良渚古城水坝内外沉积物记录的 5 ka 以来人类活动与环境演变

The Mid-Late Holocene was a crucial period of profound environmental evolution and cultural change for frequently occurring of extreme climate events and quickly collapsing of civilizations in Old World. Liangzhu culture, located in the lower Yangtze Region, is considered as the peak of prehistoric cultural and social development in China, however, it suddenly declined during this period. Whether environmental change is the main driving factor of its decline has been controversial. Although previous studies have achieved many important achievements in revealing the development of rice agriculture and the occurrence of climate and environmental events, there is relatively little research on the relationship between human activities and environmental evolution. One important reason is the lack of continuous, stable, comparable sediments which can record regional human activities, agricultural development and environmental evolution during Liangzhu culture. The sediments inside of Liangzhu dams recorded the whole environment evolution during Liangzhu culture period. This project will employ micro-plants fossil analysis, combing with high-precision dating, using sediments inside the dam to reconstruct the environmental evolution process, using the sediments outside the dam - the ancient city cultural layers to reveal the process of rice agriculture; on the basis of comparative analysis, we will try to explore the relationship between human activities, agricultural development and environmental evolution during the Liangzhu culture period, which will provide key clues for the cause of Liangzhu culture decline and will provide scientific evidence for studying the intrinsic relationship between human activities and environmental evolution.

中-晚全新世是气候环境和人类社会发生深刻变革的关键时期，极端气候事件频发，旧大陆原始文明衰退。长江下游地区的良渚文化被认为是中国史前文化发展的巅峰，在此期间也突然衰落，环境变化是否是其衰落的主要驱动因素，一直存在争议。虽然以往的研究在揭示良渚稻作农业发展、环境演变等方面取得了许多重要成果，但对于人类活动与环境演变相互关系的研究相对较少，原因之一是缺少良渚文化时期连续的、稳定的、可对比的区域人类活动、农业发展与环境演变的沉积记录。良渚水坝内的沉积物完整记录了良渚文化由盛转衰期间的自然环境演化过程，本项目拟采用微体化石分析方法，结合高精度测年，利用水坝内自然沉积物重建环境演变过程，利用水坝外古城文化层沉积物，揭示稻作农业发展过程；在对比分析基础上，探讨良渚文化时期人类活动、农业发展和环境演变之间的关系，为良渚文化衰退原因提供关键线索，为研究人类活动和环境演变的内在关系提供新的材料与科学证据。

农业发展与环境演化的关系一直是国际学术界研究的热点问题，农业的发展和集约化伴随着大规模的景观改造和环境后果。水稻作为最早驯化的作物之一，支撑着文化和社会转型，并最终为亚洲古代文明的崛起奠定了基础。然而，关于稻作农业发展是何时以及如何开始改变景观的、水稻驯化的时空格局以及稻田的出现和判定等问题，一直存在争议。本项目对长江下游地区的良渚蜜蜂垄水坝内沉积物、上山文化五个遗址，淮河流域的张王庄遗址，长江中游地区大张庄等十个仰韶文化遗址进行了系统的样品采集和植硅体分析，结合碳十四和光释光年代测定，新的研究成果显示：1）良渚蜜蜂垄水库的使用时间为4900-1500 cal BP，在2500-1500 cal BP期间密集的水稻种植活动可能通过森林砍伐和禾本科植物结构变化改变周围的景观。这些发现为理解农业发展与景观变化之间的关系提供了新的见解；2）张王庄遗址可能具有距今6000年前的稻田，这是中国北方稻旱混作区内最早的稻田，揭示了水稻核心起源区之外稻田遗迹的存在；3）汉水中游地区在7000-5000 cal BP之间稻作农业是持续发展的，并且混作农业至少在约7000 cal BP已经出现并在后续时段一直延续；4）长江下游地区在一万前已经开始驯化水稻，但是驯化过程在区域内不同遗址间有明显差异，靠近河流干流的遗址驯化速度更快；5）更新了水稻扇型植硅体的定量判定水稻野生-驯化性质的指标。综上，本项目为研究人类活动、稻作农业发展与环境变化的关系提供了系列新证据。