Nature conservation

Threatened species

River-Flat Eucalypt Forest on Coastal Floodplains of the New South Wales North Coast, Sydney Basin and South East Corner Bioregions - profile

Indicative distribution


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The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: River-Flat Eucalypt Forest on Coastal Floodplains of the New South Wales North Coast, Sydney Basin and South East Corner Bioregions
Conservation status in NSW: Endangered Ecological Community
Commonwealth status: Not listed
Gazetted date: 17 Dec 2004
Profile last updated: 06 Jul 2019

Description

As the name suggests, this EEC is found on the river flats of the coastal floodplains. It has a tall open tree layer of eucalypts, which may exceed 40 m in height, but can be considerably shorter in regrowth stands or under conditions of lower site quality. While the composition of the tree stratum varies considerably, the most widespread and abundant dominant trees include Eucalyptus tereticornis (forest red gum), E. amplifolia (cabbage gum), Angophora floribunda (rough-barked apple) and A. subvelutina (broad-leaved apple). Eucalyptus baueriana (blue box), E. botryoides (bangalay) and E. elata (river peppermint) may be common south from Sydney, E. ovata (swamp gum) occurs on the far south coast, E. saligna (Sydney blue gum) and E. grandis (flooded gum) may occur north of Sydney, while E. benthamii is restricted to the Hawkesbury floodplain.

A layer of small trees may be present, including Melaleuca decora, M. styphelioides (prickly-leaved teatree), Backhousia myrtifolia (grey myrtle), Melia azaderach (white cedar), Casuarina cunninghamiana (river oak) and C. glauca (swamp oak).

Scattered shrubs include Bursaria spinosa, Solanum prinophyllum, Rubus parvifolius, Breynia oblongifolia, Ozothamnus diosmifolius, Hymenanthera dentata, Acacia floribunda and Phyllanthus gunnii.

The groundcover is composed of abundant forbs, scramblers and grasses including Microlaena stipoides, Dichondra repens, Glycine clandestina, Oplismenus aemulus, Desmodium gunnii, Pratia purpurascens, Entolasia marginata, Oxalis perennans and Veronica plebeia . The composition and structure of the understorey is influenced by grazing and fire history, changes to hydrology and soil salinity and other disturbance, and may have a substantial component of exotic shrubs, grasses, vines and forbs.

For a comprehensive list of species that characterize the community open the Scientific Determination - http://www.environment.nsw.gov.au/determinations/riverflat36a.htm.

The combination of features that distinguish River-Flat Eucalypt Forest on Coastal Floodplains from other endangered communities on the coastal floodplains include: its dominance by either a mixed eucalypt canopy or by a single species of eucalypt belonging to either the genus Angophora or the sections Exsertaria or Transversaria of the genus Eucalyptus; the relatively low abundance or sub-dominance of Casuarina and Melaleuca species; the relatively low abundance of Eucalyptus robusta; and the prominent groundcover of soft-leaved forbs and grasses.

River-Flat Eucalypt Forest on Coastal Floodplains of the NSW North Coast, Sydney Basin and South East Corner bioregions includes and replaces Sydney Coastal River-Flat Forest Endangered Ecological Community.

Distribution

Known from parts of the Local Government Areas of Port Stephens, Maitland, Singleton, Cessnock, Lake Macquarie, Wyong, Gosford, Hawkesbury, Baulkham Hills, Blacktown, Parramatta, Penrith, Blue Mountains, Fairfield, Holroyd, Liverpool, Bankstown, Wollondilly, Camden, Campbelltown, Sutherland, Wollongong, Shellharbour, Kiama, Shoalhaven, Palerang, Eurobodalla and Bega Valley but may occur elsewhere in these bioregions.

Major examples once occurred on the floodplains of the Hunter, Hawkesbury, Moruya, Bega and Towamba Rivers, although many smaller floodplains and river flats also contain examples of the community. The remaining area is likely to represent much less than 30% of its original range. Recently recorded, major occurrences include: about 2,000 ha in the lower Hunter region; less than 10,000 ha on the NSW south coast from Sydney to Moruya, of which up to about three-quarters occurred on the Cumberland Plain in 1998; and less than 1,000 ha in the Eden region.

Small areas of the community are contained within existing conservation reserves, including Blue Mountains, Cattai, Dharug, Georges River, Marramarra, Morton, Deua and Wadbilliga National Parks, and Gulguer and Mulgoa Nature Reserves, but these are unevenly distributed throughout the range and unlikely to represent the full diversity of the community. The reserved examples are on localised, sheltered river flats between hills, rather than the large open floodplains that comprised the majority of the original habitat.

Habitat and ecology

  • Given its habitat, the community has an important role in maintaining river ecosystems and riverbank stability
  • Associated with silts, clay-loams and sandy loams, on periodically inundated alluvial flats, drainage lines and river terraces associated with coastal floodplains.
  • Generally occurs below 50 m elevation, but may occur on localised river flats up to 250 m above sea level.
  • The structure of the community may vary from tall open forests to woodlands, although partial clearing may have reduced the canopy to scattered trees.
  • Typically form mosaics with other floodplain forest communities and treeless wetlands, and often fringe treeless floodplain lagoons or wetlands with semi-permanent standing water.
  • River-Flat Eucalypt Forest on Coastal Floodplains provides habitat for a broad range of animals, including many that are dependent on trees for food, nesting or roosting. These include cormorants and egrets, the Osprey (Pandion haliaetus), Whistling Kite (Haliastur sphenurus), White-bellied Sea-eagle (Haliaeetus leucogaster), as well as the Brush-tailed Phascogale (Phascogale tapoatafa), Yellow-bellied Glider (Petaurus australis), Squirrel Glider (Petaurus norfolcensis), Sugar Glider (Petaurus breviceps) and Grey-headed Flying Fox (Pteropus poliocephalus).

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.


Threats

Recovery strategies

Activities to assist this species

Information sources

IBRA Bioregion IBRA Subregion Known or predicted Geographic restrictions region
NSW North CoastKaruah Manning Known None
Other StateJervis Bay Territory Known None
South East CornerBateman Known None
South East CornerSouth East Coastal Ranges Known None
Sydney BasinBurragorang Known between Thirlmere and Werombi
Sydney BasinCumberland Known None
Sydney BasinHunter Known None
Sydney BasinIllawarra Known None
Sydney BasinJervis Known None
Sydney BasinPittwater Known vicinity of Canada Bay LGA, within 1 km of Hawkesbury-Nepean River
Sydney BasinSydney Cataract Known northern and western edge of sub-region, near Cumberland Plain
Sydney BasinWollemi Known within 1 km of Hawkesbury-Nepean River
Sydney BasinWyong Known None
Sydney BasinYengo Known within Cumberland Plain at southern end of sub-region