云南哀牢山亚热带常绿阔叶林土壤CH_(4)通量特征  

Characteristics of Soil CH_(4) Flux in the Subtropical Evergreen Broad-leaved Forest in Ailao Mountain,Yunnan,Southwest China

作　　者：陈丽娟 周文君[1,2,5] 易艳芸 宋清海 张一平[1,2] 梁乃申[4] 鲁志云 温韩东[1,3] MOHD Zeeshan[1] 沙丽清 CHEN Lijuan;ZHOU Wenjun;YI Yanyun;SONG Qinghai;ZHANG Yiping;LIANG Naishen;LU Zhiyun;WEN Handong;MOHD Zeeshan;SHA Liqing(CAS Key Laboratory of Tropical Forest Ecology/Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Mengla 666303,P.R.China;Center for Plant Ecology,Core Botanical Gardens,Chinese Academy of Sciences,Mengla 666303,P.R.China;Ailaoshan Station for Subtropical Forest Ecosystem Studies,Jingdong 676209,P.R.China;Center for Global Environmental Research,National Institute for Environmental Studies,Tsukuba,Ibaraki,305-8506,Japan;University of Chinese Academy of Sciences,Beijing 100049,P.R.China;Institutional Center for Shared Technologies and Facilities of Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Mengla 666303,P.R.China)

机构地区：[1]中国科学院西双版纳热带植物园热带森林生态学重点实验室,云南勐腊666303 [2]中国科学院核心植物园植物生态中心,云南勐腊666303 [3]中国科学院哀牢山亚热带森林生态系统研究站,云南景东676209 [4]日本国立环境研究所,筑波305-8506 [5]中国科学院大学,北京100049 [6]中国科学院西双版纳热带植物园公共技术中心,云南勐腊666303

出　　处：《生态环境学报》2022年第5期949-960,共12页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(31870467,42073080);云南省自然科学基金项目(2019IB018);云南省第四批博士后定向培养项目;中国科学院“一三五”专项(2017XTBG-F01,2017XTBG-T01);云南省中青年学术和技术带头人后备人才项目(202205AC160045)。

摘　　要：甲烷(CH_(4))是仅次于二氧化碳(CO_(2))的重要温室气体,对全球气候变化有重要的反馈作用。亚热带森林土壤是全球陆地生态系统重要的CH_(4)汇,但因在亚热带的观测较少,致使模型估算得出的结果具有不确定性,因此需对土壤CH_(4)通量进行现场观测和实验,以便准确估计亚热带森林土壤CH_(4)通量及其对该生态系统碳汇能力的贡献。采用大型多点自动开闭箱式自动连续测定法在哀牢山亚热带常绿阔叶林开展土壤CH_(4)通量、气温(t_(a))、地表温度(t_(0))、土壤5 cm温度(t_(5))、降雨量(P)和土壤含水量(C_(sw))进行连续1年定位观测。结果表明,(1)云南哀牢山亚热带常绿阔叶林土壤为CH_(4)的汇,年通量为(−11.79±0.001)kg·hm^(-2)·a^(-1),年均速率为(−0.13±0.05)mg·m^(-2)·h^(-1),呈现出显著的季节动态,表现为干季土壤CH_(4)的吸收通量[(−0.17±0.06)mg·m^(-2)·h^(-1)]显著高于雨季[(−0.10±0.03)mg·m^(-2)·h^(-1)](P<0.05)。(2)土壤CH_(4)通量与地表温度(r^(2)=0.2125,P<0.001)、土壤5 cm温度(r^(2)=0.1948,P<0.001)和气温(r^(2)=0.0983,P<0.001)呈显著相关关系,但土壤CH_(4)通量与土壤5 cm温度的相关关系在12.35℃由正相关转为负相关。(3)土壤CH_(4)通量对土壤含水量的变化响应较温度敏感,土壤含水量可解释其90.36%的相关性(P<0.001),单因素和双因子关系模型进一步证明土壤含水量是调节哀牢山亚热带常绿阔叶林土壤CH_(4)通量的主导因子。(4)在20年和100年时间尺度上,CH_(4)通量的全球增温潜势(global warming potential,GWP)分别可以抵消土壤CO_(2)排放产生增温潜势的2.2%和0.7%,可以增加该生态系统碳汇的10.6%和3.5%。为此,在未来降水格局变化的情景下,土壤含水量可用于预测哀牢山亚热带常绿阔叶林土壤CH_(4)通量的变化和生态系统CH_(4)汇的强度,进而反映其对该森林生态系统碳汇能力的贡献。Methane(CH_(4)),one of the important greenhouse gases,has significant effects on global climate change.Subtropical forest soil plays an important role in CH_(4) sink,which,however,are still uncertain by models due to few in situ observation in the subtropical zone.Field based investigations of CH_(4) flux and its contribution to the carbon sink capacity of forest ecosystem are needed.In this study,we collected the one-year experimental dataof CH_(4) flux in Ailao Mountain subtropical evergreen broad-leaved forest by continuous automatic flux chambers systems.The regulating factors including air temperature(t_(a)),surface temperature(t_(0)),soil temperature at 5 cm depth(t_(5)),precipitation(P)and soil water content(C_(sw))were analyzed.The results showed that(1)the subtropical forest soil acted as the sink of CH_(4).The annual CH_(4) uptake were(−11.79±0.001)kg·hm^(-2)·a^(-1) in the subtropical evergreen broad−leaved forest of Ailao Mountain.The seasonal dynamic with the soil CH_(4) flux in dry season(−0.17±0.06)mg·m^(-2)·h^(-1)was significantly stronger than that in rainy season(−0.10±0.03)mg·m^(-2)·h^(-1)(P<0.05).(2)There were significant correlations between soil CH_(4)flux and surface temperature(r^(2)=0.2125,P<0.001),and between soil temperature at 5 cm(r^(2)=0.1948,P<0.001)and air temperature(r^(2)=0.0983,P<0.001).Soil CH_(4)flux was correlated with soil temperature at 5 cm positively when the temperature was at or below 12.35℃and negatively when it was above 12.35℃.(3)The relationship between CH_(4)flux and soil water content showed statistical significance,which explained the correlation of soil CH_(4)90.36%(P<0.001).The fitting results of single and two factors relationship models showed that soil water content was the dominant factor affecting soil CH_(4)flux absorption in the subtropical evergreen broad-leaved forest in Ailao Mountain.(4)The global warming potential of soil CH_(4)flux for 20 years(990.15 CO_(2))and 100 years(330.05 CO_(2))was 2.2%and 0.7%of soil CO_(2)and 10.6%and

关 键 词：亚热带森林土壤 CH_(4)通量 土壤含水量 温度敏感性(Q_(10)) 全球增温潜势 

分 类 号：X16[环境科学与工程—环境科学]