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) bryophila (Hindmarsh Valley Greenhood)

2. Description The Hindmarsh Valley Greenhood is an orchid with bright green and white flowers that grows on the ground in small to large colonies and forms tubers. The species occurs in mossy areas with loamy soils near gullies, and in grassy woodlands dominated by the South Australian Blue Gum, Eucalyptus leucoxylon, and the Pink Gum, Eucalytpus fasciculosa.

3. National Context The Hindmarsh Valley Greenhood is endemic to South Australia where it is confined to the Fleurieu Peninsula region (Adelaide Herbarium 2005; Bickerton 2001; Jones 1997). The Hindmarsh Valley Greenhood is known to occur in only two locations. One location includes Mount Billy Conservation Park and the adjacent Hindmarsh Reservoir Reserve. A second location is at Talisker Conservation Park, over 40 km away. The habitat of the Hindmarsh Valley Greenhood has been selectively cleared for agriculture in the Southern Mount Lofty Ranges with remaining habitat being fragmented and often weed invaded (Bickerton 2001; Davies 1992).

A previous population, now presumed extinct, was known to occur in the Hindmarsh Falls Recreation Reserve.

The Hindmarsh Valley Greenhood is currently 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 critically 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 The Hindmarsh Valley Greenhood is endemic to South Australia where it is confined to the Fleurieu Peninsula region (Adelaide Herbarium 2005; Bickerton 2001; Jones 1997). In the Hindmarsh Valley, one population is confined to Mount Billy Conservation Park and the adjacent Hindmarsh Valley Reservoir Reserve. In 2004, an additional population was discovered in Talisker Conservation Park, 45 km to the south west of the two Hindmarsh Valley populations (Adelaide Herbarium 2005; R. Bates 2005, pers. comm.).

Annual monitoring at all sites except the Talisker site has occurred since 1999, including total counts for each population. The species’ area of occupancy was accurately determined for all sites in Mount Billy Conservation Park and Hindmarsh Valley Reservoir Reserve in 2004. In the same year, seven permanent quadrats were set up at the same sites to monitor the orchid (J. Quarmby 2005, pers. comm.). The block of native vegetation, including Mt Billy Conservation Park, that contains the majority of known of the Hindmarsh Valley Greenhood was surveyed in 2003 and 2004.

Annual monitoring since 1999 indicates that the numbers of flowering and vegetative individuals vary greatly from year to year according to seasonal conditions and that, in any one year, a number of individuals are dormant as tubers. Current surveys indicate a total population size of at least 3 850 individuals. However, there are no data to indicate to what extent the species’ population size may have declined in the past.

Despite intensive annual searches, the population at Hindmarsh Falls Recreation Reserve has not been recorded since 2000, and is presumed to be extinct (J. Quarmby 2005, pers. comm.). Assuming that the small population recorded at Hindmarsh Falls Recreation Reserve between 1998 and 2000 is extinct (M. Robertson 2005, pers. comm.; J. Quarmby 2005, pers. comm.), this would indicate that the Hindmarsh Valley Greenhood’s extent of occurrence has declined from 1.06 km2 to 0.27 km2 within the last four years (i.e. a 75% decline).

Future changes in the Hindmarsh Valley Greenhood’s extent of occurrence are dependent on whether weeds continue to spread in Mount Billy Conservation Park and Hindmarsh Valley Reservoir Reserve, where the only large population of the species occurs. Weeds species likely to have an impact on the species include Bridal Creeper, Asparagus asparagoides, Pittosporum undulatum, Watsonia meriana ssp. Bulbillifera, and Phalaris aquatic (Bickerton 2001, R. Bates 2005, pers. comm.).

Plants of the Hindmarsh Valley Greenhood in Mount Billy Conservation Park are also potentially threatened by increased trampling due to the presence of fauna trapping sites in the vicinity, and the opening of the area to public access (M. Robertson 1998, pers. comm.). This population is also under threat from trampling by orchid enthusiasts. Bickerton (2001) refers to 19-30% of plants in the largest population in Mount Billy Conservation Park as being grazed by native and introduced herbivores and that grazing may result in long term recruitment reduction in the species.

Despite a recorded decline in the species’ extent of occurrence (i.e. the presumed loss of the population at Hindmarsh Falls Recreation Reserve), it is unclear to what degree the Hindmarsh Valley Greenhood has undergone, or is likely to undergo, a reduction in numbers. There are insufficient data currently available to determine either past or likely future population trends in the species.

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

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

The Hindmarsh Valley Greenhood is known to occur in only two locations and is confined to the higher rainfall areas of the Fleurieu Peninsula (R. Davies 2004, pers. comm.). One location is an area that consists of Mount Billy Conservation Park and the adjacent Hindmarsh Reservoir Reserve, both of which cover parts of the same area of native vegetation. A second location is at Talisker Conservation Park, over 40 km away. Annual searches at a third location, Hindmarsh Falls Recreation Reserve, have failed to locate the species, and the species is presumed to be extinct there. While suitable habitat downstream of Hindmarsh Falls still needs to be searched (J. Quarmby 2005, pers. comm.) areas of suitable habitat are now extremely rare throughout the range of the species, and it is highly unlikely that extensive new areas containing the species exist.

The estimated extent of occurrence for the population at Mount Billy Conservation Park and the adjacent Hindmarsh Reservoir Reserve is 0.26 km2. This estimate is based on population information in Bickerton (2001), herbarium collections, and data from annual surveys between 1998 to 2004 (J. Quarmby 2005, pers. comm.). The population in Talisker Conservation Park consists of approximately twenty plants over an area of less than one hectare. The total extent of occurrence of the Hindmarsh Valley Greenhood is estimated to be 0.27 km2, calculated by adding the extent of occurrences of the disjunct Mount Billy and Talisker populations together. The Hindmarsh Falls Recreation Reserve population was excluded from the extent of occurrence estimate as this population is presumed to be extinct.

The total area of occupancy of the Hindmarsh Valley Greenhood is estimated to be less than 0.07 km2.

The extinction of the Hindmarsh Falls Recreation Reserve population in the last four years has not resulted in a significant decrease in the species area of occupancy as this population covered only 0.09 m2 (M. Robertson, pers. comm. 2005). Inadequate data exist to determine whether the areas of occupancy of the remaining populations has declined.

The species’ geographic distribution is very restricted and precarious for the survival of the species. The Hindmarsh Valley Greenhood is threatened by invasion of weeds; competition from other flora species following intense fire; collection and trampling; and direct grazing from herbivores.

Therefore, the species is eligible for listing as critically 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 Annual monitoring since 1999 indicates that the numbers of flowering and vegetative individuals vary greatly from year to year according to seasonal conditions and that, in any one year, a number of individuals are dormant as tubers. Species numbers counted in 2003, an optimum year for orchid flowering, provide the best indication of the Hindmarsh Valley Greenhood’s population size. In that year, 442 and 3 204 flowering plants were counted for the two Mount Billy Conservation Park populations respectively, while 215 flowering plants were counted for the Hindmarsh Valley Reservoir Reserve population. It was impossible to determine the numbers of vegetative plants with any reliability since flowers are needed for species identification. The population in Talisker Conservation Park consists of approximately twenty individuals (R. Bates 2005, pers. comm.).

The total population size is therefore at least 3 850 individuals.

Due to the variable nature of the species from year to year (e.g. flowering, dormancy) there remains a degree of uncertainty concerning the species actual population size and trends. With current data it is difficult to reliably conclude that the species estimated total number of mature individuals is limited to a particular degree.

There are 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 under Criterion 3, the total population size is at least 3 850 individuals. The estimated total number of mature individuals is not extremely low, very low, or low.

Therefore, the species is not eligible for listing under this criterion.

Criterion 5 – Probability of extinction in the wild

There are no data available to assess the species against this criterion.

5. CONCLUSION The Hindmarsh Valley Greenhood is known to occur in only two locations. The species has a very restricted geographic distribution with an estimated extent of occurrence of less than 0.5 km2 and an estimated area of occupancy of less than 0.07 km2. The total population size of the species is currently estimated to be at least 3 850 individuals. The Hindmarsh Valley Greenhood is threatened by invasion of weeds, competition from other flora species following intense fire, collection and trampling; and direct grazing from herbivores.

The species is eligible for listing as critically endangered under criterion 2.

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 critically endangered category:

Pterostylis bryophila (Hindmarsh Valley Greenhood)

References cited in the advice

Adelaide Herbarium (2005). ADHERB database.

Bates, R.J. Personal communication 2005.

Bates R.J., and J.Z.Weber (1990). Orchids of South Australia. Government Printer, Adelaide.

Bickerton D. (2001). Draft Recovery Plan for Pterostylis bryophila (Hindmarsh Valley Greenhood). National Parks and Wildlife SA: Adelaide.

Davies R.J.P. (1992). Threatened species of the Murray Mallee, Mount Lofty Ranges and Kangaroo Island regions of South Australia. Conservation Council of South Australia.

Davies R.J.P. Personal observation 2003.

Davies R.J.P. Personal communication 2004.

Davies R.J.P. Personal communication 2005.

Jones D.L. (1997). Two rare new species of Pterostylis R. Br. () allied to P. alveata Garnet. The Orchadian, 12:180-184.

Quarmby, J. Personal communication 2005.

Robertson, M. Personal communication 1998.

Robertson, M. Personal communication 2005.

Rogers R.S. (1922). in Black J.M., Flora of South Australia. Edn 1, part 1: 152. Government Printer, Adelaide.

Rogers R.S. (1943). in Black, J.M., Flora of South Australia. Edn 2, part 1: 246. Government Printer, Adelaide.