Abstract The reconstruction of vegetation evolution and climate changes at low latitudes since the Last Glacial Maximum (LGM) remains incomplete. In this study, we reconstructed the palynological history of vegetation changes since the LGM using a sediment core collected from the slope in the southern South China Sea (SCS). The chronology of the core was based on eight AMS14C dates, and 85 stratigraphic samples were palynologically analyzed. Our results denote that the vegetation reconstructed during the LGM in the southern SCS was characterized by a relatively high percentage of herb pollen and a modest decrease in the number of fern spores, suggesting a temperature decline and humidity change in this region. Further, the preservation of a rich diversity of pollen from the tropical lowland rainforest indicated that the rainforests might have covered large areas of the exposed Sunda Shelf during the LGM. The dynamic concentration of the Pinus pollen in the core, which is a proxy for the East Asian winter monsoon (EAWM), satisfactorily matched the changes in the Atlantic meridional overturning circulation and Australian-Indonesian summer monsoon, especially during the Heinrich Stadial 1. This suggests that the climate at the high latitudes of the Northern Hemisphere can drive the Intertropical Convergence Zone (ITCZ) southwards based on the enhanced EAWM. The southward-shifting ITCZ may change the hydrological climate of the equator and the Southern Hemisphere. The pteridophyte spores, which are good regional precipitation indicators, were positively correlated with the warm pool convection and inversely related with the EAWM, possibly indicating the considerable impact of the high-latitude climate in the Northern Hemisphere on precipitation in the tropical regions. Our results indicate that during the last deglaciation, the tropical hydrological changes were relatively moderate when compared with the drastic change observed at high latitudes and were attributed to the regulation of the El Nino-Southern Oscillation-like state. Our sequence of pollen and spores from the southern SCS can be used to observe the detailed dynamics of climatic evolution in tropical regions. The results of this study are essential to understand the complicated climate processes and the relation between high and low latitudes.

中文翻译：

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南海南部LGM以来基于植被演化的水文气候史

摘要 末次盛冰期（LGM）以来低纬度地区植被演化和气候变化的重建仍不完整。在这项研究中，我们使用从南海南部 (SCS) 斜坡收集的沉积物核心重建了自 LGM 以来植被变化的孢粉学历史。岩心的年代基于 8 个 AMS14C 日期，并对 85 个地层样本进行孢粉学分析。我们的研究结果表明，南海南部 LGM 期间重建的植被的特点是草本花粉百分比相对较高，蕨类孢子数量略有减少，表明该地区的温度下降和湿度发生变化。更多，热带低地雨林丰富多样的花粉的保存表明，热带雨林可能在 LGM 期间覆盖了大片暴露的巽他大陆架。作为东亚冬季风 (EAWM) 代表的核心松树花粉的动态浓度与大西洋经向翻转环流和澳大利亚-印度尼西亚夏季风的变化令人满意地匹配，尤其是在 Heinrich Stadial 1 期间。表明北半球高纬度的气候可以基于增强的 EAWM 驱动热带辐合带（ITCZ）向南。南移的 ITCZ 可能会改变赤道和南半球的水文气候。蕨类植物孢子是良好的区域降水指标，与暖池对流呈正相关，与EAWM呈负相关，可能说明北半球高纬度气候对热带地区降水的影响较大。我们的研究结果表明，在最后一次冰消期间，热带水文变化与高纬度地区的剧烈变化相比相对温和，这归因于厄尔尼诺-南方涛动状状态的调节。我们来自南海南部的花粉和孢子序列可用于观察热带地区气候演变的详细动态。这项研究的结果对于理解复杂的气候过程和高低纬度之间的关系至关重要。可能表明北半球高纬度气候对热带地区降水有相当大的影响。我们的研究结果表明，在最后一次冰消期间，热带水文变化与高纬度地区的剧烈变化相比相对温和，这归因于厄尔尼诺-南方涛动状状态的调节。我们来自南海南部的花粉和孢子序列可用于观察热带地区气候演变的详细动态。这项研究的结果对于理解复杂的气候过程和高低纬度之间的关系至关重要。可能表明北半球高纬度气候对热带地区降水有相当大的影响。我们的研究结果表明，在最后一次冰消期间，热带水文变化与高纬度地区的剧烈变化相比相对温和，这归因于厄尔尼诺-南方涛动状状态的调节。我们来自南海南部的花粉和孢子序列可用于观察热带地区气候演变的详细动态。这项研究的结果对于理解复杂的气候过程和高低纬度之间的关系至关重要。我们的研究结果表明，在最后一次冰消期间，热带水文变化与高纬度地区的剧烈变化相比相对温和，这归因于厄尔尼诺-南方涛动状状态的调节。我们来自南海南部的花粉和孢子序列可用于观察热带地区气候演变的详细动态。这项研究的结果对于理解复杂的气候过程和高低纬度之间的关系至关重要。我们的研究结果表明，在最后一次冰消期间，热带水文变化与高纬度地区的剧烈变化相比相对温和，这归因于厄尔尼诺-南方涛动状状态的调节。我们来自南海南部的花粉和孢子序列可用于观察热带地区气候演变的详细动态。这项研究的结果对于理解复杂的气候过程和高低纬度之间的关系至关重要。我们来自南海南部的花粉和孢子序列可用于观察热带地区气候演变的详细动态。这项研究的结果对于理解复杂的气候过程和高低纬度之间的关系至关重要。我们来自南海南部的花粉和孢子序列可用于观察热带地区气候演变的详细动态。这项研究的结果对于理解复杂的气候过程和高低纬度之间的关系至关重要。