New Study Sheds Light on How Tall Trees Cope With Changing Climate

A series of bushfires ravaged the state of Victoria in Australia in 2009, after a period of drought and extended heat wave.

The bushfires, dubbed as Black Saturday bushfires, claimed more than 150 human lives and caused massive damage to property. At least 21 of 33 long-term Victorian weather stations broke all-time records for high temperatures, including Melbourne's 154-year record for maximum air temperatures.

Several trees were destroyed, however, the mountain ash trees which survived the blaze did not die as anticipated from the heat wave.

Researchers from University of Sydney and University of Western Sydney have now explained how the mountain ash trees were able to survive.

Researchers recorded the impact of the 2009 heat wave from within the Mountain Ash forest at Britannia Creek, near Warburton in Australia. They found that the tree was able to survive the heat wave, as they were able to store their water, use it and refill it in their stems, during the night.

It was assumed that water storage taking place in the night is a minor process. But when experts analyzed the water uptake of mountain ash trees, they found the trees took up water in the night, up to 30 percent of what they were taking in during the daytime.

"The wood in the tree acts like a sponge which is emptied during the day and refilled with water at night," Dr Sebastian Pfautsch, from the University of Western Sydney, said in a statement.

Researchers pointed out that there are high chances that mountain ash forests and the Melbourne water catchments will be facing more droughts and higher temperatures in the future.

"This research is a key step in predicting how they will respond and their capacity to support the ecosystem through services such as carbon sequestration and water yield," said Mark Adams, Dean of the Faculty of Agriculture and Environment at the University.

It is believed that tall trees are vulnerable to drought and heat wave as they find it difficult getting water from the soil up to the leaves. But the mountain ash trees' ability to store water during drought sheds light on how tall trees evolve to acclimatize to climate change.

The findings of the study are published in the journal Oecologia.