Postglacial climate variability at the northern limit of the East Asian monsoon and its impact on environments and humans in the Hokkaido region, northern Japan

来自北海道地区的高分辨率植被和气候档案（i）对于更好地理解现代环境变化至关重要，因为晚第四纪气候变暖和海平面上升对这个岛屿地区产生了巨大影响; ㈡了解环境因素对沿海地区土地利用战略和人口的作用;验证区域气候模式的预测潜力。以往的古环境研究表明，在日本北部和亚洲季风区的其他地区的冰后期气候和植被发展的不同模式。为了研究这些区域差异及其背景机制，本研究计划设计了两个连续的沉积档案，从北海道的北方（礼文岛）和南部（龟田半岛）的一部分，覆盖了最后一个世纪。分别是17,000年和14,000年。该项目的主要目标包括：（i）生成高分辨率的化石花粉记录，用于（ii）详细重建日本北方区域植被和气候发展的时空模式，以便将结果用于（iii）与东亚季风区其他部分的冰后期气候演变的相关性，（vi）重建随时间变化的生活环境和人类与环境的相互作用;（v）为测试气候和植被数值模式的结果提供定量信息。除孢粉学调查外，还将进行各种沉积学（如微相、地球化学）和生物学（如硅藻）分析，有助于查明环境条件的短期变化（如火山爆发、海啸）。广泛的放射性碳测年和微相分析将为所分析的沉积档案提供精确的年代控制。为了与来自北海道的考古序列直接相关，主要文化层的年龄将根据无化石的陆生植物宏体化石（果实和种子）的放射性碳测年来确定。该项目范围内所需的考古数据将来自日本政府管理的考古数据库以及德国和国际合作伙伴正在进行的考古研究项目。

High-resolution vegetation and climate archives from the Hokkaido region (North Japan) are of critical importance (i) for a better understanding of modern environmental changes because late Quaternary climate warming and sea level rise had a dramatic impact on this island region; (ii) for understanding the role of environmental factors on land use strategies and human populations in coastal regions and (iii) for validating prognostic potential of regional climate models. Previous palaeoenvironmental studies suggest different patterns of post-glacial climate and vegetation development in North Japan and other regions of Monsoon Asia. In order to investigate these regional differences and their background mechanisms, the current research project has been designed, which uses two continuous sedimentary archives from the northern (Rebun Island) and southern (Kameda Peninsula) part of Hokkaido covering the last ca. 17,000 and 14,000 years, respectively. The main objectives of the project include: (i) generating high-resolution fossil pollen records for (ii) detailed reconstruction of the spatio-temporal patterns of the regional vegetation and climate development in northern Japan in order to use the results for (iii) correlation with the post-glacial climate evolution in other parts of the East Asian monsoon domain, (vi) reconstructing the living environments and human-environmental interactions over time and (v) providing quantitative information for testing results of numerical climate and vegetation models. The palynological investigations will be supplemented by various sedimentological (e.g. microfacies, geochemical) and biological (e.g. diatom) analyses helpful for identification of short-term changes in environmental conditions (e.g. volcanic eruptions, tsunami). Extensive radiocarbon dating and microfacies analysis will provide a precise chronological control for the analysed sedimentary archives. To allow for direct correlation with the archaeological sequences from Hokkaido, the ages of the main cultural layers will be determined based on radiocarbon dating of reservoir-free terrestrial plant macrofossils (fruits and seeds). The archaeological data required within the scope of this project will be derived from the archaeological database run by the Japanese government and from ongoing archaeological research projects of the German and international cooperation partners.