An ambitious tree planting program has begun on the Monaro in southern New South Wales to counter the effect of an extremely large tree dieback episode in the region. Source: ABC News
Dieback has killed the native eucalypt species, leaving the hills south of Cooma scarred with the remains of thousands of dead gum trees.
Their skeletons stand as a stark reminder of what has been lost.
Over some 5000 square kilometres between Cooma and Berridale almost every gum tree is affected by dieback.
“It’s bad,” Upper Snowy Landcare’s Dieback Project manager Lauren Van Dyke said.
“Almost all the Eucalyptus viminalis species, known as manna or ribbon gum have died out, causing what appears to be like a tree cemetery in this region.”
The cause is uncertain, but most suspect the decade-long drought weakened the trees, allowing more virulent attack by the eucalyptus weevil, which ultimately causes the dieback.
Whatever the cause, tree loss has fractured habitat connectivity, making it difficult for animal species such as small bush birds, reptiles and mammals to move under the safety of the tree canopy to feed and breed.
The tree loss has also opened up country to new erosion events and weed incursion, along with the danger of trees falling on people and fences.
Now four small plots are being replanted with a mix of species in the hope of bringing back the trees and creating a viable ecosystem.
About 5000 trees and shrubs are being planted across the four dieback revegetation plots, under the supervision of Michael Platts from Monaro Tree Nursery in Bombala.
“You can never recreate exactly what was there because it’s always changing anyway,” he said. “But we are trying to put species back in that were occurring here naturally.”
But there is no point replanting if those trees simply die as well.
To prevent future dieback, included in the mix are shrubs which act as a home for small birds – which in turn eat the eucalypt weevils.
Species being re-established will mimic what has been lost, while adding more diversity in a mix of eight eucalyptus species, four acacia species, along with five species of shrubs including tea tree and callistemon.
“There’s been many factors that have caused the dieback … one is that you haven’t got the diversity of birdlife and natural animals,” Mr Platts said. “The dieback insect is always here, we’re not going to get rid of it – so we’ve just got to have the right mix.”
But Ms Van Dyke said there were also major benefits for landholders.
“The loss of trees has caused a reduction in shelter belts and shade for stock in this region,” she said.
Mr Platts said most of the dieback occurred on farms.
“We’d like to show that environmental outcomes out of planting should also work in with production outcomes on farms because the farmers are the holders of the land where it’s all happening,” he said.