Genoplesium vernale (East Lynne Midge-orchid)

Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee (TSSC) on Amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)

1. Scientific name, common name (where appropriate), major taxon group

Genoplesium vernale (East Lynne Midge-orchid)

Note: the species name was incorrectly spelt 'vernalis' at the time of publication.

2. National Context

The species is restricted to NSW. Formerly known only from the type locality at East Lynne, the species has now been located at several other locations within the State.

3. How judged by TSSC in relation to the EPBC Act criteria

TSSC judges the species to be eligible for listing as vulnerable under the EPBC Act. The justification against the criteria is as follows:

Criterion 1 - Decline in numbers

There is no evidence of substantial population reduction. There is no quantitative data to substantiate an observed or inferred rate of ongoing decline in the total population or at any individual site. Whilst there is evidence of one-off events resulting in the localised destruction of habitat and individuals within the known range of the species, the impact has not been quantified at any site, and is limited to a low number of individuals due to the species' low population density. Such events are not a frequent occurrence nor are they likely to be of a large scale at the majority of sites. A total of 16 sites (out of the 29 total) are under, or in the process of being transferred to, National Park management.

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

Criterion 2 - Geographic distribution

The nomination indicates the species is known from 19 sites with the area of occurrence being approximately 500km2. The presence of the species at additional sites including the Budawang National Park have now been confirmed. This increases the known sites from 19 to 29 and further extends the area of occurrence and occupancy beyond those provided to 924km2 and 1.45km2 respectively.

The evidence of habitat destruction within the species known range is limited to one-off events associated with road construction, utility easements, and agricultural clearing (only one of the currently recorded sites is not under State Forest or National Park management). The draft survey report indicates that 22 of the 29 sites have been burnt or logged, or in 9 cases, both, since 1980 indicating some resilience to site disturbance from fire or logging activities.

The transfer of management of 11 additional sites from NSW Forestry to the NSW NPWS for conservation purposes under a Regional Forest Agreement began on 1 January 2001 and is due to be finalised by the end of March 2001. A total of 16 sites are thus included in National Parks and 12 in State Forest.

The geographic distribution is not considered precarious for the survival of the species. It is known from more than ten locations, is not severely fragmented within the area of occurrence, and is not subject to a continuing decline or extreme fluctuations in occurrence, occupancy, suitable habitat, or numbers of locations or individuals.

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

Criterion 3 - Population size and decline in numbers or distribution

A conservative estimate of population according to the nomination is 950 calculated at 10 plants/ha. The nomination indicates that an estimate of 1900 is quite realistic and possibly 10,000 as the number of actual sites is likely to be at least twice the number currently recorded. The figure of 10,000 is, however, not supported by the available data which records a total of 296 observed individuals.

Using the nominator's estimate of the species density (10 plants/ha) for the increased number of currently recorded sites, the population could be estimated at 1,450. Whilst the observed and conservatively estimated population is limited, there is no evidence of substantial decline, nor that the current geographic distribution is precarious for survival of the species.

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

Criterion 4 - Population size

On the basis of available site information, the population is estimated at approximately 1,450 individuals. However, as the survey data only recorded 296 individual specimens the population is considered low.

Therefore, the species is eligible for listing as vulnerable under this criterion.

Criterion 5 - The probability of its extinction in the wild is at least 10% in the medium-term future.

The probability of extinction in the wild has not been calculated.

4. Conclusion

Based on a conservative estimate of the total population (1,450 individuals), the lack of observed or inferred decline in the population, and secure geographic distribution, the species could be considered ineligible for listing. However, as the total observed population is 296 individuals, the species is considered to exist in sufficiently low numbers to justify listing as vulnerable, as nominated. The species is eligible for listing as vulnerable under criterion 4.

5. Recommendation

TSSC recommends that the list referred to in section 178 of the EPBC Act be amended by

transferring from the endangered category to the vulnerable category:

Genoplesium vernale (East Lynne Midge-orchid)