Many species provide living evidence of the Gondwanan origin of the Tasmanian flora. Today, their closest relatives are found on the other continents that once comprised the supercontinent of Gondwana -- South America, New Zealand, Antarctica and southern Africa. Some species are representative of plant communities which were once widespread across the Australian mainland.
The WHA is the Australian stronghold of cool temperate rainforest -- a type of rainforest very different to the better-known tropical rainforests. Some cool temperate rainforest communities are characterised by an open and verdant, cathedral-like quality; a silent, cool, dark and damp place where both the trunks of trees and the forest floor are covered with a luxuriant carpet of mosses and lichens.
The shading canopy of
cool temperate rainforest
(Photo by Steve Johnson)
Within these forests are the descendants of some of the most ancient of Australia's plants. Some species date back over 60 million years, and were dominant components of the vegetation across the Australian continent long before the arrival of the eucalypts and acacias which today dominate the Australian flora. The ancestors of many rainforest species, such as myrtle-beech (Nothofagus cunninghamii), native plum (Cenarrhenes nitida) and leatherwood (Eucryphia lucida) evolved on the ancient continent of Gondwana.
Many rainforest species are extremely fire sensitive. It can take 400 years or more, in the absence of any further fires, for a rainforest to recover to its former glory after fire. Other threats to our rainforests include pests and diseases such as myrtle wilt and phytophthora root rot.
Full details of Tasmania's cool temperate rainforest can be found in our plants of Tasmania section.
Unique alpine communities
Deciduous beech paints the mountains every autumn
(Photo by Steve Johnson)
The most extensive and pristine areas of alpine vegetation in Australia occur within the Tasmanian Wilderness World Heritage Area. These communities differ from the alpine communities of mainland Australia in that the dominant species are shrubs rather than tussock grass and herb-dominant communities of the Australian Alps.
Some 60% of the alpine flora is endemic to Tasmania. These include such species as cushion plants (Donatia, Dracophyllum and Abrotanella spp.) scoparia (Richea scoparia) and Tasmania's only native deciduous species, the deciduous beech (Nothofagus gunnii). The latter species provides the superb autumnal colours of the alpine environment.
The alpine environment is extremely fragile. Bushwalkers and hoofed animals can impact upon the pristine values of alpine vegetation communities, while fire can destroy many alpine species. It is important that management policies reflect the fragility of the environment.
Ancient pencil pines on a lonely moor
(Photo by Steve Johnson)
Most of Tasmania's unique conifers occur within the WHA, including the Huon pine (Lagarostrobus franklinii), which is typically a component of the riverine rainforest habitats in the west of the WHA. It is the second longest lived organism in the world after the Californian bristlecone pine, reaching ages in excess of 3000 years.
The endemic King Billy pine (Athrotaxis selaginoides), pencil pine (A. cuppressoides) and their natural hybrid, A. laxifolia, are the sole representatives of the family Taxodiaceae to be found in the southern hemisphere. This family includes the world's tallest plant, the Californian redwood (Sequoia sempervirens).
As with rainforest species, the conifers of Tasmania are highly susceptible to fire. In certain areas, extensive stands of dead 'stags' bear testimony to the ravages of previous fires. Some species will never recover due to their very slow growth and poor seed dispersal abilities. An as yet unidentified dieback disease is killing pencil pines in the northeast of the WHA.
Buttongrass moorlands are extensive throughout the WHA. The dominant component of these moorlands is the sedge, Gymnoschoenus sphaerocephalus, commonly known as buttongrass. Over 150 vascular plant species from a diverse range of families are found in buttongrass moorlands. One third of these are endemic to Tasmania.
This vegetation occurs on very acid peat soil which are among the most nutrient poor in the world. Nutrients are slow to accumulate due to the high frequency of fires within buttongrass moorlands.
The tallest flowering plant in the world, the swamp gum (Eucalyptus regnans) is one of a number of eucalypt species that dominate the sclerophyllous forests of the WHA. This species can grow to heights in excess of 100 metres.
These forests are noted for their aesthetic beauty, their high biomass production on relatively infertile soils and the successional processes that involve the transition of vegetation from buttongrass moorland through scrub, wet eucalypt forest to rainforest in the absence of fire. Old-growth sclerophyllous forests contain the greatest diversity of living plants and animals in Tasmania.
The WHA is rich in habitats containing rare and threatened plants. Nearly a third of the plant species in Tasmania that are listed as rare or threatened occur within the boundaries of the WHA. Such species include the ancient Kings Holly (Lomatia tasmanica), which is confined to two small areas in the southwest of the WHA, the lily Milligania longifolia which is restricted to cliff faces along a few western rivers, and Centrolepis pedderensis, which is now restricted to the shores of a single lake.
For full details on the threatened species of Tasmania, visit our threatened species site.