Vegetation, hydrology, and quantitative monsoon precipitation since the Last Glacial Maximum in Central China
Vegetation, hydrology, and quantitative monsoon precipitation since the Last Glacial Maximum in Central China
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DOI：
10.1016/j.gloplacha.2023.104298
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发表时间：
2023-11
影响因子：
3.9
通讯作者：
Zhenhui Huang;Chunmei Ma;Shi Feng;Yan Zhao;Zhuo Zheng;Xiayun Xiao;Michael E Meadows;Cheng Zhu
中科院分区：
文献类型：
--
作者：
Zhenhui Huang;Chunmei Ma;Shi Feng;Yan Zhao;Zhuo Zheng;Xiayun Xiao;Michael E Meadows;Cheng Zhu
长江流域是我国季风区的重要组成部分，重建长江流域的水文和降水演变过程对于更好地理解东亚夏季风的演变具有重要意义。江汉盆地地层剖面（JZ 2010）的花粉记录揭示了近24万年以来古植被、古环境和古气候条件的变化。我们进行定量降水重建（基于加权平均偏最小二乘法）。研究结果表明，该区植被经历了从针阔混交林到万年青落叶混交林再到次生针叶林的演替过程。在过去的24 kyr，气候相对干燥的冰消期，特别是在HS 1和新仙女木冷事件，由温暖和潮湿的Bølling-Allerød中断。全新世早期的降水量达到最大，峰值在10.0和7.0 cal kyr BP之间，其次是6.5和4.5 cal kyr BP之间的干燥条件。随后的潮湿条件持续到3.8 cal kyr BP，之后降水量逐渐下降。总的来说，定量降水重建与长江流域其他基于代理的降水重建是一致的。然而，降水变化的时间模式是不同的北方中国季风区，那里的降水高峰期出现在中全新世。研究表明，全新世以前，气候变化主要受太阳辐射动力学和高纬遥相关的控制，而全新世主要受低纬遥相关的影响，包括厄尔尼诺-南方涛动，它控制了中国季风区的偶极降水格局。东亚季风区从末次盛冰期到全新世的高分辨率气候变化记录为模拟全球变暖背景下中国南方和北方未来的降水变化提供了一个有用的基准。
The Yangtze River Basin is a crucial region in the monsoon region of China, and reconstructing its hydrological and precipitation evolution is important for developing a more robust understanding of the evolution of the East Asian Summer Monsoon. A pollen record from a strata profile (JZ2010) in the Jianghan Basin of Central China reveals variations in paleovegetation and paleoenvironmental and paleoclimatic conditions covering the last 24 cal kyr BP at ∼90 years resolution. We perform a quantitative precipitation reconstruction (based on a weighted averaged partial least squares method). Results of the study show that the vegetation in the region experienced a succession from coniferous and broad-leaved mixed forest to evergreen and deciduous mixed forest and then to secondary coniferous forest. Over the past 24 kyr, the climate was relatively dry during the deglacial period, particularly during HS1 and the Younger Dryas cold event, interrupted by a warm and humid Bølling-Allerød. Precipitation in the early Holocene was at its maximum, peaking between 10.0 and 7.0 cal kyr BP followed by drier conditions between 6.5 and 4.5 cal kyr BP. Subsequent wetter conditions lasted until 3.8 cal kyr BP, after which precipitation gradually declined. Overall, the quantitative precipitation reconstruction is consistent with other proxy-based precipitation reconstructions in the Yangtze River region. However, the temporal pattern of variations in precipitation is distinct from that of the northern China monsoon region, where the precipitation peak occurred during the mid-Holocene. The study suggests that, prior to the Holocene, climate change was controlled by insolation dynamics and high latitude teleconnections, while during the Holocene it was primarily influenced by low latitude teleconnections, including the El Niño-Southern Oscillation, which controlled the dipolar rainfall pattern in the monsoon region of China. The high resolution record of changing climate in the East Asian monsoon region over a period spanning the LGM and Holocene provides a useful benchmark for modelling future precipitation change in southern and northern China against the background of global warming.