Gum trees fire up history revision

Feb 16, 2011
Gum trees fire up history revision
The study suggests bushfires have been part of the Australian landscape for more than 60 million years.

(PhysOrg.com) -- Australian bushfires appeared 50 million years earlier than previously thought and probably contributed to transforming the landscape from rainforest into the country’s dry eucalypt forests of today, according to the authors of a new study from The Australian National University.

The study, led by Professor Mike Crisp of the Research School of Biology at ANU, sheds new light on the history of the of Australia and is a “smoking gun” that eucalypts and bushfires are inextricably linked in Australian history. The results of the study are published today in Nature Communications.

By studying pollen fossils, the researcher’s were able to identify when eucalypts developed their unique ability to recover from bushfires. They found that this time coincides with when the landscape of Australia started to change.

“In other parts of the world that have similar environmental conditions to Australia, such as California with its oak-dominated forests, a severe bushfire will kill everything above ground. Eucalypts, however, have developed a unique capacity to recover from ,” said Professor Crisp.

“Our work suggests the ancient ancestors of the eucalypt moved out of the and into the woodlands that you see today, at about the same time as this adaptation arose. It’s a smoking gun of evidence that the timing of both things originated at the same time as fire became a presence in Australian vegetation.”

Previous studies have indicated that bushfires have been a significant presence in the landscapes worldwide for less than 15 million years, but Professor Crisp says this study shows a much older relationship.

“We traced this adaptation skill of the eucalypt back more than 60 million years – soon after the asteroid that killed the dinosaurs. That’s a pretty significant jump from the current literature,” he said.

The researchers speculate that this adaptation by eucalypts was the reason Australia ended up with a dry forest landscape.

“It is possible that it was the change in eucalypts that changed the landscapes, pushing back the rainforests and causing the expansion of the dry forest landscape. We think that there was a feedback loop between the eucalypt surviving fire and creating an environment that favoured the eucalypt,” said Professor Crisp.

Explore further: Scientists monitoring Hawaii lava undertake risks

Provided by Australian National University

4.7 /5 (7 votes)

Related Stories

Protecting natural forests crucial for climate change

Aug 06, 2008

(PhysOrg.com) -- South-east Australia’s natural forests are among the most carbon dense in the world and store three times more carbon than Australian and international climate change experts realise, a ...

Introduced plants 'becoming Australian'

Jan 31, 2011

(PhysOrg.com) -- A number of introduced plant species have become more like natives, suggesting rapid evolution could happen far more frequently than previously thought, according to new research from UNSW.

Australian researcher discovers giant asteroid impact

Oct 24, 2010

(PhysOrg.com) -- A geothermal energy researcher from the University of Queensland (UQ) has found evidence of a major asteroid impact that occurred more than 300 million years ago in the South Australian outback.

First Australians did not boost fire activity

Dec 06, 2010

(PhysOrg.com) -- The arrival of the first people in Australia about 50,000 years ago did not result in significantly greater fire activity, according to a landmark new research report on the continent's fire history going ...

Recommended for you

Scientists monitoring Hawaii lava undertake risks

4 hours ago

New photos from the U.S. Geological Survey's Hawaiian Volcano Observatory give a glimpse into the hazardous work scientists undertake to monitor lava that's threatening to cross a major highway.

NASA sees Odile soaking Mexico and southwestern US

15 hours ago

Tropical Storm Odile continues to spread moisture and generate strong thunderstorms with heavy rainfall over northern Mexico's mainland and the Baja California as well as the southwestern U.S. NASA's Tropical ...

NASA sees Tropical Storm Polo intensifying

15 hours ago

Tropical storm warnings now issued for a portion of the Southwestern coast of Mexico as Polo continues to strengthen. Infrared imagery from NASA's Aqua satellite showed powerful thunderstorms around the center ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

Vreejack
5 / 5 (1) Feb 16, 2011
"We think that there was a feedback loop..." It would be nice to hear a suggestion as to how this feedback loop might have worked.
LariAnn
3 / 5 (2) Feb 16, 2011
Yes, seems to me that the most important factor was a decline in annual rainfall, favoring the drier forest over the rainforest. Eucalypts just happened to be the best colonizers as the drier climate set in.
zevkirsh
not rated yet Feb 16, 2011
during the time when there was a very high oxygen content in the air, the fires and dragon flies were bigger than they are now.
Sinister181
1 / 5 (1) Feb 16, 2011
True. The higher Oxygen content around that time probably allowed for the fires to burn for much longer, and as a result -- caused much drier forests, as the plants which weren't able to recover died out.
mg1
1 / 5 (2) Feb 17, 2011
Most Australian bush fires are cause by people and of those some are firemen.

Are you seriously telling me they had firemen 60million years ago.

For instance: The toojay fires were caused by Western Power, now come on even i doubt they were around back then.