DOI: 10.1016/j.quascirev.2017.02.008
Scopus记录号: 2-s2.0-85013018530
论文题名: The validity of the Asteraceae: Poaceae fossil pollen ratio in discrimination of the southern African summer- and winter-rainfall zones
作者: Fitchett J.M. ; Bamford M.K.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2017
卷: 160 起始页码: 85
结束页码: 95
语种: 英语
英文关键词: Climate dynamics
; Data analysis
; Pollen
; Precipitation indices
; Quaternary
; Seasonality
; Southern Africa
Scopus关键词: Data reduction
; Location
; Storms
; Climate dynamics
; Pollen
; Precipitation indices
; Quaternary
; Seasonality
; Southern Africa
; Rain
; angiosperm
; climate variation
; data assimilation
; fossil record
; Pleistocene
; pollen
; precipitation assessment
; proxy climate record
; Quaternary
; seasonality
; topography
; Drakensberg
; Asteraceae
; Poaceae
英文摘要: Situated at the transition between the mid-latitudes and the sub-tropics, southern Africa has a climatic dichotomy between winter- and summer-rainfall zones (WRZ and SRZ). The latitudinal extent of the winter-rainfall zone during the late Pleistocene remains contentiously debated within the regional palaeoscience literature. One method posited to reflect the seasonality of rainfall at a given location throughout late Pleistocene records for South Africa is the ratio of fossil pollen Asteraceae to Poaceae. Although adopted for a range of southern African locations, the veracity of this method has not been tested. This study explores the extent to which this ratio can discriminate between the SRZ and WRZ, and the extent of the region subject to fluctuation during the late Quaternary. The ratio is found to successfully discriminate regions which are, and would have remained during the past 20,000 cal yr BP, in the SRZ and WRZ exclusively. On the basis of these statistics, it appears that WRZ conditions can be inferred from ratio scores >0.6 and SRZ conditions from scores <0.2. For locations situated between 28 and 32°S, no clear discrimination can be made. It is argued that this region has been subjected to fluctuations in the latitudinal extent of the Westerlies and consequently in the influence of mid-latitude cyclones over the past 20,000 cal yr BP, with the rugged topography of the Drakensberg Mountains resulting in a complex precipitation climatology controlled by both frontal and orographic uplift. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59291
Appears in Collections: 过去全球变化的重建
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作者单位: Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa; School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa
Recommended Citation:
Fitchett J.M.,Bamford M.K.. The validity of the Asteraceae: Poaceae fossil pollen ratio in discrimination of the southern African summer- and winter-rainfall zones[J]. Quaternary Science Reviews,2017-01-01,160