Spatiotemporal origin of soil water taken up by vegetation
Spatiotemporal origin of soil water taken up by vegetation
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DOI：
10.1038/s41586-021-03958-6
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发表时间：
2021-10
期刊：
影响因子：
64.8
通讯作者：
G. Miguez-Macho;Ying Fan
中科院分区：
文献类型：
--
作者：
G. Miguez-Macho;Ying Fan
植被调节地球的水、能量和碳循环。它的功能在未来会如何变化很大程度上取决于它如何应对干旱。有证据表明，在干旱的地方和时期，植被将水分吸收转移到更深的土壤，岩石，水分以及地下水。在这里，我们区分和评估植物使用四种类型的水源：在当前月份的降水（源1），过去的降水存储在较深的非饱和土壤和/或岩石（源2），过去的降水存储在地下水（源3，本地补给）和地下水降水下降到高地通过河流，地下水收敛到低地（源4，远程补给）。我们研究了全球和季节性模式和驱动程序，在植物吸收的四个来源，使用逆向建模和同位素为基础的估计。结果表明：（1）在全球范围内，70%的植物蒸腾量依赖于源1，18%依赖于源2，只有1%依赖于源3，10%依赖于源4;（2）在区域和季节上，源1在半干旱地区仅占19%，在地中海地区仅占32%，在冬季干旱的热带地区仅占17%;在景观尺度上，在干旱月份，由深层包气带中的深层根系吸收的源2在高地中是关键的，而在河岸森林和荒漠绿洲的山谷中，源4高达47%。在不同的时空尺度上移动，对气候和人为力量的敏感性也不同，了解植物水源的空间和时间起源可以为生态系统管理和地球系统模型提供有关降水与植被
Vegetation modulates Earth’s water, energy and carbon cycles. How its functions might change in the future largely depends on how it copes with droughts, , –. There is evidence that, in places and times of drought, vegetation shifts water uptake to deeper soil, –and rock,moisture as well as groundwater, –. Here we differentiate and assess plant use of four types of water sources: precipitation in the current month (source 1), past precipitation stored in deeper unsaturated soils and/or rocks (source 2), past precipitation stored in groundwater (source 3, locally recharged) and groundwater from precipitation fallen on uplands via river–groundwater convergence toward lowlands (source 4, remotely recharged). We examine global and seasonal patterns and drivers in plant uptake of the four sources using inverse modelling and isotope-based estimates. We find that (1), globally and annually, 70% of plant transpiration relies on source 1, 18% relies on source 2, only 1% relies on source 3 and 10% relies on source 4; (2) regionally and seasonally, source 1 is only 19% in semi-arid, 32% in Mediterranean and 17% in winter-dry tropics in the driest months; and (3) at landscape scales, source 2, taken up by deep roots in the deep vadose zone, is critical in uplands in dry months, but source 4 is up to 47% in valleys where riparian forests and desert oases are found. Because the four sources originate from different places and times, move at different spatiotemporal scales and respond with different sensitivity to climate and anthropogenic forces, understanding the space and time origins of plant water sources can inform ecosystem management and Earth system models on the critical hydrological pathways linking precipitation to vegetation.