WA Premier Colin Barnett has flatly rejected an offer from environmentalists to 'buy back' part of a South West forest, insisting it will be logged and will grow back.

About 80 people protested outside Parliament today and brought with them a cheque for $90,000 they had hoped to give to the State Government.

In exchange, they wanted the Forests Products Commission to stop logging 1,600 hectares of the 8,000-hectare Mowen forest, near Margaret River.

The Save Mowen Forest group said questions in Parliament last year revealed the Forest Products Commission would earn a net income of about $90,000 from the logging.

Group spokeswoman Naomi Godden said the money was raised through a crowd-funding program.

"This is a government that's foundational ideology is economic rationalism," Ms Godden said.

"If that's what the Government requires then we're prepared to meet them on that.

"Obviously, our line around protecting habitat is not being heard by our Government; the importance of a local community saving their environment for future generations is not important to this Government.

"But it seems in a time of austerity, money is.

"So we've calculated the sum of $90,000 and we're making this offer to the Government, based on their own political ideology."

At a separate press conference, Mr Barnett was asked if he would take the money.

"No, I won't," he said.

"And look, the old growth forest is protected - large areas, massive areas.

"But we also have a forestry industry and this has been one of the blocks that will be forested, and it will re-grow. This is not old growth forest."

Ms Godden said the group would keep protesting.

She said Forestry Minister Mia Davies had refused to meet with them.

Ms Davies office has been contacted for comment.