Astrotricha sp. Wallagaraugh - endangered species listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Astrotricha sp. Wallagaraugh (R.O. Makinson 1228), Merimbula Star-hair, a shrub, 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.
The NSW Threatened Species Scientific Committee undertook a review of this species in August 2024 and found that the threat status is unchanged. More information can be found in the Conservation assessment report of Astrotricha sp. Wallagaraugh (R.O.Makinson 1228) NSW Herbarium (Araliaceae) (PDF 845KB).
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. Astrotricha sp. Wallagaraugh (R.O. Makinson 1228) (family Araliaceae), 'Merimbula Star-hair', is an inconspicuous small single- or multistemmed shrub up to 1 m (rarely to 1.8 m) tall, stems more or less erect; branchlets, leaf undersurfaces, and inflorescence axes covered with small stellate hairs; leaves spreading, linear or sometimes broadening a little near the rounded tip, 20-40 mm long (to 60 mm in juveniles) and 1.5-2 mm wide; leaf upper surface convex with conspicuous short wrinkles, these often each capped with a small asperity, leaf margin recurved; leaf lower surface densely packed with stellate hairs; inflorescence a loose compound panicle 30-100 (rarely 200) mm long, made up of pedunculate (stalked) umbels; petals 5, pale green those of the terminal umbel slightly darker; stamens 5, soon falling; fruit a laterally compressed obovoid schizocarp 3-3.5 mm long, c. 3 mm wide.
2. Astrotricha sp. Wallagaraugh (R.O. Makinson 1228) 'Merimbula Star-hair', is a shrub found in south-eastern NSW. It has been distinguished from a cryptic complex of species around A. linearis, under which name it was subsumed in the Flora of New South Wales vol. 3. (Henwood and Makinson, 1992). The genus, including this species complex, is currently under taxonomic revision. The only description of Astrotricha sp. Wallagaraugh (R.O. Makinson 1228) published to date is that under the interim (Victorian) name ' Astrotricha sp. 5' in Henwood, Makinson and Maling (1999). Most of the other species of Astrotricha species that could be confused with this one are described and distinguished in that work. An additional similar and undescribed species occurs only in NSW, endemic to Deua National Park and adjacent areas, and this is easily distinguished by the completely smooth upper surfaces of the leaves, contrasting with the pronounced wrinkles and asperities of Astrotricha sp. Wallagaraugh.
3. Astrotricha sp Wallagaraugh (R.O Makinson 1228) in NSW has a highly restricted and severely fragmented distribution, currently known from only two localities about 50 km apart. One population is along the upper reaches of the Wallagaraugh River about 30 km south- east of Eden (in Yambulla and Timbillica State Forests). The scanty records and observations from this area to date provide evidence for only a very limited area of occurrence, and low numbers of plants. The other population is about 50 km to the north-east, a few kilometres north of Merimbula over a three kilometre stretch beside the Tathra road, lying partly along one edge of Bournda National Park. Much of this population is apparently concentrated in disturbed roadside habitat (K. McDougall pers. comm., R.O. Makinson pers. comm), supporting several thousand plants (K. McDougall pers. comm.). It also occurs in adjacent and relatively undisturbed bushland but at apparently lower frequency; its extent and numbers there are uncertain. The currently known NSW occurrences of the species are in the Bega Valley Shire Local Government Area, and in the region covered by the Southern Rivers Catchment Management Authority. In Victoria, the species is known from occasional records in the catchments of the lower Wallagaraugh River and the upper lake of Mallacoota Inlet, areas which are more or less contiguous with the more southerly of the NSW populations. All occurrences of the species (both States) are in the South East Corner Bioregion (Thackway and Creswell 1995).
4. In NSW, the species is recorded from two somewhat different habitats. The southern (Yambulla/Timbillica) population occurs on shallow gravelly granitic soils in fairly dry open forests dominated by rough-barked eucalypts including Eucalyptus consideniana and E. croajingalongensis, with a rich shrub layer including some or all of Leptospermum spp., Kunzea ambigua, Dodonaea viscosa, Grevillea parvula, Daviesia sp., Banksia sp., Hakea sp., Pomaderris sp., and Acacia terminalis. The northern (Bournda) population occurs on deep grey-white sands in rough-barked eucalypt forest ( Eucalyptus sieberi and E. globoidea dominant) with Banksia serrata, Acacia longifolia and Grevillea mucronulata.
5. Flowering is recorded for the period October to December. The species is known to reproduce from seed. Field observations at the Bournda site (R. Makinson pers. comm.) show that the species is capable of resprouting from the base after fire and slashing. The species may be advantaged by certain types and frequencies of disturbance.
6. Several closely related species have a capacity for spread and for post-fire resprouting from rhizomes, but that capacity is not confirmed for this species, although substantial subsurface lateral roots have been noted (specimen R.O. Makinson 1224). Several related species of Astrotricha exhibit patterns of locally high frequency within small, sporadic and widely separated areas of occurrence; several are also thought to depend on infrequent fire for substantial recruitment from long-lived, soil-stored seed, and numbers of standing plants may fluctuate between fires, especially in cases where rhizomatous reproductive capacity is lacking.
7. The probable growth rate of Astrotricha sp. Wallagaraugh (R.O. Makinson 1228) is likely to allow first production of seed within three years of seedling establishment but patterns of fecundity, recruitment, longevity, genetic variation and fitness, and self-pollination capability are not known. The response of the species to pathogens is unknown.
8. Threats operating at the southern (Yambulla/Timbillica population) sites are not thought to be immediate. These sites are located within a Forests NSW exclusion zone free from forestry operations other than routine maintenance of nearby roads (J. Shields pers. comm.), but the small size of the sub-populations observed to date, and the uncertainty of both current fire regime and long-term response of the species to fire, are cause for concern. No significant weeds have been reported from these sites. Occurrences of the soil pathogen Phytophthora cinnamomi are known from the Mount Imlay area, about 5 km to the north-east, and the dirt roads near the population are used extensively by recreational and forestry/fire vehicles. 'Infection of native plants by Phytophthora cinnamomi is listed as a Key Threatening Process under Schedule 3 of the Act.
Threats operating at the northern (Bournda population) site are more obvious. The apparently linear, roadside concentration of the population, if confirmed, increases its vulnerability. The majority of plants known are vulnerable to road widening and road verge maintenance (including slashing, although this may be beneficial at certain frequencies). Weed invasion and associated weed control measures may both adversely affect this population. Inappropriate fire regimes may also threaten this population, and are likely to be increasingly dictated by nearby residential development. Other urban-boundary threats may include clearing, nutrient enrichment of soil, and damage by vehicles. The closest confirmed and suspected Phytophthora cinnamomi occurrences are about 25-30 km away (Ben Boyd National Park and Nullica State Forest), but closer occurrences are possible.
9. Astrotricha sp. Wallagaraugh (R.O. Makinson 1228) is not eligible to be listed as a critically endangered species.
10. Astrotricha sp. Wallagaraugh (R.O. Makinson 1228) 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 Amendment Regulation 2002:
Clause 15
The geographic distribution of the species is estimated or inferred to be:
(a) highly restricted,
and
(d) a projected or continuing decline is observed, estimated or inferred in
(ii) geographic distribution, habitat quality or diversity, or genetic diversity; and
(e)
(i) the population or habitat is observed or inferred to be severely fragmented; and
(ii) all or nearly all mature individuals are observed or inferred to occur within a small number of populations or locations,
Clause 16
The estimated total number of mature individuals of the species is:
(a) low,
and
(d) a projected or continuing decline is observed, estimated or inferred in:
(ii) geographic distribution, habitat quality or diversity, or genetic diversity; and
(e)
(i) the population or habitat is observed or inferred to be severely fragmented; and
(ii) all or nearly all mature individuals are observed or inferred to occur within a small number of populations or location
Associate Professor Lesley Hughes
Chairperson
Proposed Gazettal date: 16/02/07
Exhibition period: 16/02/07 - 13/04/07
References
Environment Australia (2000) Revision of the Interim Biogeographic Regionalisation of Australia (IBRA) and the Development of Version 5.1 - Summary Report. (Department of Environment and Heritage, Canberra).
Henwood MJ, Makinson RO (1992) 109 Araliaceae - 2 Astrotricha. In 'Flora of New South Wales. Volume 3.' (Ed. GJ Harden) pp. 80-84. (New South Wales University Press: Kensington).
Henwood MJ, Makinson RO, Maling KL (1990) Araliaceae - Astrotricha. In 'Flora of Victoria. Volume 4.' (ed NG Walsh and TJ Entwisle). Pp 244-252. (Inkata Press, Melbourne).
Thackway R, Creswell ID (1995) An Interim Biogeographic Regionalisation of Australia: a framework for setting priorities in the National Reserves System Cooperative Program, version 4.0. (Australian Nature Conservation Agency: Canberra)