Abrupt vegetation change after the Late Quaternary megafaunal extinction in southeastern Australia


Autoria(s): Lopes dos Santos, Raquel A; de Deckker, Patrick; Hopmans, Ellen C; Magee, John W; Mets, Anchelique; Sinninghe Damsté, Jaap S; Schouten, Stefan
Cobertura

MEDIAN LATITUDE: -36.059939 * MEDIAN LONGITUDE: 138.413681 * SOUTH-BOUND LATITUDE: -36.960700 * WEST-BOUND LONGITUDE: 137.406500 * NORTH-BOUND LATITUDE: -29.121914 * EAST-BOUND LONGITUDE: 147.052866 * DATE/TIME START: 2003-02-20T19:33:00 * DATE/TIME END: 2003-02-20T19:33:00

Data(s)

21/11/2013

Resumo

A substantial extinction of megafauna occurred in Australia between 50 and 45 kyr ago, a period that coincides with human colonization of Australia. Large shifts in vegetation also occurred around this time, but it is unclear whether the vegetation changes were driven by the human use of fire-and thus contributed to the extinction event-or were a consequence of the loss of megafaunal grazers. Here we reconstruct past vegetation changes in southeastern Australia using the stable carbon isotopic composition of higher plant wax n-alkanes and levels of biomass burning from the accumulation rates of the biomarker levoglucosan from a well-dated sediment core offshore from the Murray-Darling Basin. We find that from 58 to 44 kyr ago, the abundance of plants with the C-4 carbon fixation pathway was generally high-between 60 and 70%. By 43 kyr ago, the abundance of C-4 plants dropped to 30% and biomass burning increased. This transient shift lasted for about 3,000 years and came after the period of human arrival and directly followed megafauna extinction at 48.9-43.6 kyr ago. We conclude that the vegetation shift was not the cause of the megafaunal extinction in this region. Instead, our data are consistent with the hypothesis that vegetation change was the consequence of the extinction of large browsers and led to the build-up of fire-prone vegetation in the Australian landscape.

Formato

application/zip, 3 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.823146

doi:10.1594/PANGAEA.823146

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Lopes dos Santos, Raquel A; de Deckker, Patrick; Hopmans, Ellen C; Magee, John W; Mets, Anchelique; Sinninghe Damsté, Jaap S; Schouten, Stefan (2013): Abrupt vegetation change after the Late Quaternary megafaunal extinction in southeastern Australia. Nature Geoscience, 6(8), 627-631, doi:10.1038/ngeo1856

Palavras-Chave #Acc rate A odd; Acc rate levogluc; Accumulation rate, levoglucosan; Accumulation rate, odd numbered n-alkanes; Age; AGE; Age, 14C AMS; Age, 14C calibrated; Age, dated; Age, dated standard deviation; Age, maximum/old; Age, minimum/young; Age, oxygen isotope; Age dated; Age max; Age min; Age model; Age std dev; A odd/sed; BIT; BP, one sigma; BP, two sigma; Branched and isoprenoid tetraether index; C27-29-31-33; C4 plant; Calculated; Calculated from UK'37 (Müller et al, 1998); d13C n-alkanes; delta 13C, n-alkanes; Depth; DEPTH, sediment/rock; Environment; Event; G. bulloides d13C; G. bulloides d18O; Globigerina bulloides, d13C; Globigerina bulloides, d18O; inferred from stable isotopes; Isotope ratio mass spectrometry; Latitude; LATITUDE; Levogluc/sed; Levoglucosan per unit sediment mass; Longitude; LONGITUDE; No; Number; Sea surface temperature, annual mean; SST (1-12); Sum odd numbered n-alkanes per unit sediment mass; vs. VPDB; Weighted mean C27-29-31-33, vs. VPDB
Tipo

Dataset