新疆吐-哈盆地4000 a BP以来绿洲农业演替及其环境适应研究

How to positively response to global warming and improve human ability for adapting climate change in future? These are challenging subjects for global change research. Important climate and ecology areas were selected, and then from the point of agricultural evolution and development, the relationship between agricultural activities and climate change was analyzed. The method was proved as an effective one for solving the existing problems mentioned above. The Turpan and Hami Basin were important sites along the Silk Road for connecting different populations from the East and West. There were abundant cereal remains unearthed from archaeological sites. In addition, dry climate condition and vulnerable ecology system make the basin as an ideal area for analyzing the relationship between climate change and human adaption. Five typically archaeological sites, in variable period after 4000 a BP, are selected in this project. Cereal remains including caryopses, spikelets and inflorescences are dated by AMS14C, and then quantitatively counted. Based on these data, we can know when crops domesticated in the East (millet, rice) and West Asia (wheat, barley) appeared in the basin, their composing proportions and dispersal routes. Apart from that, strategies of human adaption are revealed by comparing high resolution climate records with the process of agricultural activities. This project will provide scientific references for sustainable development of agriculture and human adaption in arid region.

如何应对全球增温的影响，提高人类适应未来气候环境变化能力，是当前全球变化研究富有挑战性的课题。选择关键气候和生态环境地区，从早期农业演化和发展角度，开展农业活动与气候环境变化关系研究，是解决上述问题的有效途径。吐鲁番盆地、哈密盆地是古代丝绸之路的重要通道，东西方经济文化交流频繁，保留了丰富的农业遗存。另外，该地区气候干旱，生态脆弱，是探索气候-人类适应关系的理想区域。本项目选取吐-哈盆地4000 a BP以来5个不同时期典型考古遗址，通过颖果、小穗、花序等农作物大化石的量化分析，结合高精度AMS14C测年，重建东亚（粟类、水稻）和西亚（麦类）驯化农作物在吐-哈盆地的起讫时间、结构演替以及扩散和传播过程。同时，综合分析已有高分辨率古气候记录，揭示研究区早期农业活动与气候环境变化的关系，探讨先民的调整方式和应对策略，为未来干旱区农业可持续发展和人类适应提供科学依据。

气候环境变化与人类适应是当前全球变化研究的热点问题。选择关键区域，从较长时间尺度来探索人与环境相互作用的过程和机制，可以为未来人类的适应方式和策略提供历史借鉴和科学参考。本项目选择气候干旱、环境脆弱的吐鲁番-哈密盆地作为研究区，系统采集盆地内典型考古遗址的植物遗存，结合高精度AMS14C测年，重建了当地青铜时代以来绿洲农业发展的时间序列和种植结构演变过程，同时还初步建立研究区农业活动演替与气候环境阶段性变化的关系。结果表明吐鲁番盆地农作物最早出现于青铜时代晚期3200 a BP的苏贝希文化，以少量的黍、小麦和青稞为主。而哈密盆地农业信号出现于4000 a BP的天山北路文化，但是目前农作物种子的发现是在焉不拉克文化（3200-2300 a BP）时期。哈密五堡墓地（3000-2400 a BP）农作物种类包含粟、黍、小麦、青稞，其中粟的花序很小，表明其产量低，可能是导致当时粟在中亚干旱区未被广泛种植的重要原因。早期铁器时代园艺作物枣（2400 a BP）和葡萄（2300 a BP）开始出现。汉代丝绸之路开通后多种豆类、果蔬类（苹果、梨、杏、桃、沙枣、哈密瓜、核桃、葫芦、瓠子）农作物融入到当地农业生产体系中。不仅是农作物，本项目还充分研究重要遗址的野生植物，如苏贝希文化中用来制作弓箭的木材种类包括云杉、桦树等非本地干热盆地内生长的树种，侧面证明吐鲁番先民可能在天山南部中高海拔牧场和低海拔绿洲内有季节性迁移放牧行为，丰富了对先民农牧兼营生计模式的了解。4000 a BP以来水分条件持续改善，可能是吐-哈盆地绿洲农业生产持续强化的重要环境因素。以上研究为探索典型干旱区农业发展历史及其与环境演变的关系提供了重要的参考依据，也为进一步了解东西方交流背景下农作物传播与扩散的时间和过程提供了重要资料。