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: Eucalyptus benthamii
Gazetted date:
28 Apr 2023
Profile last updated:
19 Nov 2024
Description
A tall tree to 40 m high with smooth, white bark and numerous long, loose bark ribbons, and a persistent, flaky bark stocking at the base. Immature leaves are rounded, adult leaves are long, lanceolate in shape with irregular lateral venation and evenly coloured on both sides. White flowers occur in summer and autumn, although buds and sporadic flowering occurs throughout the year. Capsules are small and usually bell-shaped.
Distribution
Occurs on the alluvial flats of the Nepean River and its tributaries. There are two major subpopulations: in the Kedumba Valley of the Blue Mountains National Park and at Bents Basin State Recreation Area. Several trees are scattered along the Nepean River around Camden and Cobbitty, with a further stand at Werriberri (Monkey) Creek in The Oaks. At least five trees occur on the Nattai River in Nattai National Park. Large areas of habitat were inundated by the formation of Warragamba Dam in 1933.
Habitat and ecology
- Requires a combination of deep alluvial sands and a flooding regime that permits seedling establishment. Recruitment of juveniles appears to be most successful on bare silt deposits in rivers and streams.
- The recorded elevation range for the species is from 30m ASL at Bents Basin to 750m ASL in the Kedumba population. Most of the individuals are around 60 to 300m ASL.
- Occurs in open forest. Associated species at the Bents Basin site include Eucalyptus elata, E. bauerina, E. amplifolia, E. deanei and Angophora subvelutina. Understorey species include Bursaria spinosa, Pteridium esculentum and a wide variety of agricultural weeds. The Kedumba Valley site lists E. crebra, E. deanei, E. punctata, Leptospermum flavescens, Acacia filicifolia and Pteridium esculentum among its associated species.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Changes to fire intensity and frequency.
- Loss of regeneration opportunities.
- Impacts on genetic integrity.
- Competition from weeds inlcuding Gleditsia tricanthos, African olive, privet, Acer negundo, Opuntia spp., Cardiospermum grandiflorum, Asparagus asparagoides, Rubus spp. & exotic grasses such as Cynodon & Paspalum. Annual weeds establishing on fresh silt deposits also reduce the successful recruitment of this species.
- Feral pigs rooting friable sandy soils that cover about 50% of the population at Kedumba. Severly impacts on seedlings and saplings.
- Potential for removal of key habitat via urban development.
- Threats from raising Warragamba Storage.
- Habitat degradation through park management activities or recreational usage.
- Herbivory and environmental degradation caused by feral deer and goats.
- Forest eucalypt dieback associated with over-abundant psyllids and Bell Miners and potential species susceptibility to Phytophthora cinnamomic.
- Small populations of Camden White Gum are reported to have low genetic diversity (CSIRO study) due to elevated kinship within individual stands and are more susceptible to inbreeding depression and interspecific hybridization with related species Manna Gum (E. viminalis) (Butcher et al. 2005); causing loss of genetic integrity, population viability and evolutionary potential, and thereby increasing the risk of potential extinction.
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
- Maintain ex-situ collection.
- Prevent fire reaching sites. Remove debris build-up at tree bases to reduce fire duration and intensity.
- Rehabilitate and restore existing vegetation.
- Research germination requirements ie, formerly provided by floods.
Information sources
- Benson, D.H. (1985) Aspects of the ecology of a rare tree species Eucalyptus benthamii at Bents Basin, Wallacia. Cunninghamia 1(3), 371-383.
- Gardiner, C. and Larmour, J. (1995) Seed collections and ex-situ conservation measures for Eucalyptus benthamii from the Kedumba Valley. CSIRO Division of Forestry, Canberra.
- Larmour, J. (1993) Seed collections of Eucalyptus benthamii, Kedumba Valley. CSIRO Division of Forestry, Canberra.
- Thomas, J., Burkitt, J. and Benson, D. (1984) Vegetation Survey of Bents Basin State Recreation Area. National Herbarium, Royal Botanic Gardens, Sydney.
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