Nineteen Bob Brown Foundation forest defenders are in Tasmania's Florentine Valley this morning, protecting the tallest flowering trees on Earth which continue to be destroyed by logging.

This valley full of giant eucalypts has been the site of ongoing protests recently as shocking footage emerged of gigantic trees being hauled out of this ancient forest.

One protester is in a treesit high above the forest floor with another locked onto logging machinery.

"It is criminal behaviour to harvest this forest. If anyone tells you that native forest logging sequesters carbon, please think about that for a moment. Clear felling massive trees and burning the soil, it will take centuries for the forest to re-capture that carbon," said treesitter Aden Wachtel, a 33-year-old gardener.

"Our biodiversity is precious, and all our lives are on the line. That's why I'm climbing up into a tree sit to defend this forest," Mr Wachtel said.