亚热带人工针叶林叶绿素荧光参数日变化及其与植被生产力的关系  

Diurnal changes in chlorophyll fluorescence parameters and their relationships with vegetation productivity in subtropical coniferous plantations

作　　者：陈敬华 王绍强[1,2] 李悦 王辉民 杨风亭[1] 居为民[3] 张乾[3] 梁琛[2,4] CHEN Jinghua;WANG Shaoqiang;LI Yue;WANG Huimin;YANG Fengting;JU Weimin;ZHANG Qian;LIANG Chen(Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;International Institute for Earth System Science,Nanjing University,Nanjing 210023,China;Key Laboratory of Land Surface Pattern and Simulation,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]中国科学院地理科学与资源研究所,生态系统网络观测与模拟重点实验室,北京100101 [2]中国科学院大学资源与环境学院,北京100049 [3]南京大学国际地球系统科学研究所,南京210023 [4]中国科学院地理科学与资源研究所,陆地表层格局与模拟重点实验室,北京100101

出　　处：《生态学报》2019年第15期5603-5615,共13页Acta Ecologica Sinica

基　　金：国家重点研发计划(2017YFC0503803);国家自然科学基金项目(41571192);中国科学院重点部署项目(KFZD-SW-310-01)

摘　　要：叶绿素荧光技术能够快速、灵敏、无损地测定植物光合功能对环境变化的响应,已成为当前植物光合能力测定的重要技术手段之一,但是探讨亚热带森林叶绿素荧光参数在不同季节日变化特征受环境因子影响的研究较少,更缺乏与植被生产力关系的研究。以亚热带人工针叶林为研究对象,利用2016年叶绿素荧光测量和涡度相关通量观测数据,分析了不同季节湿地松和马尾松叶片荧光参数实际光化学效率(Photochemical efficiency of PSⅡ,ΦPSⅡ)和非光化学淬灭(Non?photochemical quenching,NPQ)的日变化特征,并结合增强回归树等统计方法,定量化环境因子对其影响,最后探讨了荧光参数与总初级生产力(Gross primary productivity,GPP)和光能利用率(Light use efficiency,LUE)的关系。结果表明,ΦPSⅡ日变化总体上呈现“U型”,早晚高午间低,而NPQ先升后降,午间达到峰值,与ΦPSⅡ的日变化显著负相关。研究发现,光照是影响亚热带人工针叶林ΦPSⅡ日变化最主要的环境因子,ΦPSⅡ随着光合有效辐射(Photosynthetically active radiation,PAR)的升高而降低,PAR对湿地松和马尾松叶片ΦPSⅡ的相对贡献率分别为83.0%和51.1%。PAR对湿地松叶片NPQ日变化的相对贡献率也最高(77.2%),但马尾松的NPQ主要受叶片温度(Leaf temperature,Tleaf)的影响(59.6%)。此外,GPP与ΦPSⅡ显著负相关,而与NPQ有显著的正相关关系。LUE随着ΦPSⅡ增长,但存在ΦPSⅡ高而LUE低的情况,LUE与NPQ显著负相关,热耗散的比例越高,光能利用效率也相应降低。Chlorophyll fluorescence has become a very powerful technique to estimate the photosynthetic capacities of different plants in a rapid and non?invasive way.However,the effect of environmental factors on the diurnal variations in chlorophyll fluorescence parameters in different seasons has been less studied,and their relation to vegetation productivity has hardly been discussed.In this study,we characterized the diurnal changes in fluorescence parameters(photochemical efficiency of PSⅡand non?photochemical quenching(NPQ)),and quantified the influence of the three environmental factors(photosynthetically active radiation(PAR),leaf temperature(Tleaf),and relative humidity(RH)using Boosted Regression Trees(BRT)and Pearson correlation analysis).In addition,the relationships between the fluorescence parameters and vegetation productivity(gross primary productivity(GPP)and light use efficiency(LUE))were explored.We conducted in situ chlorophyll fluorescence measurements on Slash Pine(Pinus elliottii Engelm.)and Masson Pine(Pinus massoniana Lamb.)in the Qianyanzhou(QYZ)subtropical coniferous plantation,Jiangxi province,China,during 2016.Our results showed thatΦPSⅡdecreased to a minimum at midday and subsequently progressively rose,whereas NPQ was highest at midday,significantly contrary toΦPSⅡ.Among the three environmental factors,PAR played the strongest role in determining the diurnal changes ofΦPSⅡ(83.0%in Slash Pine and 51.1%in Masson Pine).ΦPSⅡdecreased with PAR.PAR also had an important influence on NPQ in Slash Pine(77.2%).However,NPQ in Masson Pine was mainly affected by Tleaf(59.6%).In addition,we obtained the synchronous LUE and GPP from the eddy covariance flux observation in QYZ and found that GPP had a significantly negative correlation withΦPSⅡ,but a positive correlation with NPQ.LUE increased withΦPSⅡ,but sometimes highΦPSⅡwas accompanied by low LUE.LUE decreased with NPQ,indicating that higher proportion of heat dissipation resulting in lower light use efficiency.

关 键 词：亚热带针叶林 荧光参数 日变化 环境因子 植被生产力 

分 类 号：Q94[生物学—植物学]