柴达木盆地超千米深钻岩芯孢粉记录的晚中新世以来干旱生态环境演变

Aridification of the Asian inland is an important scientific issues in the research of global and regional climatic and environmental changes, its occurrence and development may be related to the uplift of Tibetan Plateau and global cooling, and also is important to the ecological environment construction in Northwest China. However, great debate remains on the origin, development and mechanism of the aridification of Asian inland due to there is still lack of available long sequence of high-resolution climatic and environmental change record, particularly vegetation environment record. Therefore, the project will obtain high-resolution sporopollen record from the precise age controlled 1720m-deep drill cores drilled by Sino-German at west of the Qaidam Basin, to reconstuct the vegetation evolution of the Qaidam Basin since the Late Miocene, to indicate the major drought events, to discuss its possible mechanism, so as to provide an high-quality ecological environment proof and reference for the related aridification research and ecological environment construction of the Northwest China.

亚洲内陆干旱化是全球和区域气候环境变化中一个重要的科学问题，其发生发展可能与青藏高原隆升和全球变冷等密切相关，并对西部生态环境建设有重要意义，但目前对其演化过程、发展趋势和变化机制仍不清楚，主要原因是缺少可供分析的长序列高精度高分辨率的气候环境变化记录，尤其植被生态环境变化记录。本项目拟利用有精确年代控制的中德柴达木盆地西部一期和二期共1720米深钻岩芯，通过对岩芯中高分辨率孢粉的研究，恢复晚中新世以来柴达木盆地详细的植被演化历史，捕获重大干旱化事件，反演西北内陆生态环境演化和干旱化的细节过程，探讨其可能的机制，为西北内陆干旱化的相关研究和生态环境建设提供一条可供与之对比的高质量生态环境记录和地质历史参照物。

西北内陆干旱化与我国西部人类的生存环境、生态环境建设和社会可持续发展密切相关，其发生发展可能与青藏高原隆升和全球变冷等密切相关，并对西部生态环境建设有重要意义，目前对其演化过程、发展趋势和变化机制尚不清晰，亟需长序列高分辨率的气候环境变化记录，尤其是植被生态环境变化记录的支持。本项目通过对有精确年代控制的中德柴达木盆地西部一期和二期深钻岩芯进行孢粉指标研究，获得了7.4-0.1Ma期间孢粉植被变化谱，重建了晚中新世以来柴达木盆地详细的植被演化历史，结果表明在7.4-4.9Ma期间植被以耐旱的麻黄、藜科等植物为主，指示当时气候已经干旱，但周边山地仍有云冷、松属等针叶树分布，4.9Ma后针叶林分布减少，其后又在3.6Ma、0.8Ma旱生植被含量逐步增多，指示干旱化进一步增强，推测可能是全球变冷驱动了干旱化的进程，但在2.6Ma第四纪冰期开始之际植被并未呈现明显的响应。对于干旱机制的探讨仍需后续研究的深入开展，但本项目的结果可对西北内陆干旱化的相关研究和生态环境建设提供可与之对比的植被演化记录。