炭化植物遗存分析是了解古代农业的重要途径,目前已取得大量研究成果.由于古代农业形成的复杂性和遗址的多样性,如何选择合适遗址以提高炭化植物遗存研究的科学性和代表性已成为重要的课题.选择中原地区新石器文化发达的洛阳盆地,选取分布在不同地貌部位上的23个新石器-青铜时期中小遗址,从灰坑和文化层中采集土样进行浮选和炭化植物遗存鉴定,并与周边地区的大遗址进行了比较.中小遗址和大遗址的炭化植物遗存分析均表明中原地区在新石器时期属于以粟和黍为主的北方旱作农业,并逐渐出现了稻、小麦和大豆,到二里头时期发展成为五谷齐全的农业经济.相比之下,中小遗址农作物种类多样化的出现要早于大遗址,但二里头时期中小遗址稻和小麦在农业中的比重远低于大遗址,这种差异可能反映了它们遗址功能的不同.另外,分布在不同地貌部位上的中小遗址的炭化植物遗存分析表明:在仰韶、龙山文化时期,台塬沟谷区农作物种类比冲积平原区丰富;而到二里头时期,冲积平原区在农作物种类和数量上都超过台塬沟谷区.造成这种差异的原因可能与地貌、土壤、水文等自然环境因素有关.研究表明,中小遗址的炭化植物遗存分析是对区域农业考古研究的极大补充,更能反映区域内农业形成和发展的复杂过程,今后应加强对中小遗址的炭化植物遗存研究.
Analysis of charred plant remains is an efficient way to study ancient agriculture and has yielded many insights. Because of the complexity and diversity of ancient agriculture, how to select the best sites to improve the representativeness of charred plant remains is an important research topic. An assemblage of charred plant remains were obtained using flotation samples collected from ash pits and cultural layers of 22 small sites from the Neolithic to the Bronze Age in the Luoyang Basin, North China, where Neolithic cultures developed. The species of the plant remains were identified stereoscopically. Previous research on both small and large sites had shown that foxtail millet(Setaria italica subsp. italica) and broomcorn millet(Panicum miliaceum) were the major corps in the Luoyang Basin during the Neolithic period, where rainfed agriculture practiced. Rice(Oryza sativa), wheat(Triticum aestivum), and soybean(Glycine max) were cultivated later. In the Erlitou period, five crops were grown in this area. The diversification of crops in small sites occurred earlier than in large sites. Small sites had higher proportions of rice and wheat than did large sites in the Erlitou period, reflecting the differences in site function. Plant remains taken from different landforms showed that the agricultural structures on alluvial plains were different from those on loess terraces. More crop species were grown on loess terraces than on alluvial plains from the Yangshao to the Longshan period, but the species and quantities of crops on the alluvial plains were greater in the Erlitou period. Environmental factors such as climate, landform, and hydrology are probably the main reasons for these patterns. The results demonstrated the effectiveness of charred plant remains analysis of small sites. More attention should be paid to small sites in future research.