9 April 2009

Australia’s unique plant life could be under threat from global climate change, according to University of Queensland research.

As part of an international team of researchers from Australia, New Zealand, South America, the USA and Switzerland, Dr Lyn Cook from UQ’s School of Biological Sciences said the inability of plants to adapt to new environments quickly has implications for the future of Australian plants.

The study included the largest analysis of plants ever undertaken – about 11000 species, an estimated 15 percent of all plant species in the southern hemisphere. The research was recently published in scientific journal Nature.

“We used DNA data and the fossil record to reconstruct the history of plants in the southern hemisphere, including Australia,” Dr Cook said.

“What we found was that most plants are found in the same type of environment as their ancestors.

“A plant species whose ancestor lived in a forest environment is highly likely also to live in a forest environment.

“In the past, it has been rare for plants to adapt to different environments.

Dr Cook said the movement of continents after the break-up of Gondwana (about 167 million years ago) explained some of the similarity of plants on different continents in the southern hemisphere such as the protea family in Australia and South Africa and southern beeches in Australia and South America.

“This study gives us a more complete picture – some plants have dispersed between similar environments on different continents,” she said.

“It appears that, when dispersal is possible, it is easier for an invading plant to colonise a new location that has its preferred environment than it is for native plants to adapt to a different environment.”

“That is why we think climate change will have an impact on our native plants.

“If weeds arrive in Australia that are already adapted to our new climate regimes, they are likely to spread before our native plants can adapt.

“Climate change will lead to some local plants going extinct, and some will become rarer.

“Some native plants might do even better – those whose preferred environment expands with climate change.”

Media: Dr Lyn Cook (07 3365 2070) or Andrew Dunne at UQ Communications (07 3365 2802 or 0433 364 181).