We found out when the Nullarbor Plain dried out, splitting Australia's ecosystems in half
Yet millions of years ago, many species roamed more freely between connected habitats across the continent.
- Yet millions of years ago, many species roamed more freely between connected habitats across the continent.
- Our new research, published in Geophysical Research Letters, provides insights into ancient climate change that shaped our modern landscapes and ecosystems.
Billions of people live in drylands
- Drylands cover almost half of Earth’s land surface and are home to around 3 billion people.
- As the driest inhabited continent, Australia (70% is considered arid or semi-arid) also faces many challenges, including droughts and bushfires.
- Southern Australia’s Nullarbor Plain covers an area about the size of Great Britain (roughly 200,000 square kilometres).
The drying of the Nullarbor
- For most people, rust is something they want to avoid, as it damages our cars, fences, and steel appliances.
- In our work, we used an iron-bearing mineral called goethite – the main part of rust – to unlock the timing of drying on the Nullarbor.
- We found goethite in rocks some 25 metres below the Nullarbor Plain.
- As the climate shifted, the drying changed the local ecosystems, effectively creating a wall for many species.
Splitting of the species
- Through isolation, the drying of the Nullarbor played a key role in creating the species richness of southwest Australia.
- Many native species are already facing or will face existential problems due to climate change and habitat degradation – including the iconic Carnaby’s cockatoo.
A history locked in minerals
- By studying minerals formed during groundwater decline, we improve our understanding of our continent’s past and its biosphere.
- These minerals form as a direct result of continental drying, often in sediment with fossils of interest.
- Chris Kirkland receives funding from Australian Research Council and the Minerals Research Institute of Western Australia.