Woronora Plateau population of Callitris endlicheri (a tree) - endangered population listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the Woronora Plateau population of Callitris endlicheri (Parl.) Bailey, 'Black Cypress Pine', as an ENDANGERED POPULATION on Part 2 of Schedule 1 of the Threatened Species Conservation Act. Listing of endangered populations is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Callitris endlicheri (Parl.) Bailey (family Cupressaceae) has been described by Harden and Thompson (1990) as: "Tree with mostly erect sometimes spreading branches, mostly dark green in colour; bark tough and often deeply furrowed. Leaves 2-4 mm long. Female cones solitary or several together on rather slender, usually clustered, fruiting branchlets; cones ovoid to globose or depressed-globose, 15-20 mm diam.; columella variable, usually short, deeply 3-lobed or with 3 or 4 separate parts. Usually found on stony hills or ridges, common, from the plains to the coastal ranges."

2. Callitris endlicheri is not currently listed as an endangered species on Part 1 of Schedule 1 and, as a consequence, populations of this species are eligible to be listed as endangered populations.

3. The population of Callitris endlicheri on Woronora Plateau, in the local government area of Wollongong, represents the coastal limit of the species' range and is disjunct from other known populations of the species. Woronora Plateau is also the wettest area (in terms of mean annual rainfall) from which records are known, with the majority of populations occurring in substantially drier climates on the western slopes and plains, and drier parts of the coastal ranges.

4. The Woronora Plateau population is restricted to a single outcrop of sandstone c. 2 ha in area. The soils at the site are skeletal sandy loams and the heathlands on sandstone outcrops in the area are restricted and highly distinctive (Keith 1994).

5. Prior to the 2001-2002 bushfires, the Woronora Plateau population of Callitris endlicheri comprised c. 700 plants; c. 200 mature individuals and c. 500 juveniles (Mackenzie & Keith pers. comm.). The majority of these plants were killed by a fire in summer 2001-2002. Recent surveys indicate only 4 mature individuals and 12 juveniles persist at the site. Of these 3 juvenile plants subsequently died. An estimated 250 - 450 seedlings occurred at the site in summer 2003-2004, indicating that a substantial decline has occurred in the population since 2002 (Mackenzie & Keith pers. comm.). During 2004 the seedling population declined by more than 10% as a result of grazing and drought.

6. The population is threatened by demographic and environmental stochasticity due to its small size, and by high fire frequency as Callitris seedlings and juveniles are known to be fire-sensitive (Bowman  et. al., 1988, Benson & McDougall 1993; Bowman & Harris 1995) and take many years to reach maturity and produce their first seeds. In the Woronora plateau population, shrubs rarely set seed until they grow more than one metre tall. Recent surveys also indicate grazing of seedlings is also threatening recruitment (Mackenzie & Keith pers. comm.).

7. In view of the above, the Scientific Committee is of the opinion that the Woronora Plateau population of Callitris endlicheri (Parl.) Bailey, 'Black Cypress Pine' is eligible to be listed as an endangered population because it is facing a high risk of becoming extinct in nature in New South Wales and it is of conservation value at the State and regional level for the following reasons: it is disjunct or near the limit of its geographic range, and it is otherwise of significant conservation value because it represents the coastal and moist climatic limit of the species' geographic range.

Associate Professor Paul Adam
Chairperson
Scientific Committee

Proposed Gazettal date: 12/11/04
Exhibition period: 12/11/04 - 24/12/04

References 

Benson DH, McDougall L (1993) Ecology of Sydney plant species. Part 1. Ferns, fern-allies, cycads, conifers and dicotyledon families Acanthaceae to Asclepiadaceae. Cunninghamia 3, 257-422.

Bowman DMJS, Wilson BA Davis GW (1988) Response of Callitris intratropica R.T. Baker & H.G. Smith to fire protection, Murgenella, northern Australia.  Australian Journal of Ecology 13,  147-159.

Bowman DMJS, Harris S (1995) Conifers of Australia's dry forests and open woodlands. In Enright, NJ. & Hill, RS (Eds) Ecology of the southern conifers, Melbourne University Press: Melbourne.

Harden GJ, Thompson J (1990) Cupressaceae. In Harden, GJ (Ed) Flora of New South Wales Vol 1, University of New South Wales Press: Sydney.

Keith DA (1994) Floristics, structure and diversity of natural vegetation in the O'Hares Creek catchment, south of Sydney. Cunninghamia 3, 543-594.