Proposed loosening of NSW's land-clearing controls could leave more than a third of the state's woodlands exposed to bulldozers including prime koala habitat, a report commissioned by WWF-Australia has found.

The study by consultants Eco Logical Australia examined how the potential impacts of proposed changes to the Equity Code as part of the Baird government's new biodiversity conservation plans that would ease limits on some vegetation clearing.

It found the elimination of existing controls – such as curbs on properties smaller than 100 hectares and where protected vegetation makes up less than 10 per cent of holdings – would open up 8 million hectares of forests to clearing.

That total, which amounts to about 38 per cent of the state's woodlands, also includes 2.2 million hectares of koala habitat or roughly 10 per cent of the state's tally, the report said.