This subtropical forest occurs on the coastal floodplains of the North Coast of NSW. It has a tall open tree layer of eucalypts, angophoras, melaleucas and bloodwoods, 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. siderophloia (grey ironbark), Corymbia intermedia (pink bloodwood) and, north of the Macleay floodplain, Lophostemon suaveolens (swamp turpentine).
Other trees may be scattered throughout at low abundance or locally common at few sites, particularly where there is an influence from lithic substrates upslope. These include Eucalyptus moluccana (grey box), E. propinqua (grey gum), E. seeana (narrow-leaved red gum), Angophora subvelutina (broad-leaved apple), E. robusta (swamp mahogany), Eucalyptus resinifera subsp. hemilampra (red mahogany), E. acmenoides (white mahogany), Angophora woodsiana, A. paludosa and rainforest trees such as Ficus spp. (figs) and Cupaniopsis spp. (tuckeroos).
A layer of small trees may be present, including Allocasuarina torulosa (forest oak), Alphitonia excelsa (red ash), Glochidion ferdinandi (cheese tree), Callistemon spp., Melaleuca spp. and Casuarina glauca (swamp oak).
Scattered shrubs include Breynia oblongifolia, Acacia concurrens, Commersonia spp., and Hibiscus spp. Occasional vines include Eustrephus latifolius, Parsonsia straminea and Geitonoplesium cymosum. The groundcover is composed of abundant forbs, scramblers and grasses including Imperata cylindrica, Themeda australis, Vernonia cinerea, Dianella caerulea, Pratia purpurascens, Cheilanthes sieberi and Dichondra repens.
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 grasses, vines and forbs. For a comprehensive list of species that characterise the community open the Scientific Determination link in the top right box.
Distribution
Subtropical Coastal Floodplain Forest is known from parts of the Local Government Areas of Tweed, Byron, Lismore, Ballina, Richmond Valley, Clarence Valley, Coffs Harbour, Bellingen, Nambucca, Kempsey, Hastings, Greater Taree, Great Lakes and Port Stephens, but may occur elsewhere in this bioregion. Major examples once occurred on the floodplains of the Tweed, Richmond, Clarence, Macleay, Hastings and Manning Rivers, although smaller floodplains would have also supported considerable areas of this community.
The extent of the Subtropical Coastal Floodplain Forest prior to European settlement has not been mapped across its entire range. However, the remaining area of Subtropical Coastal Floodplain Forest is likely to be considerably smaller and is likely to represent much less than 30% of its original range. There are less than 350 ha of native floodplain vegetation on the Tweed lowlands.
Small areas of Subtropical Coastal Floodplain Forest are contained within existing conservation reserves, including Stotts Island, Ukerebagh and Limeburners Creek Nature Reserves and Bundjalung and Myall Lakes National Parks. These are unevenly distributed throughout the range and unlikely to represent the full diversity of the community.
Habitat and ecology
- Occupies central or marginal parts of floodplains and sandy flats, including Pleistocene back-barrier flats; habitats where flooding is periodic and soils are rich in silt and sand, sometimes humic, and show little influence of saline ground water.
- Associated with clay-loams and sandy loams, on periodically inundated alluvial flats, drainage lines and river terraces associated with coastal floodplains.
- Generally occurs below 50 m, but may occur on localised river flats up to 250 m elevation.
- May form mosaics with other floodplain forest communities and treeless wetlands, and often fringe treeless floodplain lagoons or wetlands with semi-permanent standing water.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.