DOI: 10.1016/j.palaeo.2016.03.001
论文题名: 50,000 years of vegetation and climate change in the southern Namib Desert, Pella, South Africa
作者: Lim S. ; Chase B.M. ; Chevalier M. ; Reimer P.J.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 451 起始页码: 197
结束页码: 209
语种: 英语
英文关键词: Climate reconstruction
; Late Quaternary
; Namib Desert
; Pollen
; Rock hyrax middens
; South Africa
英文摘要: This paper presents the first continuous pollen record from the southern Namib Desert spanning the last 50,000 years. Obtained from rock hyrax middens found near the town of Pella, South Africa, these data are used to reconstruct vegetation change and quantitative estimates of temperature and aridity. Results indicate that the last glacial period was characterised by increased water availability at the site relative to the Holocene. Changes in temperature and potential evapotranspiration appear to have played a significant role in determining the hydrologic balance. The record can be considered in two sections: 1) the last glacial period, when low temperatures favoured the development of more mesic Nama-Karoo vegetation at the site, with periods of increased humidity concurrent with increased coastal upwelling, both responding to lower global/regional temperatures; and 2) the Holocene, during which time high temperatures and potential evapotranspiration resulted in increased aridity and an expansion of the Desert Biome. During this latter period, increases in upwelling intensity created drier conditions at the site.Considered in the context of discussions of forcing mechanisms of regional climate change and environmental dynamics, the results from Pella stand in clear contrast with many inferences of terrestrial environmental change derived from regional marine records. Observations of a strong precessional signal and interpretations of increased humidity during phases of high local summer insolation in the marine records are not consistent with the data from Pella. Similarly, while high percentages of Restionaceae pollen has been observed in marine sediments during the last glacial period, they do not exceed 1% of the assemblage from Pella, indicating that no significant expansion of the Fynbos Biome has occurred during the last 50,000 years. These findings pose interesting questions regarding the nature of environmental change in southwestern Africa, and the significance of the diverse records that have been obtained from the region. © 2016 Elsevier B.V.. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68447
Appears in Collections: 过去全球变化的重建
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作者单位: Centre National de la Recherche Scientifique, UMR 5554, Université de Montpellier, Institut des Sciences de l'Evolution de Montpellier, Bat. 22 CC061, Place Eugène Bataillon, Montpellier cedex 5, France; School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
Recommended Citation:
Lim S.,Chase B.M.,Chevalier M.,et al. 50,000 years of vegetation and climate change in the southern Namib Desert, Pella, South Africa[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,451