Paleoclimate history and its influence on ecosystem changes and human occupation/abandonment of East African high mountain ecosystems in Ethiopia

埃塞俄比亚东非高山生态系统的古气候历史及其对生态系统变化和人类占领/废弃的影响

• 批准号: 451220720
• 负责人: Professor Dr. Michael Zech
• 金额: --
• 依托单位: Professur für Physische Geographie mit Schwerpunkt Paläoumweltforschung
• 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/451220720?language=en
• 关键词: Paleoclimate; history; its; influence; ecosystem

Periods of human occupation and abandonment in the afroalpine region of the Bale Mountains, Ethiopia, were very likely triggered at least partly by paleoclimate changes. This is suggested by first results obtained from a previous project. Within this follow-up project proposal, which accompanies the DFG Research Unit 2358 ‘The Mountain Exile Hypothesis’, it is therefore planned to contribute to the paleoclimate reconstruction of the study area. The results will be essential for complementing the full picture of ‘climate-human-environment interactions’ of the Research Unit 2358 and they will be interpreted in close interdisciplinary cooperation with the colleagues from the fields of archeology, pedology, paleoecology and glaciology.Work Package (WP) 1 will continue monitoring the isotopic signature of modern-day precipitation in order to better understand the modern-day atmospheric circulation patterns including their specific isotopic signatures affecting the Bale Mountains. This is justified given that isotope records in East Africa are usually interpreted in terms of ‘precipitation amount’. The actually responsible effect might, however, rather be a ‘source effect’. This is of utmost importance for the correct paleoclimatic interpretation of δ2H and δ18O records from the Bale Mountains as well as of other East African paleoclimate isotope records. WP2 aims at establishing a multi-proxy paleoclimate isotope record. The rationale here is that the so far established δ2Hn-alkane and δ18Osugar records from Lake Garba Guracha may not be unambiguously attributable to aquatic versus terrestrial sources. In order to test this, hyrax middens as unambiguous terrestrial archives (in close collaboration with Subproject P3 Paleoecology of the Research Unit 2358) as well as diatoms and the aquatic-derived biomarker dinosterol will be investigated. Last but not least, we will continue investigating sedimentary archives in close collaboration with the Subprojects P2 Anthrosols and P3 Paleoecology of the Research Unit 2358. Within WP3 we will analyze already retrieved and dated sediment and peat cores from the Wergoba Valley, the Sanetti Plateau and the Harena Forest in order to check for spatial and temporal heterogeneity of our paleoclimate proxy signals; within WP4 we will investigate presumably pre-LGM (last glacial maximum) and LGM cores from Lake Cheleleka in the close-by Arsi Mountains. Last but not least, WP5 will focus at highest possible resolution on the topmost core sections of Garba Guracha, for which human occupation/abandonment is most obviously confirmed by P1 Archeology, P2 Anthrosols and P3 Paleoecology.

埃塞俄比亚贝尔山脉的非洲高山地区的人类占领和遗弃时期很可能至少部分是由古气候变化引发的，这一点是从该后续项目提案中获得的初步结果得出的。 DFG研究单位2358“山地流放假说”，因此计划为研究区域的古气候重建做出贡献，其结果对于补充全貌至关重要。研究单位 2358 的“气候-人类-环境相互作用”，并将与来自考古学、土壤学、古生态学和冰川学领域的同事密切的跨学科合作来解释它们。工作包 (WP) 1 将继续监测现代降水，以便更好地了解现代大气环流模式，包括影响贝尔山脉的特定同位素特征，鉴于东非的同位素记录通常是合理的。然而，实际的影响可能是“源效应”，这对于正确解释贝尔山脉和其他东部地区的 δ2H 和 δ18O 记录至关重要。非洲古气候同位素记录 WP2 旨在建立多代理古气候同位素记录，其基本原理是迄今为止已建立的 δ2Hn-烷烃和加尔巴古拉查湖的 δ18Osugar 记录可能无法明确归因于水生与陆地来源。为了测试这一点，蹄兔贝丘作为明确的陆地档案（与研究单位 2358 的 P3 古生态学子项目密切合作）以及硅藻和水生来源。最后但并非最不重要的一点是，我们将继续研究衍生生物标志物地甾醇。与研究单位 2358 的 P2 Anthrosols 和 P3 古生态学子项目密切合作，建立沉积档案。在 WP3 中，我们将分析来自 Wergoba 山谷、Sanetti 高原和 Harena 森林的已检索并测年的沉积物和泥炭岩芯，以检查空间以及我们的古气候代理信号的时间异质性；在 WP4 中，我们将研究来自湖泊的末次盛冰期之前和末次盛冰期的核心。最后但并非最不重要的一点是，WP5 将以尽可能高的分辨率聚焦于加尔巴古拉查 (Garba Guracha) 的最顶层核心部分，P1 考古学、P2 人类溶胶和 P3 古生态学最明显地证实了人类的占领/遗弃。