Recent leveling off of vegetation greenness and primary production reveals the increasing soil water limitations on the greening Earth
Recent leveling off of vegetation greenness and primary production reveals the increasing soil water limitations on the greening Earth
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DOI：
10.1016/j.scib.2021.02.023
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发表时间：
2021-07-30
期刊：
影响因子：
18.9
通讯作者：
Penuelas, Josep
中科院分区：
文献类型：
--
作者：
Feng, Xiaoming;Fu, Bojie;Penuelas, Josep
自20世纪80年代以来，全球植被的光合作用和生产力大幅增加，但这一趋势在时间和空间上都是不均匀的。在这里，我们将全球植被绿色化的长期趋势分为持续绿化，持续布朗宁和绿化到布朗宁。我们发现，到2016年，全球植被绿色度的增加已经开始趋于平稳，在过去十年中，布朗宁面积增加，达到3900万平方公里（占世界植被面积的35.9%）。这一面积大于持续增长的面积（2780万km 2，26.4%）;因此，自2010年以来，先前增加的12.0% +/- 3.1%（0.019 +/- 0.004 NDVI a-1）已被抵消（2010-2016年，P < 0.05）。全球初级生产总值也随着植被在时间和空间上的绿色化趋势而趋于平稳。这种稳定是由于干旱的空间扩展导致土壤水分限制增加造成的，干旱的影响超过了温度和太阳辐射的影响。全球初级生产总值对土壤水分限制的这种响应在地球系统模型中的陆地子模型中没有得到确认。我们的研究结果提供了经验证据，全球植被绿化和初级生产力被水压力所抵消，并表明，随着全球变暖的持续，土地子模型可能高估了世界的能力，以吸收全球植被绿化的碳。(c)中国科学出版社.爱思唯尔公司、科学中国出版社出版。All rights reserved.
Global vegetation photosynthesis and productivity have increased substantially since the 1980s, but this trend is heterogeneous in both time and space. Here, we categorize the secular trend in global vegetation greenness into sustained greening, sustained browning and greening-to-browning. We found that by 2016, increased global vegetation greenness had begun to level off, with the area of browning increasing in the last decade, reaching 39.0 million km2 (35.9% of the world's vegetated area). This area is larger than the area with sustained increasing growth (27.8 million km2, 26.4%); thus, 12.0% +/- 3.1% (0.019 +/- 0.004 NDVI a-1) of the previous earlier increase has been offset since 2010 (2010-2016, P < 0.05). Global gross primary production also leveled off, following the trend in vegetation greenness in time and space. This leveling off was caused by increasing soil water limitations due to the spatial expansion of drought, whose impact dominated over the impacts of temperature and solar radiation. This response of global gross primary production to soil water limitation was not identified by land submodels within Earth system models. Our results provide empirical evidence that global vegetation greenness and primary production are offset by water stress and suggest that as global warming continues, land submodels may overestimate the world's capacity to take up carbon with global vegetation greening. (c) 2021 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.