Castlereagh swamp woodland community - endangered ecological community listing

NSW Scientific Committee - final determination



The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the Castlereagh Swamp Woodland Community as an ENDANGERED ECOLOGICAL COMMUNITY on Part 3 of Schedule 1 of the Act. Listing is provided for by Part 2 of the Act.

The Scientific Committee has found that:

1. The Castlereagh Swamp Woodland (CSWL) is the name given to the plant community that is characterised by the following assemblage of species:

  • Angophora bakeri
  • Banksia oblongifolia
  • Baumea articulata
  • Boronia polygalifolia
  • Callistemon linearis
  • Cyperus flaccidus
  • Dianella revoluta
  • Elatine gratioloides
  • Eleocharis sphacelata
  • Eragrostis elongata
  • Eucalyptus parramattensis subsp. parramattensis
  • Eucalyptus sclerophylla
  • Eucalyptus sideroxylon
  • Goodenia paniculata
  • Gratiola pedunculata
  • Hakea sericea
  • Kunzea capitata
  • Lepidosperma spp
  • Leptospermum polygalifolium
  • Lepyrodia anarthria
  • Lepyrodia muelleri
  • Lythrum hyssopifolia
  • Melaleuca decora
  • Melaleuca erubescens
  • Melaleuca nodosa
  • Melaleuca thymifolia
  • Philydrum lanuginosum
  • Pultenaea villosa
  • Themeda australis
2. The total species list of the community is larger than that given in 1 (above), with many species present in only one or two sites or in very small quantity. In any particular site not all of the assemblage listed in 1 may be present. At any one time, seeds of some species may only be present in the soil seed bank with no above-ground individuals present. The species composition of the site will be influenced by the size of the site and by its recent disturbance history. The number of species and the above-ground composition of species will change with time since fire, and may also change in response to changes in fire frequency.

3. The structure of the community is generally woodland or may occur as remnant trees. Characteristic tree species in the CSWL are Eucalyptus parramattensis subsp. parramattensis and Melaleuca decora. Small billabongs and/or wetlands may occur within the community.

4. Species composition at any site depends on local topography and drainage conditions; understorey may be seasonally waterlogged.

5. CSWL has been recorded from the local government areas of Bankstown, Hawkesbury, Liverpool and Penrith.

6. CSWL typically is associated with poorly-drained depressions and creeklines on clay soils associated with Tertiary alluvium.

7. CSWL includes the vegetation described as map unit 14c of Benson (1992) and as Castlereagh Woodlands and Wetlands in the Urban Bushland Biodiversity Survey, NPWS (1997).

8. CSWL provides habitat for a number of plant species recognised as being of regional conservation significance in the Urban Bushland Biodiversity Survey, NPWS (1997). These include:

  • Cyperus haspan
  • Eriocaulon scariosum
  • Glossostigma cleistanthum
  • Goodenia dimorpha var. angustifolia
  • Isachne globosa
  • Lepidosperma longitudinale
  • Myriophyllum simulans
  • Sacciolepis indica
9. CSWL has an understorey that may be either grassy or herbaceous with many annual and ephemeral species which respond to wet conditions. The shrub layer can be mid-dense to sparse depending on frequency and period since the last fire.

10. Adjacent communities are generally on better-drained soils derived from Tertiary alluvium and may include Castlereagh Ironbark Forest, Castlereagh Scribbly Gum Woodland and Shale-Gravel Transition Forest, Urban Bushland Biodiversity Survey, NPWS (1997). Castlereagh Swamp Woodland may intergrade with adjacent Castlereagh Woodland communities, and these intergrade areas should be considered part of the Castlereagh Swamp Woodland community.

11. Occurrences of CSWL are all less than 100 hectares in size and are restricted to low-lying terrain. They are subject to weed invasion related to nutrient enrichment from surrounding urban and rural areas as well as from direct destruction for hobby farm, rural and residential development, and clay and shale extraction. Additional threatening processes include sedimentation, rubbish dumping, recreational vehicles and trail bikes.

12. Small areas of CSWL are included in Castlereagh Nature Reserve.

13. In view of the small size of existing remnants the threat of further clearing and other threatening processes, the Scientific Committee is of the opinion that the Castlereagh Swamp Woodland Community is likely to become extinct in nature in New South Wales unless factors threatening its survival or evolutionary development cease to operate and that listing as an endangered ecological community is warranted.

Proposed Gazettal date: 24/12/99

Exhibition period: 24/12/99 - 4/2/00


References

NPWS (1997) Urban Bushland Biodiversity Survey (NSW National Park and Wildlife Service: Hurstville).

Benson, D. (1992) The natural vegetation of the Penrith 1:100 000 map sheet. Cunninghamia 2(4):541-596.

About the NSW Scientific Committee

Page last updated: 28 February 2011