Eidothea sp. Nightcap Range (P.H.Weston 2469) (Nightcap Oak), a tree

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 Act1999 (EPBC Act)

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

Eidothea sp. Nightcap Range (P.H.Weston 2469) (Nightcap Oak), a tree.

2. National Context

The species is endemic to northern NSW and is provisionally listed as endangered under NSW legislation. It is currently not listed under the EPBC Act.

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

Extensive surveys undertaken at known sites and in areas considered to be suitable habitat indicate the Nightcap Oak has a very restricted geographic distribution, the extent of occurrence and area of occupancy being less than 10km2. The species exists at a single location within one catchment of the Nightcap Range. The species is confined to rainforest habitat and preliminary research indicates it is adversely affected by disturbance. It occurs close (10-20m) to the transition zone with mixed hardwood forest that has been identified for logging during 2002-2003. Whilst areas identified as rainforest are protected from logging under current logging licences, rainforest areas are not protected from disturbance due to road construction associated with access to logging compartments. The immediate proximity of the population to proposed logging compartments increases the potential for habitat disturbance and degradation associated with changes in microclimate. The area, extent and quality of habitat would decline if roads are constructed through rainforest habitat. Recruitment to the population is evidenced by the presence of approximately 80 immature specimens (tree stems < 10cm diameter at breast height) amongst the approximately 88 mature specimens. Whilst this level of recruitment may indicate the species is not currently in a state of decline, the low number of mature individuals in a single location renders the species vulnerable to stochastic disturbance events such as fire. The threat of a decline in the area, extent and quality of the species' habitat, in combination with all known specimens existing in a single location, indicate that the geographic distribution is precarious for the survival of the species.

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

Criterion 3 - Population size and decline in numbers or distribution

Whilst the number of mature individuals is very low, approximately 88, recruitment of juveniles to the total population is evident, and there is no data from which historic or future declines in the number of mature individuals may be inferred.

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

Criterion 4 - Population size

The number of mature individuals has been determined during extensive surveys to be approximately 88.

Therefore, the species is eligible for listing as 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, the extent of occurrence and area of occupancy being less than 10km2. The species exists at a single location within one catchment of the Nightcap Range, is confined to rainforest habitat and may be adversely affected by disturbance. The immediate proximity of the population to proposed logging compartments increases the potential for habitat disturbance and degradation associated with changes in microclimate. The area, extent and quality of habitat would decline if roads are constructed through rainforest habitat. The low number of mature individuals in a single location also renders the species vulnerable to stochastic disturbance events such as fire. The geographic distribution is very restricted and precarious for the survival of the species. The species is eligible for listing as critically endangered under criterion 2.

5. Recommendation

TSSC 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:

Eidothea sp. Nightcap Range (P.H.Weston 2469) (Nightcap Oak), a plant.