Tasmanian Temperate Eucalyptus Forests

Depending on altitude and other factors, the eucalypt forests of Tasmanian may be dominated by various species like Eucalytus bicostata, E. dalrympleana, E. delegatensis, E. ovata, E. regnans, E. subcrenulata and a variety of endemic species such as E. amygdalina, E, coccifera, E. gunnii, E. johnstonii, E. tasmanica, E. urnigera and E. vernicosa (Myrtaceae). In fact, there are some 13 eucalypts endemic to Tasmania. In the lowlands, E. ovata is the most widely distributed species, while other lowland species include the giant E. regnans, which is the tallest of all eucalypts reaching heights of 130 m. These grand forests are limited by their requirement for good fertile soils. On the chert ridges near Maydena, for example, E. regnans is replaced by the endemic E. amygdalina. But where it does occur, it often dwarfs understory trees such as Bedfordia salicina, Olearia argophylla and Pomaderris apetala, which can reach heights of 30 m or so. The few shrubs of these forests include Pittosporum bicolor and various endemic species like Aristolelia peducularis (Elaeocarpaceae) and Tasmannia lanceolata (Winteraceae). Studies show, however, that E. regnans, with a life span of some 350 years, is eventually replaced by the near endemic Nothofagus cunninghamii in the absence of forest fires. Also of predominantly lowland distribution, is the near endemic Eucalytus globulus. It forms forests up to 50 m tall in some coastal areas. Outside Tasmania, two small, possibly relict stands of this species occur in southern Victoria. At elevations between 350-1000m, Eucalytus dalrympleana and E. delegatensis usually become the main species, especially on soils of low fertility. Here the under storey species typically include Bedfordia salicina, Pomaderris apetala and Tasmania lanceolata, while in more open stands, especially under Eucalytus dalrympleana, are Acacia dealbata and the endemic Lomatia tinctoria (Proteaceae). The main eucalypts extending up to the tree line (at an altitude of about 1400 m) are Eucalytus subcrenulata and the endemic E. coccifera, where they experience several months of snow and frost. In fact, these are the most cold resistant of the eucalypts except for the shrubby Eucalytus vernicosa found on the plateaus.

At lower altitudes, particularly in the southeast, Eucalytus coccifera may be partially replaced by the endemic E. johnstonii, and another endemic species Eucalytus urnigera becomes an important constituent of the forest. The shrub layer species of these montane forests vary from place to place. On the dolerite, in the Mt Wellington area near Hobart these include various endemic species such as Cyathodes parvifolia, Richea dracophylla (Epacridaceae), Gaultheria hispida (Ericaceae) and Telopea truncata (Proteaceae). In the Cradle Mountain area, a mallee-like (i.e. tracks of land dominated by many-stemmed eucalypts) community has developed in which Eucalytus coccifera is co-dominant with Nothofagus cunninghamii and the endemic Phyllocladus aspeniifolius (Podocarpaceae). In these boulder-strewn forests there is a wealth of shrubs including the endemic conifer Microcachrys tetragona (Podocarpaceae), and Bellendena montana (Proteaceae), which is also endemic at generic level. Moving to the northeast to the Ben Lomond, for example, Eucalytus coccifera is replaced by the endemic Eucalytus gunnii as the main tree line species. It also occurs on the central Plateau, where it may be associated with another endemic Eucalytus rodwayi. The latter tends to occur on or around bleak waterlogged moors. Here the few under storey species that can tolerate such conditions include Leptospermum lanigerum and the endemic Callistemon viridiflorus (Myrtaceae).

Tasmanian Temperate Nothofagus cunninghamii Forest

These once widespread ancient, temperate rainforests dominated by the near endemic Nothofagus cunninghamii are now mainly confined to Tasmania, with a few isolated occurrences in Victoria and in the eastern highlands. In Tasmania they occupy the wetter western areas and range from sea level to about 1000 m, with some of the best stands on the eastern slopes of the Harz Mountains, Nothofagus cunninghamii is an evergreen species that can reach heights of 50 m. The most common associate tree is Atherosperma moschatum while others include endemics such as Dacrydium franklinii (Podocarpaceae), Eucryphia lucida and E. milligani (Eucryphiaceae), and in the sub-alpine zones Phyllocladus aspleniifolius (Podocarpaceae). Shrubs are usually absent, but the tree fern Dicksonia antarctica is frequently present. As with all temperate rain forest, the trees are usually festooned with epiphytes including many bryophytes and ferns and also the unusual Tmesipteris (a member of the primitive seedless vascular plant group Psilopsida that may have given rise to the ferns). The only angiosperm epiphyte is the endemic Prionotes ceritheroides, which is regarded as the most primitive member of the Epacridaceae. The herbaceous ground layer typically includes Histiopteris incisa, Hypolepis rugulosa, and the sedge Gahnia psittacorum in some of the wetter areas. In more open parts of the forest, shrubs and small trees are usually more evident and typically include various endemic species such as Agastachys odorata, Cenarrhenes nitida, Telopea truncata (Proteaceae), Anopterus glandulosus (Escalloniaceae), Aristotelia peduncularis (Elaeocarpaceae) and Richae pandanifolia (Epacridaceae). At higher altitudes, bordering the alpine zones Nothofagus cunninghamii forms thickets, either in pure stands or in association with the two endemics Anodopetalum biglandulosum (Cunonaceae) and Telopea truncata (Proteaceae).

References

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