摘要
Vegetation restoration is the primary task of ecological reconstruction and rocky desertification control in Karst areas. With vegetation net primary productivity and coverage as two key indicators, a vegetation ecological quality evaluation model was built based on meteorological and remote sensing data. Spatiotemporal variation of vegetation ecological quality index and its response to climate change in rocky desertification areas in Southwest China during 2000-2020 were also analyzed by using the difference method and linear trend method. The results showed that:(1) Vegetation ecological quality in rocky desertification areas in Southwest China showed a fluctuating upward trend during 2000-2020. In 2020, the vegetation ecological quality index reached 69.7, which was 19.9% and 9.3% higher than the averaged values for 2000 and 2000-2019, respectively, ranking the fourth highest since 2000.(2) Vegetation ecological quality of the rocky desertification areas in Yunnan, Guangxi and Guizhou provinces have been improved by 89.2%, 99.2% and 98.5%, respectively, from 2000 to 2020, with their vegetation ecological quality index values increasing by 0.5-0.75 per year in southeast Yunnan, most areas in Guizhou and northwest Guangxi.(3) Precipitation was an important meteorological factor affecting the vegetation ecological quality in rocky desertification areas. The vegetation ecological quality index in the northwest and central Yunnan rocky desertification areas has been rising slowly, but with localized declines at a yearly rate of nearly 0.25 caused by climatic warming and drying.
石漠化是我国西南地区突出的生态环境问题之一,植被恢复是喀斯特地区生态重建和石漠化治理的首要任务。选择植被生产力和覆盖度两个关键指标,基于气象、遥感等多源数据构建了石漠化区植被生态质量监测评估模型,采用差值法和线性趋势法分析了2000-2020年西南滇桂黔三省石漠化区植被生态质量时空变化趋势及对气候变化的响应。结果表明:(1) 2000-2020年滇桂黔石漠化区植被生态质量整体呈波动性上升趋势,2020年植被生态质量指数达69.7,较2000年和2000-2019年平均值分别提高19.9%和9.3%,居2000年以来第四高位。(2)2000-2020年滇桂黔石漠化区植被生态质量呈改善趋势的面积比例分别为89.2%、99.2%和98.5%,其中云南东南部、贵州大部、广西西北部等地改善明显,植被生态质量指数平均每年增加0.5-0.75。(3)降水量是影响石漠化区植被生态质量的重要气象因子;受气候暖干化趋势影响,云南西北部和中部等地植被生态质量指数上升较慢,局地以平均每年近0.25的速率下降。
基金
The National Natural Science Foundation of China (31700421)。
