青藏高原东部植被变化与冰期-间冰期气候旋回

The Tibetan Plateau has great influences not only on climate aridity in central Asia and Asian monsoon dynamics but also on the climate in the Northern Hemisphere. Therefore it is an important region for the study on glacial-interglacial climate cycles on both global and regional scales. In the proposed project a 300-m-long lake sediment core will be collected from the Zoige Basin in the eastern Tibetan Plateau. The chronology will be established based mainly on palaeomagnetism, AMS C-14, OSL and U-series dating. Fossil pollen will be analyzed and used for vegetation reconstructions, while organic geochemistry and geophysical proxies will be used to reconstruct local environments and also climate history. Past vegetation (biomes) and climate will be quantitatively reconstructed on the basis of modern lake surface pollen dataset and fossil pollen assemblages. Statistical analysis will be used to reveal the cyclicity of climate change, duration of past interglacials and multi-millennial variability within the interglacials. Furthermore, global and regional correlations will be evaluated to understand the regional climate features, monsoon dynamics and vegetation response to glacial-interglacial climate cycles. Our results will potentially provide insights into the climate processes and feedbacks under different boundary conditions and monsoon dynamics, which has important implications for understanding present interglacial and predicting future climate change.

青藏高原对亚洲干旱气候的形成及季风的形成与加强，乃至北半球气候起着重要的作用，因而青藏高原无论在全球尺度还是区域尺度上都是是冰期-间冰期旋回气候研究的一个关键区域。本研究在青藏高原东部利用连续的湖泊沉积物进行古地磁与AMS C-14 测年建立年代序列，采用孢粉分析为主有机地球化学和常规指标为辅的多指标分析，重建青藏高原东部过去90万年植被与气候变化历史；定量化建立生物群区及气候变化序列；揭示冰期-间冰期周期在青藏高原的表现，间冰期的气候变化强度、持续时间及间冰期内部多千年尺度的波动特征。进而通过区域及全球气候对比，理解区域气候及季风变化特征，以及植被对气候变化的响应。研究结果将有助于理解在不同气候边界条件下的气候过程、反馈，冰期-间冰期的季风动态与机制，和区域植被对冰期-间冰期旋回气候的响应，同时为认识现代间冰期及模拟预测未来气候提供基础数据与研究问题。

青藏高原对亚洲干旱气候的形成及季风的形成与加强，乃至北半球气候起着重要的作用，因而青藏高原无论在全球尺度还是区域尺度上都是是冰期-间冰期旋回气候研究的一个关键区域。本研究在青藏高原东部利用连续的湖泊沉积物进行古地磁与AMS C-14、光释光测年建立年代序列，采用孢粉分析为主有机地球化学和常规指标为辅的多指标分析，重建了青藏高原东部过去90万年植被与气候变化历史；定量化建立生物群区及气候变化序列；揭示出冰期-间冰期周期及中更新世转型在青藏高原的表现特征 (由2万年周期为主导转为以10万年周期为主导)。进而通过区域及全球气候对比，提出全球冰量的增长导致低纬日照量vs高纬冰量在时间上的动态变化是高原东部植被与气候变化的重要因素。研究结果将有助于理解在不同气候边界条件下的气候过程、反馈，冰期-间冰期的季风动态与机制，和区域植被对冰期-间冰期旋回气候的响应，同时为认识现代间冰期及模拟预测未来气候提供基础数据与研究问题。