Chin J Plant Ecol ›› 2024, Vol. 48 ›› Issue (1): 41-55.DOI: 10.17521/cjpe.2022.0397

Special Issue: 生态遥感及应用

• Research Articles • Previous Articles     Next Articles

Study of spatio-temporal variation in fractional vegetation cover and its influencing factors in Xinjiang, China

WU Han1,2,3, BAI Jie1,3,*(), LI Jun-Li1,3, Guli JIAPAER1,3, BAO An-Ming1,3   

  1. 1State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    3Key Laboratory of GIS&RS Application Xinjiang Uygur Autonomous Region, Ürümqi 830011, China
  • Received:2022-10-10 Accepted:2023-03-19 Online:2024-01-20 Published:2023-06-15
  • Contact: (baijie@ms.xjb.ac.cn)
  • Supported by:
    National Natural Science Foundation of China(42071141);Western China Young Scholars Program, Chinese Academy of Sciences(2020-XBQNXZ-009);Third Xinjiang Scientific Expedition Project(2021xjkk0703);CAS Interdisciplinary Innovation Team(JCTD-2019-20)

Abstract:

Aims As the core area of the ecological security barrier in northwest China, Xinjiang has been highly concerned for the spatial variations in its ecological environment status and quality and their driving mechanisms.

Methods Based on the MODIS surface albedo data set (MOD09 A1) from 2003 to 2020, this study uses the advanced three-band gradient difference vegetation index (advanced TGDVI) to obtain the fractional vegetation cover (FVC), and uses multiple statistical methods, such as linear regression, partial correlation analysis, Tukey-test to analyze the spatio-temporal variation of FVC and to quantify the contribution of temperature, precipitation, and groundwater storage (GWS) to FVC in Xinjiang.

Important findings (1) In the past 18 years, the average FVC of Xinjiang has increased from 20.08% to 21.76%, showing an increasing trend as a whole, with a growth rate of 0.19%∙a-1, and a rapid growth stage is found after 2008. Among them, cropland has the largest growth rate (0.66%∙a-1), and sparse grassland has the slowest growth rate (0.11%∙a-1). (2) Temperature is an important factor affecting FVC in the whole growing season in Xinjiang. The influence of temperature on FVC is mainly concentrated in spring and autumn, while precipitation and GWS are the main factors in summer. (3) In summer, GWS is the main factor affecting FVC of shrubland and cropland, precipitation has the greatest impact on FVC of grassland, and GWS has a greater impact on FVC of sparse grassland in summer. (4) With the hydrothermal conditions becoming wetter, the influence of temperature on FVC in Xinjiang gradually decreases, while the influence of precipitation increases. The influence of GWS on FVC increased from arid to semi-arid condition, and then it decreased from semi-arid to humid condition. The results of this study could provide theoretical foundation for ecological restoration and construction in Xinjiang, and have great significance for promoting the construction of ecological civilization and green sustainable development in Xinjiang.

Key words: fractional vegetation cover, advanced three-band gradient difference vegetation index, partial correlation analysis, spatio-temporal variation, arid land, Xinjiang