秦岭地区更新世气候环境变化及其对古人类行为的影响

The impact of vegetation and climate change on early human behaviors is hotly investigated by anthropologists and geologists. Extensive evidence in Europe infers that climate changes through glacial and interglacial periods significantly affect their survival and migration. In East Asia, however, it is still controversial whether human had the parallel behaviors, and the human adaptation process remains unclear. To date, research in China about paleolithic environmental archaeology mainly focuses on single sites, with few quantitative paleoclimate data, which hinders the understanding of relationship between human behaviors and environmental change. Archeological compilation shows that Qinling area is a key area to study this issue. In this project, we will first compile the abundant palaeolithic archeological data in the Qinling region to clarify the temporal and spatial pattern of early human activities. Then, two typical sections from the northern and southern Qinling Mountains are selected for pollen analysis to quantitatively reconstruct paleovegetation and climate change since late Early Pleistocene. Based on these data, the impact of climate change on human migration and adaptation in Qinling region can be revealed. This research will contribute to understanding the relationship between human behaviors and climate change in East Asia.

过去气候环境变化对古人类行为的影响是前沿的科学问题，欧洲的研究发现，冰期-间冰期尺度上的气候变化推动着古人类的收缩和扩散；而在东亚地区，面对频繁的气候环境变化，更新世古人类具有怎样的行为模式？不同时期古人类对气候的适应能力如何？这些问题的解答尚需要从两个方面开展综合研究：1）关键区域古人类活动时空分布格局研究；2）古人类生存的气候环境背景的定量化重建。本研究选取我国古人类南北迁移的关键区域-秦岭地区，首先详细整理这一地区丰富的旧石器时代考古资料，获得早更新世以来古人类活动的时空分布格局；同时，在秦岭北麓和南麓开展古植被、古气候定量化重建工作，获得晚早更新世以来气候环境变化序列；在此基础上，分析环境变化对古人类迁移和适应的影响，为东亚地区古人类行为与环境变化关系的研究做出贡献。

过去气候环境变化如何影响东亚地区的古人类行为是前沿的科学问题。本项目选取我国古人类生活的关键区域—秦岭地区，开展典型剖面的孢粉分析，并利用多种方法定量化重建了这一地区中更新世以来的古植被、古气候变化；同时，项目详细整理秦岭地区的旧石器考古资料，获得了中更新世以来古人类活动的时空分布格局；在此基础上，系统分析气候环境变化对古人类行为的影响。研究结果表明，秦岭地区中更新世期间，植被和气候在轨道时间尺度上发生了显著的变化，间冰期时，森林植被较为发育，气候温暖湿润，年均温在10℃以上，最冷月温度约-2~0℃，降水量可达800~1000mm；而冰期时，草原扩张，气候变冷干，年均温约4~6℃，最冷月温度低于-10℃，年降水量约400mm；秦岭以北到秦岭以南，温度在冰期-间冰期尺度上的变化幅度逐渐减小。在更长的时间尺度上，气候在约0.3–0.25Ma发生了明显的转型，这一时期之后，气候整体上更为冷干，变化幅度显著增加。~0.3Ma之前，古人类尚不能适应秦岭北麓冰期时的寒冷环境，他们选择向南迁移，秦岭南麓成为了冰期时的避难所；~0.3Ma以来，气候波动幅度的增加和冰期环境的恶化，迫使他们改变石器技术和行为模式，并逐渐适应了秦岭以北寒冷的冰期气候。项目研究为认识东亚地区古人类应对环境变化的行为方式提供了重要证据。