Coastal Palm Swamps
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WETLAND MANAGEMENT PROFILE COASTAL PALM SWAMPS Feather and fan palm swamps were once a This typology, developed by the Queensland conspicuous feature of the coastal lowlands of Wetlands Program, also forms the basis for a set North Queensland’s Wet Tropics bioregion. of conceptual models that are linked to Agricultural and urban clearing and wetland dynamic wetlands mapping, both of which can drainage over many years have signifi cantly be accessed through the WetlandInfo website reduced the distribution of these wetlands to <www.derm/qld.gov.au/wetlandinfo>. the point where they are now endangered communities. Ongoing threats to remaining Description feather and fan palm swamps include weed This wetland management profi le describes the palm invasion, wind damage, hydrological changes swamp habitat type that is predominately found in the and the impact of feral pigs. This profi le covers Wet Tropics bioregion of North Queensland. This palustrine wetland habitat type occurs in mesophyll the habitat type of wetlands termed coastal and notophyll vine forests and can be dominated by and sub-coastal tree swamps. one or both of the following palm species: the feather palm Archontophoenix alexandrae (also commonly known as Alexandra palm), and the fan palm Licuala ramsayi (also commonly known as licuala palm). Both typically grow in areas with greater than 3000 mm annual rainfall on very wet poorly drained soils and on sand dunes with seasonally impeded drainage of the Wet Tropics coastal lowlands. Feather palm swamps are found in the lowland fl oodplain and estuarine complexes of river drainage systems. They occur in very wet lowland areas, generally less than 15 m above sea level, on sand dunes with seasonally impeded drainage, or on waterlogged alluvial soils where the watertable is always very high. The soils of these areas are derived from basaltic and granitic parent material, and are generally highly fertile when drained. The agricultural potential of these wetlands was recognised soon after European settlement and consequently they have largely been cleared. Those that remain today are generally on poorer soils. Feather palms get their common name from their pinnate (featherlike) leaves that reach up to 2 m long. The palms grow to approximately 20 m tall and dominate the swamp, with up to 150 000 stems per hectare in some sites. Seedling palms form up to 95 per cent of the total number of palm stems. Fan palm swamps are found below 150 m elevation Map showing the distribution of palm swamps in on the foot slopes, colluvial fans and alluvial plains of Queensland; grey lines indicate drainage basins. coastal ranges with very poorly draining soils that are Map: From Queensland Wetlands Mapping v2.0 (September 2009) seasonally swampy. They are generally associated with poorer quality, metamorphically derived soils, when compared to feather palm swamps. The micro-relief of the palm swamps consists of small incised streams and associated fl ats and depressions between these. Fan palms have almost circular fan-shaped leaves up to 2 m across. In palm swamps they are slow growing, reaching up to 20 m tall, with other scattered emergent trees, including sclerophyllous species, to 36 m. In contrast to feather palm swamps, fan palms constitute only up to 20 per cent of the total number of stems in any site, and these are predominantly mature trees rather than seedlings, since fan palms have low seedling numbers with commonly only 50–500 per hectare. There is greater plant species diversity here than in the feather palm swamps with 247 plant species recorded in recent studies. Of these 60 per cent are trees, with around 20 species present in most fan palm swamps and also in adjacent vine forest and swamp forest types. The fan palm swamps also host a variety of shrubs, vines, epiphytes and herbs. A feather palm swamp Photo: Roger Jaensch, Wetlands International Featherlike leaves of the feather palm Archontophoenix alexandrae Photo: Sue Gardiner Fan-shaped leaves of the fan palm Licuala ramsayi Photo: Roger Jaensch, Wetlands International Up to 150 000 feather palms can be found per hectare of feather palm swamp. Fan palms are found with other scattered emergent Photo: Roger Jaensch, Wetlands International trees in fan palm swamps. Photo: Sue Gardiner 2 state, local and the federal governments. More FEATHER palm swamps formerly information on relevant legislation is available from occurred on the coastal plain between the WetlandInfo website <www.derm.qld.gov.au/wetlandinfo>. Tully and Cairns, while fan palm swamps were distributed between Cape National conservation status Tribulation and Innisfail. Only around Sixty per cent of palm swamps fall within the Wet 40 per cent of the original extent of Tropics of Queensland World Heritage Area. The Wet these wetland habitats remains and they Tropics of Queensland was inscribed on the World Heritage List in 1988 in recognition of its outstanding are restricted to small patches. natural universal values: as an outstanding example representing the major stages in the Earth’s evolutionary history; as an outstanding example representing signifi cant ongoing ecological and Distribution biological processes; as an example of superlative Feather palm swamps formerly occurred on the natural phenomena; and containing important and coastal plain most frequently between Tully and signifi cant habitats for in situ conservation of Cairns, whereas fan palm swamps were distributed biological diversity. between Cape Tribulation and Innisfail. Both are now Some plants and animals of the palm swamps in Info restricted to small patches only. The Wetland Queensland are listed as endangered or threatened website provides in-depth data, detailed mapping and under the Commonwealth Environment Protection distribution information for this wetland habitat type. and Biodiversity Conservation Act 1999 (EPBC Act) The WetlandInfo website provides in-depth data, and/or the Queensland Nature Conservation Act 1992 detailed mapping and distribution information for this and/or the IUCN Red List (see Species of conservation wetland habitat type. signifi cance). Recovery plans which set out research and management actions to support the recovery of Queensland status and legislation threatened species under the EPBC Act are available for some of these species, for example the cassowary Wetlands have many values – not just for conservation (see <www.environment.gov.au/biodiversity>). purposes – and the range of values can vary for each wetland habitat type and location. The Queensland World Heritage properties and threatened species are Government maintains several processes for matters of national environmental signifi cance under establishing the signifi cance of wetlands. These the EPBC Act and, as such, are afforded protection processes inform legislation and regulations to protect under the Act. Any action that will, or is likely to, wetlands, for example, the status assigned to wetlands have a signifi cant impact on a World Heritage under the regional ecosystem (RE) framework. property or threatened species will be subject to an environmental assessment and approval regime under A comprehensive suite of wetlands assessment methods the EPBC Act. for various purposes exists, some of which have been applied in Queensland. More information on wetland Cultural heritage values signifi cance assessment methods and their application is available from the WetlandInfo website Wetland ecosystems are of material and cultural <www.derm.qld.gov.au/wetlandinfo>. Queensland has importance to Indigenous people and many will have also nominated wetlands to A Directory of Important profound cultural signifi cance and values. Indigenous Wetlands of Australia (DIWA), see the appendix. and non-Indigenous (historic) cultural heritage sites have been recorded within palm swamps in The Queensland Government has direct responsibility Queensland. However, most palm swamps have not for the protection, conservation and management of been systematically surveyed or assessed for cultural wetlands in Queensland, a responsibility shared with heritage signifi cance. local government and the Australian Government (for some wetlands of international signifi cance). These Evidence of traditional occupation and use recorded responsibilities are found in laws passed by the within palm swamps include painted and engraved Queensland parliament, laws of the Commonwealth, rock art, burials, ceremonial earth and stone international obligations and in agreements between arrangements, scarred and carved trees, quarries, 3 middens, stone artefacts and scatters, dwellings, open Ecological values camps, fi sh traps, food and fi bre resources and Both feather palm and fan palm swamps contain historic contact sites. Some palm swamp areas have diverse vegetation, with fan palm swamps generally particular signifi cance as story places, landscape being greater in plant species diversity. features and as sites for cultural activities. Almost all plant and animal species have some form Feather palm swamp occur in different positions in the of traditional use or cultural signifi cance (for example landscape: some occur in lowland swamps on alluvial totemic signifi cance). Many plant and animal species soils derived from basaltic and granitic parent material, were used traditionally for food and fi bre. For in the very wet rainfall zone and may have an Acacia example, the seeds, fruits, leaves, shoots, stems, roots celsa canopy. Others occur on steep upper slopes and and tubers of plants were processed