An environmental activist has been sent to jail in Tasmania for the first time in more than a decade over protests at logging and mining sites.
Colette Joan Harmsen, 47, locked herself onto an excavator at MMG's mine on the state's west coast in 2021 and refused to leave when asked by police.
She also protested at a forestry site and Venture Minerals' mine in the northwest, on three separate occasions from 2021-23.
Harmsen appeared in Hobart Magistrates Court on Friday after pleading guilty to four counts of trespassing, as well as other related offences.
Her offending was in breach of three-month suspended jail term, which was activated by Magistrate Chris Webster.
Mr Webster noted Harmsen had a long history of trespassing dating back to 2010.
"The original penalty was to encourage (her) to stop her illegal protest activities," he said.
"It was a series of breaches spread over two years. Obviously she intended to pursue the course of conduct for which she has been charged."
Bob Brown Foundation campaign manager Jenny Weber said Harmsen, who works as a veterinarian, had been preparing to go to jail.
"It's been more than a decade since Ali Alishah and Nishant Datt, two people who stood up for Tasmania's forests, were imprisoned," she said.
"This is the first time a woman (in Tasmania) has been to prison, sentenced, for protesting.
"(Environmental activist) Karen Weldrick went to prison because she refused to pay exorbitant fines."
The court was told Harmsen, who was protesting with the Bob Brown Foundation, breached bail conditions stating she wasn't allowed to travel a certain distance from her home.
"I love you guys. Doing it for the forests," she told supporters in court, including her parents, after being sentenced.
Mr Webster rejected Harmsen's claim she would have difficulty taking medication in prison, noting she travelled to wilderness areas far from a doctor or hospital.
He said Harmsen had told community corrections workers she intended to continue protesting.
Several dozen of her supporters were outside court before the sentence.
"I am not a menace to society yet here I am ... while the real criminals are sitting in parliament subsidising the destruction of our environment," Harmsen said.
"I am a peaceful forest protester."
Bob Brown described Harmsen as a friend of many years and deserving of an Order of Australia.
Mr Webster sentenced Harmsen to six months' jail, wholly suspended for two years, for related offending including failing to comply with a direction of a police officer.
"No doubt she will learn a lesson from her imprisonment," he said.
