北极高纬度苔原CO_(2)净通量的空间变异规律及影响因素  

The spatial variation of net CO_(2) fluxes(NEE) and their influence factors in tundra in high Arctic

作　　者：陈清清 包韬[3] 朱仁斌 徐华[4] Chen Qingqing;Bao Tao;Zhu Renbin;Xu Hua(College of Life Science,Resources and Environment,Yichun University,Yichun 336000,China;Anhui Province Key Laboratory of Polar Environment and Global Change,School of Earth and Space Science,University of Science and Technology of China,Hefei 230026,China;Key Laboratory of Regional Climate-Environment for Temperate East Asia,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210091,China)

机构地区：[1]宜春学院生命科学与资源环境学院,江西宜春336000 [2]中国科学技术大学地球和空间科学学院极地环境与全球变化安徽省重点实验室,安徽合肥230026 [3]中国科学院东亚区域气候-环境重点实验室,中国科学院大气物理研究所,北京100029 [4]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,江苏南京210091

出　　处：《极地研究》2021年第4期482-495,共14页Chinese Journal of Polar Research

基　　金：国家重点研发计划重点专项(2020YFA0608500);国家自然科学基金(41776190,41976220)资助。

摘　　要：北极夏季无冰区苔原CO_(2)的释放对全球碳循环起着重要的作用。在第4次北极科学考察(2008年7月26日—8月5日)期间,采用密闭箱法在北极新奥尔松(Ny-Ålesund)黄河站区附近的鸟类保护区苔原(Tundra in Seabird Sanctuary,TSB)、普通海滩苔原(Tundra in Non-seabird Colony,TNS)和两者间的过渡苔原(Tundra in Transition Zone,TTR)监测CO_(2)净通量(Net CO_(2)Fluxes,NEE)空间变异规律及其影响因素。结果表明:鸟类保护区苔原TSB的平均NEE为(–39.0±6.0)mg·m^(–2)·h^(–1),为CO_(2)吸收汇,且对CO_(2)的吸收随着植被覆盖度和海鸟活动强度的增强而显著增强;普通海滩苔原TNS和过渡苔原TTR的平均NEE分别为(12.0±6.3)mg·m^(–2)·h^(–1)和(40.5±29.3)mg·m^(–2)·h^(–1),均为CO_(2)净排放源。普通海滩苔原TNS的CO_(2)排放强度随土壤水分的减少和地势增高而增强;过渡苔原TTR中高地苔原区的平均NEE为(106.4±23.1)mg·m^(–2)·h^(–1),为CO_(2)强排放源;而泥炭苔原区的平均NEE为(–58.3±9.5)mg·m^(–2)·h^(–1),为CO_(2)强吸收汇。苔原土壤的理化性质对苔原NEE有重要影响,鸟类保护区苔原TSB和普通海滩苔原TNS的NEE与土壤含水率呈显著负相关关系(r=–0.44,P=0.003)。鸟类保护区苔原TSB的NEE与土壤温度弱正相关(r=0.32,P=0.06),与NH4+-N(P<0.05)和NO_(3)^(–)-N(P<0.05)含量均显著负相关。在全球变暖的驱使下,不同地形地貌和海鸟活动特征的北极苔原区域CO_(2)排放的复杂性将显著增强,对全球碳循环产生较大的影响,本研究也将为此提供科研资料。The release of CO_(2)from summer ice-free tundra of the high Arctic plays an important role in the global carbon cycle.These net ecosystem exchanges(NEEs)and their influence factors from Seabird Sanctuary Tundra(TSB),Tundra in Non-Seabird Colony(TNS)and Tundra in Transition Zone(TTR)were measured using the closed chamber method during the Fourth Arctic Scientific Exploration(26 July–5 August 2008)in the High Arctic.The spatial variations of NEE show that TSB was a sink for CO_(2),with an average NEE of(−39.0±6.0)mg·m^(–2)·h^(–1).Typically,absorption of CO_(2)in areas with high vegetation cover and strong seabird usage was greater than in areas with lower vegetation cover and seabird usage.In contrast,TNS and TTR were emission sources for CO_(2),with average NEEs of(12.0±6.3)mg·m^(–2)·h^(–1)and(40.5±29.3)mg·m^(–2)·h^(–1),respectively.Highland TTR((106.4±23.1)mg·m^(–2)·h^(–1))was the strongest emission source,while peatland TTR[(−58.3±9.5)mg·m^(–2)·h^(–1)]was a strong sink.Spatial variation of NEEs was linked to differences in vegetation cover and hydrological conditions related to seabird activity in all tundra types.Physical and chemical properties of tundra soils also affected NEE values,showing negative correlations with soil mois-ture(r=−0.44,P=0.003)in TSB and TNS,but a positive correlation with soil temperature(r=0.32,P=0.06)and negative correlations with NH4+-N(P<0.05)and NO3–-N(P<0.05)concentrations in TSB.

关 键 词：CO_(2) 净通量 北极 新奥尔松 高纬度苔原 

分 类 号：S154.1[农业科学—土壤学]