不同叶面积指数遥感数据模拟中国总初级生产力的时空差异  

Spatial and Temporal Differences of GPP Simulated by Different Satellite-derived LAI in China

作　　者：侯吉宇 周艳莲[1] 刘洋[2] Hou Jiyu;Zhou Yanlian;Liu Yang(School of Geography and Ocean science,Nanjing University,Nanjing,Jiangsu 210023,China;Institute of Geographical Sciences and Resources,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]南京大学地理与海洋科学学院,江苏南京210023 [2]中国科学院地理科学与资源研究所,北京100101

出　　处：《遥感技术与应用》2020年第5期1015-1027,共13页Remote Sensing Technology and Application

基　　金：国家重点研发计划项目(2019YFA0606604);国家自然科学基金项目(41671343)。

摘　　要：陆地生态系统总初级生产力(GPP)反映了植物吸收固定大气中CO2的能力,是碳循环过程中的重要环节。光能利用率(LUE)模型被广泛应用于GPP模拟。叶面积指数(LAI)数据是LUE模型的重要输入数据,不同的LAI数据差异较大,从而导致GPP模拟存在很大差异。利用3种常用的卫星遥感LAI数据(MCD15、GLASS和GlobMap)和气象数据模拟中国2003~2017年的GPP,比较了3种LAI数据在中国区域的时空差异,分析不同LAI数据模拟的中国GPP的时空差异。研究结果表明:3种LAI数据在中国区域的年平均值和LAI变化趋势的空间分布格局存在明显差异,森林区域的差异较大;2003~2017年间,中国区域3种LAI年平均值均呈显著增加趋势(p<0.01),但不同LAI数据年平均值的年际变化差异明显;站点尺度GLASS LAI模拟的GPP与观测值相关性较好;不同LAI数据模拟的中国GPP总量多年平均值差异明显,最大值为7.46 Pg C a-1(GLASS),最小值为6.39 Pg C a-1(GlobMap);3种LAI数据模拟的中国GPP总量在2003~2017年呈显著增加趋势(p<0.05),但不同的LAI数据模拟的中国GPP年总量的年际变化差异明显;不同LAI数据模拟的年均GPP和GPP变化趋势的空间分布格局存在明显差异,森林和农田区域的差异较大。研究结果有助于评估由于LAI数据造成的区域GPP模拟结果的不确定性。Terrestrial Gross Primary Production(GPP)is a key component of the carbon cycle,which represents the ability of plants to absorb and fix CO2 in the atmosphere.Light Use Efficiency(LUE)model is commonly used in regional simulation of GPP.Leaf Area Index(LAI)is a key input data in TL-LUE model.There are great spatial and temporal difference between various LAI data.Difference in spatial and temporal patterns between GPP simulations derived with different LAI needs to be investigated further.In this study,three satellite-derived LAI data,MCD15,GLASS and GlobMap,were used to simulate GPP in China from 2003 to 2017.Firstly,three LAI data were compared to investigate the difference in the spatial and temporal patterns.Then,GPP simulated by three LAI data were compared to investigate the difference.Results showed that spatial and temporal patterns of LAI differed substantially among different LAI data,and there were great differences in forest regions.Averaged annual value of three LAI data showed significant increasing trends from 2003 to 2017(p<0.01).However,the interannual variation of the annual mean value of different LAI data were obviously different.The GPP simulated by GLASS LAI had high correlation with EC GPP.Mean annual total GPP in China simulated with different LAI data has great difference,varied from 6.39 Pg C a-1(GlobMap)to 7.46 Pg C a-1(GLASS).Annual total GPP in China simulated by three LAI data showed significant increasing trends from 2003 to 2017(p<0.05).However,the interannual variation of different annual total GPP were obviously different.The spatial and temporal patterns of GPP differed substantially among different simulated GPP,and there were great differences in forest and crop regions.This study was helpful to assess the uncertainties of regional GPP simulation derived from input data.

关 键 词：叶面积指数(LAI) 总初级生产力(GPP) 两叶光能利用率模型(TL-LUE) 时空差异 

分 类 号：TP75[自动化与计算机技术—检测技术与自动化装置]