Revisiting the cumulative effects of drought on global gross primary productivity based on new long- term series data (1982– 2018)
Revisiting the cumulative effects of drought on global gross primary productivity based on new long- term series data (1982– 2018)
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根据新的长期系列数据重新审视干旱对全球总初级生产力的累积影响（1982年至2018年）
DOI：
10.1111/gcb.16178
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发表时间：
2022
影响因子：
11.6
通讯作者：
Xiaoyu Li
中科院分区：
文献类型：
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作者：
Zhenyu Zhang;Weimin Ju;Yanlian Zhou;Xiaoyu Li
干旱对植被有着广泛而深刻的影响。关于干旱对植被的影响的研究已经进行了多年。近年来，干旱的累积效应被认为是影响植物生长的另一个关键因素。然而，对这一现象的全球性研究仍然缺乏。因此，基于新的基于卫星的总初级生产力（GPP）和多时间尺度标准化降水蒸散指数数据集，我们探索了干旱对全球植被GPP的累积效应持续时间（CED），并分析了其在不同海拔和气候带的变化。主要研究结果如下：（1）干旱对GPP的累积影响是广泛的，平均持续时间为4.89个月。(2)干旱对GPP的CED因植被类型而异。具体而言，草地表现出最长的持续时间，平均值为5.28个月，其次是灌木丛（5.09个月），湿地（5.03个月），农田（4.85个月），稀树草原（4.58个月）和林地（4.57个月）。(3)干旱对GPP的CED随气候条件的变化而变化。在热带和干旱气候区，它分别随最干月降水量（Pdry）和年平均降水量的减少而减少。在温带和寒带，干旱对GPP的CED在冬干区比夏干区短。在热带气候区，它随年平均气温的降低而增加;在温带和寒冷气候区，它随夏季气温的升高而减少。(4)随着海拔的升高，干旱对GPP的CED呈现出先增加（0-3000 m），后减少（3000-5000 m），再增加（>5000 m）的规律。我们的研究结果强调了干旱对GPP的CED的异质性，这是由于植被类型，长期水热条件，海拔等的差异。该结果可以加深我们对干旱对全球植被影响的理解。
Drought has broad and deep impacts on vegetation. Studies on the effects of drought on vegetation have been conducted over years. Recently, the cumulative effect of drought is recognized as another key factor affecting plant growth. However, global‐scale studies on this phenomenon are still lacking. Thus, based on new satellite based gross primary productivity (GPP) and multi‐temporal scale Standardized Precipitation Evapotranspiration Index data sets, we explored the cumulative effect duration (CED) of drought on global vegetation GPP and analyzed its variability across elevations and climatic zones. The main findings were as follows: (1) The cumulative effect of drought on GPP was widespread, with an average CED of 4.89 months. (2) CED of drought on GPP varied among vegetation types. Specifically, grasslands showed the longest duration, with an average value of 5.28 months, followed by shrublands (5.09 months), wetlands (5.03 months), croplands (4.85 months), savannas (4.58 months), and forestlands (4.57 months). (3) CED of drought on GPP changes with climate conditions. It decreased with the decrease of precipitation in the driest month (Pdry) and mean annual precipitation in tropical and arid climate zones, respectively. In both temperate and cold climate zones, CED of drought on GPP was shorter in areas with dry winter than that in areas with dry summer. It increased with the decrease of mean annual air temperature in tropical climate zones and decreased with the increase of summer temperature in temperate and cold climatic zones. (4) With increasing elevation, CED of drought on GPP showed a pattern of increasing (0–3000 m), then decreasing (3000–5000 m), and increasing again (>5000 m). Our findings highlight the heterogeneity of CED of drought on GPP, owing to differences in vegetation types, long‐term hydrothermal conditions, elevation, etc. The results could deepen our understanding of the effects of drought on global vegetation.