The High Court has dismissed the Bob Brown Foundation's application to appeal a decision that allows native forest logging to continue in Tasmania.
The conservation group had sought to appeal a Federal Court judgment validating regional forest agreements.
Dr Brown says the High Court decision would "send shock waves through the majority of Australians who want our forests saved".
"The bizarre state of affairs where Commonwealth responsibility for protection of endangered species and their habitats ... is deferred to state agencies devoted to destroying them is upheld in this decision," the former federal Greens leader said in a statement on Wednesday.
His foundation had argued argued Tasmania's regional forestry agreement is invalid because it does not properly protect threatened native animals.
"The RFAs are a spectacular failure in protection of forests harbouring a long list of birds, animals, insects and plants headed for extinction, including koalas, Tasmanian devils, black cockatoos and greater gliders," Dr Brown said.
Tasmania's Liberal government, Labor opposition, peak forestry body and state-owned forestry company Sustainable Timber Tasmania (STT) all supported the Federal Court's ruling.
Tasmania's forestry industry says it employs more than 5700 people, directly and indirectly.
The Federal Court judgment agreed with STT that there is a broader suite of environmental protections in force in Tasmania.
