Tasmanian temperate rainforests
The Tasmanian temperate rain forests are a temperate broadleaf and mixed forests ecoregion in western Tasmania. The ecoregion is part of the Australasian realm, which includes Tasmania and Australia, New Zealand, New Guinea, New Caledonia, and adjacent islands.
Rainforest communities in Australia are classified as closed forests in which the canopy comprises 70–100% cover. It can be divided into tropical, subtropical, monsoon and temperate rainforest. Tasmanian rainforest is classified and as cool temperate rainforest, it represents the most floristically complex and best developed form of this forest type in Australia. In Tasmania, they can be found in the West, Savage River National Park, South West, North East and in patches on the East Coast. On the mainland of Australia, cool temperate rainforest have a wide variety of woodland trees, but Tasmania only has a limited number of woodland and vascular plants such as mosses, liverworts, lichen and fungi. Because of this, the definition of Tasmanian cool temperate rainforest was redefined in the 1980s to allow for communities that did not meet the canopy requirements and clearly separate cool temperate rainforest from mixed forest; The current definition states that cool temperate rainforests are those with trees usually greater than in height and capable of regenerating in the absence of large scale catastrophic events, such as fire. These forests are climax vegetation and are dominated by angiosperms such as Nothofagus cunninghamii, Atherosperma moschatum, and Eucryphia lucida as well as gymnosperms such as Athrotaxis selaginoides, Lagarostrobos franklinii and Phyllocladus aspleniifolius. The limited number of woody species is thought to be due to repeated glaciation.
Tasmanian cool temperate rainforest can be divided into four types: Callidendrous rainforest, Thamnic rainforest, Implicate rainforest and Open Montane. These four major types differ in many of their characteristics such as structure, floristics, distribution, level of endemism and ecology.
Community composition and descriptions
The Tasmanian cool temperate rainforest is composed of two alliances, the myrtle-beech alliance and the pencil pine alliance. The former is made up of callidendrous, thamnic and implicate, whilst the latter is all open montane.Callidendrous rainforest
This is the simplest rainforest community in Tasmania; it is typically represented by medium to tall forests dominated by Nothofagus cunninghamii and/or Atherosperma moschatum, often together with Leptospermum lanigerum or Acacia melanoxylon. Typically, these forests are at least in height. Trees are usually well formed and widely spaced, and the understorey is open and often described as park-like. The diversity of woody species is low, and they are usually sparse and inconspicuous throughout the understorey. However, at mid to low altitudes, the understorey may contain a few small trees or shrubs such as Olearia argophylla, Pimelea drupacea, Pittosporum bicolor, Aristotelia peduncularis and Comprosma quadrifida.Fern diversity is high in many areas, and in these areas, epiphytes often flourish. The dominant tree ferns are commonly Dicksonia antarctica and/or Polystichum poliferum. Common epiphyte species include Rumohra adiantiformis, Asplenium gracillimum, Asplenium terrestre, Microsorum diversifolium ," Hymenophyllum flabellatum, Hymenophyllum australe, Hymenophyllum cupressiforme, and Polyphlebium venosum. Histiopteris incisa and Hypolepis rugosula occur in disturbed sites such as along roads where there have been breaks in the canopy.
As altitude increases, the height of the forest decreases, Nothofagus cunninghamii becomes multi-stemmed, develops crooked leaning stems and abundant epiphytic bryophytes, and lichens produce a patterned effect on the trunks. The typical understorey becomes dominated by Tasmannia lanceolata and Telopea truncata, and the ground layer becomes host to Oxalis megellancia and Lagenophora stipitata. The pteridophyte diversity decreases and only small species such as Lycopodium fastigiatum, Hymenophyllum peltatum, Grammitis billardierei and Blechnum penna-marina persist.
Callidendrous rainforests occurs in the eastern half of the state and in northwestern and central Tasmania.
| Species found | %Cover | Type/form |
| Atherosperma moschatum | >75 | Dominant spp |
| Histiopteris insica | 1 | Understorey |
| Dicksonia antarctica | 5 | Understorey |
| Chiloglottis cornuta | 1 | scattered |
| Corybas diemenicus | 1 | scattered |
| Clematis aristata | 1 | scattered |
| Comprosma quadrifida | 1 | scattered |
| Hymenophyllum australia | 1 | scattered |
Thamnic rainforest
Thamnic rainforests are characterised by well-formed trees of medium height, well below, and a distinct shrub layer. The canopy is typically dominated by a mixture of 2–5 species, including Nothofagus cunninghamii, Eucryphia lucida, Atherosperma moschatum, Lagarostrobos franklinii, Eucryphia milliganii, Phyllocladus aspleniifolius, Athrotaxis selaginoides and, rarely, Nothofagus gunnii.The shrub layer is more prominent and has an increased diversity of woody trees. Common species are: Anopterus glandulosus, Anodopetalum biglandulosum, Acradenia frankliniae, Archeria hirtella, Archeria eriocarpa, Cenarrhenes nitida, Trochocarpa cunninghamii, Trochocarpa gunnii, Orites diversifolia, Prionotes cerinthoides, Richea pandanifolia and, at high altitudes, Richea scoparia. The increase in understorey shrub is due to the larger number of gaps in the canopy, and the differing light requirements of competing species. Fern diversity decreases, as a result, because of the decrease in light from the understorey. Parablechnum wattsii is the main ground fern; it prefers damp shaded areas and forms a very dense layer in some areas but can be absent in others. Small epiphytes are widespread, these include Hymenophyllum rarum and Grammitis billardierei. Apteropteris applanata can occur in areas containing Athrotaxis. Other larger epiphytes are usually present, but they are rarely prominent. At higher altitudes, the general appearance resembles that of a callidenderous rainforest, but the floristic differences remain the same.
Thamnic rainforests occur mostly in western and southwestern Tasmania.
| Species | % cover | Type/form |
| Blechnum nudum | 1 | ground cover |
| Anodopetalum bilandulosum | >75 | Understorey |
| Anopteris glandulosa | >50 | Understorey |
| Nothofagus cunninghamii | >75 | Dominant |
| Atherosperma moschatum | >75 | Dominant |
| Eucryphia lucida | 20 | Understorey |
| Phyllocladus asplenifolius | 5 | shrublayer |
Table 2: The Creepy Crawly Nature Walk, Mt Field, Tasmania: Species composition in Thamnic rainforest community; Height ~, 95% of ground leaf cover, scattered rock and bare ground.