Reconstructing Holocene landscape development in Mongolia influenced by climate and pastoralism, based on geomorphological archives

基于地貌档案重建受气候和畜牧业影响的蒙古全新世景观发展

• 批准号: 429299280
• 负责人: Professor Dr. Manfred Anton Frechen
• 金额: --
• 依托单位: Leibniz-Institut für Angewandte Geophysik (LIAG)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/429299280?language=en
• 关键词: Reconstructing; Holocene; landscape; development; Mongolia

The key question of this project, i.e., since when and to what extent humans have influenced the vegetation pattern in the semihumid to arid forest steppe and steppe regions of Mongolia, has not yet been finally resolved. The archeological record provided by graves and sacral buildings only starts with the Bronze Age (3.5 ka BP). At that time, the nomadic lifestyle, including the whole spectrum of herd animals, was already fully established. However, the preceding period of the transition from the lifestyle of hunters and gatherers to stockbreeding is poorly documented, as artefacts of this period are rare. This project is based on the hypothesis that the development of pastoralism since the end of the Neolithic period led to a substantial change in the vegetation, which in turn triggered an intensification of geomorphological processes. In this project, we will develop and apply an innovative scientific approach that will allow us to identify the spatial and temporal patterns of the onset of human-induced landscape changes at local and regional scale. The approach will include a combination of geomorphological-pedological field and laboratory analysis, numeric dating, charcoal and biomarker analyses. The involved geomorphological-pedological methods are based on the following causal chain: Human activities such as woodcutting, fire-setting and wood pasture caused reduction of forest area and degradation of steppe vegetation by overgrazing. These anthropogenic impacts on the landscape resulted in increased soil erosion, as well as fluvial and eolian sediment redistribution. This causal chain led to a strikingly extensive distribution of stratified sediments in this landscape, containing organic layers, paleosols and charcoal. These sediments represent excellent archives for the reconstruction of the Holocene geomorphodynamics and their chronological course in this landscape. They will be the key study objects of this project. Direct evidence for the first occurrence of domestic livestock and corresponding pastoral economy will be obtained from the analysis of lipid biomarkers. In particular, fecal steroids that are preserved as stable compounds in paleosols and sediments, will serve as indicators of the local presence of relevant animal species such as horse, yak, cattle, sheep and goat.The successful implementation of the intended combination of geomorphological, pedological and geochemical methods will also contribute an important new approach to the identification of anthropogenic signals in paleoclimate reconstructions. This contribution will be highly relevant, as the existing uncertainties in the reconstruction of the late Holocene paleoclimatic development of Mongolia derive mainly from the interference of climatic and anthropogenic signals in the proxy data that are hardly separable by existing methods.

该项目的关键问题，即，由于人类在何时何地影响了蒙古森林草原和草原地区的植被模式，因此尚未得到最终解决。坟墓和萨克拉建筑提供的考古记录仅始于青铜时代（3.5 ka bp）。当时，游牧生活方式，包括整个牛群动物，已经完全确立。但是，从猎人和收集者的生活方式过渡到库存繁殖的前一个时期的文献很少，因为这一时期的人工制品很少。该项目基于以下假设：自新石器时代结束以来，牧民的发展导致植被发生了实质性变化，这反过来又引发了地貌过程的强化。在这个项目中，我们将开发并采用一种创新的科学方法，使我们能够确定当地和区域规模下人类引起的景观变化的空间和时间模式。该方法将包括地貌学领域和实验室分析，数字约会，木炭和生物标志物分析的结合。所涉及的地貌理学方法基于以下因果链：诸如木刻，火灾和木牧场之类的人类活动导致森林面积的减少和草原植被的降解，从而过度覆盖了草原植被。这些人为影响对景观的影响导致土壤侵蚀增加，以及河流和Eolian沉积物的重新分布。这种因果链导致了该景观中分层沉积物的广泛分布，其中含有有机层，古质质量和木炭。这些沉积物代表了重建全新世地质动力学及其在这种景观中的年代课程的绝佳档案。它们将是该项目的关键研究对象。从脂质生物标志物的分析中，将获得国内牲畜和相应的田园经济首次出现的直接证据。特别是，在古化合物和沉积物中保存为稳定化合物的粪便将作为当地存在的指标，例如马，牛，牛，牛，绵羊和山羊。这项贡献将是高度相关的，因为蒙古晚期全新世古气候发展的现有不确定性主要源于代理数据中气候和人为信号的干扰，而代理数据几乎无法通过现有方法分离。