Study finds future heat waves a threat to Australian plant life

Future heat-waves could have a devastating effect on Australia's flora, a new Australia-led research has found.

The study, published by environmental journal Global Change Biology on Monday, said Australian plants were near at a tipping point in their ability to cope with rising high-temperature and this could spell bad news for the plants in the future.

The study was undertaken by a group of international researchers from the ARC Centre of Excellence in Plant Energy Biology at the Australian National University (ANU), researchers from the Western Sydney University, and several leading institutions in the United States, Britain, Sweden and New Zealand.

The study was led by ANU Professor Owen Atkin.

"We surveyed plant life around the globe for their high-temperature tolerance," Atkin said.

"We show that, while heat tolerance is higher in plants near the equator than in the arctic, the potential for damage is most severe for hot, inland, mid-latitude regions. Here, maximum air temperatures during heat-waves are most extreme," he said.

"Plants growing in the dry, inner regions of Australia are at particularly high risk. We could see dramatic changes to the face of Aussie plant life in the future," said Atkin.

The international team of researchers looked at plants from habitats all over the world, including nineteen remote sites in the arctic, tropics and deserts.

The study is known to be the most comprehensive analysis of heat tolerance in plants to date.

Researchers were able to pinpoint the exact temperatures where leaf metabolism becomes damaged by heat after exposing leaves to increasing temperatures during controlled tests.

The study said the researchers found that two critical processes for plant growth and survival, namely photosynthesis and leaf respiration, were damaged by high-temperature extremes.

Western Sydney University Hawkesbury Institute for the Environment Professor Mark Tjoelker who co-authored the study said the potential for high-temperature heat-damage was the greatest during periods of drought when plants were unable to use water to naturally cool off its leaves.

The findings of the study also have important implications for farmers growing crops in hot and inland regions of Australia.

"We know that crop yields are negatively affected by heat-waves, often when crops are flowering," Atkin said.

"The potential for such damage will only increase as global temperatures rise," he said. Endit