Eastern Suburbs Banksia Scrub in the Sydney Basin Bioregion - Determination to make a minor amendment to Part 3 of Schedule 1 of the Threatened Species Conservation Act

The Scientific Committee is of the opinion that the amendment is necessary or desirable to correct minor errors or omissions in the Determination in relation to the Thackway and Cresswell (1995) reference and to clarify the description of the ecological community.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. The Eastern Suburbs Banksia Scrub is the accepted name for the ecological community occurring on nutrient poor sand deposits in the Sydney Basin Bioregion. Bioregions are defined in Thackway and Cresswell (1995).

2. It has the structural form predominantly of sclerophyllous heath or scrub occasionally with small areas of woodland or low forest, with, depending on local topography and drainage conditions, limited wetter areas.

3. The Eastern Suburbs Banksia Scrub in the Sydney Basin Bioregion is characterised by the following assemblage of species.

4. The total flora species list for the community may be larger than that given above, with many species present only in one or two sites or in very small quantity. In any particular site, not all of the assemblage listed above may be present. At any one time some species may only be present as seeds in the soil seed bank with no above ground individuals present. Invertebrate species are poorly known but some species may be restricted to soils or canopy trees and shrubs. The species composition of a site will be influenced by the size of the site and by its recent disturbance history. For a number of years after a major disturbance dominance by a few species (such as Kunzea ambigua or Leptospermum laevigatum ) may occur, with gradual restoration of a more complex floristic composition and vegetation structure over time. The balance between species will change with time since fire, and may also change in response to changes in fire regimes (e.g. fire frequency).

5. The Eastern Suburbs Banksia Scrub in the Sydney Basin Bioregion is distinguished from the coastal heath which occurs along the eastern seaboard on soils derived either directly from sandstone or, if aeolian, of younger age than those of the Eastern Suburbs Banksia Scrub. Coastal heath is characteristically much lower than Eastern Suburbs Banksia Scrub and, although sharing many species with the Eastern Suburbs Banksia Scrub, characteristically contains a more maritime element including Baeckea imbricata, Correa alba and Westringia fruticosa.

Heathland with Banksia aemula has been recorded from the Central Coast by Benson & Howell (1994). These stands have a less dense shrub layer, a greater density of graminoids in the ground layer and differences in total floristics when compared with Eastern Suburbs Banksia Scrub in the Sydney Basin Bioregion as defined in this determination and are not regarded as part of this community.

6. The Community has been reported from areas of sand deposits in the local government areas of Botany, Manly, Randwick, Waverley and Woollahra which are all within the Sydney Basin Bioregion. On North Head, within Manly local government area the ecological community occurs on a sand sheet of similar age and composition to that on which the ecological community occurs further south. Bioregions are defined in Thackway and Cresswell (1995).

7. The Scientific Committee noted that general information on the Eastern Suburbs Banksia Scrub is provided in Benson D & Howell J 1990. 'Taken for Granted – The Bushland of Sydney and its Suburbs'. Kangaroo Press, Kenthurst.

8. Less than 1% of the original area of the community currently exists in the form of a number of remnants.

9. Threats to the survival of the community include fragmentation, development, increased nutrient status, inappropriate fire regimes, invasion by exotic plants, grazing by horses and rabbits, erosion from use of bicycles, motorcycles and from excessive pedestrian use.

10. Although a small part of the surviving Eastern Suburbs Banksia Scrub in the Sydney Basin Bioregion is included within the Botany Bay National Park, this in itself does not ensure the survival of the community unless the threats to the integrity of the community are ameliorated.

11. In view of the above the Scientific Committee is of the opinion that the Eastern Suburbs Banksia Scrub in the Sydney Basin Bioregion is likely to become extinct in nature in New South Wales unless the circumstances and factors threatening its survival cease to operate.

Dr Richard Major
Chairperson
Scientific Committee

Proposed Gazettal date: 14/10/11
Exhibition period: 14/10/11 - 9/12/11

Note this ecological community was originally listed in 2002 as indicated in the determination

Reference:

Benson, D. & Howell, J. (1994). The natural vegetation of the Sydney 1:100,000 map sheet. Cunninghamia 3(4), 679 – 787

Thackway R, Cresswell ID (1995) An interim biogeographic regionalisation for Australia: a framework for setting priorities in the National Reserves System Cooperative Program. (Version 4.0. Australian Nature Conservation Agency: Canberra.)