Euphrasia gibbsiae subsp. psilantherea (an Eyebright)
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
Euphrasia gibbsiae subsp. psilantherea (an Eyebright)
2. National Context
The species is endemic to Tasmania. The species is currently listed as endangered under the EPBC Act and the Tasmanian Threatened Species Protection Act 1995.
3. How judged by TSSC in relation to the EPBC Act criteria.
TSSC 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 - Decline in numbers
There is no quantitative data available against this criterion.
Criterion 2 - Geographic distribution
The geographic distribution of the species is precarious for the survival of the species and is very restricted. The species is known from a single population. The area of occupancy is 0.25ha and the extent of occurrence is 0.0025km2. A decline in the area, extent and quality of habitat, and the number of mature individuals has been observed due to track braiding caused by four-wheel drive vehicles and fire regimes. The species is considered to be susceptible to the Phytophthora fungus should it be introduced to the area. As a short-lived species (generation span of two years), with seedling recruitment dependent on open habitat due to disturbance, it is considered susceptible to extreme fluctuations in the area, extent and quality of habitat, the number of populations and the number of mature individuals.
Therefore, the species is eligible for listing as critically endangered under this criterion.
Criterion 3 - Population size and decline in numbers or distribution
The total number of mature individuals is very low, ten plants having been recorded in dedicated field surveys. A continuing decline is projected due to ongoing threats from track braiding caused by four-wheel drive vehicles and fire regimes. As all known plants occur in a single population the geographic distribution of the species is also precarious for its survival.
Therefore, the species is eligible for listing as critically endangered under this criterion.
Criterion 4 - Population size
The total number of mature individuals is extremely low, a total of ten specimens having been identified in dedicated field surveys. All specimens are located in a single population.
Therefore, the species is eligible for listing as critically endangered under this criterion.
Criterion 5 - Probability of extinction in the wild
There is no quantitative data available against this criterion.
4. Conclusion
The species has a very restricted geographic distribution that is precarious for the survival of the species. The species is contained in a single population, the area of occupancy is 0.25ha and the extent of 0.0025km2. The total population is comprised of ten mature individuals. Continuing decline in the area, extent and quality of habitat, and the number of mature individuals has been observed due to track braiding caused by four-wheel drive vehicles and fire regimes. The species is considered to be susceptible to the Phytophthora fungus should it be introduced to the area. As a short-lived species (generation span of two years), dependent on openness due to disturbance for seedling recruitment, it is considered susceptible to extreme fluctuations in the area, extent and quality of habitat, the number of populations and the number of mature individuals. The species is eligible for listing as critically endangered under criteria 2, 3 and 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 critically endangered category:
Euphrasia gibbsiae subsp. psilantherea (an Eyebright)