Selective harvesting in state forests on the NSW North Coast does not adversely affect koala numbers, a three-year research program has found — to the indignation of a forest conservation group.
- Research has found that selective harvesting in the northern coastal state forests does not affect koalas
- A forest protection group is outraged by the results of the report and describes it as “dangerous propaganda”
- The report says that the nutritional quality of the trees is crucial for koala survival, as blackcurrant is the lowest quality
But the state’s spearhead body says the results justify foresters.
As part of the research, which was overseen by the State Natural Resources Commission (NRC), an independent government body, acoustic sensors were set up in 2019 to monitor koalas in state forests and control sites in national parks.
When researchers from the NSW DPI Forest Science Unit returned after harvest last year, they found no difference in koala numbers.
“We do the work in the spring, it’s the koala growing season, and that’s when the males bellows to attract females and also to advertise themselves to other males,” said Dr. Brad Law.
“We put these recorders out at a distance of 400 meters in a grid and we let them stand out in the woods for two weeks and record all night continuously.
“Our places are very large … about 400 acres in size, and it varied from place to place, but on average it’s about 0.05 koalas per acre, so that means about one koala per 20 acres.”
To find horror conservation group
The North East Forest Alliance’s Dailan Pugh has labeled the finding that deforestation does not affect koalas as “dangerous propaganda” that further threatens the species’ survival, and he questions Dr. Law’s research.
“The recorder will say, ‘Yes, we have a male koala calling somewhere near this recorder,’ and the recorder may be over a mile away and it does not tell you how many koalas there are. in the woods, said Mr. Pugh.
“They have extrapolated it to claim that if you had a koala calling somewhere within a mile before an area was logged, and they called again somewhere in the vicinity after it was logged, it shows, that logging has no bearing.
“That koala could have been somewhere in an unlogged patch far away from where the actual logging took place, there could have been a whole bunch of koalas in that area before and only one after.”
The Natural Resources Commission’s CEO Bryce Wilde has defended the results of the research program.
“It was managed by an expert panel that we drew together, and we had an extensive process of selecting the researchers and then quality assured, the work has been thoroughly peer reviewed and is up for review,” he said.
Nutritional quality of trees is critical
ANU Fellow Dr. Karen Ford sampled leaves from 900 trees of 22 different eucalyptus species in nearly 60 locations.
Blackbutt, an important timber species, proved to be one of the lowest nutritional quality species.
“If you change the composition of the wood of the forest by increasing the proportion of koala -browse species, you get an increase in the nutritional quality of the forest, and if you change it by increasing the amount of blackbutt in the forest than you get a decrease in the nutritional value of forests for koalas, ”she said.
The study found that if there were too many non-browse species, there could be a decline in the number of koalas in the forest.
Finds ‘justify’ foresters
Timber NSW’s CEO Maree McCaskill said the results decided without a doubt that koalas could coexist with selective harvesting.
“I’m not saying the forests are completely out of the woods by any means … and I think that after fires, there is still a significant amount of work to be done.”
The NRC also found that more research was needed on koalas’ response to intensive harvesting practices, and that climate change and the increased risk of wildfires posed greater risks to their long-term survival.
Wilde said the research looked at how koalas were recovering from the devastating forest fires of Black Summer 2019-2020.
“In the areas where the fires were moderately severe, research shows that there was a reduction in detection rates of about 50 percent, but that subsequently koalas are returning, and there are koalas returning to these places.”