Eucalyptus parramattensis subsp. decadens - profile

Indicative distribution

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Key:

known

predicted

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: Eucalyptus parramattensis subsp. decadens

Conservation status in NSW: Vulnerable

Commonwealth status: Vulnerable

Profile last updated: 10 Sep 2019

Description

A woodland tree, up to 15 m, but usually to about 8 – 10m in height. Bark sheds in large plates to leave a smooth, granular and mottled white or grey surface. Juvenile and adult leaves are disjunct. Juvenile leaves are narrow-lanceolate to lanceolate, dull green both sides. Adult leaves are usually lance-shaped to about 15 cm long and 2 cm wide. Inflorescences are 7–flowered. Buds are ovoid 4 – 10mm long, 4 – 6 mm in diameter with a scar present. Fruit is hemispherical or globose 4 – 9 mm long, 5 – 9 mm in diameter, with the disc flat or slightly raised, usually with four exserted valves.

Distribution

There are two separate meta-populations of E. parramattensis subsp. decadens. The Kurri Kurri meta-population is bordered by Cessnock—Kurri Kurri in the north and Mulbring—Abedare in the south. Large aggregations of the subspecies are located in the Tomalpin area. The Tomago Sandbeds meta-population is bounded by Salt Ash and Tanilba Bay in the north and Williamtown and Tomago in the south.

Habitat and ecology

Generally occupies deep, low-nutrient sands, often those subject to periodic inundation or where water tables are relatively high.
It occurs in dry sclerophyll woodland with dry heath understorey. It also occurs as an emergent in dry or wet heathland. Often where this species occurs, it is a community dominant.
In the Kurri Kurri area, E. parramattensis subsp. decadens is a characteristic species of ‘Kurri Sand Swamp Woodland in the Sydney Basin Bioregion’, an endangered ecological community under the TSC Act.
In the Tomago Sandbeds area, the species is usually associated with the ‘Tomago Swamp Woodland’ as defined by NSW NPWS (2000).
Very little is known about the biology or ecology of this species.
Flowers from November to January. Propagation mechanisms are currently poorly known. Seed dispersal is likely to be effected by wind and animals.
Likely to be sensitive to over-frequent fire, however there is evidence (i.e. coppicing, epicormic shoots) that the species may be tolerant of low intensity fires. The species has a canopy stored seed bank for dispersal after fire events.

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.

Threats

Habitat loss and fragmentation resulting from development, particularly sand mining, road construction and residential/industrial developments.
Weed invasion, in particular Lantana and Bitou Bush.
Water extraction from the Tomago sand beds, impacting the species as it is groundwater dependent.
Repeat arson leading to too frequent fire which may prevent recruitment of new individuals to the population, leading to long-term decline.
Lack of understanding of the species fire ecology.
Lack of knowledge about the species susceptibility to myrtle rust.
Fluoride damage to vegetation from the Tomago Smelter causes yellowing of leaves and restricts new growth.
Cutting down individuals for use as firewood.
Recreational vehicle access causing erosion and land degradation and affecting recruitment.

Recovery strategies

Priority actions are the specific, practical things that must be done to recover a threatened species, population or ecological community. The Office of Environment and Heritage has identified 13 priority actions to help recover the Eucalyptus parramattensis subsp. decadens in New South Wales.

Activities to assist this species

Prevent frequent fires from impacting on the populations.
Habitat rehabilitation though weed removal.
Protect known habitat from clearing, fragmentation, disturbance and modifications to drainage patterns.

Information sources

Harden, G.J. (ed.) (2002) Flora of New South Wales. Volume 2, Revised Edition. UNSW, Sydney.
NSW National Parks and Wildlife Service (2000) Vegetation survey, classification and mapping, Lower Hunter and Central Coast Region. Report prepared for the Lower Hunter and Central Coast Regional Environment Management Strategy. (NSW NPWS, Sydney)