Parks Victoria and the Conservation Regulator are urging anyone with information about illegal firewood operators felling trees around the Kyneton, Taradale, Castlemaine and Macedon areas to come forward.

It is not clear whether any of the crimes are related, but the tree felling has deeply concerned enforcement officers with the scale of habitat destruction in grassy woodlands timber.

Patrols and surveillance as part of Operation CENTAUR are targeting this illegal behaviour throughout central Victoria this spring.

The felled trees would have provided critical hollows for nesting birds and mammals, which are particularly vulnerable this time of year.

The thefts come in the midst of a biodiversity crisis crippling many Victorian forests. The problem has been fueled by deforestation, climate change and other threats, a recent parliamentary probe found.

The crisis affects more than just the threatened animals clinging to life in central Victoria's forests.

The bush is a repository of insects and other animals that help pollinate farmers' crops, for example.

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But it is the loss of trees that might be old enough to finally start forming natural hollows that has most alarmed authorities.

Central Victoria's forests are growing back after being decimated in the 19^th and 20^th centuries and many animals need hollows for shelter.

Many threatened birds and small marsupials desperately need hollows in spring to shelter their young.

Victoria's black market firewood industry is fuelled by demand for heating, many conservationists say.

In the Wellsford Forest near Bendigo, a resident last year revealed evidence of illegal harvesting.

"They are really well organised. You can see by how they come in, cut the tree and then it's gone before you next walk through the area," the resident said.

It is only legal to take firewood from forests in limited circumstances and authorities urge people to ask questions before they buy.

They are urging people to report suspicious behaviour but says people should not endanger themselves as they gather information.

"Your safety is most important," Parks Victoria's Goldfield area chief ranger Karen Doyle said.

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Parks Victoria has issued $5500 in infringement notices for illegal collections, destruction of habitat and off-road driving in the Kyneton, Taradale, Castlemaine and Macedon areas.

The maximum fine it can dole out for illegal harvesting is a far higher $9246 and/or a year in prison.

People can also lose the chainsaws, vehicles and other equipment they use for their crimes.

Anyone with a low income can get government help to heat their homes, the government says.

To report suspicious behavior call Parks Victoria on 13 19 63.

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