The vast Nullarbor Plain located between Western and South Australia is the world's largest limestone karst landscape. The term Nullarbor, is a Latin word which means "no tree" and for more than 100 years, it has been known to be a treeless vast land. A new study, however, shows that the plain used to be filled with trees and flowering plants.
Published in the journal Proceedings of the National Academy of Sciences, the study says that the plain, rather than being treeless, was full of vegetation such as banksias, eucalyptus trees and other flowering plants around 5 million years ago. The scientists at the University of Melbourne claim that the dramatic transformation was driven by climate change.
"The Nullarbor region had a relatively dry climate until five million years ago, but then the vegetation suddenly changed," Dr. Kale Sniderman, a paleoclimate scientist, said.
In the past, fossilized pollen is used to determine what type of plants grew throughout time. Samples taken by scientists only show important information about these plants for about 500,000 years ago. Today, the new study sheds light in a new way to examine and date pollen found in stalagmites, flowstones and stalactites.
To be able to date fossilized pollens, the researchers examined ancient pollen trapped in old samples and used their distinctive shapes to determine the plants growing at the particular time. The samples which contain pollens reveal the nature of the plants and through the discovery, the researchers were able to generate a deeper understanding of the vast plain's history.
The study shows that the plain is more than just unique limestone formations. It has a rich lush history that can provide further understanding on the Earth's climate changes throughout time. The researchers plan to use their discovery as a basis for their upcoming paper on the implications for contemporary climate change.
"It [Nullarbor Plain] is also home to a scientific treasure trove of palaeoclimate information that has potential global significance," Dr. Sniderman said.
"In just 100,000 years, it became a forest of gums and banksias, which suggests a rainfall of two or up to four times higher than today," he added.
Photo: Chris Fithall | Flickr