Advice to the Minister for the Environment and Heritage 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)

1. Scientific name (common name) Prasophyllum goldsackii (Goldsack’s Leek-orchid)

2. Description Goldsack’s Leek-orchid is a small, slender terrestrial orchid, between 10 cm and 30 cm tall (Weber and Bates 1978). It has a single limp leaf that is either red or green at its base (Bates and Weber 1990). The flowers are in groups of 5-12 and are green with dark purple edges and tips (Weber and Bates 1978). The leaf is 1-2 mm wide and the flowers only open occasionally during hot weather. Early buds and open flowers appear withered (Weber and Bates 1978). Habitat includes areas of light-coloured limestone on reddish-brown soils or sands containing lime. The species occurs in mallee woodlands or open scrublands in areas that have an annual rainfall between 400 and 600 mm (Bates and Weber 1990). Goldsack’s Leek-orchid is mature at five years and usually does not flower two years in a row. One plant is known to have survived for 30 years (B. Bates pers comm.).

3. National Context Goldsack’s Leek-orchid is endemic to South Australia and occurs on the lower Eyre Peninsula and on Yorke Peninsula. On Eyre Peninsula the species occurs at two locations. One location includes records from Bascombe Well Conservation Park and Mount Hope, and the second location includes records within 50 km of the township of Port Lincoln (State Herbarium of SA; DEH reserves database 2005). On Yorke Peninsula, the species also occurs at two locations. One location includes records from the southern part of Yorke Peninsula and the other location includes records near the townships of Moonta, Maitland and Minlaton in the central to northern part of Yorke Peninsula. The species is listed as endangered under the South Australian National Parks and Wildlife Act 1972.

4. How judged by the Committee in relation to the EPBC Act criteria The Committee judges the species to be eligible for listing as endangered under the EPBC Act. The justification against the criteria is as follows:

Criterion 1 – It has undergone, is suspected to have undergone or is likely to undergo in the immediate future a very severe, severe or substantial reduction in numbers Goldsack’s Leek-orchid occurs only on the lower Eyre Peninsula and on the Yorke Peninsula in South Australia. Weber and Bates first described the species in 1978 and suggested that collectors had probably overlooked the species in the past because it only flowers occasionally and the flowers rarely open. Several collections of the plant were made in the early 1980s (State Herbarium of South Australia 2005) and more recent collections have been made for the South Australian DEH Survey database and Reserves database. The species has been recorded from 14 subpopulations, two of which are presumed extinct (Corny Point and Hundred of Koppio). Although several collections have been made, there have been no surveys specifically targeting this species. It is possible there has been a historical decline in the population size of Goldsack’s Leek-orchid given there has been extensive clearing of native vegetation for agriculture on the Eyre and Yorke

Peninsulas. On the Eyre Peninsula, only 31.2% of native vegetation remains (DEH 2002a). Clearing of vegetation on the Yorke Peninsula has been extensive with the exception of the southern tip area (DEH 2002a, 2002b). Remnant native vegetation in South Australia is concentrated in areas that are not suitable for agriculture, such as sheet limestone, deep sands or saline soils or regions with low rainfall (Graham et al. 2001, DEH 2002a). Goldsack’s Leek-orchid occurs on shallow limestone areas which has enabled this species to survive in remnant vegetation on the southern Yorke Peninsula. There is insufficient information on the historical distribution of the species and therefore, it is not possible to quantify the impact of vegetation clearance across the Eyre and Yorke Peninsulas on the species’ population size. There is some evidence of a decline in population size as two subpopulations are now known to be extinct. However, as the historical population size of the two subpopulations is not known, it is not possible to determine whether the extinction caused a substantial reduction in numbers of the total population. Future threats to the Goldsack’s Leek-orchid include dryland salinity, declines in quality of habitat and reductions in rainfall. On the Eyre Peninsula, dryland salinity has affected soils on drainage lines in the Koppio Hills north of Port Lincoln in the region where Goldsack’s Leek-orchid has been collected (DEH 2003b). The species’ tolerance to salinity is not known, however, most orchid species are not found on saline soils (Bates and Weber 1990). Dryland salinity may be an ongoing threat to subpopulations in the Koppio Hills and other sites on the western Eyre Peninsula. Threats that may be contributing to a decline in habitat quality in these small areas of remnant vegetation include over-grazing, weed invasion, trampling and grazing by pest animals such as rabbits, insect damage (Bates and Weber 1990) and a reduction of rainfall due to climate changes. In addition, the biological characteristics of the Goldsack’s Leek-orchid indicate it may have very low genetic diversity (Weber and Bates 1978). This species produces seeds without fertilisation, which gives rise to offspring that are identical to the parent plant (Bates and Weber 1990). It is likely that the species has very low genetic diversity (Bates and Weber 1990, Weber and Bates 1978), which may mean that it is less able to adapt to changes in environmental conditions, such as reductions in rainfall. There are three subpopulations within reserves managed for conservation: Lincoln National Park, Bascombe Well Conservation Park and Warrenben Conservation Park, however, none of these Parks include management strategies for Goldsack’s Leek-orchid. There is one subpopulation within a Heritage Agreement1 near Wangary and one subpopulation in Wanilla Forest on Eyre Peninsula. The adverse impacts of dryland salinity, vegetation clearance, declines in the quality of small remnant vegetation areas from over-grazing, weed invasion and trampling and grazing by pest animals, and reductions in rainfall would indicate that this species is likely to undergo a substantial reduction in numbers in the immediate future. Therefore, this species is eligible for listing as vulnerable under this criterion.

Criterion 2 – Its geographic distribution is precarious for the survival of the species and is very restricted, restricted or limited

The current extent of occurrence of Goldsack’s Leek-orchid is 5250 km2. The extent of occurrence is disjunct between the Eyre and Yorke Peninsulas. The extent of occurrence on the Eyre Peninsula is 3000 km2 and the extent of occurrence on the Yorke Peninsula is 2250 km2 (State Herbarium of South Australia database and the South Australian DEH Reserves and Survey databases 2005). ______1A Heritage Agreement is a contract between a landholder and the State Government of South Australia to protect a specified area of native vegetation in perpetuity.

The area of occupany of Goldsack’s Leek-orchid is estimated to be 0.002 km2. This estimate is based on an assumed area of occupancy of 1 hectare at each collection location for the species, as known populations typically do not exceed 50 plants (B. Bates pers comm.). Extensive vegetation clearance within the agricultural districts of the Eyre and Yorke Peninsulas indicate that there has been a decline in the area of occupancy of Goldsack’s Leek-orchid. The species was described as being abundant on the Yorke Peninsula in areas that are now under cultivation (Weber and Bates 1978). There is no information about more recent declines in the extent of occurrence or area of occupancy. The geographic distribution of the Goldsack’s Leek-orchid is severely fragmented. There are records of 14 small subpopulations of Goldsack’s Leek-orchid on Eyre and Yorke Peninsulas that are geographically isolated and not likely to have any genetic exchange between them. There are a number of threats to the species including dryland salinity, vegetation clearance, over- grazing, weed invasion and trampling and grazing by pest animals and a lack of protection in reserves. Only three subpopulations exist within reserves managed for conservation, however, none of these reserves include management strategies specifically for Goldsack’s Leek-orchid. There is one subpopulation within a Heritage Agreement near Wangary on private property and one subpopulation in Wanilla Forest on Eyre Peninsula. Additional threats to this species may include severe droughts. The geographic distribution of Goldsack’s Leek-orchid is restricted and severely fragmented. The ongoing decline of quality habitat, vegetation clearance, over-grazing, weed invasion and trampling and grazing by pest animals, indicate that the current geographic distribution of this species is precarious for its survival. Therefore, the species is eligible for listing as endangered under this criterion. Criterion 3 – The estimated total number of mature individuals is limited to a particular degree and: (a) evidence suggests that the number will continue to decline at a particular rate; or (b) the number is likely to continue to decline and its geographic distribution is precarious for its survival The species has been recorded from 14 subpopulations, two of which are presumed extinct (Corny Point and Hundred of Koppio). Current records and surveys are inadequate to provide accurate estimates of population size. The species is described as ‘locally common’ in the southern Yorke Peninsula (Bates and Weber 1990) and one population south of Port Lincoln is described as comprising a ‘few’ plants (State Herbarium of South Australia 2005). At the Curramulka scrubs on Yorke Peninsula the species is described as ‘common’ (State Herbarium of South Australia 2005). There is insufficient data available to assess the species against this criterion. Criterion 4 – The estimated total number of mature individuals is extremely low, very low or low As discussed in Criterion 3, current records and surveys are inadequate to provide accurate estimates of population size. There is insufficient data available to assess the species against this criterion.

Criterion 5 – Probability of extinction in the wild

There is insufficient data available to assess the species against this criterion.

5. CONCLUSION Goldsack’s Leek-orchid occurs only on the lower Eyre Peninsula and on the Yorke Peninsula in South Australia. The species has been recorded from 14 subpopulations, two of which are presumed extinct. Threats to this species include dryland salinity, vegetation clearance, declines in the quality of small remnant vegetation areas from over-grazing, weed invasion and trampling and grazing by pest animals, reductions in rainfall and a lack of protection in reserves. Furthermore, the disjunct and restricted geographic distribution of the Goldsack’s Leek-orchid and the ongoing decline in habitat quality indicate that the current geographic distribution of this species is precarious for its survival. The species is eligible for listing as endangered under criterion 2 and as vulnerable under criterion 1.

6. Recommendation The Committee recommends that the list referred to in section 178 of the EPBC Act be amended by including in the list in the endangered category:

Prasophyllum goldsackii (Goldsack’s Leek-orchid)

References cited in the advice Bates B. Personal communication. 1 August 2005. Bates R.J. and Weber J.Z. 1990. Orchids of South Australia. Flora and Fauna of South Australia Handbooks Committee, South Australia. Department for Environment and Heritage, South Australia. Reserves database. Extracted 31/5/2005. DEH 2002a. Department for Environment and Heritage. Biodiversity Plan for Eyre Peninsula. Department for Environment and Heritage, South Australia. DEH (2002b). Remnant vegetation data within IBRA region boundaries for South Australia, as calculated December 2002. Unpublished database, Department for Environment and Heritage, South Australia. DEH (2003b). Eyre Peninsula – estimated area affected by dryland salinity 2000. Available from: http://www.environment.sa.gov.au/reporting/land/salinity/affected.html Graham, A., Oppermann, A. and Inns, R.W. 2001. Biodiversity Plan for the Northern Agricultural Districts. Department for Environment and Heritage, South Australia. State Herbarium of South Australia, Adelaide. Database. Extracted 31/5/2005. Weber, J.Z. and Bates, R. 1978. A new species of Prasophyllum (Orchidaceae) from South Australia. Journal of the Adelaide Botanic Garden 1: 167-169.