植物生态学报 ›› 2010, Vol. 34 ›› Issue (9): 1033-1044.DOI: 10.3773/j.issn.1005-264x.2010.09.004

• 研究论文 • 上一篇    下一篇

基于祁连山树轮宽度指数的区域NDVI重建

王文志, 刘晓宏*(), 陈拓, 安文玲, 徐国保   

  1. 中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室, 兰州 730000
  • 收稿日期:2010-03-22 接受日期:2010-05-18 出版日期:2010-03-22 发布日期:2010-10-08
  • 通讯作者: 刘晓宏
  • 作者简介:* E-mail: liuxh@lzb.ac.cn

Reconstruction of regional NDVI using tree-ring width chronologies in the Qilian Mountains, northwestern China

WANG Wen-Zhi, LIU Xiao-Hong*(), CHEN Tuo, AN Wen-Ling, XU Guo-Bao   

  1. State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environment and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2010-03-22 Accepted:2010-05-18 Online:2010-03-22 Published:2010-10-08
  • Contact: LIU Xiao-Hong

摘要:

利用祁连山自东向西5条树轮宽度年表序列和1986-2003年间的归一化植被指数(NDVI), 分析了NDVI的时空变化及其与树轮宽度年表之间的关联。结果表明, 祁连山地区植被的生长主要集中在6-8月。空间上, NDVI值从祁连山东段向西段逐渐减小; 在1986-2003时段内, 东、中和西段生长季的NDVI值分别增长了3.28%、4.82%和7.75%。整个祁连山地区的NDVI变化与5个宽度年表的第一主成分相关性较高(r = 0.74, p < 0.01)。基于此, 利用树轮宽度RES年表的第一主成分重建了1843-2003年间祁连山地区生长季的NDVI变化曲线。重建的NDVI曲线表现出6个高值期和6个低值期, 其中1923-1932的10年间植被生长状况最差。另外, 在1989-2003时段内NDVI年际波动较大, 总体上表现为NDVI低于平均值, 但是从1991年开始, NDVI有上升的趋势。

关键词: 归一化植被指数, 祁连山, 树轮宽度指数

Abstract:

Aims Many recent studies indicated that the regional climate of northwest China had changed from a warm-dry to a warm-wet pattern. Therefore, it is important to assess vegetation cover change in this area. Our objective is to evaluate the normalized difference vegetation index (NDVI) record in eastern, middle and western parts of the Qilian Mountains and assess past long-term vegetation cover change with tree-ring chronologies.

Methods Temporal and spatial changes of NDVI, and its relationship with tree-ring width were analyzed using 8 km × 8 km resolution multi-temporal NOAA/AVHRR-NDVI data from 1986-2003 and five ring-width chronologies in the Qilian Mountains. Then, we used liner regression to reconstruct annual NDVI varieties for 1843-2003.

Important findings Vegetation cover in the Qilian Mountains decreased from east to west, and the main growing season lasted from June to August. In addition, during the period 1986-2003, an increasing NDVI-trend was evident in three regions in the Qilian Mountains, indicating that vegetation activity has been rising recently. In the eastern, central and western parts of the Qilian Mountains, values of NDVI during the growing season have increased by 3.28%, 4.82% and 7.75% per year, respectively. We also found a strong relationship between NDVI and the first principal component (PC1) of the five tree-ring width chronologies (r = 0.74, p < 0.01). Growing season NDVI was reconstructed based on correlation analysis. Six periods characterized by high and low values were reflected in the NDVI curve, and the poorest period of plant growth was 1923-1932. Moreover, the amplitude of the fluctuation was larger during 1989-2003, accompanied by an increasing trend since 1991.

Key words: normalized difference vegetation index (NDVI), Qilian Mountains, tree-ring width index