2000~2018年中国植被生态质量时空变化特征

Characteristics of Spatio-temporal Variation of Ecological Quality for Vegetation in China from 2000-2018

监测植被变化对评价中国生态环境质量和生态过程具有重要意义。以MODIS数据反演得到的中国总初级生产力、叶面积指数、植被覆盖度、温度植被干旱指数和陆面温度5项指标为基础,构建了植被生态指数(VEI),并利用SEN+Mann-Kendall、Hurst指数及变异系数等方法对2000~2018年中国植被生态质量的时空变化特征、可持续性及稳定性等方面进行了分析。结果表明:(1)从空间分布看,植被生态质量差和较差区面积占全国植被覆盖区总面积的25.46%,主要分布在新疆的大部分地区、甘肃西北部、青藏高原中西部及内蒙古中西部地区,优良区占比42.91%,主要分布在东北的东部和北部地区、华东的中部及南部地区、华中和华南以及秦岭地区;(2)从年际变化看,植被生态质量呈现出较为明显的增长趋势,年增长率为0.1%;(3)从空间格局变化趋势看,植被生态质量呈增加、基本不变和降低的面积分别占植被区总面积的34.82%、54.19%和10.99%;(4)从稳定性和未来变化趋势看,在过去的近20年我国植被生态质量的变化幅度较小,稳定性较好;我国植被生态质量未来的变化趋势与过去近20年一致,即将保持继续改善的趋势;(5)从不同植被类型看,13种植被类型的生态质量均呈改善趋势,且常绿阔叶林、落叶阔叶林和稠密灌丛的生态质量最优,永久湿地、草地和稀疏灌丛的生态质量较差。

Monitoring vegetation changes is momentous for evaluating the quality of ecological environment in China.The Vegetation Ecology Index(VEI)was constructed based on five indicators of Gross Primary Productivity,Leaf Area Index,Fractional Vegetation Cover,Temperature Vegetation Drought Index and Land Surface Temperature obtained from MODIS data in China.And the spatio-temporal variation characteristics,sustainability and stability of vegetation ecology quality in China from 2000-2018 were analyzed by using the SEN+Mann-Kendall,Hurst exponent and coefficient of variation.The results showed that:(1)The area of poor and inferior vegetation ecology quality accounted for 25.46%of the total area covered by vegetation,mainly distributed in the most regions of Xinjiang,the northwestern Gansu,the central and western Qinghai-Tibet Plateau,the central and western Inner Mongolia.The excellent areas accounted for 42.91%,mainly distributed in the eastern and northern regions of northeast China,the central and southern regions of east China,the central and southern China,the central and southern Inner Mongolia,and the Qinling region.(2)The ecological quality of vegetation showed a significant increase trend,with an annual growth rate of 0.1%.(3)From the spatial change trend,the area with increasing,basically unchanged and decreasing ecological quality of vegetation accounted for 34.82%,54.19%and 10.99%of the total vegetation area,respectively.(4)The change in the ecological quality of China’s vegetation over the past nearly 20 years has been relatively small and stable.The future trend in the ecological quality of vegetation would be consistent with the past nearly 20 years and maintain the trend of continued improvement.(5)The ecological quality of all vegetation types tended to be improved,and the ecological quality of evergreen broad-leaved forest,deciduous broad-leaved forest and dense scrub was the best,while the ecological quality of permanent wetland,grassland and sparse scrub was the worst.