Lowland Rainforest of Subtropical Australia - profile

Gazetted date: 25 Nov 2011

Profile last updated: 11 Oct 2022

Location The ecological community primarily occurs from Maryborough in Queensland to the Clarence River (near Grafton) in New South Wales (NSW). The ecological community also includes isolated areas between the Clarence River and Hunter River such as the Bellinger and Hastings valleys. The ecological community occurs in the following Interim Biogeographic Regionalisation for Australia Version 6.1 (IBRA) Bioregions: South Eastern Queensland Bioregion and NSW North Coast Bioregion. Physical environment The ecological community occurs on basalt and alluvial soils, including sand and old or elevated alluvial soils as well as floodplain alluvia. It also occurs occasionally on enriched rhyolitic soils and basaltically enriched metasediments. Lowland Rainforest mostly occurs in areas <300 m above sea level. Aspect can result in the ecological community being found at >300 m altitude on north-facing slopes, but typically 300 m defines the extent of the lowlands. In addition, Lowland Rainforest typically occurs in areas with high annual rainfall (>1300 mm). The physical environment where the ecological community occurs is differentiated from the EPBC listed Littoral Rainforest and Coastal Vine Thickets of Eastern Australia ecological community (hereafter referred to as Littoral Rainforest) by the level of coastal or estuarine influence (such as windshear). Lowland Rainforest typically occurs more than 2 km from the coast, however, it can (and does) intergrade with Littoral Rainforest in some coastal areas. Vegetation structure The ecological community is generally a moderately tall (=20 m) to tall (=30 m) closed forest (canopy cover =70%). Tree species with compound leaves are common and leaves are relatively large (notophyll to mesophyll). Typically there is a relatively low abundance of species from the genera Eucalyptus, Melaleuca and Casuarina. Buttresses are common as is an abundance and diversity of vines. Lowland Rainforest has the most diverse tree flora of any vegetation type in NSW (Floyd, 1990a) and the species composition of the canopy varies between local stands and between regions (Keith, 2004). The ecological community typically has high species richness (= 30 woody species from Appendix A). The canopy comprises a range of tree species but in some areas a particular species may dominate e.g. palm forest, usually dominated by Archontophoenix cunninghamiana (bangalow palm) or Livistona australis (cabbage palm); and riparian areas dominated by Syzygium floribundum (syn. Waterhousea floribunda) (weeping satinash/weeping lilly pilly). The canopy is often multilayered consisting of an upper, discontinuous layer of emergents, over the main canopy and subcanopy. Below the canopy is an understorey of sparse shrubs and seedlings. The upper, discontinuous layer includes canopy emergents that may be 40–50 m tall and have large spreading crowns. This layer is composed of species such as Araucaria cunninghamii (hoop pine), Ficus spp. (figs), Lophostemon confertus (brushbox), and in some sites, Eucalyptus spp.. Typically non-rainforest species such as eucalypts and brushbox comprise <30% of canopy emergents. The canopy/subcanopy layer contains a diverse range of species. Representative species include: hoop pine, figs, Argyrodendron trifoliolatum/Heritiera trifoliolata (white booyong), Castanospermum australe (black bean), Cryptocarya obovata (white walnut, pepperberry) Dendrocnide excelsa (giant stinging tree), Diploglottis australis (native tamarind), Dysoxylum fraserianum (rosewood), Dysoxylum mollissimum (red bean), Elattostachys nervosa (green tamarind), Endiandra pubens (hairy walnut), Flindersia schottiana (bumpy ash, cudgerie, silver ash), Gmelina leichhardtii (white beech), Neolitsea australiensis (bolly gum), Neolitsea dealbata (white bolly gum), Sloanea australis (maiden?s blush), Sloanea woollsii (yellow carabeen), Toona ciliata (red cedar), and epiphytes such as Platycerium spp. and Asplenium australasicum (bird?s nest fern). In areas where the canopy is lower (<25 m) due to coastal or estuarine influences the Littoral Rainforest ecological community typically replaces the Lowland Rainforest ecological community. The understorey contains a sparse layer of species such as Cordyline stricta (narrow-leaved palm lily), Linospadix monostachya (walking stick palm), Neolitsea dealbata (white bolly gum), Notelaea johnsonii (veinless mock olive), Pittosporum multiflorum (orange thorn), Triunia youngiana (native honey-suckle bush), Wilkiea austroqueenslandica (smooth wilkiea) and Wilkiea huegeliana (veiny wilkiea) as well as seedlings of a variety of canopy species. A variety of vines may be present such as Calamus muelleri (lawyer vine), Cissus antarctica (native grape vine, water vine), Cissus hypoglauca (giant water vine), Dioscorea transversa (native yam), Flagellaria indica (whip vine), Morinda jasminoides (sweet morinda), Pandorea floribunda (wonga wonga vine) and Smilax australis (sarsaparilla). Ferns such as Adiantum hispidulum (rough maidenhair fern), Doodia aspera (rasp fern), Lastreopsis decomposita (trim shield fern) and Lastreopsis marginans (bordered shield fern, glossy shield fern) may also be present. Fauna The diversity of rainforest plants and the high nutritional content of their fruits and leaves provide the foundation for the high diversity of animals in the ecological community. This is a direct reflection of the high nutrient soils and moist environment occupied by this rainforest type. Remnants and regenerating patches of Lowland Rainforest provide important habitat and food resources for a range of fauna. In turn the Lowland Rainforest flora also relies on the native fauna for pollination and seed dispersal. Lowland Rainforest is characterised by a high proportion of frugivorous birds, epiphyte and litter foraging vertebrates, micro- and mega-chiropteran bats, and a broad range of invertebrate groups associated with the decomposition cycle (such as insects and snails). Lowland Rainforest has an influx of birds in the cooler months (mainly April to September) from higher altitudes (Holmes, 1987; Osborne, 1991). These species include the regent bowerbird, Acanthorhynchus tenuirostris (eastern spinebill), Columba leucomela (white Threatened species headed pigeon), Dicrurus bracteatus (spangled drongo), Gerygone mouki (brown gerygone), Lopholaimus antarcticus (topknot pigeon), Petroica rosea (rose robin), Pachycephala pectoralis (golden whistler), Ptilonorhynchus violaceus (satin bowerbird), Rhipidura albiscapa (grey fantail), and Zoothera lunulata (Bassian thrush). Frugivorous species present throughout the year include the Australasian figbird, wompoo fruit-dove, Ailuroedus crassirostris (green catbird), Alisterus scapularis (Australian king-parrot), Lalage leucomela (varied triller), Macropygia amboinensis (brown cuckoo-dove), Meliphaga lewinii (Lewin?s honeyeater) and Strepera graculina (pied currawong) (Holmes, 1987). The relationships between the Lowland Rainforest ecological community and associated fauna is emphasised by the distributional limits of some vertebrate species aligning with the distributional limit of the ecological community. The rose-crowned fruit-dove (Vulnerable in NSW), although widely distributed in subtropical rainforest, reaches its southern breeding limit in the lower Clarence Valley and does not occur regularly south of the Hunter River NSW Scientific Committee, 2008). The southern limit of the marbled frogmouth, whiteeared monarch and eastern tube-nosed bat also align with the southern limit of the ecological community (Milledge pers. comm. 2010). The northern limits of distribution of some other rainforest vertebrates align with the northern limit of the ecological community. These include the green catbird, southern forest dragon, Hoplocephalus stephensii (Stephen?s banded snake), Ptiloris paradiseus (paradise riflebird), Saproscincus rosei (Rose?s shadeskink) and Thylogale thetis (red-necked pademelon) (Milledge pers. comm. 2010). Several other rainforest vertebrates are also endemic to the latitudinal extent of the ecological community but also extend to higher elevations. These include the subtropical antechinus, Menura alberti (Albert?s lyrebird) and Philoria loveridgei (Loveridge?s frog) (Milledge pers. comm. 2010). In order to meet the definition of the TEC sites must satisfy condition criteria stipulated in the Listing Advice and/or Conservation Advice. Typically condition is assessed by reference to patch size and vegetation structure thresholds or species composition metrics.