Tasmania is fortunate in possessing a very large number of unique plant species that occur nowhere else in the world. Our rainforest and alpine communities are unique assemblages of plants of great botanical significance. One such group of plants, the native conifers, is particularly important, not only for its botanical values, but also for the role that conifers have played in the history of Tasmania.
The Huon Pine (Lagarostrobos franklinii) derives its common name from the stands which once occurred along the Huon River, itself named after Captain Huon Kermandec, commander of the French ship, L'Esperance. The species is restricted to western and southern Tasmania, where it is largely confined to riverine habitats.
Estimates of the area of living Huon pine vary, but are in the order of 10 500 ha. In addition there are about 800 ha of standing, fire-killed pine. The current area of remaining pine is the remnant of a much wider original range that has been reduced by fire, inundation, logging and mining. Today, the remaining stands are well protected within reserves, the majority being within the World Heritage Area.
Although extremely slow growing, the tree may attain heights of over 40 m. Growth rates average a mere 1mm per year, but can vary from 0.3 mm to 2 mm, depending on conditions. Huon pine can reproduce both vegetatively (from fallen individuals) and by seed. Seed dispersal is largely limited to the area downstream from riverine stands.
The Huon pine can reach prodigious ages, often in excess of 2000 years, with the oldest dated trees exceeding 3000 years of age, making it among the longest-lived organisms on Earth. The bristle-cone pine of North America and the Chilean rainforest species, Fitzroya cupressoides exceed it in age. International headlines were made with the discovery of a stand of Huon pines on Mt Read that was widely quoted as being in excess of 10 000 years of age. All the individuals in this population are genetically identical, and are all males. The stand arose from one or a small number of individuals, and has maintained itself by vegetative reproduction. It is important to remember that no individual tree in the Mt Read stand is 10 000 years old -- rather, the stand itself has been in existence for that long.
The leaf-like cladodes of celery-top pine.
Compare the needles of pencil pine
(left) and King Billy (right).
Laxifolia, a hybrid between
the two, is shown in the centre.
The celery-top pine (Phyllocladus aspleniifolius) is so named due to the resemblance of its 'leaves' to those of celery. In fact, these are not true leaves, but rather cladodes (flattened stems); although very young seedlings have needle-like leaves. the development of cladodes is thought to be an adaptation to the low light levels often present in the habitat in which this species occurs. The tree grows to 30 m in height and may attain a maximum age of 800 years.
Today this slow-growing tree is exploited as a by-product of clearfelling in old-growth forests and is commonly used for external cladding and poles in the building industry.
King Billy pine
The King Billy pine (Athrotaxis selaginoides) is thought to derive its common name from the Tasmanian Aborigine William Lanney, who was referred to as 'King Billy'. It reaches a height of 40 m and may reach ages in excess of 1200 years. The species is restricted to regions above 600 m where it grows in highland rainforest.
Dead pencil pine stags at Mt Field
A close relative of the King Billy pine, the pencil pine (Athrotaxis cupressoides), is generally restricted to sub-alpine areas above 800 m. Like its relative, it can reach ages greater than 1200 years.
Pencil pines are often seen around the shores of highland lakes and tarns, creating the unique ambience of these beautiful areas of Tasmania.
At the mercy of fire
Tasmania's native conifers are highly susceptible to fire. In certain areas of the state, extensive stands of dead 'stags' give testimony to the ravages of previous fires. Some of the largest pure stands of pencil pine have been lost due to campfires which have escaped. Some species will never recover due to their very slow growth and poor seed dispersal abilities. Indeed, one-third of the State's King Billy pines have been eliminated by fire.
The Tasmanian Wilderness World Heritage Area has been declared a "fuel stove only area" in an attempt to prevent the loss of further stands of pine, as well as rainforest and alpine communities, which are also highly susceptible to fire.