Ozothamnus vagans – endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the shrub Ozothamnus vagans (C.T. White) Anderb. as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Act. Listing of Endangered species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Ozothamnus vagans (C.T. White) Anderb. (family Asteraceae) is described as a “straggling, spindly shrub to 2 m high, branches prominently ridged, glabrous or with loose webby hairs on the young growth. Leaves lanceolate, usually 15–50 mm long and 3–5 mm wide, rarely to 100 mm long and 15 mm wide, margins slightly recurved; lamina discolorous and with 3 longitudinal veins prominent on both surface, upper surface dark green with glandular hairs or ± glabrous, lower surface pale green with a dense short tomentum; petiole 1–1.5 mm long. Heads 2-3 mm long, 2-3 mm diam., in small compact corymbose panicles; involucral bracts pale golden, stiff, ovate, spreading, webby at the base on lower surface. Florets 12–14, with 6 outer florets filiform, female. Pappus bristles not or scarcely clavate apically.” (Everett 1992).  Helichrysum vagans C.T.White is a synonym for  Ozothamnus vagans (APNI 2012; PlantNET 2012).

2. Ozothamnus vagans is restricted to the high elevation ranges in the Mount Warning area and the McPherson and Tweed Ranges of far north east NSW, and the Lamington Plateau of south east Queensland.  Ozothamnus vagans is generally associated with wet sclerophyll forest / rainforest margins at elevations of greater than 500 m, on rhyolite or basalt (A. Benwell pers. comm. Dec 2010). O. vagans grows in sunny locations and occurs on escarpment edges, in large gaps in the rainforest, and along roadsides (Hunter 2002).

3. Whilst little is known about the biology of Ozothamnus vagans, it is thought to be a fairly short-lived shrub that produces a persistent seed bank, and germination may be promoted by an increase in light and temperature (R. Kooyman pers. comm. Dec 2010). It would appear to be an obligate seeder and may germinate en masse after fires, though fires are not common in this habitat (A. Benwell pers. comm. Dec 2010).

4. The geographic distribution for Ozothamnus vagans is highly restricted. The extent of occurrence is estimated to be approximately 700-1000 km2 , covering the populations in NSW and the area north to the Queensland border. The extent of occurrence was measured by a convex polygon encompassing the currently known sites, as recommended in the IUCN Guidelines (IUCN, 2010), and extending this to the Queensland border in alignment with the sites within southern Queensland. This gave a more realistic measure of the extent of occurrence as the habitat for  Ozothamnus vagans extends into southern Queensland. The area of occupancy was estimated to be 72-100 km2 , equivalent to 18-25 (2x2) km grids, the recommended measure for area of occupancy in NSW in the IUCN Guidelines (IUCN, 2010).

5. There was estimated to be between 6 and 10 populations of Ozothamnus vagans in NSW (Scott, 2011). The number of mature individuals of  O. vagans is unknown. It is only found in small numbers (tens of plants rather than hundreds) at any one location.

6. The main threat to Ozothamnus vagans and its habitat is the recent invasion of weed species, particularly Crofton Weed ( Ageratina adenophora) and Mistflower ( Ageratina riparia), especially in the high altitude transitional zones and exposed rocky edges where  O. vagans normally occurs (R.J. Hunter pers. comm. Sept 2011). This has resulted in a decline in habitat quality for  O. vagans and other native species, with many areas on the edges of the escarpment that had an understorey of Kangaroo Grass (Themeda australis) now taken over by weeds particularly Crofton and Mistflower (R.J. Hunter pers. comm. Sept 2011). ‘Loss and degradation of native plant and animal habitat by invasion of escaped garden plants, including aquatic plants’ is listed as a Key Threatening Process under the Threatened Species Conservation Act 1995.

7. Ozothamnus vagans (C.T. White) Anderb. is not eligible to be listed as a Critically Endangered species.

8. Ozothamnus vagans (C.T. White) Anderb. is eligible to be listed as an Endangered species as, in the opinion of the Scientific Committee, it is facing a very high risk of extinction in New South Wales in the near future as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation 2010:

Clause 7 Restricted geographic distribution and other conditions

The geographic distribution of the species is estimated or inferred to be:

(b) highly restricted,

and

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

(a) an index of abundance appropriate to the taxon, or

(b) the geographic distribution, habitat quality or diversity, or genetic diversity of the species.

Associate Professor Michelle Leishman
Chairperson
Scientific Committee

Gazettal date: 21/12/2012
Exhibition period: 21/12/2012-08/03/2013

References:

APNI (2012) Australian Plant Name Index, IBIS database, Centre for Australian National Biodiversity Research, Australian Government, Canberra. Ozothamnus vagans – [accessed 5 March 2012]

Everett J (1992) ‘Ozothamnus’, In: Harden, GJ (Ed.) Flora of New South Wales, vol. 3, University of New South Wales Press, Sydney, pp. 237-243.

Hunter RJ (2002) Survey for Threatened and Significant Plants along Tweed Range Scenic Drive and the Booyong Walking Track system, Border Ranges National Park. Unpublished report prepared for Kyogle Area, NSW National Parks and Wildlife Service.

IUCN Standards and Petitions Subcommittee (2010). Guidelines for Using the IUCN Red List Categories and Criteria. Version 8.1. Prepared by the Standards and Petitions Subcommittee in March 2010.

PlantNET (2012) - The Royal Botanic Gardens and Domain Trust. PlantNET - The Plant Information Network System of The Royal Botanic Gardens and Domain Trust, Sydney, Australia [accessed 5 March 2012]

Scott J (2011) Ozothamnus vagans Report to the Scientific Committee. An unpublished report to the NSW Scientific Committee.