10 cm,20 cm at Xiaopohu Wetland(P<0.05),but no other significant correlations were found,which was mainly due to the hysteresis effects of surface soil temperature and water content.In general,global warming has some effects on the greenhouse gas emission flux from Alpine meadow in Qinghai Lake,and the response of different types of Alpine meadow to global warming was also different.The information is important for understanding the future carbon balance of the Qinghai Lake Basin and Tibetan plateau.

关 键 词：青海湖 高寒沼泽草甸 全球变暖 温室气体通量 

分 类 号：S812[农业科学—草业科学]