Trapped in the sediments of lakes or swamps for thousands, and even millions of years, pollen and charcoal can reveal the past.
Paleoecologist Simon Haberle visited an area the Australian National University Professor of Natural History calls “Bega Swamp”, near Bemboka, to try and better understand the relationships between Indigenous Australians, the environment and fire.
The sediment, sampled at a very fine resolution, paints a picture of the landscape in freeze frames of every 20 years, stretching back over 15,000 years.
“The results show that the number of samples including charcoal has increased since European settlement, confirming other studies that big fires have occurred more frequently than during the time of Aboriginal land tenure in the Australian high country,” Professor Haberle said.
“It also shows that in the past mega fires only occurred very rarely, once every 4000 years, and that the current situation of big and intense fires is unusual in the long-term history of the region.”
He describes the swamp as a “rain gauge”, showing the shift from a cold environment to warm around 10,000 years ago.
“You see big changes in fire management, because you can look at the charcoal and see what burning regime took place,” he said.
“It was a regular regime, Aboriginal people knew how to keep fuel loads lower.”
According to Professor Haberle’s research from Tasmania to the Kimberley, big fire events are becoming more common, fires are starting sooner and problematic trends are forming.
“Big disturous fires used to be rare, but are more common now,” he said.
“The difference now is the regular burning doesn’t occur anymore, so we don’t know what will happen in the future.
“Things that happened in the past can be beneficial, and regular small scale burning in the forest may be a reason for less big fires.”
He is hoping to build a detailed record of pre-Colonial Australian land management, and plans to meet with Elders across Australia to learn different community’s connections with the land.