Drought Risk of Global Terrestrial Gross Primary Productivity Over the Last 40 Years Detected by a Remote Sensing-Driven Process Model
Drought Risk of Global Terrestrial Gross Primary Productivity Over the Last 40 Years Detected by a Remote Sensing-Driven Process Model
复制标题
遥感驱动过程模型检测近40年全球陆地初级生产力干旱风险
DOI：
10.1029/2020jg005944
复制
发表时间：
2021-06-01
影响因子：
3.7
通讯作者：
Mao, Guangxiong
中科院分区：
文献类型：
--
作者：
He, Qiaoning;Ju, Weimin;Mao, Guangxiong
总初级生产力(GPP)是全球陆地碳循环中最大的通量。近几十年来，干旱对全球陆地GPP产生了重大影响，并预计将以越来越高的频率和强度发生。然而，全球陆地GPP的干旱风险尚未得到很好的研究。本文利用基于过程的北方生态系统生产力模拟器模型对1981-2016年全球陆地GPP进行了模拟。在此基础上，利用标准化降水蒸散量指数，将GPP的干旱风险量化为干旱概率与干旱引起的GPP减少的乘积。在研究期间，美国东南部、南美洲大部分地区、南欧、中非和东非、东亚和东南亚以及澳大利亚东部的GPP干旱风险很高。北半球的一些高纬度地区和热带南美洲的部分地区的陆地GPP较低，那里的陆地GPP在干旱年份略有增加。在24个气候带中，有21个气候带的陆地GPP干旱风险在2000-2016年间大于1981-1999年期间。GPP的全球平均干旱风险从1981-1999年的13.6gCm(-2)yr(-1)增加到2000-2016年的19.3gCm(-2)yr(-1)。GPP干旱风险增加的主要原因是干旱脆弱性的增加。模拟试验表明，GPP的干旱脆弱性主要是由气候变化引起的。这项研究加深了我们对干旱对全球GPP影响的理解。然而，全球陆地GPP的干旱风险尚未得到很好的研究。基于基于过程模型的模拟结果，我们评估了1981-2016年间GPP的干旱风险。GPP的干旱风险是根据干旱发生的可能性和干旱将导致的GPP预期减少来量化的。世界各地的结果各不相同，美国东南部、南美大部分地区、南欧、中非和东非、东亚和东南亚以及澳大利亚东部的情况都很严重。北半球一些高纬度地区和南美洲热带部分地区的全球初级生产力的干旱风险并不成问题。在这些地区，与常年相比，干旱年的GPP略有增加。在24个气候带中，有21个气候带的陆地GPP干旱风险在2000-2016年间大于1981-1999年期间。GPP的全球平均干旱风险从1981-1999年的13.6gCm(-2)yr(-1)增加到2000-2016年的19.3gCm(-2)yr(-1)。GPP干旱风险的增加主要是由气候变化引起的。
Gross primary productivity (GPP) is the largest flux in the global terrestrial carbon cycle. Drought has significantly impacted global terrestrial GPP in recent decades, and has been projected to occur with increasing frequency and intensity. However, the drought risk of global terrestrial GPP has not been well investigated. In this study, global terrestrial GPP during 1981-2016 was simulated with the process-based Boreal Ecosystem Productivity Simulator model. Then, the drought risk of GPP was quantified as the product of drought probability and reduction of GPP caused by drought, which was determined using the standardized precipitation evapotranspiration index. During the study period, the drought risk of GPP was high in the southeastern United States, most of South America, southern Europe, central and eastern Africa, eastern and southeastern Asia, and eastern Australia. It was low at some high latitudes of the Northern Hemisphere and in part of tropical South America, where terrestrial GPP increased slightly in drought years. The drought risk of terrestrial GPP was greater during 2000-2016 than during 1981-1999 in 21 out of 24 climatic zones. The global mean drought risk of GPP increased from 13.6 g C m(-2) yr(-1) during 1981-1999 to 19.3 g C m(-2) yr(-1) during 2000-2016. The increase in drought risk of GPP was mainly caused by the increase in drought vulnerability. Simulation experiments indicated that the drought vulnerability of GPP was mainly induced by climatic variability. This study advances our understanding on the impact of drought on GPP over the globe.Plain Language Summary Drought generally affects gross primary productivity (GPP) of terrestrial ecosystems. However, the drought risk of global terrestrial GPP has not been well investigated. We assessed the drought risk of GPP based on the simulation by a process-based model for the years 1981-2016. The drought risk of GPP was quantified in terms of the chances of drought occurring and the anticipated reduction of GPP that would be caused by the drought. The results were variable across the world, being serious in the southeastern United States, most of South America, southern Europe, central and eastern Africa, eastern and southeastern Asia, and eastern Australia. The drought risk of GPP at some high latitudes of the Northern Hemisphere and in part of tropical South America was not found to be problematic. In those areas, GPP increased slightly in drought years in comparison with that in normal years. The drought risk of terrestrial GPP was greater during 2000-2016 than during 1981-1999 in 21 out of 24 climatic zones. The global mean drought risk of GPP increased from 13.6 g C m(-2) yr(-1) during 1981-1999 to 19.3 g C m(-2) yr(-1) during 2000-2016. The increase in drought risk of GPP was mainly caused by climatic variability.