干旱区生态环境知识资源中心(Arid): Holocene Hydroclimate Variability and Vegetation Response in the Ethiopian Highlands (Lake Dendi)

Arid

DOI	10.3389/feart.2020.585770
	Holocene Hydroclimate Variability and Vegetation Response in the Ethiopian Highlands (Lake Dendi)
	Jaeschke, Andrea; Thienemann, Matthias; Schefuss, Enno; Urban, Jonas; Schaebitz, Frank; Wagner, Bernd; Rethemeyer, Janet
通讯作者	Jaeschke, A (corresponding author), Univ Cologne, Inst Geol & Mineral, Cologne, Germany.
来源期刊	FRONTIERS IN EARTH SCIENCE
EISSN	2296-6463
出版年	2020
卷号	8
英文摘要	Northern Africa's past climate is characterized by a prolonged humid period known as the African Humid Period (AHP), giving origin to the Green Sahara and supporting human settlements into areas that are now desert. The spatial and temporal extent of climate change associated with the AHP is, however, subject to ongoing debate. Uncertainties arise from the complex nature of African climate, which is controlled by the strength and interactions of different monsoonal systems, resulting in meridional shifts in rainfall belts and zonal movements of the Congo Air Boundary. Here, we examine a similar to 12,500-years record of hydroclimate variability from Lake Dendi located in the Ethiopian highlands based on a combination of plant-wax-specific hydrogen (delta D) and carbon (delta C-13) isotopes. In addition, pollen data from the same sediment core are used to investigate the response of the regional vegetation to changing climate. Our delta D record indicates high precipitation during peak AHP (ca. 10 to 8 ka BP) followed by a gradual transition toward a drier late Holocene climate. Likewise, vegetation cover changed from predominant grassland toward an arid montane forest dominated by Juniperus and Podocarpus accompanied by a general reduction of understory grasses. This trend is corroborated by delta C-13 values pointing to an increased contribution of C-3 plants during the mid-to late Holocene. Peak aridity occurred around 2 ka BP, followed by a return to a generally wetter climate possibly linked to enhanced Indian Ocean Monsoon strength. During the last millennium, increased anthropogenic activity, i.e., deforestation and agriculture is indicated by the pollen data, in agreement with intensified human impact recorded for the region. The magnitude of delta D change (40 parts per thousand) between peak wet conditions and late Holocene aridity is in line with other regional delta D records of East Africa influenced by the CAB. The timing and pace of aridification parallels those of African and Indian monsoon records indicating a gradual response to local insolation change. Our new record combining plant-wax delta D and delta C-13 values with pollen highlights the sensitive responses of the regional vegetation to precipitation changes in the Ethiopian highlands.
英文关键词	African Humid Period Ethiopia Lake Dendi n-alkanes δ D δ C-13 pollen
类型	Article
语种	英语
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:000599409700001
WOS关键词	SEA-SURFACE TEMPERATURES ; LATE PLEISTOCENE DESICCATION ; AFRICAN HUMID PERIOD ; ALKANE DELTA-D ; CLIMATE EVOLUTION ; NORTHERN AFRICA ; SEDIMENT RECORD ; EAST-AFRICA ; RAINFALL ; NILE
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/348861
作者单位	[Jaeschke, Andrea; Thienemann, Matthias; Wagner, Bernd; Rethemeyer, Janet] Univ Cologne, Inst Geol & Mineral, Cologne, Germany; [Schefuss, Enno] Univ Bremen, MARUM Ctr Marine Environm Sci, Bremen, Germany; [Urban, Jonas; Schaebitz, Frank] Univ Cologne, Inst Geog Educ, Cologne, Germany
推荐引用方式 GB/T 7714	Jaeschke, Andrea,Thienemann, Matthias,Schefuss, Enno,et al. Holocene Hydroclimate Variability and Vegetation Response in the Ethiopian Highlands (Lake Dendi)[J],2020,8.
APA	Jaeschke, Andrea.,Thienemann, Matthias.,Schefuss, Enno.,Urban, Jonas.,Schaebitz, Frank.,...&Rethemeyer, Janet.(2020).Holocene Hydroclimate Variability and Vegetation Response in the Ethiopian Highlands (Lake Dendi).FRONTIERS IN EARTH SCIENCE,8.
MLA	Jaeschke, Andrea,et al."Holocene Hydroclimate Variability and Vegetation Response in the Ethiopian Highlands (Lake Dendi)".FRONTIERS IN EARTH SCIENCE 8(2020).