Spatiotemporal Characteristics of Vegetation Greenness Changes in China from 2000 to 2021
Vegetation plays a crucial rule in the global carbon cycle and climate change.Understanding vegetation and its dynamic changes is of great importance for addressing climate change and biodiversity conservation.This study uses the Leaf Area Index(LAI)as an indicator of vegetation greenness and employs Theil-Sen Median trend analysis and the Mann-Kendall test to examine the trends in vegetation greenness.The spatiotemporal characteristics of vegetation greenness changes in China from 2000 to 2021(excluding data from Hong Kong,Macau,and Taiwan,hereinafter the same)were analyzed.The results are as follows:(1)The overall trend shows an increase in vegetation greenness,especially in the southeast region of the Hu Huanyong Line,where a'significant increase'indicates substantial improvements in the ecological environment.However,some areas of ecologically fragile regions,such as the Tibetan Plateau,are still facing degradation issues.(2)Among different ecosystem types,the grenness of forests and farmlands showed the most prominent increases,with significant greenness improvements observed in 82.18%and 75.47%of their respective areas.The greenness of shrublands showed a 66.06%increase,though changes in some regions were limited.Grassland ecosystems face greater challenges,with greenness decreasing in 17.54%of the areas,indicating the need for more targeted management and ecological restoration efforts in grasslands.(3)In the analysis of key regions,the Inner Mongolia Autonomous Region contributed the most to national vegetation greenness growth,accounting for 12.9%.Together with Sichuan,Heilongjiang,and three other provinces,these regions contributed 39.1%of the total national increase in vegetation greenness.The vegetation greenness in the Yellow River Basin and the Yangtze River Economic Belt has shown a'significant increase',which collectively accounted for over 70%of the greenness improvement.In contrast,localized regions of the Tibetan Plateau showed'significant'or'slight declines'in vegetation greenness,with a decline rate exceeding 15%.These findings indicate that China's ecological restoration policies have been highly effective,though more refined management and protection are still required in certain areas.The study provides a scientific basis for further understanding the trends in vegetation cover and their ecological impacts in China.
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万方数据
