Indicative distribution
The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas.
(
click here to see geographic restrictions).
The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Triplarina nowraensis
Gazetted date:
06 Jun 1997
Profile last updated:
17 Aug 2018
Description
Nowra Heath Myrtle is a small, erect shrub to 5 m tall. The branchlets have a grey, scaly bark. The small paired leaves are blunt-tipped with the broadest part above the middle. Leaves are only 5 mm long by 1.7 mm wide. They have a row of large oil dots on either side of the mid-rib and are highly aromatic when crushed. The tea-tree flowers are creamy-white and occur in pairs. The fruits are hemispherical and wrinkled.
Distribution
There are five known populations of Nowra Heath Myrtle. Three of these form a cluster to the immediate west of Nowra. A fourth, much smaller population is found 18km south-west of Nowra in the Boolijong Creek Valley. The fifth population is located north of the Shoalhaven River on the plateau above Bundanon.
Habitat and ecology
- Nowra Heath Myrtle occurs on poorly drained, gently sloping sandstone shelves or along creek lines underlain by Nowra Sandstone.
- The sites are often either treeless or have a very open tree canopy due to the impeded drainage.
- Individuals have been observed to resprout from lignotubers and they are also expected to reproduce from seed though this needs to be confirmed.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- A regional landfill is found above the creek lines where two populations exist. This could have an adverse impact on soil and water quality and could also result in weed infestation.
- Proposed future land-use changes in the catchments where the species occurs including the Nowra bypass and residential subdivision.
- Habitat disturbance during powerline, road and trail maintenance is a potential threat to parts of the population.
- Myrtle rust infection causing loss of populations.
- Proposed new residential developments in areas adjoining known populations of the Nowra Heath Myrtle are likely to result in increased recreational activity within the species' habitat. This may have detrimental impacts through trampling of plants and seedlings, soil compaction and potential erosion started by activities such as trail bike riding.
- Given the proximity of the main population to urban areas there is likley to be increasing pressure to undertake fire hazard reduction burning within the habitat of the species. The impacts of fire are not currently known but there is concern that too frequent burning may have an adverse impact on the species.
- A large proportion of the population occurs on private properties and apart from the threat of proposed urban development, the survival of the species on these sites is also under threat from other possible future land uses that are unfavourable to the species.
- Mixed weeds establishing in species habitat due to run off from surrounding properties.
- Hydrological disturbance in catchments saturating species habitat, generating higher peak run off causing frequent erosion events that impact species survivorship.
Recovery strategies
A targeted strategy for managing this species has been developed under the Saving Our Species program; click
here for details. For more information on the Saving Our Species program click
here
Activities to assist this species
- Ensure personnel planning and undertaking hazard reduction burns are able to identify the species and are aware of its habitat.
- Develop a fire management plan for the species.
- Searches should be conducted in suitable habitat in proposed development areas.
- OEH should be consulted when planning development to minimise impact on populations.
- Erect on-site markers to alert maintenance staff to the presence of this species.
- Monitor known populations for changes in numbers.
- Undertake further research into the species’ response to fire.
- Mark Nowra Heath Myrtle sites and potential habitat onto maps used for planning road and track maintenance work.
Information sources
- Bean, A.R. (1995) Reinstatement and revision of Triplarina Raf. (Myrtaceae). Austrobaileya 4(3): 353-367.
- Harden, G.J. (ed.) (2002) Flora of New South Wales. Volume 2, Revised Edition. UNSW, Sydney.
- Mills, K. (1998) Rare Plant Species in the Illawarra: Triplarina nowraensis (Myrtaceae). Illawarra Vegetation Studies (11), Coachwood Publishing, Jamberoo, NSW.
- NSW National Parks and Wildlife Service (2003) Draft NSW and National Recovery Plan for the Nowra Heath-myrtle (Triplarina nowraensis). NSW NPWS, Sydney.
- NSW Scientific Committee (1997) Triplarina nowraensis (a shrub) - Endangered species determination - final. DEC (NSW), Sydney.
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