若尔盖高原不同深度泥炭植物残体去除对甲烷排放及其温度敏感性的影响  

Impact of plant residue removal on peat methane emission and its temperature sensitivity at different depths on the Zoige Plateau

作　　者：刘亮锋 陈槐[1] LIU Liangfeng;CHEN Huai(Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610213,China)

机构地区：[1]中国科学院成都生物研究所,成都610213

出　　处：《应用与环境生物学报》2025年第1期33-40,共8页Chinese Journal of Applied and Environmental Biology

基　　金：四川省自然科学基金项目(2022NSFSC0984);国家自然科学基金项目(42101063);中国科学院成都生物研究所青年探索项目(QNTS202301);四川省青年科技创新研究团队项目(2021JDTD011)资助。

摘　　要：泥炭地是陆地重要的甲烷排放源.植物残体是泥炭地碳的重要组成,具有通过调控土壤微环境影响泥炭地甲烷排放的作用;然而,去除植物残体作为当前泥炭地甲烷排放动态研究中主要的前处理方法,对泥炭地甲烷排放产生的影响目前还不清楚.以青藏高原东缘的若尔盖高原泥炭地为研究对象,通过室内控制试验,探究植物残体去除对泥炭地不同深度土壤甲烷排放动态及温度敏感性的影响.结果表明:若尔盖高原泥炭地土壤甲烷排放随深度呈递增状态,且其温度敏感性表现为表层(1.6±0.2)显著高于亚表层和深层土壤,为2.5-3.4倍(P<0.01).去除植物残体显著增加了不同深度泥炭甲烷排放速率,其中表层增加了2.4倍(P<0.05),亚表层和深层土壤分别增加了2.3倍(P<0.01)和2.1倍(P<0.05),同时降低了表层泥炭甲烷排放的温度敏感性(P>0.05),增加了亚表层(P>0.05)和深层(P<0.01)泥炭甲烷排放的温度敏感性.进一步分析表明未去除植物残体的泥炭甲烷排放主要受土壤酶活性的影响,而去除植物残体的泥炭甲烷排放主要受土壤微生物生物量的限制.去除植物残体后泥炭土壤甲烷排放显著增加的现象表明以往去除植物残体的研究结果可能高估了泥炭地土壤甲烷排放潜势,在以后泥炭地土壤甲烷排放评估研究中需要保留植物残体.(图3表2参53)Peatlands are a vital source of methane(CH4)emissions.Plant residues,the major components of peat,can affect CH4 emissions by regulating the peat microenvironment.Plant residues have traditionally been removed during research on peat CH4 emissions;however,the impact of removing plant residues on CH4 emissions remains unknown.This study aimed to investigate how the removal of plant residues affects CH4 emissions from peat soil at different depths in the Zoige Plateau.Through an incubation experiment,the CH4 emissions of sieved(removed)and unsieved(unremoved)peat from different layers(Layer 1:0-20 cm;Layer 2:20-70 cm;and Layer 3:70-115 cm)of the peatland were monitored.The results showed that CH4 emissions from unsieved peat were lower in Layer 1 than those in the two deeper layers.However,the temperature sensitivity(Q10)was signiffcantly higher in Layer 1(1.6±0.2)than that in Layers 2 and 3 by 2.5 and 3.4 times,respectively(P<0.01).Removing plant residue signiffcantly increased CH4 emissions from all three layers of peat,in which Layer 1 soil increased by 2.4 times(P<0.01)and Layers 2 and 3 soil increased by 2.3(P<0.01)and 2.1 times(P<0.05),respectively.It also decreased the Q10 of Layer 1(P>0.05)and increased the Q10 of Layers 2(P>0.05)and 3(P<0.01)soil CH4 emissions.Furthermore,enzymatic and microbial biomass were vital factors in regulating CH4 emissions from unremoved and removed peat,respectively.In conclusion,the significant increase in CH4 emissions implies that past experiments involving plant residue removal probably overestimated the CH4 emission potential of peatland soil and that plant residue should be retained in future peatland soil CH4 emission research.

关 键 词：青藏高原 泥炭地 植物残体 甲烷 温度敏感性 

分 类 号：X144[环境科学与工程—环境科学]