Once-green SA landscape now 'barren' in efforts to stop pest

Residents of Adelaide's north-eastern suburbs are lamenting the loss of trees as authorities try to stop the spread of giant pine scale, an invasive sap-sucking insect.

Almost 5,000 trees in the area have so far been removed because of the pest.

Authorities say tree removal is the only scientifically agreed response to the pest and resilient native species will be used to replace them.

A once-green landscape across Adelaide's north-eastern suburbs is being transformed with almost 5,000 pine trees removed in an effort to stop the spread of an invasive pest.

Giant pine scale is an insect that sucks sap to slowly drain trees of moisture and nutrients, eventually killing them.

Authorities say removing infected trees, along with surrounding susceptible trees, is currently "the only scientifically agreed" way to manage the outbreak.

But local residents are critical of the large-scale removal, saying the loss of mature trees had stripped their neighbourhoods of shade, changed the landscape and destroyed important wildlife habitat.

For Highbury resident Simon Roocke, the pine trees behind his home were a major part of the area's charm.

"The trees came down just before winter this year," he said.

"Part of the appeal of this place was the trees up the back, they were beautiful, they gave us some amazing shade in the summertime.

Mr Roocke's home now backs onto a largely cleared hillside, with the once-established canopy gone.

"We raised a lot of issues regarding the stability of the hill now that the trees are gone, because it is a significant hill there but at this point it has happened and we'll have to deal with it," he said.

Mr Roocke said he also worried about the practical impact of the lack of trees, particularly the loss of shade.

"Our daughter has just moved out but her bedroom was out the back and within the first few weeks she noticed her bedroom was a lot hotter," he said.

"Naturally we're going to have to be using more air-conditioning."

Further along the affected area, resident Greg Atkins said the scale of the clearing left parts of his neighbourhood appearing barren.

Mr Atkins said residents were told the revegetation project would include thousands of replacement plants, but felt the effort had fallen short behind his property.

"We were told there were three and a half thousand plants to be put in. They must've run out when they got to our place," he said.

He hoped the government would continue its replanting efforts to fill the space near his back fence.

Community advocate Sonia Blackwell said the loss of mature pine trees raised questions about the impact on local wildlife.

She said the trees provided important habitat and protection for a range of species.

"We have lost a lot of habitat for our red-tailed black cockatoos, for our koalas, for all of our wildlife that use those trees as habitat and weather protection," she said.

Ms Blackwell said she was "purely outraged" about the management of giant pine scale, describing the impact on local residents as significant.

"Residents are selling their homes," she said.

"Houses are filling up from displaced wildlife. One lady had to remove three snakes in one week from her yard."

The sap-sucking insects continue to be detected in the area, with ForestrySA chief executive Nathan Paine confirming another 19 trees had been found to have giant pine scale at Highbury and Hope Valley.

He said those trees were being felled, along with others within a 50-metre buffer zone.

"Those trees are being removed around the reservoir, the aqueduct and along Lyons Road," Mr Paine said.

Mr Paine said future detections of the pest were also anticipated.

A state government spokesperson said it had contributed $5.4 million towards the response to giant pine scale since 2023 and another $5.5 million for revegetation and restoration works.

"Presently, the removal of impacted trees and surrounding susceptible trees is the only scientifically agreed response available to manage giant pine scale," they said.

"While we recognise the significant impact that removing mature trees has on local communities, these measures are critical to reduce the risk of further spread."

The spokesperson said the removed trees would be replaced with native species that are not susceptible to the pest.