Quorrobolong Scribbly Gum Woodland 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, established by the Threatened Species Conservation Act, has made a Determination to make a minor amendment to Part 3 of Schedule 1 (Endangered ecological communities) of the Act by inserting the Quorrobolong Scribbly Gum Woodland in the Sydney Basin Bioregion (as described in the determination of the Scientific Committee under Division 5 Part 2) and as a consequence to omit reference to the Quorrobolong Scribbly Gum Woodland in the Sydney Basin Bioregion (as described in the final determination to list the ecological community) which was published on pages 6422 to 6425 in the NSW Government Gazette No. 33 dated 23 August 2002. Minor amendments to the Schedules are provided for by Division 5 of Part 2 of the 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.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Quorrobolong Scribbly Gum Woodland is the name given to the ecological community occurring on a residual sand deposit overlying the Permian clay sediments in the Hunter Valley. The Ecological Community is characterised by the species assemblage listed below.

2. The total flora species list for the community may be larger than that given 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 above may be present. At any one time, above ground individuals of some species may be absent, but the species may be represented below ground in the soil seed bank or as dormant structures such as bulbs, corms, rhizomes, rootstock or lignotubers. The community includes invertebrates, many of which are poorly known, as well as vertebrates; some invertebrate species may be restricted to sediments or canopy trees and shrubs. 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 regime, e.g. fire frequency.

3. Quorrobolong Scribbly Gum Woodland in the Sydney Basin Bioregion is known from a small area between Quorrobolong and Mulbring in the Cessnock Local Government Area but may occur elsewhere. It occupies gentle slopes and rises on a residual sand deposit overlying the Permian clay sediments of the Hunter Valley floor. Bioregions are defined in Thackway and Cresswell (1995).

4. Quorrobolong Scribbly Gum Woodland differs in floristic composition from other woodland communities on sand deposits within the region in the presence and importance of Eucalyptus racemosa in the canopy and the presence of  Eucalyptus piperita,  E. resinifera and  Syncarpia glomulifera. Quorrobolong Scribbly Gum Woodland Ecological Community was not described in NSW NPWS (2000) but is a distinct community differing from other communities described in that report.

5. The currently known extent of the Quorrobolong Scribbly Gum Woodland is about 70 ha; the pre-European extent is estimated as about 160 ha, a reflection of the limited area of the sand deposit on which it occurs.

6. No part of the Quorrobolong Scribbly Gum Woodland occurs within a conservation reserve. A small part, about 6 ha, is within the Bow Wow Creek Gorge site listed on the Register of the National Estate.

7. Threats to the Quorrobolong Scribbly Gum Woodland include the very limited extent of the community, exposing it to stochastic disturbance events, clearing, grazing, inappropriate fire regimes and the spread of weeds.

8. In view of the above the Scientific Committee is of the opinion that the Quorrobolong Scribbly Gum Woodland in the Sydney Basin Bioregion is likely to become extinct in nature in New South Wales unless the circumstances and factors threatening its survival or evolutionary development 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:

NSW NPWS (2000). Vegetation Survey and Mapping – Lower Hunter and Central Coast Region. Report prepared for the Lower Hunter and Central Coast Regional Environment Management Strategy, Version 1.1, April 2000. 178pp.

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.)