Robertson Rainforest in the Sydney Basin Bioregion - Determination to make a minor amendment to Part 3 of Schedule 1 of the Threatened Species Conservation Act

NSW Scientific Committee

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 Robertson Rainforest 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 Robertson Rainforest in the Sydney Basin Bioregion (as described in the final determination to list the ecological community) which was published on pages 3702 to 3706 in the NSW Government Gazette No. 97 dated 15 June 2001. 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.

 

The Scientific Committee has found that:

 

1. Robertson Rainforest in the Sydney Basin Bioregion is the name given to the ecological community characterised by the species assemblage listed in 2 below. The community occurs on high nutrient soils in high rainfall areas of the Southern Highlands. All sites are within the Sydney Basin Bioregion. Bioregions are defined in Thackway and Cresswell (1995).

 

2. Robertson Rainforest is characterised by the following assemblage:

 

Acacia melanoxylon

Acmena smithii

Acronychia oblongifolia

Alectryon subcinereus

Alphitonia excelsa

Aphanopetalum resinosum

Arthropteris tenella

Asplenium attenuatum

Asplenium australasicum

Asplenium flabellifolium

Asplenium flaccidum

Australina pusilla

Austrocynoglossum latifolium

Blechnum nudum

Blechnum patersonii

Blechnum wattsii

Carex appressa

Cassinia trinerva

Celastrus australis

Ceratopetalum apetalum

Cissus hypoglauca

Citriobatus pauciflorus

Clematis aristata

Clematis glycinoides

Coprosma quadrifida

Cryptocarya glaucescens

Cyathea australis

Cyathea leichhardtiana

Dendrobium pugioniforme

Dennstaedtia davallioides

Dicksonia antarctica

Diospyros australis

Diplazium australe

Doodia aspera

Doryphora sassafras

Elaeocarpus holopetalus

Elaeocarpus kirtonii

Elaeocarpus reticulatus

Elatostema reticulatum

Eucalyptus fastigata

Eucryphia moorei

Eustrephus latifolius

Ficus coronata

Fieldia australis

Galium propinquum

Geitonoplesium cymosum

Geranium homeanum

Grammitis billardieri

Guioa semiglauca

Gymnostachys anceps

Hedycarya angustifolia

Helicia glabrifolia

Hibbertia scandens

Histiopteris incisa

Hydrocotyle laxiflora

Hymenanthera dentata

Hymenophyllum cupressiforme

Hymenophyllum flabellatum

Lastreopsis acuminata

Lastreopsis decomposita

Lastreopsis microsora

Livistona australis

Lomandra longifolia

Marsdenia rostrata

Microsorum pustulatum subsp. pustulatum

Microsorum scandens

Morinda jasminoides

Muellerina eucalyptoides

Notelaea venosa

Olearia argophylla

Ozothamnus diosmifolius

Ozothamnus ferrugineus

Palmeria scandens

Pandorea pandorana

Parsonsia brownii

Parsonsia straminea

Pellaea falcata

Pennantia cunninghamii

Pimelea ligustrina

Pittosporum revolutum

Pittosporum undulatum

Plantago debilis

Plectorrhiza tridentata

Polyosma cunninghamii

Polyphlebium venosa

Polyscias murrayi

Polyscias sambucifolia

Polystichum proliferum

Prostanthera lasianthos

Pteris umbrosa

Pyrrosia rupestris

Quintinia sieberi

Ranunculus lappaceus

Ranunculus plebeius

Rapanea howittiana

Rubus Moluccanus var. trilobus

Ripogonum album

Rubus nebulosus

Rubus rosifolius

Sambucus australasica

Sarcochilus falcatus

Sarcopetalum harveyanum

Schizomeria ovata

Smilax australis

Solanum aviculare

Solanum pungetium

Stellaria flaccida

Stenocarpus salignus

Sticherus lobatus

Symplocos thwaitesii

Synoum glandulosum

Tasmannia insipida

Tristaniopsis collina

Tylophora barbata

Urtica incisa

Veronica plebeia

Viola hederacea

 

 

3 The total species list of the flora and fauna of the community is considerably larger than that given in 2 (above), with many species present in only one or two sites or in very small quantity. The community includes vertebrates and invertebrates, many of which are poorly known. Invertebrate species may be restricted to soils or canopy trees and shrubs. In any particular site not all of the assemblage listed above 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.

 

4 Robertson Rainforest is a warm temperate/cool temperate rainforest type characterised by Quintinia sieberi, Polyosma cunninghamia and Doryphora sassafras (Mills & Jakeman 1995). Eucryphia moorei was probably common along streams. Tree and shrub species typically associated with this rainforest type are Acmena smithii, Acacia melanoxylon, Quintinia sieberi, Hymenanthera dentata, Coprosma quadrifida, Tasmannia insipida and occasionally Ceratopetalum apetalum. Cool temperate components include Olearia argophylla, Hedycarya angustifolia, Eucryphia moorei, Dicksonia antarctica and Parsonsia brownii. Ground cover is a dense fern cover including Lastreopsis microsora and Microsorum pustulatum subsp. pustulatum.

 

5 Robertson Rainforest is found on high fertility soils derived generally from Tertiary basalts (mainly the Robertson Basalt and Kangaroo Valley Basanite), at high altitudes (500-750 m) and under high rainfalls (1000-1600 mm per annum) (Mills & Jakeman 1995).

 

6 Robertson Rainforest is or has been known to occur in the Wingecarribee and Shoalhaven Local Government Area, but may occur elsewhere in the Sydney Basin Bioregion (sensu Thackway and Cresswell 1995). It has been reported from the Robertson plateau and Cambewarra Range (Mills & Jakeman 1995).

 

7 Disturbed Robertson Rainforest remnants are considered to form part of the community including areas where the vegetation would respond to assisted natural regeneration, such as where the natural soil and associated seedbank is still at least partially intact.

 

8 Robertson Rainforest has been extensively cleared for agriculture and rural development. About 400-600 ha or about 20% of its original extent is estimated to survive though mostly as fragmented remnants (Mills 1988). Remnants are often dominated by Acmena smithii, Doryphora sassafras and Acacia melanoxylon.

 

9 A remnant of Robertson Rainforest is conserved in Robertson Nature Reserve at Robertson.

 

10 Much of the remaining area of Robertson Rainforest is highly fragmented with much of it occurring on private land. Threatening processes include invasion of exotic weed species including Ligustrum sinense, Hedera helix, Lonicera japonica, Ilex aquifolium and clearing, grazing, trampling and further fragmentation.

 

11 In view of the originally restricted distribution of this community, its inadequate representation within conservation reserves, and threats from fragmentation and weed invasion, the Scientific Committee is of the opinion that Robertson Rainforest 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 and that the community is eligible for listing as an endangered ecological community.

 

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 2001 as indicated in the determination

 

References

 

Mills, K. (1988) The clearing of Illawarra rainforest: problems in reconstructing pre-european vegetation patterns. Australian Geographer 19(2): 230-240.

 

Mills, K. & Jakeman, J. (1995) Rainforests of the Illawarra District. (Coachwood Publishing:Jamberoo)

 

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.)

 

Page last updated: 14 October 2011