Pomaderris reperta - critically endangered species listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the shrub Pomaderris reperta N.G. Walsh & F. Coates as a CRITICALLY ENDANGERED SPECIES in Part 1 of Schedule 1A of the Act, and as a consequence, to omit reference to Pomaderris reperta N.G. Walsh & F. Coates from Part 1 of Schedule 1 (Endangered species) of the Act. Listing of Critically Endangered species is provided for by Part 2 of the Act.
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. Pomaderris reperta N.G. Walsh & F. Coates (Denman Pomaderris) (family Rhamnaceae) is a perennial shrub described by Harden (2000) as follows: “Shrub 1-3 m high, young stems densely villous with rusty simple and stellate hairs simple. Leaves ovate to broad-ovate, elliptic to broad-elliptic or obovate to broad-obovate, 1-3.5 cm long, 8-20 mm wide, apex usually rounded to emarginate; upper surface green, velvety with short simple hairs; lower surface pubescent with loosely appressed or spreading pale and rusty simple hairs over dense white or greyish stellate hairs; secondary and tertiary veins raised and prominent on the lower surface; stipules 3-5 mm long, shed early. Flowers creamish, in short dense panicles. Sepals not persistent in fruit. Petals usually absent (rarely 1-3 per flower). Capsule not seen; hypanthium and ovary with simple hairs, sepals with short stellate hairs.”
2. Pomaderris reperta was first described as a new species by Walsh & Coates (1997) and is most closely related to P. cocoparrana, but the adiaxial indumentum of the leaves of P. reperta is sparser and coarser and the flowers are larger (sepals 2.0-2.2 mm long in P. cocoparrana, compared to 2.3-2.8 mm in P. reperta).
3. Pomaderris reperta is currently known from two ridgelines in the Denman area in the upper Hunter Valley, New South Wales. The species has been found at 3 locations within a 4 km radius along these two ridgelines. Despite the species being regarded as conspicuous within its preferred habitat, extensive vegetation surveys undertaken in reserved land (Bell 1997, 1998; Hill 1999; Peake 1999; Hill et al. 2001) and in areas of suitable habitat surrounding the Denman area have failed to record P. reperta (T. Peake pers. comm. 2009).
4. The only known locations of Pomaderris reperta occur on private property, Crown land or Commonwealth land. One of these occurs on land that is the subject of an approved open cut coal mine, while the other two occur mostly on land managed by the Commonwealth Department of Defence. Pomaderris reperta is not currently known to occur in any conservation reserves.
5. Pomaderris reperta occupies woodland in association with Eucalyptus crebra, E. blakelyi, Notelaea microcarpa and Allocasuarina littoralis. It is associated with sandy loam soils on sandstone or conglomerate or colluvial soils on similar substrate.
6. Pomaderris reperta has a very highly restricted geographic distribution. The species is known from three localities within a total extent of occurrence of no more than 12 km2, based on occupancy of three 2 × 2 km grid cells, the scale of assessment recommended by IUCN (2008).
7. Pomaderris reperta is likely to regenerate primarily from seed (Threatened Species Scientific Committee 2008). Like other members of the Pomaderris genus, this species flowers in the spring, around October–November. Large quantities of seeds are usually produced and dropped close to the parent plant, with the seed capsules opening in early summer (Threatened Species Scientific Committee 2008). Pomaderris seeds require heat to germinate and thus high rates of germination are expected to occur after wild fires. Based on other similar Pomaderris species, it is estimated that P. reperta reaches reproductive maturity at around 1-2 years and longevity is estimated to be 10-30 years (T. Auld pers. comm. 2009). The generation length of P. reperta is therefore estimated to be 5 to 16 years.
8. Low population numbers and restricted distribution make the species susceptible to demographic and environmental stochasticity.
9. The largest population of Pomaderris reperta may be threatened by impacts associated with open cut coal mining, such as clearing of native vegetation, changes in hydrology and road maintenance or widening. Other potential threats include vegetation clearance and physical damage associated with vehicular traffic and public access, and possibly also prolonged drought (Threatened Species Scientific Committee 2008). ‘Clearing of native vegetation’ is listed as a Key Threatening Process under the Threatened Species Conservation Act 1995.
10. The number of mature individuals of Pomaderris reperta in New South Wales is unknown, but estimated to be 300 – 2000 (Threatened Species Scientific Committee 2008).
11. The habitat of Pomaderris reperta is fragmented. Land management practices, such as clearing and grazing, are likely to have led to the removal of contiguous areas of the woodland habitat suitable for the species, thereby creating barriers to dispersal.
12. Pomaderris reperta N.G. Walsh & F. Coates is eligible to be listed as a Critically Endangered species as, in the opinion of the Scientific Committee, it is facing an extremely high risk of extinction in New South Wales in the immediate future as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation 2002:
Clause 15
The geographic distribution of the species is estimated or inferred to be:
(a) very highly restricted,
and
(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.
Dr Richard Major
Chairperson
Scientific Committee
Proposed Gazettal date: 16/07/10
Exhibition period: 16/07/10 - 10/09/10
References:
Bell S (1997) ‘Vegetation survey and mapping of Crown land south of Manobalai NR, upper Hunter Valley.’ Unpublished report to the NSW National Parks and Wildlife Service, Upper Hunter District.
Bell S (1998) ‘Vegetation survey of Wollemi National Park: A fire management document. Vols 1 & 2.’ Unpublished report to NSW National Parks and Wildlife Service, Upper Hunter District.
Hill L (1999) ‘Goulburn River National Park & Munghorn Gap Nature Reserve. Vegetation survey for fire management purposes. Vol. 1: Main report.’ NSW National Parks and Wildlife Service, Upper Hunter District.
Hill L, Peake T, Bell S, Raine A (2001) ‘The vegetation of Towarri National Park, Cedar Brush Nature Reserve & Wingen Maid Nature Reserve for fire management purposes.’ Unpublished Report to NSW National Parks and Wildlife Service, Hunter District. Eastcoast Flora Survey.
Harden GJ (2000) Pomaderris. In ‘Supplement to Flora of New South Wales’. (Eds GJ Harden and LJ Murray) pp. 40-54. (New South Wales University Press: Kensington)
IUCN (2008) ‘Guidelines for using the IUCN Red List Categories and Criteria. Version 7.0.’ (Standards and Petitions Working Group of the IUCN Species Survival Commission Biodiversity Assessments Sub-committee: Switzerland).
Peake T (1999) ‘The Vegetation of Manobalai Nature Reserve.’ Prepared for NSW National Parks and Wildlife Service, Upper Hunter District, Muswellbrook.
Threatened Species Scientific Committee (2008) ‘Advice to the Minister for the Environment, Heritage and the Arts from the Threatened Species Scientific Committee (the Committee) on Amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).’
Walsh NG, Coates F (1997) New taxa, new combinations and an infrageneric classification in Pomaderris (Rhamnaceae). Muelleria 10, 27-56.