20世纪初以来沂蒙山区森林植被动态及其对气候变化的响应——基于遥感和树轮的研究  

Combining remote sensing and tree ring techniques to investigate forest vegetation dynamics and its response to climate change in Yimeng mountainous area from the early 20th century

作　　者：赵兴云[1] 郭媛媛[1] 朱利凯 田金梅 曲晓倩 任佳璇 李文静 卜祥凤 王树鑫 ZHAO Xingyun;GUO Yuanyuan;ZHU Likai;TIAN Jinmei;QU Xiaoqian;REN Jiaxuan;LI Wenjing;BU Xiangfeng;WANG Shuxin(Shandong Provincial Key Laboratory of Soil and Water Conservation&Environmental Protection,College of Resources and Environment,Linyi University,Linyi 276005,China;School of Geography,Liaoning Normal University,Dalian 116029,China;College of Geography and Tourism,Qufu Normal University,Rizhao 276826,China;College of Resources and Environmental Science,Hebei Normal University,Shijiazhuang 050024,China)

机构地区：[1]临沂大学资源环境学院山东省水土保持与环境保育重点实验室,临沂276005 [2]辽宁师范大学地理科学学院,大连116029 [3]曲阜师范大学地理与旅游学院,日照276826 [4]河北师范大学资源与环境科学学院,石家庄050024

出　　处：《地球环境学报》2020年第3期265-279,共15页Journal of Earth Environment

基　　金：国家自然科学基金项目(41541020,41701220,41072139)。

摘　　要：遥感能够直接反映植被生长信息,但目前观测时间较短;树轮资料可以弥补遥感手段的不足,但往往缺乏与植被生长状况(如植被生产力)的直接关联。已有研究往往计算不同植被指数指标和树轮指数的相关性,并基于此来重建长时间尺度的植被动态信息。但基于相关性所选取的指标在不同地区存在较大差异,不利于空间对比研究。以沂蒙山区为研究区,选取能够有效表征植被年初级生产力的生长季NDVI累积值指标,利用Bootstrap法建立了其与树轮宽度的关系,重建了20世纪初期以来植被动态时间序列,并分析了变化特征及其与气候变化的关系。结果表明:沂山地区生长季NDVI累积值的多年平均值为7.36,低于蒙山和塔山地区;蒙山地区植被状况呈现好转趋势,特别是20世纪90年代之后植被好转趋势更加明显,而塔山和沂山地区植被无显著变化。小波分析结果表明研究区植被动态存在较显著的2 a、4 a或8 a尺度的周期变化,与生长季帕尔默干旱指数及平均温度的周期变化相一致,但干旱指数与植被动态具有更高的相关性。本研究综合运用树轮与遥感技术发展了长时间尺度植被动态时间序列重建方法,有助于更好地理解植被动态及其对气候变化的响应。Background,aim,and scope Remote sensing is an effective approach of vegetation monitoring,and remote sensing-based vegetation indices can well capture vegetation growth curve.However,the longest remote sensing observations are only available for about 40 years,which limits their use in research on longterm vegetation dynamics.Tree ring data usually have longer records,which overcomes the limitations of remote sensing observations,but there is no direct link between tree ring and vegetation properties(e.g.,gross primary productivity,biomass).Previous studies combine tree ring width and satellite-based vegetation index to reconstruct vegetation dynamics for a long period.However,the selection of indicators depends much on correlation,and thus different indicators might be chosen for different regions,which is not suitable for comparison spatially.Here,we took Yimeng mountainous area as the study area,reconstructed long-term accumulative NDVI values of the growing season,an effective indicator of annual gross primary productivity,from the earlier 20th century,and characterized their temporal changes.Materials and methods(1)225 tree ring cores were collected from three sites within our study area:Mengshan Mountain,Tashan Mountain and Yishan Mountain.The ring widths of all the cores were measured using MeasureJ2X professional measurement software under the LINTAB tree ring width meter(measuring accuracy 0.01 mm),and then COFECHA program was used to test the cross-dating quality.Finally,the standardized chronology(STD),difference chronology(RES)and autoregressive standardized chronology(ARS)were established by the ARSTAN program.(2)To derive the time series of accumulative NDVI of the growing season,we extracted NDVI time series at 15-day interval for each sampling site,used the TIMESAT software to determine the start,end,and length of the growing season,and finally got the sum of NDVI values within the range of the growing season.(3)The Bootstrap method was used to establish the empirical relationships between tree ri

关 键 词：树轮 遥感 NDVI 沂蒙山区 森林植被动态 

分 类 号：S718.5[农业科学—林学] S771.8