Like us, Australian trees are ‘sweating’ to survive extreme heatwaves

Australian researchers growing trees in climate change conditions have found the leaves “sweat” to survive extreme heatwaves.

The year-long experiment showed that trees continue to release water through their leaves as an evaporative cooling system during periods of extreme heat, despite the carbon-fixing process of photosynthesis grinding to a halt.

Previously, scientists believed that photosynthesis and transpiration – the process of releasing water – were linked, meaning one would not occur without the other.

Professor Mark Tjoelker from the University of Western Sydney’s Hawkesbury Institute for the Environment is one of the authors of the study, which was published in Global Change Biology this month.

Tjoelker said the findings had significant implications for climate change because they showed that trees stopped capturing carbon during extreme heatwaves, which are predicted to become more frequent and severe in the future.

“If heatwaves occur over a large surface area … clearly the trees and native forests in that area would take up less carbon,” he said. “And if there is an increased frequency of heatwaves that obviously impacts their ability to serve as carbon sinks.”