THREATENED SPECIES SCIENTIFIC COMMITTEE Established under the Environment Protection and Biodiversity Conservation Act 1999

The Minister’s delegate approved this Conservation Advice on 01/04/2016.

Conservation Advice Myoporum turbinatum

salt myoporum

Conservation Status

Myoporum turbinatum (salt myoporum) is listed as Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act). The species is eligible for listing as prior to the commencement of the EPBC Act, it was listed as Vulnerable under Schedule 1 of the Endangered Species Protection Act 1992 (Cwlth) (ESP Act).

The species was originally listed as Endangered under the ESP Act in 1992 and was downlisted to Vulnerable in 1998. These changes appear to coincide with the species’ status on the ANZECC Threatened Australian Flora List, where the species was downlisted from Endangered to Vulnerable at the end of 1997 and then uplisted back to Endangered category at the end of 1998.

The species is also listed as Critically Endangered under the Wildlife Conservation Act 1950 (Western Australia).

Description The salt myoporum is an erect shrub to 4 m tall. When young it is multi-stemmed and broom-like but when mature consists of one or a few long slender stems with leafy branches that are restricted to the uppermost part. The species has sticky branches with prominent wart-like projections. The shiny, dark green linear leaves, which are 11 to 80 mm long by 1 mm wide with a distinctly grooved midrib, also have prominent wart-like projections and are arranged alternately along the stem. The leaf margins have small conical teeth that are more obvious towards the tip. The dull, white flowers are often tinged with lilac and have four stamens that protrude just beyond the petals. Four to eight flowers are held in each leaf axil. Flattened fruits are beaked at the end and have four ribs or wings (Brown et al., 1998; Craig & Coates 2001).

Myoporum turbinatum is closely related to M. platycarpum. The fruit of M. turbinatum however, is not flattened in the lower half (Chinnock 1986).

Distribution This salt myoporum is known only from a region about 80 km northeast of Esperance in Western Australia, where it is found over a small range along road verges (Taylor et al., 2004). It grows on the margins of saline depressions in sandy duplex soils in mallee heath scrub with species of bottlebrush (Melaleuca spp.), pincushion hakea (Hakea laurina) and various Eucalyptus species (Chinnock 1986; Brown et al., 1998; Taylor et al., 2004).

Relevant Biology/Ecology Members of the Myoporaceae are often suitable ornamental garden plants. Most adapt well to cultivation and generally withstand extended dry periods, frosts, alkaline and salty soils (Richmond and Ghisalberti 1995). The plants and flowers in the Myoporaceae family are also hermaphroditic (CALM, 1998).

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It is believed that fire kills adult plants of the species and regeneration is largely from seed, however there has been no specific research conducted on the taxon. The susceptibility of M. turbinatum to dieback disease (caused by Phytophthora spp.) and disturbance are unknown and require research.

The salt myoporum is a short-lived disturbance species which is not generally found in the wild without some disturbance event (Craig & Coates 2001). The species has been recorded flowering in May, and October through to February (Craig & Coates 2001). Threats Habitat loss disturbance and modifications • Road and firebreak maintenance - Threatens all road reserve populations and most populations on private property. Threats include grading, chemical spraying, construction of drainage channels and the mowing of roadside vegetation. Several of these actions also encourage weed invasion. • Rising saline water tables - Likely future threat. All populations are adjacent to salt lakes in seasonally wet/waterlogged areas that in 2004 showed signs of rising salinity.

Invasive species • Weeds suppress early plant growth by competing for soil moisture, nutrients and light. They also exacerbate grazing pressure and increase the fire hazard due to the easy ignition of high fuel loads that are produced annually by many grass weed species.

Fire frequency • It is not known how the species responds to fire; however overly frequent fire is likely to kill plants before they reach maturity.

Poor recruitment • In 2004 few seedling plants had being observed.

Conservation Actions

Conservation and Management priorities

Habitat loss disturbance and modifications

o Maintain and protect existing populations of salt myoporum, and protect and enhance habitat to provide potential for reproduction of plants within existing populations.

o Ensure land owners and managers manage important sites for the species on private property so that populations are not accidentally damaged or destroyed, through exclusion fencing or other barriers.

o Provide maps of the locations of populations to councils and other land managers so that the are aware of the species location when performing road and firebreak maintenance.

Invasive species

o Identify and undertake weed control in the local area that could become a threat to the salt myoporum, using targeted application of herbicide or hand removal of weeds. Consider the possible disturbance/overspray threats associated with the control method. Myoporum turbinatum (salt myoporum) Conservation Advice Page 2 of 4

Fire frequency

o As the impact of fire is unclear, critically, any use of prescribed or experimental fires must be very well justified, and is typically an action of last resort. It must have a carefully planned weed management strategy and demonstrated funding to ensure post-fire monitoring and control actions occur (eg weed control based on sound scientific evidence).

o Provide maps of known occurrences to local and state Rural Fire Services and seek inclusion of mitigation measures in bush fire risk management plan/s, risk register and/or operation maps.

Breeding, propagation and other ex-situ recovery action

o Continue cultivating plants ex-situ for inclusion in living collections to safeguard against any unforeseen destruction of wild populations from road maintenance or fire. o Continue collecting seeds for a seed bank and determine seed viability. o Establish a minimum population size of cultivated plants.

Stakeholder engagement

o Consult with private landowners with the species on their properties and develop site- specific management actions and the implementation of conservation agreements. o The importance of biodiversity conservation and the need for the long-term protection of wild populations of this species will be promoted to the community through the local print and electronic media and poster displays. Formal links with local naturalist groups and interested individuals will also be encouraged.

Survey and Monitoring priorities

• Undertake more accurate assessment of the current population size of salt myoporum, including the species’ extent of occurrence and area of occupancy. • Establish rates of survival, longevity, standing plants and seed bank. • Monitor populations and the habitat that these populations exist within, or is in the immediately vicinity, to identify sudden changes that may threaten the existence of remaining populations. • Monitor the hydrology of areas with known populations (using observation bores, data loggers etc.) to identify any increasing risks posed to the species by rising saline water.

Information and research priorities

• Collecting seed from all populations and from a range of plants will ensure an adequate representation of genetic diversity. It is also important that the size and viability of the soil seed bank is determined and further research is undertaken to develop techniques for stimulating germination of soil-stored seed. • Undertake seed germination and/or vegetative propagation experiments for salt myoporum to determine the requirements for successful establishment. • Determining the reproductive method, phenology and seasonal growth of the species. • Develop better understanding as to how fire positively and negatively impacts the species. While it is suggested that fire may kill mature individuals, it may also trigger regeneration of

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the species from seed. This information may be able to better inform management of fire practices in areas the species occurs. • Investigate the merits of a translocation strategy for this species from areas where populations are low and not fully protected from threats. • Studying the impact of salinity and waterlogging on Myoporum turbinatum and its habitat.

References cited in the advice

Brown A, Thomson-Dans C & Marchant N (eds.) (1998). Western Australia's Threatened Flora. Western Australian Department of Conservation and Land Management, Como, Western Australia.

CALM (1998) Western Australian Herbarium FloraBase – Information on the Western Australian Flora. Department of Conservation and Land Management, Perth, Western Australia.

Chinnock RJ (1986). Five endangered new species of Myoporaceae from south-western Australia. Nuytsia, vol. 5(3): 391 – 400.

Craig GF & Coates DJ (2001). Declared Rare and Poorly Known Flora in the Esperance District. Western Australian Wildlife Management Program No. 21, Western Australian Department of Conservation and Land Management. Viewed: 2 October 2015 Available on the Internet at: http://www.dpaw.wa.gov.au/images/documents/plants-animals/threatened- species/recovery_plans/wildlife_management_plans/Esperance_District_WMP_21.pdf

Guisan, A., & Zimmermann, N.E. (2000). Predictive habitat distribution models in ecology. Ecological Modelling 135: 147-186.

Taylor H, Butler R & Brown A (2004). Salt myoporum (Myoporum turbinatum) interim recovery plan 2004-2009. Western Australian Department of Conservation and Land Management, Western Australia.

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