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Introduction
Cool temperate rainforests of Tasmania contain the highest diversity of Bryophytes than any other Tasmanian forest vegetation type. This climax vegetation type is dominated by few angiosperms; Nothofagus cunninghamii, Atherosperma moschatum & Eucryphia lucida. These dominant tree species form a closed canopy to shade out other competing angiosperms, creating light limiting conditions in which only plants adapted for these environments can succeed. Ferns and cryptograms can occupy the forest floor, and many other niche microenvironments on a variety of substrates thanks to their rhizoidal physiology.

Bryophytes Importance
The bryophyte communities provide important ecosystem functions within cool temperate rainforests. Their growth and decay provide important nutrient cycling within the Carbon and Nitrogen cycles. Their structure and colonial growth provides habitats for many invertebrates and a few vertebrate species. The moss covered logs and terrestrial surfaces deliver a major role in providing moisture rich substrates for seedling development in cool temperate rainforests. All of these functions are important in maintaining the stability of climax vegetation status. Bryophyte Physiology Bryophytes are nonvascular plants that exist in a haploid dominant state as a gametophyte organism - this is is in contrast to other autotrophic land plants. Mosses can exist in many environments because of they are poikilohydric and desiccation tolerant. Bryophytes do not have roots but rhizoids that that allow them to cling to a variety of substrates. They hydrate their cells through ectohydric features like rhizoidal tomentum or papillae that can wick water across cell surfaces. Some mosses have specialised endohydric structures like hyaline cells that provide intra-organ conduction or hydroid cells that are similar to vascular cells in other land plants. Most bryophytes can reproduce asexually to create clonal growth “super-organisms” or use another means of distribution other than spore dispersal. The sexual sporophyte stage is transitory and is a key feature of dispersal of the bryophytes. Spores released through various means can be blown large distances, and can persist in a limited spore bank for colonization of free spaces created by disturbance. The bryophytes only limited feature is the need for free water for sexual reproduction.

Diversity
Approximately 18,000 species of bryophytes have been estimated to exist. More than 640 species described occur in Tasmania. Many of these described species can exist from costal to alpine habitats, with a majority of the species abundance found within wet forest vegetation types.

Bryophytes are broken into three major phyla. Bryophyta (Musci) – true mosses Marchantiophyta (Hepaticae) – liverworts or scale mosses Anthocerotophyta (Anthocerotae) – hornworts Approximately 157 genera of Bryophyta, or true mosses, are described in Tasmania, but most of these have only a few representative species within each genera. Over 120 genera of Hepatic Liverworts exist in Tasmania. These are divided into two morphologically different types: Jungermannioid, which are leafy liverworts like (eg. Trichocolea mollissima), and Marchantioid that are thallose liverworts (eg. Hymenophyton flabellatum). Leafy liverworts are the dominant subgroup found within Tasmanian cool temperate rainforests. Only one family of the Anthocerotophyta hornworts is represented in Tasmania by 9 species.

List of Common Tasmanian Temperate Rainforest Bryophyte species
Bryophyta - True Moss Marchantiophyta – Liverworts (L=Leafy T=Thallose) Anthocerotophyta – hornworts
 * Achrophyllum dentatum
 * Camptochaete arbuscula
 * Cyathophorum bulbosum
 * Dicranoloma billarderi
 * Dicranoloma menziesii
 * Distichophyllum pulchellum
 * Hypnodendron comosum
 * Hypnum chrysogaster
 * Hypnum cupressiforme
 * Hypopterygium didictyon
 * Leucobryum candidum
 * Ptychomnion aciculare
 * Rhizogonium novae-hollandiae
 * Rosulabryum billarderi
 * Weymouthia cochlearifolia
 * Wijkia extenuate
 * Bazzania involute (L)
 * Gackstroemia weindorferi (L)
 * Heteroscyphus fissistipus (L)
 * Hymenophyton flabellatum (T)
 * Lepidozia glaucophylla (L)
 * Plagiochila fasciculate (L)
 * Schistochila lehmanniana (L)
 * Podomitrium phyllanthus (T)
 * Symphyogyna podophylla (T)
 * Trichocolea mollissima (L)
 * Tylimanthus pseudosaccatus (L)
 * Megaceros sp

Distribution of Bryophytes within Cool Temperate Rainforest
Many bryophyte species are highly dispersed through spores over long distances . This distribution is evident in their abilities to colonize areas after significant disturbances. As such there are patterns to species specifications to age classes of forests.Bryophytes have a relay successional pattern to species transitions with a forest age association. This means that the bryophyte communities exist within a state of transitional flux from early colonizers to more specialized species existing within old growth forests. Any areas of forest that are disturbed are colonized by a succession of different bryophyte species allowing for a greater diversity within forest types. This can be seen in community census surveys where the early colonizer species persist with low numbers within old growth like cool temperate rainforests. Limited ideal environments available for spore germination are the key controlling features of distribution. Even though many bryophytes have desiccation tolerances, moisture availability is required for development. Mosses have the greatest desiccation tolerance of most of the bryophytes. Thallose and leafy Liverworts are less desiccation resistant as they lack some of the features required to survive in dry environments. This might explain the ratios of leafy liverworts to mosses within cool temperate rainforests. The moisture levels found within many western rainforests of Tasmania have a ratio of 2:1 leafy liverwort to moss ratio with no significant partitioning of species across epiphytic and terrestrial substrates. This is in some contrast to eastern Tasmanian rainforests that have a lower mean average rainfall. Liverworts show significant substrate partitioning within the eastern dryer rainforests. Substrates preferences show little effect to moss and liverwort partitioning patterns in wet conditions indicating that higher moisture levels creates an ameliorative effect on the microenvironment. It has been supposed that some bryophytes species might capitalize on this moisture controlling feature to exclude competition for space by affecting humidity at a small localized scale.





This data shows that there are many bryophytes that exist across numerous substrates. This indicates a generalist behavior that may be competitively excluded by those bryophytes that can maintain a higher degree of growth to specific substrata. The level of substrate available for bryophyte colonization is dominated largely by coarse woody debris from fallen branches, trees, and living trees and man ferns (Dicksonia Antarctica).

List of substrate affinity terms

 * Epiphytic on Trunks (Corticolous)
 * Epiphytic on Branches (Pendulous)
 * Epiphytic on Leaves (Epiphyllous)
 * Logs Lignocolous/ Epixylic.
 * Terrestrial Soil (Terricolous)
 * Epilithic on Rocks (Saxicolous)
 * Specialised like Limestone (Calcicolous)
 * Freshwater Aquatic –Riparian
 * Running water (Rheophilous)
 * Stagnant water (Limnophilous)