Knowledge Resource Center for Ecological Environment in Arid Area
| 末次冰消期以来黄土高原地区气候变化及其环境效应研究 | |
| 其他题名 | Climate change of Loess Plateau since Last Deglacial and its environmental effect |
| 张贵林 | |
| 出版年 | 2018 |
| 学位类型 | 博士 |
| 导师 | 李小强 |
| 学位授予单位 | 中国科学院大学 |
| 中文摘要 | 本文选择黄土高原南部运城市盐湖、黄土高原北部沙漠/黄土过渡带榆林市河口、白河庙泥炭、季风边缘区赤峰市玉龙湖四个地区的湖沼沉积作为研究材料，基于种子、炭屑、陆生植物残体等可靠测年材料建立的年代序列，结合高分辨率花粉、炭屑指标分析，重建了黄土高原地区以及季风边缘区末次冰消期以来高分辨率植被演替历史和气候环境变化过程。同时查看晚全新世人类活动对当地植被的影响，验证花粉记录是否可以真实的反映当地植被和气候变化。另外，通过与北方东亚季风区其他高分辨率气候记录的对比，来探索影响研究区气候变化的驱动机制。在重建黄土高原地区气候变化的基础上，结合沙漠/黄土过渡带、运城盆地仰韶到夏商时期（7-3 ka BP）考古遗址点数量及空间地理分布信息，建立遗址点的时空变化格局。由此来探讨全新世适宜期和重要气候转型期气候变化对人类活动的影响，同时进一步分析不同地区人类活动对极端干旱气候事件响应模式存在差异的原因。研究结果显示：（1）盐湖（20.7 m）、河口（4.5 m）、白河庙（6.19 m）、玉龙湖（3.86 m）岩芯的底部年代分别为36.7 ka BP、14 ka BP、6 ka BP、15 ka BP，其中盐湖、白河庙沉积稳定且连续，沉积速率快，符合高分辨率花粉样品分析的要求，而河口泥炭沉积在13-7.3 ka BP期间存在较长时间段的沉积间断，所以采用7.3 ka BP作为该沉积序列的底部年代。另外，使用深度——年龄转换模式建立的玉龙湖沉积10 ka BP以来的年代序列，可能存在一定误差；（2）末次冰消期15 ka BP以来黄土高原地区和季风边缘区植被类型由草原、森林草原逐渐向中全新世（8-4.2 ka BP）典型草原、落叶阔叶林转变，而晚全新世4.2 ka BP后植被明显退化。植被类型变化表明末次冰消期以来气候条件明显改善，总体上呈增温增湿趋势，在中全新世降水和温度均达到最大值，晚全新世气候逐渐冷干。在以上气候变化的大背景下，运城盐湖地区还叠加多次快速变化的气候事件，如YD、8.9 ka、8.2 ka、5.3 ka、4.3 ka、2.8 ka事件。末次冰消期以来气候变化的总体趋势主要受北半球夏季太阳辐射驱动。而东亚夏季风强度直到中全新世才达到最大值，明显滞后于北半球太阳辐射达到最大值的时间（10 ka BP），这可能与北半球高纬冰量的调控作用有关；（3）盐湖沉积高分辨率炭屑记录表明，炭屑浓度受气候变化、植被类型、沉积条件、可燃生物量、人类活动等多种因素影响，在使用该指标时需综合考虑以上因素。结合盐湖炭屑和花粉指标，证明2.8 ka BP以来，人类活动对当地植被造成显著的影响，以藜科花粉含量占绝对优势的花粉谱也揭示了植被的响应过程；（4）中全新世气候温暖湿润，适宜的气候和良好的生态环境有利于黄土高原南部运城盆地和北部沙漠/黄土过渡带人类活动的扩张，奠定了新石器时代中晚期考古学文化繁荣发展的基础。龙山文化遗址点最为丰富、空间分布范围最大；（5）黄土高原地区区域气候特征、地形地貌、水资源条件等是影响史前农业经济体系和人类活动的重要因素。4.2 ka BP干旱事件之后，沙漠/黄土过渡带遗址点明显减少，人类活动大幅衰退。但运城盆地并未受到气候事件的明显影响，人类活动持续发展，并逐渐成为华夏文明中心地区之一。 |
| 英文摘要 | Lake sediments were drilled from Salt Lake and Yulong Lake, located respectively in Yuncheng City of southern Loess Plateau and Chifeng City in East Asian summer monsoon boundary. Peat sediments were obtained from Hekou and Baihemiao area of Yulin City in desert/loess transition belt. Seeds, charcoal and plant remains were selected as AMS 14C dating materials for producing reliable time sequences, and then both pollen and micro-charcoal proxies were used for reconstructing high resolution vegetation succession and paleoclimate change process since the last deglaciation. At the same time, pollen and micro-charcoal were used for examining impacts of human activities on the local vegetation, demonstrating that whether pollen spectrums actually reflected vegetation and climate of local area or a large region. Research results in present study were compared with other high resolution climate records in northern China for exploring the forcing mechanism of climate change. Based on climate reconstruction of Loess Plateau, archaeological sites from Yangshao culture to Xia and Shang dynasty (7-3 ka BP) were counted, and their geographic spatial distribution information were also analyzed. The relationship of climate change and human activities were discussed, and the reason of presenting different model of human activities when facing extreme dry climate event were analyzed. The results show that: (1) Calibrated AMS 14C dates at the bottom of the 20.7 m long Salt Lake core, 4.5 m long Hekou Peat core, 6.19 m long Baihemiao Peat core and 3.86 m Yulong Lake core were 36.7 ka BP, 14 ka BP, 6 ka BP and 15 ka BP respectively. Sediments of the Slat Lake and Baihemiao Peat were stable and continuous, and met requirement of high resolution pollen analysis. Long sedimental hiatus occurred from 13 to 7 ka BP in Hekou Peat, therefore 7.3 ka BP was considered as the reliable earliest date. In addition, there might be errors exsiting in dates of the Yulong Lake core reconstructed by depth and age transformational model since 10 ka BP. (2) Vegetation types were steppe or forest steppe in the last deglaciation, and then gradually become moisture steppe or temperate deciduous broad-leaved forest in middle Holocene. Vegetation degenerated since late Holocene. Vegetation succession indicated climate condition evidently improved from 15 ka BP. Thermal and moisture condition gradually increased, and reached their maximum values between 8 and 4.2 ka BP. Climate presented dry trend since 4.2 ka BP. Along with this background of climate change, several extreme climate events presented in Salt Lake area, such as YD, 8.9 ka, 8.2 ka, 5.3 ka, 4.3 ka, 2.8 ka. The main climate change trend was controlled by summer solar irradiation of northern hemisphere. However, our results show East Asian summer monsoon reached its highest strength in middle Holocene, distinctly lagged to the timing of summer solar irradiation peak in northern hemisphere 10 ka BP. The reason was that large scale ice sheet volume of high latitude in northern hemisphere still existed and modulate climate in early Holocene.(3) High resolution micro-charcoal record of Salt Lake testified that, micro-charcoal density were affected by several factors, including climate change, vegetation type, deposition condition, flammable biomass and human activities. When it was used in paleoclimate research, all of these factors should be considered. Pollen and micro-charcoal record demonstrated that vegetation was severely changed by human activities since 2.8 ka BP in Salt Lake. Therefore, pollen combination was not really present real vegetation type and climate change. (4) Climate was warm and moist in middle Holocene. Optimum climate and good ecological environment facilitated human activities development in middle and late Neolithic Age. Archaeological sites were largest in number, and most widely distributed in Longshan Culture, presenting the most flourishing human activities. (5) When the 4.2 ka BP extreme climate event occurred, ancient sites decreased distinctly and human activities widely declined in desert/loess transition zone. In contrast, climate fluctuation did not make a distinct effect on human activities in the Yuncheng Basin, where archaeological culture continued to develop and finally become a civilization center in China history. The different models present in southern and northern Loess Plateau were affected by geographical location, topography, water resources, ecological environment and agriculture economic system. |
| 中文关键词 | 末次冰消期以来 ; 黄土高原地区 ; 气候变化 ; 环境效应 ; 人类活动 |
| 英文关键词 | the Last Deglaciation and Holocene Loess Plateau pollen vegetation succession climate change environmental effects human activities |
| 语种 | 中文 |
| 国家 | 中国 |
| 来源学科分类 | 地球生物学 |
| 来源机构 | 中国科学院古脊椎动物与古人类研究所 |
| 资源类型 | 学位论文 |
| 条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/288097 |
| 推荐引用方式 GB/T 7714 | 张贵林. 末次冰消期以来黄土高原地区气候变化及其环境效应研究[D]. 中国科学院大学,2018. |
| 条目包含的文件 | 条目无相关文件。 | |||||
| 个性服务 |
| 推荐该条目 |
| 保存到收藏夹 |
| 导出为Endnote文件 |
| 谷歌学术 |
| 谷歌学术中相似的文章 |
| [张贵林]的文章 |
| 百度学术 |
| 百度学术中相似的文章 |
| [张贵林]的文章 |
| 必应学术 |
| 必应学术中相似的文章 |
| [张贵林]的文章 |
| 相关权益政策 |
| 暂无数据 |
| 收藏/分享 |
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
