Indigenous impacts on north Australian savanna fire regimes over the Holocene
Journal Publication ResearchOnline@JCUAbstract
Fire is an essential component of tropical savannas, driving key ecological feedbacks and functions. Indigenous manipulation of fire has been practiced for tens of millennia in Australian savannas, and there is a renewed interest in understanding the effects of anthropogenic burning on savanna systems. However, separating the impacts of natural and human fire regimes on millennial timescales remains difficult. Here we show using palynological and isotope geochemical proxy records from a rare permanent water body in Northern Australia that vegetation, climate, and fire dynamics were intimately linked over the early to mid-Holocene. As the El Niño/Southern Oscillation (ENSO) intensified during the late Holocene, a decoupling occurred between fire intensity and frequency, landscape vegetation, and the source of vegetation burnt. We infer from this decoupling, that indigenous fire management began or intensified at around 3 cal kyr BP, possibly as a response to ENSO related climate variability. Indigenous fire management reduced fire intensity and targeted understory tropical grasses, enabling woody thickening to continue in a drying climate.
Journal
Scientific Reports
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N/A
Volume
11
ISBN/ISSN
2045-2322
Edition
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Issue
1
Pages Count
8
Location
N/A
Publisher
Nature Publishing Group
Publisher Url
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Publisher Location
N/A
Publish Date
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Url
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Date
N/A
EISSN
N/A
DOI
10.1038/s41598-021-02618-z