Impacts of drought and heatwave on the terrestrial ecosystem in China as revealed by satellite solar-induced chlorophyll fluorescence
Impacts of drought and heatwave on the terrestrial ecosystem in China as revealed by satellite solar-induced chlorophyll fluorescence
复制标题
卫星太阳诱导叶绿素荧光揭示干旱和热浪对中国陆地生态系统的影响
DOI：
10.1016/j.scitotenv.2019.133627
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发表时间：
2019
影响因子：
9.8
通讯作者：
Zhang Qian
中科院分区：
文献类型：
--
作者：
Wang Xiaorong;Qiu Bo;Li Wenkai;Zhang Qian
干旱和热浪已经并将继续给陆地生态系统带来巨大风险。然而，对植物如何在广泛的空间尺度上响应干旱和热浪的了解仍然有限。本文以2009/2010年云南干旱和2013年中国南部热浪为例，研究了利用卫星观测的太阳诱导叶绿素荧光(SIF)监测植被对干旱和热浪响应的可能性。2009年秋季至2010年春季，云南连续一年的降水量低于正常水平，导致土壤水分严重不足，导致2009/2010年干旱。2013年夏天，由于气温骤增和降雨不足，南方中国遭遇了最强热浪。结果表明，SIF能较好地捕捉旱热发展的时空动态，表现为荧光产额(SIF产额)的大幅度下降。此外，在干旱和热浪事件的早期阶段，SIFYELD比传统的植被指数(增强型植被指数，EVI)表现出显著的减少和更早的响应。对这两个研究区的时空相关性分析表明，SIFYELD异常对高水汽压亏缺(VPD)比低土壤湿度更敏感。这项研究表明，卫星对SIF的观测在准确和及时监测干旱和热浪发展方面具有很大潜力。
Droughts and heatwaves have been and will continue to bring large risks to terrestrial ecosystems. However, the understanding of how plants respond to drought and heatwave over broad spatial scales is still limited. In this paper, we use the 2009/2010 drought in Yunnan and the 2013 heatwave over southern China as case studies to investigate the potential of using satellite-observed solar-induced chlorophyll fluorescence (SIF) to monitor vegetation responses to drought and heatwave over broad spatial scales. The 2009/2010 drought onset follows a strong soil moisture deficit due to the yearlong below-normal precipitation in Yunnan from the autumn of 2009 to the spring of 2010. In the summer of 2013, southern China experienced the strongest heatwave due to the sudden temperature increase and rainfall deficit. The results show that SIF can reasonably capture the spatial and temporal dynamics of drought and heatwave development, as indicated by the large reduction in fluorescence yield (SIFyield). Moreover, SIFyielddemonstrates a significant reduction and earlier response than traditional vegetation indices (enhanced vegetation index, EVI) during the early stages of drought and heatwave events. For both study areas, the spatial and temporal correlation analysis demonstrates that the SIFyieldanomalies are more sensitive to a high vapor pressure deficit (VPD) than low soil moisture. This study implies that satellite observations of SIF have great potential for accurate and timely monitoring of drought and heatwave developments.