Satellite Observations of the Contrasting Response of Trees and Grasses to Variations in Water Availability
Satellite Observations of the Contrasting Response of Trees and Grasses to Variations in Water Availability
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DOI：
10.1029/2018gl080535
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发表时间：
2019-02
影响因子：
5.2
通讯作者：
Sophia Walther;G. Duveiller;M. Jung;L. Guanter;A. Cescatti;Gustau Camps-Valls
中科院分区：
文献类型：
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作者：
Sophia Walther;G. Duveiller;M. Jung;L. Guanter;A. Cescatti;Gustau Camps-Valls
生态系统初级生产力的年际变化主要受水资源的影响。直到最近，表征不同生态系统对土壤水分异常的光合反应受到观测限制的阻碍。在这里，我们使用了一些基于卫星的生产力代理，包括光谱指数，太阳诱导叶绿素荧光和数据驱动的总初级生产力估计，以重新评估陆地光合作用和水之间的关系。与非木本植被相反，我们发现森林生态系统对土壤水分减少的适应能力。太阳诱导的叶绿素荧光和数据驱动的总初级生产力表明，尽管光利用效率降低，但由于伴随着更高的光和温度，光合作用增加。相反，绿色遥感指标达到了检测极限，基本上保持稳定。因此，我们的研究突出了生态系统的差异响应沿着一个树木覆盖梯度，并说明了区分光合作用指标的监测和了解生态系统的绿色的重要性。
Interannual variations in ecosystem primary productivity are dominated by water availability. Until recently, characterizing the photosynthetic response of different ecosystems to soil moisture anomalies was hampered by observational limitations. Here, we use a number of satellite‐based proxies for productivity, including spectral indices, sun‐induced chlorophyll fluorescence, and data‐driven estimates of gross primary production, to reevaluate the relationship between terrestrial photosynthesis and water. In contrast to nonwoody vegetation, we find a resilience of forested ecosystems to reduced soil moisture. Sun‐induced chlorophyll fluorescence and data‐driven gross primary production indicate an increase in photosynthesis as a result of the accompanying higher amounts of light and temperature despite lowered light‐use‐efficiency. Conversely, remote sensing indicators of greenness reach their detection limit and largely remain stable. Our study thus highlights the differential responses of ecosystems along a tree cover gradient and illustrates the importance of differentiating photosynthesis indicators from those of greenness for the monitoring and understanding of ecosystems.