Western Australia will end the logging of native forests from 2024 in a move that has been applauded by conservationists but will cost hundreds of jobs.
Premier Mark McGowan says the "historic" decision will protect nearly two million hectares of land, including about 400,000 hectares of karri, jarrah and wandoo forests.
About 9000 hectares of high conservation-value karri forest will receive immediate protection in a bid to help fight climate change.
The new policy will exclude forest management activities and clearing for approved mining operations, including Alcoa.
The move has drawn the ire of the forestry industry, which says it was "blindsided" by the announcement.
"We are shocked at this rushed and bizarre decision, which came without any consultation," Forest Industries Federation WA executive director Melissa Haslam said on Wednesday.
"For forests to cope with a drying climate, to control and minimise dangerous wildfires, they still need to be thinned and managed. This will now come at a huge cost to taxpayers where previously the costs were offset by timber production."
Ms Haslam said the industry employed more than 500 people and contributed about $220 million to the WA economy each year.
Forestry Minister Dave Kelly said between 300 and 400 workers in southwest WA would lose their jobs under the change.
"We are very sympathetic to those families who will be impacted," he told reporters.
Forestry workers will be supported through a $50 million transition plan to be funded in Thursday's state budget.
The budget will also include a $350 million investment over 10 years in new softwood timber plantations across the region.
Up to 50 million pine trees will be planted, "sequestering between 7.9 and 9.5 million tonnes of carbon dioxide equivalent".
It's expected to preserve about 1900 existing timber jobs and create an additional 140 positions.
"This is a historic moment ... (which) builds on the legacy of the Gallop Labor government's decision to end old-growth logging in 2001," Mr McGowan said.
"Protecting this vital asset is critical in the fight against climate change."
Existing contracts will be honoured through to their natural close at the end of 2023.
WA aspires to achieve net-zero greenhouse gas emissions by 2050 but the government is still considering whether to legislate the target.
Environment Minister Amber-Jade Sanderson said WA's southwest native forests stored about 600 million tonnes of carbon dioxide equivalent.
The Wilderness Society described the announcement as a milestone in the fight to protect native forests, while the Bob Brown Foundation urged other states including Tasmania to follow suit.
Opposition Leader Mia Davies said Labor hadn't taken the policy to voters, calling it "a direct attack" on a sustainably managed industry.
The Institute of Foresters of Australia and Australian Forest Growers labelled it a "thought-bubble policy" which could harm native forest management.
Vice president Michelle Freeman said the government was "continuing to support the flattening of forests for mining while ignoring evidence that sustainable native forestry is actually part of the solution to addressing climate change".
Australian Associated Press
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