鼎湖山天然针阔叶混交林优势树种对大气SO2的气孔吸收特征  

Sulfur Dioxide Uptake by the Dominant Canopy Tree Species in a Natural Mixed Conifer-broadleaf Forest in Dinghushan,Guangdong Province,South China.

作　　者：邓永红 王立景 黄健强 孟泽[1] 刘世忠[1] OTIENO Dennis 李跃林[1] DENG Yong-hong;WANG Li-jing;HUANG Jian-qiang;MENG Ze;LIU Shi-zhong;OTIENO Dennis;LI Yue-lin(South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China;University of Chinese Academy of Sciences,Beijing 100049,China;Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Jaramogi Oginga Odinga University of Science and Technology,210-40601 Bondo,Kenya)

机构地区：[1]中国科学院华南植物园,广东广州510650 [2]中国科学院大学,北京100049 [3]中国科学院生态环境研究中心,北京100085 [4]Jaramogi Oginga Odinga University of Science and Technology,Bondo,Kenya 210-40601

出　　处：《生态与农村环境学报》2020年第3期382-389,共8页Journal of Ecology and Rural Environment

基　　金：国家自然科学基金(31670453,41430529);广东省自然科学基金(2014A030313746)。

摘　　要：利用树干液流技术、二氧化硫(sulfur dioxide,SO2)测定技术和气象观测手段,同步获取了鼎湖山天然针阔叶混交林群落优势树种水分利用、生物特征、环境SO2浓度及相关气象因子。根据水汽与痕量气体通过气孔双向交换的耦合关系,定量计算鼎湖山针阔叶混交林中针叶树种马尾松(Pinus massoniana,Pm)及阔叶树种锥栗(Castanopsis chinensis,Cc)、木荷(Schima superba,Ss)、华润楠(Machilus chinensis,Mc)4种优势树种的冠层气孔SO2导度(GSO2)、SO2吸收通量(FSO2)及累积吸收量(F SO2,st),并分析其特征。结果表明,在日尺度上,日间SO2浓度和GSO2最大值时间基本重叠,各树种在正午前后出现最大吸收;在季节尺度上,SO2浓度干季(10—翌年3月)平均浓度为10.11 nL·L^-1,高于湿季(4—9月)的5.45 nL·L^-1。4个树种G SO2在湿季显著高于干季(P<0.001),F SO2在干季高于湿季(P<0.001)。锥栗和华润楠的F SO2,st分别为2.16和2.50 mmol·m^-2,高于马尾松(1.70 mmol·m^-2)和木荷(1.91 mmol·m^-2)。优势树种对大气SO2的气孔吸收行为主要受水汽压亏缺(vapor pressure deficit,VPD)、光合有效辐射(photosynthetically active radiation,PAR)和SO2浓度等因素影响。该研究可为评估珠三角地区针阔叶混交林乃至粤港澳大湾区森林的SO2吸收通量提供参考,为定量计算该地区环境的变化奠定基础。The water use,biological characteristics,concentration of sulfur dioxide(SO2)and meteorological data were acquired by the sap flow measurements and environmental monitoring techniques.Based on the coupling relationship between water vapor and trace gas through two-dimensional exchange of pores,the canopy stomatal conductance for SO2(GSO2),canopy SO2 uptake flux(FSO2),and accumulated stomatal SO2 flux(FSO2,st)of four dominant tree species(Pinus manssoniana,Castanopsis chinensis,Schima superba,and Machilus chinensi s)in a natural mixed conifer-broadleaf forest at Dinghushan,south China were determined.The results show that,on a daily scale,the time at which the maximum concentration of SO2 appeared was partly overlapped the time when the maximum GSO2 occurred,and the maximum absorption of the four dominant tree species occurred at around noon time.On a seasonal scale,the average concentration of SO2 in the dry season(from October to March)was 10.11 nL·L^-1,which was higher than that in the wet season(from April to September),5.41 nL·L^-1.The G SO2 of the four species was significantly higher in the wet season than that in the dry season(P<0.001),while the F SO2 in the wet season was higher than that in the dry season(P<0.001).Furthermore,the F SO2,st of C.chinensis and M.chinensis were 2.16 and 2.50 mmol·m^-2,which were higher than 1.70 and of 1.91 mmol·m^-2 for P.massoniana and S.superba,respectively.The SO2 stomatal absorption behavior of the four dominant tree species was mainly affected by factors such as vapor pressure deficit(VPD),photosynthetically active radiation(PAR)and SO2 concentration.This research provides the basic data for the reasonable evaluation of SO2 absorption flux in mixed coniferous-broadleaf forests in the Pearl River Delta region,and provides a basis for risk prevention for environmental assessment.

关 键 词：树干液流 针阔叶混交林 冠层气孔导度 二氧化硫 痕量气体 

分 类 号：Q148[生物学—生态学]