基于PML-V2模型和站点观测数据的植被水利用率及其趋势差异分析  

Difference Analyses in Vegetation Water Use Efficiency and Their Trends Based on the PML-V2 Model and Site Observations

作　　者：李淑津 袁华 孔冬冬 董文宗 黄丽娜 戴永久 LI Shujin;YUAN Hua;KONG Dongdong;DONG Wenzong;HUANG Lina;DAI Yongjiu(School of Atmosphere Science,Sun Yat-sen University,Zhuhai,Guangdong Province 519000;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai,Guangdong Province 519000;Guangdong Province Key Laboratory for Climate Change and Natural Disaster,Guangzhou 510275;School of Environmental Studies,China University of Geosciences,Wuhan 430078)

机构地区：[1]中山大学大气科学学院,广东珠海519000 [2]南方海洋科学与工程广东省实验室(珠海),广东珠海519000 [3]广东省气候变化与自然灾害研究重点实验室,广州510275 [4]中国地质大学(武汉)环境学院,武汉430078

出　　处：《气候与环境研究》2023年第1期89-102,共14页Climatic and Environmental Research

基　　金：国家自然科学基金42075160、41730962;国家重点研发计划项目2017YFA0604300。

摘　　要：运用基于Penman-Monteith公式改进得到的模型PML-V2,结合12个FLUXNET站点及其对应的叶面积指数数据,进行蒸散发分离,进而计算并分析内禀水利用率(intrinsic water use efficiency,iWUE)和冠层水利用率(canopy water use efficiency,tWUE)的趋势差异.结果表明,在站点尺度上,两种植被水利用率的变化均存在不一致性.对于落叶阔叶林(deciduous broadleaf forests,DBF),iWUE的增幅比tWUE的增幅大,而在常绿针叶林(evergreen needleleaf forests,ENF)中则相反.在DBF中,冠层导度和蒸腾作用趋势的差异可在一定程度上解释两种植被水利用率的趋势差异.通过回归分析发现森林(包括DBF和ENF)的气温和大气CO_(2)浓度的趋势对tWUE趋势的影响更大.研究结果表明,两种植被水利用率及其趋势存在差异.基于iWUE的研究结果并不能完全反映植被的实际水利用率变化程度,因此也不能全面反映植被与大气的相互作用.本文在站点尺度明确了全球气候变化背景下两种植被水利用率的趋势差异,有助于理解陆地生态系统与大气之间的相互作用,为合理有效地预测未来气候变化及陆地植被的演变提供有用的参考依据.With the PML-V2 model,the evapotranspiration was separated and the trends of intrinsic water use efficiency(iWUE)and canopy water use efficiency(tWUE)was calculated to investigate the differences between them.The results show that the change in these two types of water use efficiency is inconsistent at the site scale.The trend of iWUE is greater than that of iWUE in deciduous broadleaf forests(DBF),whereas the contrary occurs in evergreen coniferous forests(ENF).The discrepancy in canopy conductance and transpiration trends can help explain the difference in iWUE and tWUE trends in DBF.Regression analysis revealed that the trends of air temperature and carbon dioxide concentration in forests(DBF and ENF)have a stronge influence on the trend of tWUE.The results of this paper demonstratethe differences between the trends of iWUE and tWUE.Therefore,study results about iWUE cannot fully indicate the trends of the actual water use efficiency of vegetation,and they cannot thoroughly reflect the interactions between vegetation and the atmosphere.This study reveals the trend difference between iWUE and tWUE under the background of global climate change,which is useful for understanding the interactions between terrestrial ecosystems and the atmosphere and provides a useful reference for predicting future climate change and the evolution of terrestrial vegetation reasonably and effectively.

关 键 词：冠层水利用率 内禀水利用率 蒸散发分离 冠层导度 蒸腾作用 

分 类 号：P463[天文地球—大气科学及气象学]