Eucalyptus approximans - vulnerable species listing

NSW Scientific Committee - final determination

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the mallee Eucalyptus approximans Maiden as a VULNERABLE SPECIES in Part 1 of Schedule 2 of the Act, and as a consequence, to omit reference to Eucalyptus approximans Maiden from Part 1 of Schedule 1 (Endangered species) of the Act. Listing of vulnerable species is provided for by Part 2 of the Act.

 

The Scientific Committee has found that:

 

1. Eucalyptus approximans Maiden (family Myrtaceae) is a mallee that has been described by Hill (2002, p.158) as follows: “Mallee to 5 m high; bark smooth, white, green or grey, shedding in ribbons. Juvenile leaves disjunct, lanceolate, glossy green. Adult leaves disjunct, narrow-lanceolate, 7-10 cm long, 0.6-0.9 cm wide, green, glossy, concolorous. Umbellasters 7-flowered; peduncle terete, 4-10 mm long; pedicels terete, 1-4 mm long. Buds clavate, 3-6 mm long, 3-4 mm diam., scar absent; calyptra hemispherical, shorter than and as wide as hypanthium, minutely warty. Fruit cylindrical or hemispherical, 6-8 mm long, 5-7 mm diam.; disc flat; valves enclosed.”

 

2. Eucalyptus approximans was originally described by Joseph Maiden in 1920 from Barren Mountain in north-eastern NSW. Since this original description two other mallee Eucalypts, E. codonocarpa and E. microcodon, have occasionally been included within a broadly circumscribed E. approximans. Hill (2002), however, treated all three taxa as distinct species and believed that the name E. approximans should only refer to the population growing on Barren Mountain. E. approximans can be distinguished from E. codonocarpa and E. microcodon by having narrow, linear to narrow-lanceolate adult leaves c. 1 cm wide. In contrast, E. codonocarpa and E. microcodon have broader, lanceolate adult leaves to 2 cm wide. E. approximans also has a narrower disc on its fruit.

 

3. Eucalyptus approximans is endemic to New South Wales where it is known only from Barren Mountain, largely within New England National Park. Some plants also occur on the northern base of Barren Mountain, just outside the National Park boundary.

 

4. Eucalyptus approximans grows in mallee scrub in shallow soils derived from trachyte. The species usually forms dense clumps with numerous shrubs, ferns and sedges beneath them. E. approximans rarely coexists with other species of Eucalyptus, apparently because its preferred substrate is usually too shallow for the other trees to inhabit. The altitude of the area ranges from 1250-1430 m above sea level and most stands of the species are on relatively flat or northerly facing aspects. Like other mallee Eucalypts, E. approximans has been observed to resprout from a basal lignotuber after fire (Clarke et al. 2000).

 

5. Eucalyptus approximans has a very highly restricted geographic distribution. The extent of occurrence and area of occupancy are both estimated to be less than 4 km2 (Copeland 2008). This calculation is based on the species occupying a single 2 x 2 km grid square, the spatial scale of assessment recommended by the IUCN (2008).

 

6. The total population of Eucalyptus approximans has been estimated to be at least 2000 mature individuals (Copeland 2008). Eucalyptus approximans is locally abundant on Barren Mountain and is the dominant species in the mallee scrub community at that location.

 

7. At present there is no evidence that the population of Eucalyptus approximans is undergoing a continuing decline, although inappropriate fire regimes and long-term climate change may threaten the species in the future. The very highly restricted geographic distribution means that the species may be prone to the effects of human activities or stochastic events within a very short time period.

 

8. Eucalyptus approximans is not eligible to be listed as a Critically Endangered species or as an Endangered Species.

 

9. Eucalyptus approximans Maiden 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 18

 

The geographic distribution of the species is observed, estimated or inferred to be very highly restricted such that it is prone to the effects of human activities or stochastic events within a very short time period.

 

Professor Lesley Hughes

Chairperson

Scientific Committee

 

Proposed Gazettal date: 21/11/08

Exhibition period: 21/11/08 – 23/01/09

References

Clarke PJ, Copeland LM, Noble NE, Bale CL, Williams JB (2000). The vegetation and plant species of New England National Park, Botany, University of New England, Armidale.

 

Copeland LM (2008) ‘Conservation status of Eucalyptus approximans Maiden (Myrtaceae) in New South Wales.’ Report to the NSW Scientific Committee, Sydney.

 

Hill KD (2002) Eucalyptus. In ‘Flora of New South Wales. Vol. 2; Revised Edition’. (Ed. GJ Harden) pp. 96-164 (University of New South Wales Press: Sydney)

 

IUCN (2008) ‘Guidelines for using the IUCN Red List categories and criteria. vers. 7.0.’ Prepared by the Standards and Petitions Working Group of the IUCN SSC Biodiversity Assessments Sub-Committee.

Page last updated: 28 February 2011