Carbon isotope evidence for an abrupt reduction in grasses coincident with European settlement of Lake Eyre, South Australia

Bibliographic Data

ID12265256
AuthorsBeverly J Johnson (Quaternary Research Center and the School of Oceanography, University of Washington, Seattle WA 98195-7940, USA; Department of Geology, Bates College, Lewiston ME 04240, USA, corresponding author), Gifford H Miller (0000-0002-8225-2740, University of Colorado System), John W Magee (Australian National University), Michael K Gagan (0000-0002-8279-323X, Australian National University), Marilyn L Fogel (0000-0002-1176-3818, Geophysical Laboratory), Paul D Quay (0000-0001-5147-0289, University of Washington)
Year2005
Volume15
Issue6
Pages888-896
Publication date2005-08-19
Open AccessYes
TypeARTICLE
VenueThe Holocene (JOURNAL)
Journal identifiersISSN: 0959-6836 • E-ISSN: 1477-0911
PublisherSAGE Publishing (PUBLISHER • US)
DOI10.1191/0959683605hl861ra
OpenAlexW2018025789
LanguageEN
Citations received5
References cited38

Stable carbon isotopes in emu eggshell (EES) reflect emu diets and consequently the vegetation available for food sources. At Lake Eyre, South Australia, isotopic data suggest that there has been a rapid and dramatic change in vegetation at some point over the last 200 years when compared with the rest of the Holocene. The proportion of C 4 plants in emu diets has been reduced by approximately 20% in response to an overall shift in C 4 /C3 biomass at Lake Eyre. Isotopic measurement of the dominant plants at Lake Eyre indicate that the C 4 plants are almost entirely comprised of grasses and some chenopods and the C3 plants are comprised of the dominant chenopods, shrubs, trees and forbs. We surmise that the -20% reduction in C 4 plant biomass reflects landscape degradation and loss of C 4 grasses resulting from a combination of effects, including overgrazing by both introduced (e.g., sheep, cattle and rabbits) and native (e.g., kangaroos) animals, increasing drought and a change in fire regime beginning in the late 1890s. The magnitude of vegetation change that occurred in the last 200 years is as great as that which occurred during the last glacial maximum (-21 000 years ago), and provides the first evidence for major environmental change at Lake Eyre soon after Europeans settled the arid zone

Archaeology · Arid · Biology · Biomass (ecology · Geography · Glacial period · Grazing · Holocene · Isotopes of carbon · Overgrazing · Physical geography · Total organic carbon · Vegetation (pathology · Environmental Science · Geology and Paleoclimatology Research · Isotope Analysis in Ecology · Wildlife Ecology and Conservation · Ecology · Geology · Paleontology

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