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（日本北部）的高分辨率植被和气候档案具有至关重要的意义：(1)由于晚第四纪气候变暖和海平面上升对该岛屿地区产生了巨大影响，因此对更好地理解现代环境变化具有重要意义；（ii）了解环境因子对沿海地区土地利用策略和人口的作用；（iii）验证区域气候模式的预测潜力。以往的古环境研究表明，日本北部和季风亚洲其他地区的冰川后气候和植被发育模式不同。为了研究这些区域差异及其背景机制，本研究利用北海道北部（热本岛）和南部（神田半岛）的两个连续沉积档案，分别覆盖了近17000年和14000年。该项目的主要目标包括：(i)生成高分辨率的花粉化石记录，用于（ii）详细重建日本北部区域植被和气候发展的时空格局，以便将结果用于（iii）与东亚季风区其他地区冰期后气候演变的相关性；（vi）重建长期的生活环境和人与环境的相互作用；(v)为数值气候和植被模式的测试结果提供定量信息。孢粉学调查将辅以各种沉积学（例如微相、地球化学）和生物学（例如硅藻）分析，这些分析有助于查明环境条件的短期变化（例如火山爆发、海啸）。广泛的放射性碳定年和微相分析将为分析的沉积档案提供精确的年代控制。为了与北海道的考古序列直接相关，主要文化层的年龄将根据无水库陆生植物大化石（水果和种子）的放射性碳定年来确定。本项目范围内所需的考古数据将来自日本政府运营的考古数据库，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.