Comprising the lowland temperate forests around the Great Dividing Range, the Southeast Australian temperate forests encompass a wide variety of plantlife. Unlike the rest of mainland Australia, this region is well-watered with a temperate climate. Wet forest grows along the coast and dry forest and woodland is found inland of the Dividing Range. Avian and mammalian richness is high in this ecoregion, but human impact has been severe. Logging operations and pine plantations are interspersed within the wet forests, and farming and grazing over the last two centuries has modified the drier vegetation. The major urban centers of Canberra and Melbourne are also located in this ecoregion.
Location and general description
The Southeast Australia temperate forests ecoregion is situated along the southeastern coast of Australia, extending inland past the Great Dividing Range and surrounding the Australian Alps montane grasslands ecoregion. It covers most of southern Victoria and runs into the Southern and Central Tablelands regions of New South Wales. Precipitation along the south coast of New South Wales falls uniformly throughout the year, approximately 800 millimetres (mm) to 1000 mm per annum. Rainfall quickly decreases as one moves inland, and is approximately 400 mm to 600 mm per annum along the inland boundary of this ecoregion. Further west along the Victorian coast precipitaion is largely seasonal, concentrated in the austral winter.
During the last glacial maximum, approximately 15,000 years ago, the northern portion of this ecoregion was a treeless cold steppe and alpine grassland. This northern portion consists of low hills inland of the Dividing Range, and includes the lower elevations of the Dividing Range where steep and rugged ranges of Palaeozoic and Mesozoic strata extend from New South Wales into Victoria. Further east towards the coast, deeply dissected ranges of Devonian granites and Palaeozoic sediments give way to gently undulating terraces. Tertiary and Quaternary coastal plains continue along the Victorian coast. Further inland in Victoria, an extensive volcanic basaltic plain leads to the Victorian Midlands, a region of foothills and isolated ranges that comprise the lower, inland slopes of the Great Dividing Range.
A diverse mix of vegetation is found throughout this ecoregion, including coastal vegetation, dense heath, temperate rain forest, riparian communities, wet sclerophyll forests, dry sclerophyll forests, and eucalypt woodlands. Between the coast and the Great Divide, wet sclerophyll forests of medium height grow, with an understory of low shrubs. Dominant species include Brown Stringybark (Eucalyptus baxteri), Manna Gum (E. viminalis), Messmate Stringybark (E. obliqua), and Mountain Grey Gum (E. cypellocarpa). Brown stringybark is restricted to soils of low fertility, whereas messmate stringybark becomes more frequent as soil quality improves. The Great Dividing Range separates these wetter eastern vegetative assemblies from the drier woodlands of the west.
Eucalypt woodland is one of the most heavily altered native plant communities in Australia, and here consists of open, medium-sized trees, with ten to thirty percent foliage cover. Shrubs are rare, but the herbaceous layer is dominated by grasses, such as members of the Kangaroo Grass genus such as Themeda australis. Dominant trees include Grey Box (Eucalyptus microcarpa), and communities of Yellow Box (E. melliodora) and Blakely's Red Gum (E. blakelyi). Box-Ironbark vegetation is found between the drier inland plains and the wetter forests of the Great Dividing Range on gentle to moderate hills. These communities are dominated by grey box, yellow gum (E. leucoxylon) and red ironbark (E. sideroxylon). Spear grasses (Stipa scabra and S. bigeniculata) grow on flat or gently undulating treeless basalt plains near the Geelong area, and on the Southern Tablelands of New South Wales.
The quintessential Australian genus, Eucalyptus dominates in all better-watered regions of Australia, including the Southeast Australia temperate forests. There are approximately 700 species of Eucalyptus, and only seven are found outside Australia. Unlike the rest of mainland Australia, soils here are moderately fertile with a cool temperate climate. Australian temperate eucalyptus forests exhibit a long evolutionary history compared with other continents where glaciation was repeated and extensive. Alpha, beta, and gamma diversity in old growth eucalpyt forests are all high in comparison to temperate forests on other continents. Plant diversity is exceptionally high in the sandstone Grampians Ranges in Victoria, where approximately 1100 plants, or one-third of Victoria's flora are found in the 1700 square-kilometre Grampians National Park. Temperate woodlands also contain a high number of endangered plant species, including the button winklewort (Rutidosis leptorrynchoides).
The Southeast Australian temperate forests harbor a number of restricted range and endemic species. Near endemic birds include the gang-gang cockatoo (Callocephalon fimbriatum), rufous bristlebird (Dasyornis broadbenti), rock warbler (Origma solitaria), and the pilotbird (Pycnoptilus floccosus), which is found in association with the superb lyrebird (Menura novaehollandiae). The endangered swift parrot (Lathamus discolor) migrates to this region from Tasmania each winter and the endangered plains-wanderer (Pedionomus torquatus) lives on volcanic Stipa plains. Among the mammals, the smoky mouse (Pseudomys fumeus VU) is largely restricted to this ecoregion while the agile antechinus (Antechinus agilis) is near-endemic. The endangered Leadbeater's possum (Gymnobelideus leadbeateri) is restricted to wet eucalypt forests of the Victorian Central Highlands. Reptiles of the Southeast Australia Temperate Forests include the striped legless lizard (Delma impar) and the pink-tailed worm-lizard (Aprasia parapulchella). Among the invertebrates, the Mt. Piper region in Victoria is home to a threatened community of ant-attended lycaenid butterflies. This ecoregion is also know for its giant Gippsland earthworms (Megascolides australis), which are restricted to the Bass River Valley region in Victoria.
Due to the wide variety of vegetation found here, this ecoregion is known for its avian and mammalian richness. Avian species assemblages differ significantly between mesic and xeric microclimates in this ecoregion. Many species, such as dasyurid carnivores, bats, owls, and cockatoos are particularly dependent on large areas of old growth eucalypt forest. Mammals found in this ecoregion include the southern subspecies of spotted tail quoll (Dasyurus maculatus maculatus), long-nosed potoroo (Potorous tridactylus), feathertail glider (Acrobates pygmaeus), the eastern pygmy-possum (Cercartetus nanus), and the koala (Phascolarctos cinereus). The mainland subspecies of swamp antechinus (Antechinus minimus maritimus) and white footed dunnart (Sminthopsis leucopus) are largely restricted to coastal regions, while other species, such as the koala, are widespread throughout this ecoregion and excluded from the Central Highlands because of the cold winters.
This ecoregion has been heavily impacted by European settlement, and within the ecoregion the most extensive clearance of native vegetation has occurred to the west of the Dividing Range. Australia's population is highly urbanized and two major cities, Melbourne and Canberra, are located in this ecoregion. Most wet sclerophyll forests were logged and dry forest and woodland converted to pasture and cultivated land following European arrival. Over 90 percent of temperate woodlands in the State of Victoria have been cleared, mostly for agriculture, leaving less than 6,000 km2. Box-ironbark forests have also been greatly depleted and fragmented. Pine plantations, mostly Pinus radiata, are located in the wet sclerophyll forests of this ecoregion. Many of the grassy coastal forests were also cleared for agriculture, and more recently for urban and recreation development. There are protected areas in this ecoregion, but they are mostly located in coastal regions and to the east of the Great Divide, biased to include wet sclerophyll vegetation. Protected areas include Grampians and Wilson's Promontory National Parks in Victoria and Wadbilliga, Deua, and Morton National Parks in New South Wales. However, throughout Australia, approximately half of all eucalypt forests in protected areas have been subject to logging at some point.
Types and severity of threats
Dieback disease caused by Phytophthora spp., inappropriate fire regimes, harmful agricultural management, alluvial gold mining, and alien and feral species are all threats to this ecoregion. Feral species include rabbits (Oryctolagus cuniculus), foxes (Vulpes vulpes), and domesticated cats (Felis catus). A large portion of land has already been transformed into cropping or pasture but rabbits combine with overgrazing and result in additional degradation. Deforestation threatens native species, and recent studies suggest that both selective logging and the creation of linear strips or corridors within forests may be ineffective in fulfilling habitat requirements for the full suite of native fauna.
Justification of ecoregion delineation
The Southeast Australia temperate forests ecoregion includes the low elevation portions of the 'Australian Alps' Centre of Plant Diversity and six Interim Biogeographic Regions of Australis (IBRAs): 'South East Corner', 'South Eastern Highlands', 'South East Coastal Plain', 'NSW South Western Slopes', 'Victorian Midlands' and 'Victorian Volcanic Plain'.
- Australian Surveying and Land Information Group (AUSLIG). 1990. Atlas of Australian Resources: Vegetation. Australian Government Publishing Service, Canberra, Australia.
- Beadle, N. C. W. 1981. The Vegetation of Australia. Cambridge University Press, Cambridge, United Kingdom. ISBN: 0521241952
- Berra, T. M. 1998. A Natural History of Australia. Academic Press, San Diego, California, USA. ISBN: 0120931559
- Good, R. B. 1995. Australian Alps. Pages 458-461 in S. D. Davis, V. H. Heywood and A. C. Hamilton. editors. Centres of Plant Diversity. Volume 2. Asia, Australasia, and the Pacific. WWF/IUCN, IUCN Publications Unit, Cambridge, UK. ISBN: 283170197X
- Lindenmayer, D. B. 1997. Differences in the biology and ecology of arboreal marsupials in forests of southeastern Australia. Journal of Mammalogy 78(4): 1117-1127.
- Lunt, I. and A. F. Bennett. 2000. Temperate woodlands in Victoria: distribution, composition, and conservation. Pages 17-31 in R. J. Hobbs and C. J. Yates, editors. Temperate Eucalypt Woodlands in Australia: biology, conservation, management, and restoration. Surrey Beatty & Sons, Chipping Norton, New South Wales, Australia. ISBN: 0949324868
- Mac Nally, R., T. R. Soderquist, C. Tarzos. 2000. The conservation value of mesic gullies in dry forest landscapes: avian assemblages in the box-ironbark ecosystem of southern Australia. Biological Conservation 93: 293-302.
- Norton, T. W. 1996. Conserving biological diversity in Australia's temperate eucalypt forests. Forest Ecology and Management 85: 21-33.
- Read, I. G. 1994. The bush: a guide to the vegetated landscapes of Australia. University of New South Wales Press, Sydney, Australia. ISBN: 0868402540
- Strahan, R. 1998. The mammals of Australia. Australian Museum/Reed New Holland. Syndey, Australia. ISBN: 1560986735
- Stothers, K., R. Loyn, A. Bennett, A., G. Brown, L. Lumsden, and G. Horrocks. 1999. Forests with character: the box-ironbark region of Victoria. Department of Natural Resources and Environment, Victoria. Flora and Fauna Notes 0051: 1-5.
- Thackway, R. and I. D. Cresswell. editors. 1995. An Interim Biogeographic Regionalisation for Australia: a framework for establishing the national system of reserves, Version 4.0. Australian Nature Conservation Agency, Canberra.
- White, M. E. 1994. After the Greening: the browning of Australia. Kangaroo Press, Kenthurst, New South Wales. ISBN: 086417585X
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