Human planting strategies and its relation to climate change during ∼4,800–3,900 BP in the mid-lower Hulu River Valley, northwest China

Frontiers in Earth Science

Earth Science

Haiming Li¹  Guoke Chen²  Jiajia Dong³  Wenyu Wei³  Zekun Wu³  Minmin Ma³  Xiaobin Li⁴ 

[1] College of Humanities and Social Development, Nanjing Agricultural University, Nanjing, China;Institution of Chinese Agricultural Civilization, Nanjing Agricultural University, Nanjing, China;Gansu Provincial Institute of Cultural Relics and Archaeology Research, Lanzhou, China;Ministry of Education Key Laboratory of Western China’s Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China;Zhuanglang County Museum, Pingliang, China;

关键词: archaeobotanical analysis;    grain size;    carbon and nitrogen isotope analysis;    subsistence strategy;    mid-lower Hulu River Valley;    late Neolithic;   

DOI  :  10.3389/feart.2023.1137528

 received in 2023-01-04, accepted in 2023-04-07,  发布年份 2023

来源: Frontiers

【 摘 要 】

The response of agricultural societies to global climate events during the Neolithic (e.g., 4.2 ka event) is a scientific issue of general interest. In the mid-lower Hulu River Valley of northwest China, millet cultivation became the primary subsistence during the late Neolithic. Local paleoclimate studies have detected a notable decline in temperature and precipitation around 4,400 BP (Before Present), while the Qijia culture (4,200–3,600 BP) sites far outnumber those of the Lower Changshan culture (4,800–4,400 BP) in the area. Why the intensity of millet farming groups increased when climate was relatively cold and dry, however, has not been well understood. To explore the issue, we performed archaeobotanical analysis, grain size measurement, stable isotope analysis and radiocarbon dating in the excavated sites of the Zhongtianxingfucheng (ZTXFC) and Wangjiayangwan (WJYW), which were dated to between ∼4,800–4,400 BP and ∼4,200–3,900 BP, respectively. Our results demonstrate the overall declines in the proportion, grain sizes and carbon isotope values of millets from the WJYW site compared to ZTXFC. The nitrogen isotopes of millets from the two sites are similar [foxtail millet: 6.8‰ ± 1.9‰ (ZTXFC), 7.5‰ ± 1.5‰ (WJYW); broomcorn millet: 7.3‰ ± 2.0‰ (ZTXFC), 7.5‰ ± 1.2‰ (WJYW)]. These results suggest that the degree of field management during ∼4,200–3,900 BP was lower than ∼4,800–4,400 BP in the mid-lower Hulu River Valley. Instead of improving cultivation management or altering cropping patterns, Qijia millet farmers might have adopted a strategy of expanding cultivated lands to promote the social development under a relatively cold-dry climate.

【 授权许可】

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Copyright © 2023 Wei, Ma, Chen, Dong, Wu, Li and Li.