西辽河流域青铜时代（4-2 ka BP）人类适应气候变化的策略

Many sites during Bronze Age (4-2 ka BP) are located at the Western Liao River Basin. Compared with Lower Xijiadian period (4-3.6 ka BP), the ruins shrunk southward in southern plain and while extended northward in western mountain region during Upper Xijiadian period (3-2 ka BP), however, the reason of these distribution difference was indefinable. Extensive scale of climate change may serious effected on the human activities in this area. With the combination research of climate change, distribution of the archaeology sites, subsistence strategies, how human adapted to the paleoclimate change in the Western Liao River Basin will be discussed, and these works probably offer a new perspective for understanding about the man-land relationship. Based on the thoroughly archaeological survey and excavation in important sites, plant and animal remains will be collected. Based on radiocarbon dating on reliable materials such as charred seeds, the identifications of foxtail millet, broomcorn millet and so on, will be used to discuss how agriculture activity adapted to the paleoclimate change. And the identifications of the bones from pig, sheep, and dear to studied the scaling relations among agriculture, farming and hunting activities. Meanwhile, we try to reconstruct the paleoclimate change from specific sections, in order to discuss how the paleoclimate change had influenced on human activities. With the comparisons of the above researches, how paleoclimate change had influenced the human activities in the Western Liao River Basin will be discussed, and its results are representative for the ecological fragile zones.

大量青铜时代（4-2 ka BP）的遗址分布于西辽河流域。分析认为，在西辽河流域遗址的密集分布区，晚期夏家店上层文化（3-2 ka BP）较之早期的夏家店下层文化（4-3.6 ka BP）分布差异明显：南部平原区向南收缩，西部山地区向北扩张，但原因不明。大幅度的气候变化，可能严重影响该区域的人类活动。结合气候变化与遗址分布、生业模式，探讨人类在西辽河流域对气候变化的适应方式和过程，为研究古人地关系提供新的视角。本项目拟通过大量遗址的调查和部分遗址的发掘或试掘，获取动植物样本；基于炭化植物种子等精确测年材料的14C年代测定，通过黍、粟等炭化种子的鉴定探讨农业活动对气候变化的适应性，通过猪、羊和鹿等动物骨骼的鉴定探讨农业、牧业和狩猎的比例关系；通过关键剖面的古气候重建，分析气候变化对人类活动的影响。通过上述工作的对比分析，探讨西辽河流域气候变化对人类活动的影响，在生态脆弱带具有代表意义。

在西辽河流域考古调查的基础上，于21个青铜时代文化遗址分别采集浮选样品，共计55份样品、340升，出土炭化植物种子26071粒，初步厘清了西辽河流域青铜时代（4-2 ka BP）先民的生业模式。西辽河流域青铜时代先民仍然从事以粟、黍为主的农业生产活动。夏家店下层文化时期，先民的生业模式以大规模的农业活动为主；夏家店上层文化时期，先民的生活方式发生分异，南部先民仍然延续前期的农业活动，但所占比重可能有所下降，西部先民开始转化为半农半牧的生产活动。基于考古剖面（香炉山、字山遗址）和自然剖面（马莲屯、康平剖面）的OSL和14C年代测定确立了遗址和自然剖面的年代框架，通过磁化率、粒度分析等气候变化研究手段，初步认为西辽河流域青铜时代内存在气候恶化事件（3.5-3.0 ka BP）。该事件可能导致了西辽河流域青铜时代的生业模式转变，进而引起考古学文化性质的转变。西辽河流域青铜时代的气候恶化，致使土壤沙化，进而导致科尔沁沙地扩张，人类不得不向南迁徙。同时，一部分夏家店上层文化时期的人类开始从事畜牧业生产活动，逐渐向西扩张。以上研究为气候变化后的人类活动响应提供了理论基础。