Impacts of climate change and human activities on vegetation cover in hilly southern China
Impacts of climate change and human activities on vegetation cover in hilly southern China
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气候变化和人类活动对中国南方丘陵丘陵植被覆盖的影响
DOI：
10.1016/j.ecoleng.2015.04.022
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发表时间：
2015
影响因子：
3.8
通讯作者：
Zhang Chunhua
中科院分区：
文献类型：
--
作者：
Wang Jing;Wang Kelin;Zhang Mingyang;Zhang Chunhua
植被覆盖是评价陆地环境状况的常用指标。植被时空格局的变化改变了景观的结构和功能，从而影响生态过程。中国南部丘陵是重要的生态修复区域，植被覆盖和土地利用发生了显著变化。然而，很少有研究考虑该地区多种因素引起的植被变化。我们利用中分辨率成像光谱仪(MODIS)获取的植被指数(NDVI)时间序列数据和2000-2010年的气候数据，研究了植被覆盖的时空变化。研究结果表明，11年间生长季的NDVI增加了0.03个百分点。不同地区的植被覆盖变化模式不同，58.7%的研究区表现出NDVI值的增加，而在生态恢复带内，7.3%的研究区的NDVI值增加显著。退耕还林、封山育林等有效的生态修复工程，改善了环境条件。植被复盖的时空变化很可能是气候变化(温度和降水的波动)和人类活动共同作用的结果。对NDVI变化的残差分析表明，人类活动改善或退化了中国南部部分地区的植被覆盖。具体地说，2009年和2010年极端天气事件的负面影响抵消了研究区西部生态重建计划的积极效益。这表明在未来生态重建的设计和规划中应考虑极端天气事件。抗旱植物品种可能被考虑用于未来的生态工程。然而，在引进抗旱植物品种时，应进行生态风险评估。
Vegetation cover is a commonly used indicator to evaluate terrestrial environmental conditions. Changes in the spatiotemporal patterns of vegetation alter the structures and functions of the landscape, thereby affecting ecological processes. Hilly southern China is an important ecological restoration area, in which the vegetation cover and land use has changed significantly. However, very few studies have considered vegetation changes due to multiple factors in this region. We investigated the spatiotemporal variations in vegetation cover using a Normal Difference Vegetation Index (NDVI) time-series data set obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) and climate data from 2000 to 2010. Our results indicate that the NDVI during the growing season had increased by 0.03% during the 11-year period. Patterns of change in vegetation cover differed among locations, with 58.7% of the study area displaying increased NDVI values, and in 7.3% of the study area, within an ecological restoration zone, the increase was significant. Effective ecological restoration programs, such as Grain for Green and hill closure for afforestation, have improved the environmental conditions. The spatiotemporal variations in vegetation cover were likely to be a synergistic impact of climate change (fluctuations in temperature and precipitation) and human activities. A residual analysis of the changes in the NDVI indicated that human activities had either improved or degraded vegetation cover in some parts of southern China. Specifically, the negative effects of extreme weather events in 2009 and 2010 offset the positive benefits of ecological reconstruction programs in the western part of the study area. This indicates that extreme weather events should be considered in the design and planning of future ecological reconstruction. Drought-resistant plant species might be considered for future ecological projects. However, an eco-risk assessment should be conducted when introducing drought-resistant plant species.