Bertya sp. (Chambigne NR, M. Fatemi 24) - endangered species listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the shrub Bertya sp. (Chambigne NR, M. Fatemi 24) 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. Bertya sp. (Chambigne NR, M. Fatemi 24) (family Euphorbiaceae) is a species recently recognised in a taxonomic revision of the genus (Fatemi 2005). The species is not part of the taxonomic aggregate recognised in NPWS (2002) as Bertya sp. Cobar-Coolabah (Cunningham and Milthorpe s.n., 2/8/73).
2. The species is described (M. Fatemi in litt., and Fatemi 2005) as a monoecious shrub to 2 (rarely 3) m high. Branchlets are terete with a variably dense indumentum of stalked stellate hairs. Leaves are petiolate, spirally alternate, spreading; leaf lamina linear, 15-30 mm long, 1-2 mm wide; upper surface green and sparsely pubescent; lower surface densely covered with white stellate hairs; margin recurved to the midrib; leaf apex rounded; sessile marginal glands present at base of lamina. Inflorescences are mostly single-flowered and axillary. Male flowers are sessile, greenish to brown; calyx 5-lobed, hairless outside. Female flowers are sessile or shortly pedicellate; calyx 5-lobed, light green; lobes equal, revolute, hairless outside, with entire margins; petals absent; ovary 3-locular, sparsely covered with stellate hairs; style initially columnar, splitting into 3 long spreading red branches 3-3.5 mm long. Capsules are ellipsoid, 9 mm long, 4.5 mm wide, sparsely hairy, 1-seeded, calyx lobes persistent. Seeds are ovoid, 7.5-7.7 mm long, 3.7-3.9 mm wide; caruncle pyramidal, yellowish.
3. Bertya sp. (Chambigne NR, M. Fatemi 24) is related to B. gummifera, which is distinguished by having densely hairy young stems and a perianth enlarging around the fruit, and B. recurvata which has non-stellate glandular hairs on leaves and young stems; in Bertya sp. (Chambigne NR, M. Fatemi 24) these hairs are stellate and non-glandular (M. Fatemi in litt., and Fatemi 2005).
4. Bertya sp. (Chambigne NR, M. Fatemi 24) occurs in the NSW North Coast Bioregion (Thackway and Creswell 1995). It is located in the area of the Northern Rivers Catchment Management Authority. The species has been recorded from two disjunct locations. A single specimen (voucher NSW 194912) collected in 1967 from Whitemans Creek north of Grafton, in the Clarence Valley local government area, represents a population now thought to be extinct (M Fatemi, pers. comm. 2006). The known surviving population is in Chambigne Nature Reserve (in the Clarence Valley local government area, west of Coutts Crossing), and on the nearby escarpment above Shannon Creek.
5. The species is thought to reproduce from seed only, and limited field observations suggest that plants do not regenerate by vegetative means following fire (J and P Edwards pers. comm. 2003); the last fire in the area was in about 1991 (J Edwards pers. comm. 2006). Its longevity, breeding system, seed biology, and most aspects of its ecology are unknown. Limited numbers of juvenile plants, 6 to 100cm tall, were reported at the Chambigne/Shannon Creek sites in the drought year of 2003 (J and P Edwards pers. comm. 2003). Moderate rains in 2004, following some years of severe drought, stimulated germination of and establishment of 200-300 seedlings up to 30 cm height as at August 2005 (J Edwards pers. comm., August 2006).
6. In the Chambigne Nature Reserve/Shannon Creek area the species appears to be restricted to dry rocky exposed cliff edges and the foot of cliff lines in shrubby sclerophyll vegetation adjacent to eucalypt-dominated communities (dominant species include Eucalyptus planchoniana, E. psammitica, E. pyrocarpa, and E. pilularis).
7. Total population size for the species is estimated to be 500 to 600 plants, of which at least 60% are in seedling or juvenile stages (J and P Edwards, pers. comms 2003, 2004, 2006) and therefore unlikely to be major seed-producers. Approximately 30% of the total population is within the boundary of Chambigne Nature Reserve (J Edwards pers. comm. August 2006).
8. Threats to the known population derive mainly from its small size. The presently high proportion of new seedlings and juvenile plants may be susceptible to episodes of high mortality especially during severe drought. The recent significant recruitment, from a soil seed-bank of unknown size and longevity, may have lowered recruitment potential in the event of fire in the next few years, until the soil seed bank is replenished. Proposed works for a dam project on Shannon Creek are likely to directly threaten only a small percentage (c. 2-3%) of the population, although this includes some older plants.
9. Bertya sp. (Chambigne NR, M. Fatemi 24) is not eligible to be listed as a critically endangered species.
10. Bertya sp. (Chambigne NR, M. Fatemi 24) is eligible to be listed as an endangered species as, in the opinion of the Scientific Committee, it is facing an 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 17
The total number of mature individuals of the species is observed, estimated or inferred to be:
(b) very low.
Associate Professor Lesley Hughes
Chairperson
Scientific Committee
Proposed Gazettal date: 27/04/07
Exhibition period: 27/04/07 - 22/06/07
References:
Fatemi, M (2005) A systematic analysis of Bertya (Euphorbiaceae: Ricinocarpeae). PhD thesis, Faculty of Sciences, University of New England, Armidale NSW.
NPWS (2002) Bertya sp. Cobar-Coolabah (Cunningham & Milthorpe s.n., 2/8/73) Recovery Plan. NSW National Parks & Wildlife Service, Hurstville NSW.
Thackway R, Creswell ID (1995) An interim biogeographic regionalisation for Australia: a framework for setting priorities in the National Reserves System Cooperative Program. Version 4.0. (Australian Nature Conservation Agency: Canberra)