Scientists warn Australia’s “zombie tree” could vanish within a generation

Professor Rod Fensham, a botanist at the University of Queensland, said urgent action is needed to prevent the species Rhodamnia zombi from disappearing due to the fungal disease known as myrtle rust.

"This species did not have a name when it was first assessed in 2020, and since then 10 percent of the trees have died and none of those remaining are producing flowers or fruit because of myrtle rust," Professor Fensham said.

Myrtle Rust Stops the Tree From Growing or Reproducing

Rhodamnia zombi is described as a small to medium sized tree with large dark green leaves, shaggy bark, and fuzzy white flowers. It grows in rainforest areas within Queensland's Burnett region.

"It is a small to medium-sized tree with large dark green leaves, shaggy bark and hairy white flowers growing in rainforests in the Burnett region of Queensland.

"The bright yellow fungal pathogen attacks and kills off its young shoots over and over again meaning an infected tree can't grow or reproduce and eventually dies."

The fungal disease responsible for the damage, myrtle rust, was first detected in Australia in 2010. Because of the threat it poses, Rhodamnia zombi has now been placed on a list of species considered potentially critically endangered.

"Without any intervention, the 17 species on this Category X list will be extinct within a generation," Professor Fensham said.

"None of them appear to have any resistance to myrtle rust or any wild population which is not yet infected."

Scientists Hope Future Generations May Develop Resistance

Despite the dire outlook, researchers see a possible path forward. Professor Fensham, who works in UQ's School of the Environment, said related species within the broader Rhodamnia group have shown resistance to myrtle rust. That genetic connection could offer a chance for survival.

"A survival strategy starts with finding clean cuttings in the wild before myrtle rust attacks them and propagating them to grow at safe sites," he said.

"So far seedlings are being grown by specialists in Lismore and Townsville which look promising, but they need to be constantly vigilant.

"Hopefully once they produce seed, lurking in the next generation of Rhodamnia zombi some resistance will become apparent.

"It is a rare opportunity to study this evolutionary process which has happened countless of times in the wild over millennia."

A Long Shot to Save the Species

Researchers ultimately hope that if resistant trees emerge, they could eventually be replanted in forests and help restore the species to its natural ecosystem.

"It's a long shot and ambitious but the species needs time and space without being constantly walloped by myrtle rust to hopefully express some resistance," Professor Fensham said.

"Left to its own devices, the trees in the wild really will be the living dead."

The findings describing the species and its conservation outlook were published in the journal Austral Ecology.