Rainforests and vine thickets are a major vegetation group in Australia. It consists of temperate to tropical rainforests, monsoon forests, and vine thickets. Rainforests and vine thickets are generally found in small pockets across the eastern and northern portions of the continent, including western Tasmania, eastern New South Wales, eastern Queensland, the northern portion of the Northern Territory, and the Kimberley Region of northeastern Western Australia. Rainforests and vine thickets have a present extent of 36,469 km2, of which 22,694 km2 is in protected areas. Rainforests and vine thickets are present in 36 of Australia's bioregions. The largest extent of rainforest in Australia is in the Queensland tropical rain forests ecoregion (Wet Tropics bioregion). The estimated pre-1750 extent is 50,743 km2. Prior to 1750, the largest area of rainforest and vine thicket was in the South Eastern Queensland bioregion, which is part of the Eastern Australian temperate forests ecoregion.
Characteristics Rainforests and vine thickets typically:
are closed-canopy forests, generally with 70% or greater foliage cover. are characterised by trees with dense, horizontally or obliquely-held foliage in the upper layers. are described in terms of leaf size: mesophyll – more than 12.5 cm long (45 – 100 cm2), e.g. tropical rainforest notophyll – 7.5 - 12.5 cm long (2 – 45 cm2), e.g. warm temperate rainforest microphyll – less than 7.5 cm long (2.5 – 20 cm2), e.g. cloud forest. are high in plant-species diversity, which declines with increasing latitude and elevation. are ‘taxonomically-deep’ in biodiversity, with diverse representation of genera, families and orders. are home to plants that regenerate in low light conditions, typically in canopy gaps. have a species composition that varies between successional stages following different kinds of disturbance. are rarely fire-prone. Regular or intense wildfires can destroy the dense moisture-conserving forest cover, which many rainforest and vine thicket species depend on to regenerate and thrive. Where human activity and/or climatic change increase the frequency or intensity of fires, rainforests may be replaced with more fire-tolerant plant communities like sclerophyll forest or woodland. may have emergent eucalypts present within its margins or throughout, depending on disturbance history. vines, epiphytes and mosses are a conspicuous and important element of their structure in tropical and subtropical rainforests. In temperate rainforests epiphytes are less abundant and primarily cryptogams.
Characteristic flora Non-sclerophyllous species dominate rainforests and vine thickets. Many of these species are representatives of the so-called ‘primitive’ flowering plant families such as Winteraceae, Eupomatiaceae, Monimiaceae, Lauraceae, and Cunoniaceae. Other typical plant families include Capparaceae, Celastraceae, Dilleniaceae, Ebenaceae, Euphorbiaceae, Meliaceae, Myrtaceae, Pittosporaceae, Rubiaceae, Rutaceae, Sapindaceae, Sterculiaceae, and Verbenaceae.
Geography Rainforests and vine thickets cover a wide geographic range along the eastern fringe of the continent and across the north, and are absent from central and western Australia. They occur in cool temperate, warm temperate, subtropical, and tropical areas in Queensland, New South Wales, Victoria, Tasmania and as small patches in north coastal Northern Territory and the Kimberley region in Western Australia. Rainforests and vine thickets also grow on Australia's offshore islands, including Christmas Island, Lord Howe Island, and Norfolk Island.
Environment Rain forests and vine thickets occur from sea level up to 1500 metres elevation, mostly within 100 km of the coast. Outliers of vine thicket extend further inland. They are mostly confined to wetter areas or climatic refuges in eastern and northern Australia receiving more than 1200 mm of rainfall annually, but vine scrub and dry rainforest may occur in small patches where average annual rainfall is as low as 600 – 900 mm. At the drier end of the rainfall range, rainforests and vine thickets are typically confined to topographically sheltered sites. Rainforests and vine thickets grow on a range of substrates, including volcanic to sedimentary substrates, alluvial plains, and coastal sand sheets, with moderate to high levels of soil nutrients. Soils can exert a strict control on location and structure within a climatic zone. The influence of soil substrates is muted at the extremes of the tropical-monsoonal dry type and the cool-temperate wet type.
Rainforest communities Major rainforest and vine thicket communities include cool temperate rainforest, tropical or sub-tropical rainforest, warm temperate rainforest, dry rainforest or vine thickets. They can be structured as closed forest (low, mid, and tall), closed fernland (low and mid), closed palmland (low and mid), closed vineland (low and mid), and closed shrubland (tall).
Tropical rainforest Tropical rainforests are tropical evergreen mesophyll closed-canopy forests. Humid evergreen rainforest is mostly limited to northeastern Queensland. These forests are species-rich, with hundreds of tree species growing in Queensland's Wet Tropics, and no one species dominates the canopy. Characteristic genera include Ficus, Toona, Sloanea, Araucaria, Cryptocarya, Diospyros, Syzygium, Archontophoenix, Arthropteris, Linospadix, Calamus, Smilax, Cissus, Platycerium, Adiantum, Asplenium, and Dendrobium. Australia's largest remaining tropical rainforest area is in the Wet Tropics bioregion of northern Queensland, covering more than 20,000 km2. Tropical rainforests which have been extensively cleared include the Atherton Tableland and Eungella Plateau, and coastal Wet Tropics floodplains of Daintree, Barron, Johnstone, Tully–Murray, Herbert, Proserpine and Pioneer River, and tropical lowlands from Cairns to Cooktown.
… excerpt ends here. Continue reading the full article.
