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Journal of Desert Research ›› 2022, Vol. 42 ›› Issue (4): 229-241.DOI: 10.7522/j.issn.1000-694X.2022.00095

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Normalized difference vegetation indexNDVIdynamics of grassland in Central Asia and its response to climate change and human activities

Shihua Zhu1,2(), Xia Fang3,4(), Xin Hang1, Xiaoping Xie1, Liangxiao Sun1, Liangzhong Cao4,5   

  1. 1.Jiangsu Climate Center / Jiangsu Meterological Bureau,Nanjing 210008,China
    2.International Institute for Earth System Science,Nanjing University,Nanjing 210093,China
    3.Xinjiang Institute of Engineering,Urumqi 830023,China
    4.State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China
    5.Jiujiang University,Jiujiang 332005,Jiangxi,China
  • Received:2022-03-22 Revised:2022-06-01 Online:2022-07-20 Published:2022-08-29
  • Contact: Xia Fang

Abstract:

Dryland grasslands in Central Asia are threatened by climate change and human activities, but their relative contribution to grassland changes is still uncertain. Based on three sets of meteorological data and NDVI (Normalized Difference Vegetation Index), this paper uses the residual analysis to study the grassland change pattern in Central Asia and the relative contributions of environmental and human factors. The results showed that the NDVI growth rate of grassland in Central Asia was 0.026/10a during 1982 to 2014. Spatially, the NDVI variations were similar to that of precipitation, showing a downward trend in the central and western regions and an upward trend in the hilly and mountainous regions of the east. The residual analysis shows that the relative contribution of climate change (CFSR, Climate Forecast System Reanalysis) and human activities account for 71.21% and 28.79%, respectively. The areas where man-made disturbances contribute more to NDVI changes are mainly located in the Altay Mountains, Tianshan Mountains and the grasslands of southeastern Kazakhstan, while the less contribution areas are mainly located in the southern Xinjiang and the desert regions of Central Asia. In most areas of Central Asia, grassland has a significant positive correlation with precipitation, and the warming promotion mainly occurs in high-latitude and alpine mountainous areas. The correlation between NDVI and temperature is gradually decreasing. Although global warming is still a huge challenge for Central Asian grasslands in the future, with the improvement of grassland vegetation resistance, the impact of warming on grasslands may not be as severe as expected.

Key words: grassland dynamics, climate change, human activities, driver analysis, temporal and spatial characteristics

CLC Number: