Eucalyptus leucoxylon subsp. pruinosa - vulnerable species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Eucalyptus leucoxylon F. Muell. subsp. pruinosa (F. Muell. Ex. Miq.) Boland, Yellow Gum as a VULNERABLE SPECIES in Part 1 of Schedule 2 of the Act. Listing of vulnerable species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Eucalyptus leucoxylon F. Muell. subsp.  pruinosa (F. Muell. Ex. Miq.) Boland, Yellow Gum (family Myrtaceae) has been described by Hill (2002) as follows: "Tree to 15 m high; bark smooth or persistent on lower trunk, shedding irregularly, grey-brown, fibrous-flaky ('box'), smooth above, grey or yellow, shedding in short ribbons or flakes. Juvenile leaves opposite after 13th node, ovate to broad-lanceolate, glaucous. Adult leaves disjunct, narrow-lanceolate or lanceolate, 8-15 cm long, 1-1.8 cm wide, green or grey-green or yellow-green, dull, concolorous. Umbellasters 3-flowered; peduncle terete, 7-10 mm long; pedicels terete, 4-10 mm long. Buds ovoid, glaucous, 8-14 mm long, 5-6 mm diam., scar absent; calyptra conical or rostrate, shorter than and narrower than hypanthium. Outer stamens infertile; anthers cuboid. Fruit globose or hemispherical, 6-9 locular, 8-11 mm long, 8-10 mm diam.; disc depressed; valves enclosed."

2. Eucalyptus leucoxylon subsp.  pruinosa is a tree species which, in New South Wales, occurs at the bases of sandy rises and on loamy clay flats on the floodplains of the Murray River and its tributaries in the Riverina Bioregion (Thackway and Creswell 1995).

3. In New South Wales, Eucalyptus leucoxylon subsp.  pruinosa is currently known from several localities along the Murray River valley, including a concentration of six stands to the west of Moulamein, and small scattered occurrences between Barham and Euston. A disjunct occurrence of the species reported from near Boorowa on the central western slopes has been investigated and refuted. The number of records of  Eucalyptus leucoxylon subsp.  pruinosa are relatively few for NSW, despite a number of systematic vegetation surveys being carried out across its range (Porteners 1993; Sluiter  et al. 1997; Horner  et al. 2002; McNellie  et al. 2005).

4. The total population of E. leucoxylon subsp.  pruinosa in New South Wales  is estimated to comprise 1000-4000 mature trees, representing a moderately low number of mature individuals distributed across a small number of locations. The remaining stands are estimated to occupy a total area of 140-260 ha, representing only 15-40% of the species' inferred pre-European distribution in New South Wales (Benson  et al. 2006).

5. Most remaining stands of E. leucoxylon subsp.  pruinosa stands are threatened by a lack of regeneration due to grazing and soil compaction. Other threats operating at some of the stands include canopy dieback, small-scale clearing and weed invasion (Benson  et al. 2006). These threats contribute to a continuing decline of the species.

6. No stands are known to be protected in conservation reserves or under secure property agreements.

7. Eucalyptus leucoxylon F. Muell. subsp.  pruinosa (F. Muell. Ex. Miq.) Boland (Yellow Gum) is not eligible to be listed as an endangered or critically endangered species.

8. Eucalyptus leucoxylon F. Muell. subsp.  pruinosa (F. Muell. Ex. Miq.) Boland (Yellow Gum) is eligible to be listed as a vulnerable species as, in the opinion of the Scientific Committee, it is facing a high risk of extinction in New South Wales in the medium-term future as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation 2002:

Clause 16

(c) moderately low,

(d) a projected or continuing decline is observed, estimated or inferred in either:

(i) an index of abundance appropriate to the taxon, or
(ii) geographic distribution, habitat quality or diversity, or genetic diversity; or

(e) the following two conditions apply:

(i) the population or habitat is observed or inferred to be severely fragmented;
(ii) all or nearly all mature individuals are observed or inferred to occur within a small number of populations or locations.

Associate Professor Lesley Hughes
Chairperson
Scientific Committee

Proposed Gazettal date: 16/02/07
Exhibition period: 16/02/07 - 13/04/07

References: 

Benson JS, Allen, CB, Togher C, Lemmon J (2006) New South Wales vegetation classification and assessment. Part 1 Plant communities of the NSW western plains. Cunninghamia 9, 383-450.

Hill KD (2002) Eucalyptus.  In 'Flora of New South Wales'. (Ed. G. J. Harden) pp. 96-167.

(University of New South Wales: Kensington).

Horner G, McNellie M, Nott TA, Vanzella B, Scleibs M, Kordas GS, Tuner B, Hudspth TJ (2002) Native vegetation map report series No. 2. Dry lake, Oxley, Hay, One Tree, Moggumbill and Gunbar 1:100 000 map sheets. NSW Department of Land and Water Conservation, Parramatta.

McNellie M, Horner G, Nott TA, Vanzella B, Scleibs M, Kordas GS, Tuner B, Hudspth TJ (2005) Native vegetation maps and site data for the Deniliquin 1:250 000 map sheet. Unpubl. data. NSW Department of Natural Resources, Parramatta.

Porteners M (1993) The natural vegetation of the Hay plain: Booligal-Hay and Deniliquin-Bendigo 1:250 000 maps. Cunninghamia 3, 1-122.

Sluiter IRK, Minchin PR, Jaensch SC (1997) The buloke and pine woodlands of semi-arid and dry sub-humid Victoria and nearby areas. Ogyris, Birdwoodton.

Thackway R, Creswell ID (1995) (eds) 'An interim biogeographic regionalisation of Australia: a framework for establishing the national system of reserves.' (Australian Nature Conservation Agency: Canberra)