大兴安岭多年冻土区两种水体温室气体浓度动态与冬季储存特征  

Greenhouse gas concentration dynamics and winter storage characteristics of two water bodies in the permafrost zone of the Great Hing′an Mountains

作　　者：薛璟 陈辛安 王宪伟[3] 孙晓新[1,2] XUE Jing;CHEN Xinan;WANG Xianwei;SUN Xiaoxin(Key Laboratory of Sustainable Forest Ecosystem Management of Ministry of Education,School of Forestry,Northeast Forestry University,Harbin 150040,China;Heilongjiang Sanjiang Plain Wetland Ecosystem Research Station,Fuyuan 156500,China;Key Laboratory of Wetland Ecology and Environment,Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun 130102,China)

机构地区：[1]东北林业大学林学院,森林生态系统可持续经营教育部重点实验室,哈尔滨150040 [2]黑龙江三江平原湿地生态系统国家定位观测研究站,抚远156500 [3]中国科学院东北地理与农业生态研究所,中国科学院湿地生态与环境重点实验室,长春130102

出　　处：《生态学报》2024年第5期1918-1927,共10页Acta Ecologica Sinica

基　　金：中央高校基本科研业务费项目(2572020BA06,2572021DS04);黑龙江省自然科学基金联合引导项目(LH2020C033);国家自然科学基金项目(31870443)。

摘　　要：北方内陆水体是温室气体排放的热点,对量化区域碳收支起重要作用,但其排放的季节变化尚不清楚。观测了大兴安岭多年冻土区府库奇河及其改道形成的牛轭湖(演替晚期)冻结期冰层中储存的二氧化碳(CO_(2))和甲烷(CH_(4))浓度,并比较了两种水体中CO_(2)和CH_(4)浓度在三个不同时期(冻结期、非冻结期、春季融化)的差异。结果表明:两种水体CO_(2)和CH_(4)浓度季节变化存在差异。牛轭湖在冻结期水体中CO_(2)和CH_(4)浓度最高,有明显的冰下积累现象,其中CH_(4)浓度平均值为(2.21±0.54)μmo/L,分别是非冻结期和春季融化期水体CH_(4)浓度的5倍和14倍。河流水体中CO_(2)和CH_(4)浓度最高出现在春季融化期,显著高于非冻结期和冻结期(P<0.05)。水中CO_(2)和CH_(4)浓度受多种环境因子的影响,与可溶性有机碳(DOC)正相关(P<0.05),与溶解氧(DO)、水温为负相关(P<0.05)。冻结期冰层形成后,温室气体会以冰气泡的形式存储在冰层中,气泡的主要成分是CO_(2)和CH_(4),其中CO_(2)占90%以上。由于冰气泡中CO_(2)和CH_(4)浓度约为冰下水体浓度的1%—30%,忽略冰层中储存的温室气体将会增加北方水体碳排放的不确定性。研究明确了大兴安岭多年冻土区两种水体溶解性CO_(2)和CH_(4)的季节变化特征与冬季温室气体储存能力,为深入认知该区域水体碳循环过程提供重要数据支持。Boreal inland waters are hotspots for greenhouse gas emissions,and they play an important role in quantifying the regional carbon budget,but seasonal variations in their emissions are not well understood.In this study,we observed the concentration of carbon dioxide(CO_(2))and methane(CH_(4))trapped in the ice during the ice cover period of the Fukuchi River and its diverted oxbow lakes(late successional stage)in the permafrost zone of the Great Hing′an Mountains.Differences in dissolved CO_(2)and CH_(4)concentrations in the two water bodies during three periods(ice cover period,open water period,and spring thaw period)were also compared.The results showed that there were differences in the seasonal variation patterns of dissolved CO_(2)and CH_(4)concentrations in the two water bodies.Concentrations of dissolved CO_(2)and CH_(4)were highest in the water column of oxbow lakes during the ice cover period.There was a significant accumulation of CO_(2)and CH_(4)under the ice layer.The mean dissolved CH_(4)concentration in the water column was(2.21±0.54)μmo/L,which was 5 and 14 times higher than the CH_(4)concentration during the open water and spring thaw periods,respectively.River had the highest dissolved CO_(2)and CH_(4)concentrations in the water column during the spring thaw period,which were significantly higher than during the open water period and ice cover period(P<0.05).Dissolved CO_(2)and CH_(4)in water were influenced by various environmental factors and were positively correlated with dissolved organic carbon(DOC)(P<0.05)and negatively correlated with dissolved oxygen(DO)and water temperature(P<0.05).CO_(2)and CH_(4)were also trapped within the ice as bubbles when the ice formed during the ice cover period.CO_(2)was the main component in bubbles,with concentrations of about 90%or more within the bubbles.As CO_(2)and CH_(4)concentrations in bubbles are about 1%—30%of those in the water column under the ice,ignoring the greenhouse gases stored in the ice would increase the uncertainty of carbon emissi

关 键 词：溶解CO_(2)和CH_(4)浓度 冰层覆盖时期 内陆水域 冰气泡 

分 类 号：G63[文化科学—教育学]