气候变化领域集成服务门户(CCPortal): Palaeochannels of Australia's Riverine Plain - Reconstructing past vegetation environments across the Late Pleistocene and Holocene

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DOI	10.1016/j.palaeo.2019.109533
	Palaeochannels of Australia's Riverine Plain - Reconstructing past vegetation environments across the Late Pleistocene and Holocene
	Forbes M.; Jankowski N.; Cohen T.; Hopf F.; Mueller D.; Bird M.; Haberle S.; Jacobs Z.
发表日期	2020
ISSN	0031-0182
卷号	545
英文摘要	Riverine Plain palaeochannels record periods of fluvial activity for Late Pleistocene southeastern Australia. In an attempt to develop a more detailed palaeoenvironmental record for this semi-arid region, we investigate the fine overbank sediments of the palaeochannel fill that cap and underlie the coarser-grained fluvial channel sands of the Tombullen (41–29 thousand years (ka) ago) and the Yanco (29–18 ka) phases. New single grain Optically Stimulated Luminescence (OSL) age determinations for the overlying palaeochannel fills suggest an overall slowing of sedimentation rates since the phase of fluvial activity in late Marine Isotope Stages 3 and 2. δ13CTOC data for the palaeochannel fill sediments range between −28‰ and −22‰, implying variable C4 contributions (0–40%) to a predominantly C3 vegetation mosaic. Modelled C4 abundance for the last 50 thousand years (kyr) decreased from 40% to 10% at around 40 ka with predicted representation remaining low towards the Last Glacial Maximum (LGM). Post LGM C4 grasses are seen to expand to 30–40% and sustained through the Holocene. Pollen preservation is restricted to the upper two metres of the cores, with the distribution showing shifts in dominance from Poaceae and Asteraceae to Eucalyptus up sequence. Increasing Eucalyptus/Poaceae ratios correspond with increasing C4 abundance suggesting that as woodland expanded in the Holocene the associated decreasing grass component shifted from C3 to C4. However, some evidence for the persistence of Poaceae and/or Asteraceae dominance argues that the likely shift from C3 to C4 grasses during the Holocene was in places independent of expanding woodland. Bulk sediment elemental ratios reveal wetting and drying cycles during the deposition of the overbank deposits. While these traits appear to be a product of local sedimentation changes, rather than regional climate, our model of C4 contraction and subsequent expansion across the last 50 kyr is likely reflecting changing summer monsoon intensity and its effects on regional aridity. © 2019 Elsevier B.V.
英文关键词	C4 grasses; Carbon isotopes; Last Glacial Maximum; Murray Darling Basin; Optically stimulated luminescence; Palaeochannels
语种	英语
scopus关键词	C4 plant; carbon isotope; Last Glacial Maximum; luminescence dating; paleochannel; Pleistocene; reconstruction; vegetation cover; wetting-drying cycle; Australia; Murray-Darling Basin; New South Wales; Riverine Plain; Yanco; Asteraceae; Eucalyptus; Poaceae
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150559
作者单位	ARC Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong, NSW, Australia; GeoQuest Research Centre, University of Wollongong, Wollongong, NSW, Australia; School of Earth, Atmosphere and Life Sciences, University of WollongongNew South Wales 2522, Australia; Institute of Earth and Environmental Sciences, Albert-Ludwigs-Universitdat, Freiburg, Germany; Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW, Australia; School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, Australia; College of Asia and the Pacific, Australian National University, Canberra, Australian Capital Territory, Australia; Centre for Tropical Environmental and Sustainability Science, College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
推荐引用方式 GB/T 7714	Forbes M.,Jankowski N.,Cohen T.,et al. Palaeochannels of Australia's Riverine Plain - Reconstructing past vegetation environments across the Late Pleistocene and Holocene[J],2020,545.
APA	Forbes M..,Jankowski N..,Cohen T..,Hopf F..,Mueller D..,...&Jacobs Z..(2020).Palaeochannels of Australia's Riverine Plain - Reconstructing past vegetation environments across the Late Pleistocene and Holocene.Palaeogeography, Palaeoclimatology, Palaeoecology,545.
MLA	Forbes M.,et al."Palaeochannels of Australia's Riverine Plain - Reconstructing past vegetation environments across the Late Pleistocene and Holocene".Palaeogeography, Palaeoclimatology, Palaeoecology 545(2020).