Kangaroo Island’s rogue blue gums spark huge weeding effort amid fears of ecological threat

Rogue blue gum saplings have escaped KI’s plantations in the wake of the 2020 bushfires, sparking a scramble to halt the new ecological threat.

Rogue Tasmanian blue gum saplings are taking over parklands and private property after the Kangaroo Island bushfires, sparking a huge effort to deal with the ecological problem.

Kangaroo Island Landscape Board general manager Will Durack said work was done to remove the trees – treated as weeds outside of plantation areas – from about 350ha.

But he said another 3150ha still needed “significant management” and a low level of work had to be done on a further 3000ha.

If the trees were not pulled out or poisoned, they could continue to spread and out-compete native vegetation, including threatened species.

“The Tasmanian blue gum is incredibly aggressive when it regrows outside of plantations,” Mr Durack said.

The saplings, or “wildlings” have emerged as a result of the 2019-20 bushfires and soil disturbance caused by land clearance.

“People are taking it very seriously and see it as a key threat to the biodiversity on some parts of the island,” Mr Durack said.

Moving swiftly was critical because the longer the saplings were left, the harder they were to remove.

Tasmanian blue gum saplings can grow aggressively outside of plantations. Picture: Supplied

Many are working to remove the trees, including conservation groups and local landholders.

Flinders Chase was the park most affected by the blue gums, Mr Durack said, and while the Environment Department was confident they could manage the issue, removing the saplings in other areas would take “significantly longer”.

Trees for Life president Jeanette Gellard said her organisation was “really concerned” about the trees’ potential threat to ecosystems.

“Instead of being this wonderful biodiverse mix of native species that provides habitat for a whole range of fauna species, the structure of that environment will change,” she said.

Kangaroo Island Plantation Timbers (KIPT) managing director Keith Lamb said while Tasmanian blue gums were not native to the island, “it’s not as if it’s a species from the other side of the planet”.

“The simplest way to manage the problem is to restore burning practices to the level that should have been happening before the fires so we don’t see another fire occurring again,” he said. “Regular cool burning will most probably eliminate the wildlings in the future.

“It’s the lack of burning in national parks and on the native vegetation on the island that caused the excessive build-up … and contributed to the losses incurred.”

KIPT is pulling out blue gum saplings and also doing cool burning.

The State Government last year said an extra $37 million over five years would allow it to increase prescribed burns by as much as 50 per cent.