青海共和盆地晚更新世大型哺乳动物消亡前后的植被和自然环境变化

The Late Pleistocene is a crucial phase of the global climatic changes. The series of glacial/interglacial alternations have significantly impacted on the vegetational and environmental changes, as well as the migration/extinction of biota. The fragile ecosystems in Gonghe Basin on the northeastern margin of the Tibetan Plateau region are highly sensitive to global climatic changes as its unique topography. To understand the vegetation succession and climatic changes at the northeastern margin of the Tibetan Plateau in the Late Pleistocene, we reconstruct the vegetation and climate based on palynological data from Gonghe Basin, Qinghai. Based on the vegetation comparison between upper and belower layers of the large mammals fossils, combined with AMS14C dating, this study aimed to explore potential relation between the extinction events of large mammals and their food sources. By applying the Coexistence Approach, we attempt to quantitatively reconstruct the palaeoenvironmental and palaeoclimatic evolutions. Combined with charcoal records, we attempt to reveal the relationship between palaeofire and hydrological environment changes. By using the biological evidence, this research will provide a new attempt at exploring the palaeoclimatic changes of the northeastern margin of Tibetan Plateau during the Late Pleistocene.

晚更新世是全球气候发生剧烈变化的重要时期，冰期与间冰期的交替对植被变化和自然环境的改变，以及动物迁徙和灭绝都产生了重要影响。位于青藏高原东北缘的共和盆地其独特的地理特征和脆弱的生态系统对气候变化尤为敏感。本项目拟对共和晚更新统大型哺乳动物化石层及其前后层位进行高分辨采样，运用AMS14C年代学手段建立精确的地层序列年代标尺；通过分析地层中的孢粉植物群，认识和恢复古植被和古环境，并采用共存分析等古气候定量重建方法，重建该地区高分辨率的植被-气候演化序列；综合炭屑资料，揭示动植物群落演替与水文环境和森林火之间关系；同时结合该地层中发现的哺乳动物化石，从食物来源以及水文环境变化的角度来探索和理解大型哺乳动物的消亡事件。本项目的研究结果将为揭示晚更新世共和盆地生态系统与气候的关系提供重要的研究资料，为探索青藏高原东北边缘地区大型哺乳动物灭绝的原因提供新的认识和研究范例。