Coral Heath (Epacris acuminata)

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)
15 September 2005

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

Epacris acuminata (Coral Heath)

2. Description

The Coral Heath is an erect, perennial shrub, usually branching near the base and growing to between 60-100 cm tall. It has slender branches bearing thin concave leaves that are small and oval with the bases partly folded around the stem (Kirkpatrick 2000). Peak flowering occurs in spring with seed release in late summer (Keith 1997) and the flowers are white and densely clustered along the terminal branches (Kirkpatrick 2000). The maximum life span of individual shrubs has been estimated at between 30-40 years (Keith 1997) and the species is also known to resprout after damage. The Coral Heath requires fire at appropriate intervals to recruit seedlings from the soil seed bank with 'post fire' rainfall being vital in ensuring seedling establishment.

3. National contex

The Coral Heath only occurs in Tasmania. It is known from the south east, midlands and central highlands bioregions between the Channel district in south east Tasmania, the midlands and Eastern Tiers and the eastern edge of the Central Plateau (Keith 1997). The Coral Heath is found on Jurassic dolerite in subalpine heathy woodland on mountain summits at 600-1100 m or in riparian dry schlerophyll forest at 30-590 m. Exceptions occur at Goat Hills, Knights Creek (inside Wellington Park) (Keith 1997) and Serat, where the species occurs on hill slopes and plateaus.

The species is reserved in the Central Plateau Conservation Area, Cradle Mountain-Lake St Clair National Park, Devils Den Conservation Area, Franklin-Gordon Wild Rivers National Park, Great Western Tiers Conservation Area, Liffey Forest Reserve, Millers Bluff Forest Reserve, Mount Dromedary Forest Reserve, Mount Faulkner Conservation Area (approximately 3000 plants), Port Arthur Historic Site, Snug Tiers Nature Recreation Area, Swan River Forest Reserve, Table Mountain Conservation Area (approximately 3000 plants), the Lea Conservation Area, Wayatinah Conservation Area and Wellington Park.

An ex situ collection is also held at the Royal Tasmanian Botanic Gardens in Hobart and the species is in cultivation at the Australian National Botanic Gardens in Canberra.

The Coral Heath is currently listed as rare under Tasmania's Threatened Species Protection Act 1995.

4. 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

In 1997, the Coral Heath was reported to consist of 27 populations with a total population of approximately 16 000 individuals (with 91% of all individuals being mature plants) (Keith 1997). In 1999, as part of assessments leading to the Tasmanian Regional Forest Agreement, the species was reported to consist of 25-27 populations with a total population of approximately 23 000 individuals over a geographic range of 170 km (CoA 1999). Since implementation of the Forest Epacrids Recovery Plan (Keith 1997), several additional populations have been located in Wellington Park, extending the range of the species to include riparian sites, mid slopes and mountain summits. Recently, a further ten populations have reportedly been found.

The Coral Heath is now considered to exist in 40 populations consisting of approximately 75 000 individuals over 135 km2 (current data indicate that 90% of known individuals occur in less than ten populations with one population consisting of 40% of all known individuals). However, a number of populations have no estimate of size, and the sizes recorded for others are widely considered to be greatly under estimated.

There is apparently little historical data regarding the total number of plants. From 1997 to the present, due to an increased understanding of the species' abundance in the wild rather than recovery of the species, the known number of individuals has increased from approximately 16 000 to approximately 75 000 individuals.

The Coral Heath is considered to be fire sensitive and adversely affected by inappropriate fire management, particularly in riparian and forest habitats. While the Coral Heath is considered to have a low susceptibility to Phytophthora cinnamomi, this pathogen may impact on it in certain habitat types. The species is also affected by flooding, habitat clearance, trampling of plants and grazing by stock and degradation, including weed invasion (e.g. Gorse, Blackberry, Exotic grasses, Erica spp, Willow and Hawthorn, which have all been reported to impact on the species particularly adjacent to agricultural and other private lands).

Larger, dense patches of the Coral Heath are protected by Tasmania's Forest Practices Code. However, one population of the Coral Heath, considered to be the largest and best quality population of the species (estimated to make up approximately 40% of the total population) is likely to be impacted on by a proposed dam through direct inundation and degradation of riparian habitat from the downstream impacts. This proposal, at Chimney Hill, has been estimated to inundate approximately 14% of the total population of the species and approximately 11% of the species' total occupied area.

There is insufficient evidence available to indicate that the Coral Heath has undergone, or is suspected to have undergone, a very severe, severe or substantial reduction in numbers. In addition, while several factors impact on the species and one proposal is likely to have an impact on a significant population of the Coral Heath, the species is unlikely to undergo at least a substantial reduction in numbers in the immediate future.

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

Criterion 2 - Geographic distribution

In 1999, as part of assessments leading to the Tasmanian Regional Forest Agreement, it was reported that the Coral Heath consisted of 25-27 populations over a geographic range of 170 km (CoA 1999). Since implementation of the Forest Epacrids Recovery Plan, several additional populations have been located in Wellington Park extending the range of the species to include riparian sites, mid slopes and mountain summits. Recently, a further ten populations have been found. The Coral Heath is now known to exist in 40 populations over 135 km2. The actual area of occupancy of the Coral Heath is estimated to be between 10 and 60 hectares (one expert considered the species occupied approximately 150 hectares).

The species is not considered to be severely fragmented. In addition, extreme fluctuations in numbers may not be an appropriate measure of conservation status as this species regenerates from seed following fire and there is a temporary decline in numbers of mature individuals following fire. Current data indicate that 90% of known individuals occur in less than ten populations. However, a number of populations have no estimate of size, and the sizes recorded for others are considered to be greatly under estimated.

The Coral Heath is considered to be fire sensitive and adversely affected by inappropriate fire management, particularly in riparian and forest habitats. While the Coral Heath is considered to have a low susceptibility to Phytophthora cinnamomi, this pathogen may impact on it in certain habitat types. The species is also affected by flooding, habitat clearance, trampling of plants and grazing by stock and degradation, including weed invasion (e.g. Gorse, Blackberry, Exotic grasses, Erica spp, Willow and Hawthorn, which have all been reported to impact on the species particularly adjacent to agricultural and other private lands).

The Coral Heath occurs in a number of conservation reserves including Mt Falkner Conservation Area (approximately 3000 plants), Table Mountain Conservation Area (approximately 3000 plants), Barron Rock Falls Scenic Reserve, Ouse River Conservation Area, and Mt Dromedary Forest Reserve (CoA 1999).

In spite of identified potential threats and the restricted area of occupancy of the species, there is insufficient information to indicate a continuing decline. While the geographic distribution (i.e. area of occupancy) of the species is restricted, it is not considered that this distribution is precarious for the survival of the species.

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

Criterion 3 - Population size and decline in numbers or distribution

The Coral Heath is known to exist in 40 populations and consist of approximately 75 000 individuals. One expert noted that the total population of the species was actually in the range of 71 600 to 300 000 individuals with between 55 000 to 100 000 occurring in one subpopulation. Regardless of the exact number, it is evident that the Coral Heath consists of over 70 000 individuals and the estimated total number of mature individuals is not very low, low, or limited.

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

Criterion 4 - Population size

The Coral Heath has a total population of 75 000 individuals with a very restricted area of occupancy (between 10-60 and possibly up to 150 hectares) such that it is prone to a number of threatening activities.

The species is considered to be fire sensitive and adversely affected by inappropriate fire management, particularly in riparian and forest habitats. While the Coral Heath is considered to have a low susceptibility to Phytophthora cinnamomi, this pathogen may impact on it in certain habitat types. The species is also affected by flooding, habitat clearance, trampling of plants and grazing by stock and degradation, including weed invasion (e.g. Gorse, Blackberry, Exotic grasses, Erica spp, Willow and Hawthorn, which have all been reported to impact on the species particularly adjacent to agricultural and other private lands).

One population of the Coral Heath, considered to be the largest and best quality population of the species (estimated to make up 40% of the total population) is likely to be impacted on by a proposed dam. This proposal has been estimated to inundate approximately 14% of the total population of the species and approximately 11% of the species' total occupied area.

While its numbers are not extremely low, very low, or low, the Coral Heath has a total population with a restricted area of occupancy such that it is prone to the effect of human activities or stochastic events.

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

Criterion 5 - Probability of extinction in the wild

There is no quantitative data available against this criterion. Therefore, the species in not eligible for listing under this criterion.

5. Conclusion

Since its listing under the ESP Act in 1998, there has been an increase in knowledge concerning the Coral Heath's distribution and population size. The Coral Heath is now considered to exist in 40 populations consisting of at least 70 000 individuals over 135 km2. The Coral Heath is estimated to occupy between 10 to 60, and possibly up to 150 hectares. Current data indicate that 90% of individuals occur in less than ten populations with one population considered to make up 40% of the total. It is noted however, that a number of populations have no estimate of size, and the sizes recorded for others are widely considered to be greatly under estimated.

While it is acknowledged that the species is no longer eligible to be listed in the endangered category, and that a number of populations are managed in conservation areas, the total population of Coral Heath is sufficiently restricted in its geographic occurrence to be prone to the impacts of clearance, inundation, weed invasion, trampling and grazing to warrant its listing in the vulnerable category.

The species is eligible for listing as vulnerable under criterion 4.

6. Recommendation

TSSC recommends that the list referred to in section 178 of the EPBC Act be amended by deleting from the endangered category:

  • Epacris acuminata (Coral Heath)

and including in the list in the vulnerable category:

  • Epacris acuminata (Coral Heath)

Publications used to assess the nomination

Commonwealth of Australia (1999). Tasmania-Commonwealth Regional Forest Agreement: Summary of Life History and Population dynamics for vascular forest flora.

Keith, D. (1997). Recovery Plan Tasmanian Forest Epacrids 1999-2004. Tasmanian Parks and Wildlife Service, Hobart, Tasmania.

Conservation advice

The Coral Heath is an erect, perennial shrub, usually branching near the base and growing to between 60-100 cm tall. It only occurs in Tasmania (South and North Tasmanian Natural Resource Management Regions). The species is known to resprout after damage and requires fire at appropriate intervals to recruit seedlings from the soil seed bank with 'post fire' rainfall being vital in ensuring seedling establishment. The Coral Heath is considered to be fire sensitive and adversely affected by inappropriate fire management, particularly in riparian and forest habitats. The species is also affected by habitat clearance, trampling of plants and grazing by stock and degradation, including weed invasion (e.g. Gorse, Blackberry, Exotic grasses, Erica spp, Willow and Hawthorn, which have all been reported to impact on the species particularly adjacent to agricultural and other private lands).

The priority recovery and threat abatement actions required for this species are to:

  • encourage an appropriate fire management regime for the species;
  • minimise impacts on the species habitat through vegetation clearance, trampling of plants, grazing of plants by stock;
  • control weeds and where possible minimise new weed incursions; and
  • identify important populations* and activities that may have an adverse impact on them.

* An important population is one that is necessary for a species' long term survival and recovery. This may include populations that are:

  • key source populations for dispersal;
  • populations that are necessary for maintaining genetic diversity; and/or
  • populations that are near the limit of the species range.

This list does not encompass all actions that may be of benefit to this species, but highlights those that are considered to be of the highest priority at the time of listing.

Priority for the development of recovery plan: A recovery plan has already been completed and adopted under the EPBC Act (Recovery Plan Tasmanian Forest Epacrids 1999-2004). This plan will need to be updated in accordance with new information on its population distribution and size and the Threatened Species Scientific Committee's listing advice.