Bushfire regrowth could affect water flows

Bushfire regrowth could affect water flows

29 March 2007

published by www.theage.com.au

Australia — Bushfires in the high country could have abig impact on water catchments, with research showing leaves on regrowing treeslose up to five times more moisture than those they replace.

Scientists hope the findings will help determine the effect on flows to theMurray-Darling basin and Gippsland.

“The potential losses of water are very serious,” said researchleader Professor Mark Adams, of the University of NSW’s school of biological,earth and environmental sciences.

“We have relied on the high country to produce a certain amount of waterevery year, and what we are finding is that the certainty of that yield is farless than what we thought previously.”

Professor Adams is leading a $1.7 million study by the Bushfire Co-operativeResearch Centre into the impact of bushfires in high country ecosystems.

The research team has discovered that vegetation regrowth following the 2003fires loses up to five times more water from their leaves to the atmosphere thanmature trees.

As there are more leaves on mature trees, this does not mean that the totalwater use will be five times greater, but Professor Adams says it is animportant indicator of the difference between the mature forest and regrowth.

Even slight declines in the availability of water could lead to majorreductions downstream.