image: This is drifting sand in semi-arid eastern Australia. view more
Credit: Image courtesy of Robert C. Godfree
A study explores how megadroughts affect Australian ecosystems. As the planet continues to warm, the magnitude of drought is likely to increase. However, the effects of megadroughts on animals, plants, and ecosystems are unclear. Robert C. Godfree, Francisco Encinas-Viso, and colleagues developed a reconstruction of a severe, continent-wide megadrought interval that occurred in Australia between 1891 and 1903, known as the Australian Federation Drought Period (FDP). The reconstruction included 541 biotic impact records (BIR) with geocoded data from a broad range of flora and fauna and 1,748 drought impact records (DIR) extracted from more than 35,000 contemporary newspaper articles and historiographic sources. Ecosystem impacts occurred most frequently during exceptionally dry conditions and were mostly concentrated in arid, semiarid, and dry subtropical parts of Australia. In semiarid areas, severe drought combined with livestock and rabbit overgrazing resulted in the mass mortality of shrubs and grasses. During the FDP, more than 60 bird, fish, mammal, reptile, and plant genera experienced severe stress and mortality over at least 36% of the Australian continent. The presence of hyperabundant herbivores increased ecosystem sensitivity to permanent degradation. The results suggest a bottom-up, ecosystem-wide mortality pattern mostly driven by record rainfall deficiencies, which put ecosystems at high risk of collapse, according to the authors.
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Article #19-02046: "Historical reconstruction unveils the risk of mass mortality and ecosystem collapse during pancontinental megadrought," by Robert C. Godfree et al.
MEDIA CONTACT: Robert C. Godfree, Commonwealth Scientific and Industrial Research Organisation, Canberra, AUSTRALIA; tel: +61-262464956, +61-459849262; email: Robert.Godfree@csiro.au
Journal
Proceedings of the National Academy of Sciences