The primary study on landscape reconstruction and the position of the subsistence in the society from the Yayoi period to Medieval times

本研究旨在阐明冈山平原从弥生时期到中世纪时期的生存（农业）与社会之间具有地理统一性的联系的属性。在重建景观的过程中，我们运用了地史材料、考古资源和植物遗迹。考虑到土地利用模式的转变，特别是定居点和农业用地的转变，以及定居点和稻田所在的地理特征，每个时期的景观都被重建了。寻找每个时期的景观特征是重建的目的。在弥生时代的早期阶段，在一些可居住的地区有小型定居点。从中期到后期，聚落数量增加，形成冲积平原。在弥生时期，农业技术的改进和耕地面积的扩大使生产力得以提高，人口增长得以保持。通过重建的景观可以识别平原上两个地区聚落格局的差异。环境限制可能导致了模式上的差异。人们认识到聚落格局的差异影响着社会结构，这对研究弥生晚期至古坟时期提高地域差异的背景具有重要意义。我们从考古资源和地史资料中发现，平安时代到中世纪的景观是由土地重新划分制度形成的，这导致了现代景观的形成。这一时期的景观表明，土地利用模式受社会管理制度的支配，而弥生时期的土地利用受拓扑学的影响。

This study aims to elucidate the attributes of an association between the subsistence (farming) and society from the Yayoi period to Medieval period on the Okayama Plains, having geographical unity.Reconstructing the landscape, we applied geo-historic materials as well as archaeological resources and plant remains, to the method. The landscape in each period has been reconstructed with considering the transition of the pattern of land use, in particular land for settlements and farming, and with considering the geographical features in which the settlements and paddies were located. Seeking the characteristics of the landscape in each period has been intended by the reconstruction.In the early stage of the Yayoi period small settlements lay on a few habitable areas available. From the middle to the late stage, the number of settlement rose that alluvial plains were formed. It is identified that the improvement of agricultural technology and the expansion of arable areas enabled to yield higher productivity and to maintain the population growth during the Yayoi period. Differences in settlement pattern between two areas on the plains can be identified by the reconstructed landscape. The environmental constrains might have caused the differences in the pattern. The differences in the settlement pattern are recognized to influence the social structure, which is significant to study the background of raising regional distinctions from the late stage of the Yayoi to the Kofun period.We explored from archaeological resources and geo-historic materials that the landscape from the Heian period to Medieval times were formed by Zyori-sei, land rezoning system, which led to the landscape in the modern age. The landscape in this period indicates that the land use pattern was ruled by the social management system whereas the land use in the Yayoi period was influenced by topology.