基于雪岭云杉树轮宽度重建中天山巴仑台地区过去565年7~9月NDVI变化  

Reconstructed July to September NDVI of past 565 years in Baluntai region of central Tianshan Mountains based on Picea schrenkiana

作　　者：马一凡 刘禹[1,3,6] 宋慧明[4] 张权 蔡秋芳[1,3] 任萌 李珮 MA Yifan;LIU Yu;SONG Huiming;ZHANG Quan;CAI Qiufang;REN Meng;LI Pei(State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an 710061,Shaanxi;University of Chinese Academy of Sciences,Beijing 100049;Center of Excellence for Quaternary Science and Global Change,Chinese Academy of Sciences,Xi'an 710061,Shaanxi;School of Human Settlements and Architectural Engineering,Xi'an Jiaotong University,Xi'an 710054,Shaanxi;Xi'an Institute of Earth Environment Innovation,Xi'an 710061,Shaanxi;China-Pakistan Joint Research Center on Earth Sciences,Chinese Academy of Sciences-Higher Education Commission,Islamabad 45320,Pakistan)

机构地区：[1]中国科学院地球环境研究所,黄土与第四纪地质国家重点实验室,陕西西安710061 [2]中国科学院大学,北京100049 [3]中国科学院第四纪科学与全球变化卓越创新中心,陕西西安710061 [4]西安交通大学人居环境与建筑工程学院,陕西西安710054 [5]西安地球环境创新研究院,陕西西安710061 [6]中国-巴基斯坦地球科学研究中心,中国科学院和巴基斯坦高等教育委员会,伊斯兰堡巴基斯坦45320

出　　处：《第四纪研究》2024年第4期869-881,共13页Quaternary Sciences

基　　金：科技部第二次青藏高原综合科学考察研究项目(批准号:2019QZKK0101);国家自然科学基金国际(地区)合作与交流项目(批准号:42361144712);中国科学院(B类)战略性先导科技专项项目(批准号:XDB40010300);崂山实验室科技创新项目(批准号:LSKJ202203300);中国沙漠气象科学研究基金项目(批准号:Sqj2022012);中国科学院地球环境研究所黄土与第四纪地质国家重点实验室开放基金项目(批准号:SKLLQG2256)共同资助。

摘　　要：归一化植被指数(NDVI)对分析植被动态及其对气候的响应至关重要,但是对天山地区而言,现有的短时NDVI数据集不能满足长时间尺度的分析需要。因此,本研究利用天山南坡巴仑台地区雪岭云杉样本建立了树轮宽度年表(STD),发现其与7~9月的NDVI显著相关(r=0.69,n=39,p<0.001),在此基础上,设计线性回归模型,重建了研究区1455~2019年7~9月NDVI变化,方差解释量为46%。结果显示,研究区在1455~2019年期间经历了5个植被覆盖高值期和8个植被覆盖低值期,其中1988~2019年植被生长处于历史最高水平;与周边其他重建序列对比结果表明NDVI变化存在空间差异性,中天山区域近30多年来NDVI呈现增加趋势,而西天山则呈现下降趋势;此外,分析表明降水是研究区NDVI的主要影响因素。天山地区降水主要受到海温异常和遥相关的影响,分析结果显示印度洋海温增暖和东大西洋遥相关型(EA)正相位可以使天山地区降水量增加,进而促进研究区植被的生长。该研究对理解中天山植被覆盖的长期动态变化具有一定的参考意义,并为未来植被动态演化预测提供基础数据。The Normalized Difference Vegetation Index(NDVI)is crucial for analyzing vegetation dynamics and its response to climate;however,for the Tianshan Mountains,the current short-term NDVI datasets are too short to reflect long-term trends in vegetation.Therefore,in this study,a total of 86 cores(1 to 2 cores per tree)were taken from 49 Picea schrenkiana trees in the Baluntai region(42.80°~42.83°N,86.45°~86.47°E)in the summer of 2020.Then,a tree-ring width chronology was developed after cross dating.The time span of the reliable chronology was 1455~2020,the expressed population signal(EPS)of the chronology samples was greater than 0.85,the average correlation among trees for the common overlap period among series(Rbar)was greater than 0.6,and the chronology signal-to-noise ratio(SNR)was 155.73.The Baluntai standard(STD)chronology showed a significant correlation with the observed NDVI derived from NOAA polar-orbiting satellites from July to September(r=0.69,n=39,p<0.001).Subsequently,we reconstructed the variations in the July to September NDVI in the study area over the past 565 years(i.e.,1455~2019 A.D.).The reconstruction accounted for 46%of the variation in the NDVI from July to September during the calibration period(1981~2019 A.D.).The results showed that the study area experienced five periods of high vegetation cover(1460~1473 A.D.,1542~1577 A.D.,1724~1749 A.D.,1842~1873 A.D.,and 1988~2019 A.D.)and eight periods of low vegetation cover(1492~1541 A.D.,1577~1595 A.D.,1707~1723 A.D.,1750~1784 A.D.,1806~1841 A.D.,1873~1890 A.D.,1904~1925 A.D.,and 1944~1987 A.D.).Furthermore,vegetation growth peaked during 1988~2019.Comparisons with other studies revealed spatial heterogeneity in NDVI fluctuations.The vegetation of the middle Tianshan Mountains has exhibited an increasing trend over the past three decades,while that of the West Tianshan Mountains has shown a declining trend.Precipitation is the main factor influencing the NDVI in this study area,where precipitation is primarily influenced by anomalies in sea su

关 键 词：树轮宽度 归一化植被指数(NDVI) 重建 中天山 

分 类 号：S718.5[农业科学—林学] P467[天文地球—大气科学及气象学]