Giant Trees
Identified registered giant trees in Tasmania are reserved either in formal reserves including some within the Tasmanian Wilderness World Heritage Area or in informal reserves managed by Sustainable Timber Tasmania. To qualify for recognition as a giant tree it needs to either be over 85 metres in height or have a measured volume of more than 280 cubic metres. The current register, last updated in 2014, lists 149 trees and only includes trees measured on the ground. LiDAR data has identified numerous other trees that may potentially qualify for listing, including, within the Tasmanian Wilderness World Heritage Area.
The tallest living current hardwood tree known in the world, and the second tallest of all known trees in the world, Centurion, reaches 100.5 metres into the sky. Centurion is a member of the species Eucalyptus regnans, commonly known as swamp gum or mountain ash. This species is among a small number of eucalypts that are fire sensitive, with about a 50% survival rate when exposed to bushfires.

Centurion - the world's tallest hardwood tree at 100.5m tall (Image courtesy of Forestry Tasmania)
Very Tall Forest
Whilst forests more than 70 metres in height are globally rare, there are more than 6300 ha of these found within the Tasmanian Wilderness World Heritage Area. The canopy eucalypts of these forests tower over a lush dense understorey of rainforest which itself reaches heights of over 30 metres.

Very Tall Forest - Coles Creek area, Gordon Range
Fire is essential for the regeneration of these forests.
Disturbance by fire is essential for the regeneration of wet eucalypts. Eucalyptus seedlings are unable to grow in the shady understorey of mature wet forests. Without fire these extraordinary forests would be lost after 500 years. Under natural circumstances bushfires kill some of the mature canopy trees but they also clear away the understorey enabling a new cohort of eucalypts to germinate and grow.