静态箱气相色谱法高估了实验初期若尔盖表层泥炭地甲烷排放通量  

Static chamber gas chromatography method overestimates methane emission flux from surface peatland at the beginning of the experiment

作　　者：杨刚[1] 陈槐[2,3] 刘建亮[2,3] 曹芹[1] 曾嘉 白银萍 YANG Gang;CHEN Huai;LIU Jianliang;CAO Qin;ZENG Jia;BAI Yinping(School of Life Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization,Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China;Zoige Wetland Ecosystem Research Station,Chinese Academy of Sciences,Hongyuan 624400,China;School of Environment and Resources,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学生命科学与工程学院,绵阳621010 [2]中国科学院成都生物研究所山地生态恢复与生物资源利用重点实验室,成都610041 [3]中国科学院四川若尔盖湿地生态研究站,四川红原624400 [4]西南科技大学环境与资源学院,绵阳621010

出　　处：《应用与环境生物学报》2021年第4期878-883,共6页Chinese Journal of Applied and Environmental Biology

基　　金：四川省科技计划项目(2020YFS0020);国家自然科学基金项目(42077038)资助。

摘　　要：静态箱气相色谱法是最为普遍的温室气体监测方法,监测过程中埋放静态箱底座造成的土壤扰动可能会影响实验初期排放数据的准确性.为了解这一过程对泥炭地甲烷排放的确切影响,选取泥炭沼泽、沼泽草甸和高寒草甸为研究对象,利用静态箱气相色谱法监测不同类型泥炭地在模拟增温、节雨及其交互作用下的甲烷排放通量.结果表明,整个为期两年的实验中,甲烷平均排放通量为7.1 mg m^(-2) h^(-1),且甲烷在实验布设的前半年集中排放,其排放通量是下一年同一时期排放通量的37倍.对比实验初期(实验布设半年内)和实验后期(实验布设下一年同一时间段)的甲烷排放通量,发现增温和节雨交互作用显著降低了实验初期和实验后期甲烷排放通量,以整个若尔盖高原泥炭地面积来估算,其甲烷减排量在7-12月份分别为686 Gg和38 Gg,相差约18倍.可见,气相色谱法严重高估了实验初期泥炭地的甲烷排放通量,造成这一现象的主要原因可能是实验初期埋放静态箱造成了土壤扰动.因此,在后续的研究中应尽量减少野外甲烷监测过程中的土壤扰动,以优化最终的实验结果.Static chamber gas chromatography is the most commonly used method to monitor greenhouse gases. However, the soil was constantly disturbed by burying the static box base before monitoring the greenhouse gases. This study aims to investigate the effect of this process on methane emissions in peatlands. In this study, peat swamps, swamp meadows, and alpine meadows were selected to analyze the methane emissions from different peatlands under simulated warming, rain reduction, and their interactions. The results showed that the average methane emission was 7.1 mg m^(-2) h^(-1) during the entire 2-year experiment period. The large amount of methane emissions during the first half-year of this experiment was 37 times higher than that at the same time in the next year. Therefore, we compared methane emissions at two periods: the beginning of the experiment(within half a year from the beginning of the experiment) and the end of the experiment(the same period in the following year). The results showed that the interaction between warming and rain reduction significantly reduced the fluxes of methane emissions during the two periods. Based on the peat area of the Zoige peatland, the emission reductions were calculated as 686 Gg and 38 Gg, respectively. This suggests that gas chromatography overestimates the methane emission flux from peatland at the beginning of the experiment. Large interannual differences in methane emissions were probably owing to soil disturbance caused by the buried static box at the early stage of the experiment. Therefore, in situ soil disturbance in the field methane monitoring process should be minimized to optimize the final experimental results.

关 键 词：泥炭地 甲烷 水位 增温 

分 类 号：O657.71[理学—分析化学] X831[理学—化学]