Characteristics of Threatened Communities

Cool Temperate Rainforest Community

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Cool Temperate Rainforest Community

Rainforest is defined ecologically as forest vegetation with a more-or-less continuous rainforest tree canopy of variable height, and a characteristic diversity of other plant species and life forms.

Cool Temperate Rainforest is dominated by combinations of Myrtle Beech (Nothofagus cunninghamii), Southern Sassafras (Atherosperma moschatum = A. moschatum subsp. moschatum), Black Olive-berry (Elaeocarpus holopetalus) and Blackwood (Acacia melanoxylon) according to the site, the dominant tree species varying with the longitude. Cool Temperate Rainforest includes closed transitional and seral communities, with emergent eucalypts, that are similar in botanical composition to mature rainforests in which eucalypts are absent. In these situations a more or less closed rainforest canopy occurs beneath the emergent eucalypts. The understorey is typically dominated by Musk Daisy-bush (Olearia argophylla), Austral Mulberry (Hedycarya angustifolia) and tree-ferns, with a ground stratum dominated by ferns. Epiphytes are abundant on both trees and tree-ferns, and a rich bryophyte flora is also present. In undisturbed conditions, Cool Temperate Rainforest has a closed canopy.

Cool Temperate Rainforest occurs in the Otway and Strzelecki ranges, Central Highlands and East Gippsland. It often occurs along the margins of streams or forms more extensive stands where it has been undisturbed and protected from fire.

Creekline Grassy Woodland (Goldfields) Community

The Creekline Grassy Woodland (Goldfields) Community occurs as small remnants within the box-ironbark ecosystems of Victoria.

Two sub-communities have been identified. Both have River Red Gum (Eucalyptus camaldulensis) forming open overstorey canopy, often with larger old trees. Groundcover is a dense layer of grasses and sedges including Weeping Grass (Microlaena stipoides = M. stipoides var. stipoides), Tall Sedge (Carex appressa), rushes (Juncus spp.), Wirilda (Acacia retinodes = Acacia provincialis), Black Wattle (Acacia mearnsii), and Rough-barked Honey-myrtle (Melaleuca parvistaminea). Broome (Bromus spp.), Quaking-grass (Briza spp.) and Fescue (Vulpia spp.) are commonly-present weed species. Yellow Box (Eucalyptus melliodora) and Grey Box (E. microcarpa) occur in one of the sub-communities, whereas the other has a characteristic understorey dominated by Common Tussock-grass (Poa labillardierei = P. labillardierei var. labillardierei) and Kangaroo Grass (Themeda triandra).

The community occurs as a woodland interface between the undulating sedimentary rises and the geologically younger alluvial plains. It fringes shallow or ephemeral drainage lines on the lower slopes of box-ironbark forests, but is distinct from the riparian vegetation found along permanently flowing streams on the alluvial plains.

Devonian Limestone Pomaderris Shrubland Community

Structurally, the Devonian Limestone Pomaderris Shrubland Community is a low closed shrubland with the dominant shrubs including Limestone Pomaderris (Pomaderris oraria subsp. calcicola), which is most common, Sticky Hop-bush (Dodonea viscosa subsp. angustifolia) and Tree Violet (Hymenanthera dentata = Melicytus dentatus). There are occasional small emergent trees such as Limestone Blue Wattle (Acacia caerulescens), Lightwood (Acacia implexa), Drooping She-oak (Allocasuaurina verticillata), Kurrajong (Brachychiton populneus = B. populneus subsp. populneus) and Sweet Pittosporum (Pittosporum undulatum) and a diverse herb layer with the most abundant species including: Short-stem Sedge (Carex breviculmis), Barb-wire Grass (Cymbopogon refractus), Black-fruit Saw-sedge (Gahnia melanocarpa), Variable Sword-sedge (Lepidosperma laterale), Long-leaved Wallaby Grass (Danthonia longifolia = Rytidosperma longifolia), Common Wheat-grass (Elymus scaber­ = E. scaber var. scaber) and Kangaroo Grass (Themeda australis = Themeda triandra).

Forbs in this community are diverse. The most ubiquitous native species are Kidney Weed (Dichondra repens), Bedstraw (Galium migrans), Austral Tobacco (Nicotiana suaveolens) and Grassland Wood-sorrel (Oxalis perennans), together with the rock specialists Cockspur Flower (Plectranthus parviflorus), Rough Fireweed (Senecio hispidulus subsp. dissectus = Senecio bathurstianus) and Forest Nightshade (Solanum prinophyllum).

This community is a highly restricted component of the Karst landscape of the Buchan-Murrindal district in east Gippsland. It appears to be confined to dry situations associated with steep limestone areas on the crests of cliffs and the basal screes that develop in conjunction with streams. Only three stands are known: from public land at the Anticline and the Pyramids (Caves Reserves) and the Snowy River National Park at Jacksons Crossing, as well as a few sites on private land on cliffs associated with the Buchan and Murrindal River valleys. It is estimated that less than 20 ha of the community currently exists.

The unstable nature of the soils on which the community occurs predisposes it to serious and ongoing weed invasion. A lack of knowledge regarding appropriate fire regimes may lead to changes in community structure and composition, which include weed invasion and, in some cases, a conversion to Dry Rainforest.

Dry Rainforest (Limestone) Community

The Dry Rainforest (Limestone Community) is universally characterized by a continuous closed canopy of Sweet Pittosporum (Pittosporum undulatum) with occasional individuals of Drooping Sheoak (Allocasuarina verticillata) with or without emergent Kurrajong (Brachychiton populneus = B. populneus subsp. populneus).

Muttonwood (Rapanea howittiana) is often present, even as a canopy species, while Lightwood (Acacia implexa) is also capable of population maintenance by root suckering in the absence of fire. Less commonly Black Wattle (Acacia mearnsii) and occasionally the bird-dispersed Common Boobialla (Myoporum insulare) have been noted in these stands. A canopy vine flora is not always well-developed structurally, although Staff Climber (Celastrus australis) and Milk-vine (Marsdenia rostrata) and, less commonly, Wonga Vine (Pandorea pandorana) and Mountain Clematis (Clematis aristata) may be present. The sub-canopy vine flora is dominated by Wombat Berry (Eustrephus latifolius), Scrambling Lily (Geitonoplesium cymosum) and Austral Sarsaparilla (Smilax australis). The understorey is typically very open, with a few scattered spiny bushes such as Prickly Currant-bush (Coprosma quadrifida) the only regular sub-canopy species. Eastern Nightshade (Solanum pungetium) and Tree Violet (Hymenanthera dentata) are usually present but most often restricted to the margins of the stands. Significantly, there are often scattered individuals of Limestone Pomaderris (Pomaderris oraria ssp. calcicola).

The fern flora is represented mainly by lithophyte species such as Common Spleenwort (Asplenium trichomanes subsp. quadrivalens), Green Rock Fern (Cheilanthes austrotenuifolia), Bristly Cloak-fern (C. distans), Narrow Rock Fern (C. sieberi subsp. sieberi), Blanket Fern (Pleurosorus rutifolius) and Chinese Brake (Pteris vittata). The other abundant ferns are the drought-tolerant species usually expected of this type of vegetation, with Sickle Fern (Pellaea falcate), Tender Brake (Pteris tremula) and the Necklace Fern (Asplenium flabellifolium) being the most common. Tree ferns and other moisture-dependent fern taxa are consistently absent. Herbs and grasses can be particularly abundant. Both may be quite diverse on Devonian Limestone, but much less so on Tertiary Limestones. The majority of grasses found in this community are not found in Dry Rainforest (Gorges) Community. Unless otherwise indicated, these species consistently occur beneath the canopy, and include Barb-wire Grass (Cymbopogon refractus; gaps only), Weeping Grass (Microlaena stipoides = M. stipoides var. stipoides), Grey Tussock-grass (Poa sieberiana; mostly gaps), Common Wheat-grass (Elymus scaber), Kangaroo Grass (Themeda triandra; gaps only) and the highly shade-tolerant species Feathery Wheat-grass (Australopyrum retrofractum). Long-leaf Wallaby-grass (Notodanthonia longifolia) is the only species consistently and commonly found in both Dry Rainforest floristic communities. The common herbs in the Dry Rainforest (Limestone) Community are also drought-tolerant species. Those found primarily in gaps are Austral Tobacco (Nicotiana suaveolens; Devonian Limestones), Australian Stonecrop (Crassula sieberiana), Australian Hound’s-tongue (Cynoglossum australe). Beneath the canopy, where shade tolerance is needed, species such as Kidney-weed (Dichondra repens), Saloop Saltbush (Einadia hastata), Nodding Saltbush (E. nutans), Cockspur Flower (Plectranthus parviflorus), Shade Pellitory (Parietaria debilis) and Scrub Nettle (Urtica incisa) are found. The Dry Rainforest (Limestone) Community also has a complement of graminoids other than grasses: this regularly includes Short-stem Sedge (Carex breviculmis) and Black-fruit Saw-sedge (Gahnia melanocarpa), with the sedge-like drought-tolerant Black-anther Flax-lily (Dianella revoluta) also common. No vascular epiphytes have been recorded from this community.

Dry Rainforests are limited to the most fireproof sites, such as deep rocky gorges, cliff bases and elevated scree slopes, in isolated rain-shadowed valleys in the foothills of East Gippsland where there is a pronounced and extended hot, dry, summer season. The community grows exclusively on the limestone riverine cliffs, on colluvial rock screes which collect at the bases of these cliffs, in collapsed caves (dolines) and on the shores of lakes where this geology is also exposed, at altitudes from sea level to 240 m. Structurally, many stands of the Dry Rainforest (Limestone) Community are based around several very old emergent kurrajong trees, although sites on Tertiary Limestone generally lack this species.

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