Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain.
Advice to the Minister for the Environment and Water Resources from the Endangered Species Scientific Subcommittee (ESSS) on a proposal to add an ecological community to Schedule 2 of the Endangered Species Protection Act 1992 (ESP Act)
- Ecological community name
- Description
- Listed species in the proposed ecological community
- Other native species that could become endangered in the proposed ecological community
- Description of the community 'Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain' sufficient to distinguish it from any other ecological community
- Evidence that the description of the community 'Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain'is conventionally accepted
- Reasons why the community 'Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain' is considered to be endangered within the meaning of Section 6 of the Act
- Past and current distributions of the community 'Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain'
- References that support information given in the nomination
Ecological community name
Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain.
Description:
This community is characterised by woodlands with common species including Corymbia— formerly Eucalyptus—calophylla, Xanthorrhoea preissii, and Dryandra nivea. Eucalyptus wandoo is an occasional dominant. It occurs on the driest of the soils, and on sites with the lowest rainfall, of the group of three Marri (Corymbia calophylla) communities that occur on the heavy soils on the eastern side of the Swan Coastal Plain (Gibson et al. 1994). The community has been assessed by the WA Threatened Ecological Communities Advisory Committee as Critically Endangered.
Listed species in the proposed ecological community
None.
Other native species that could become endangered in the proposed ecological community
None known.
Description of the community 'Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain' sufficient to distinguish it from any other ecological community
This community occurs on the driest of the soils, and the lowest rainfall sites of the group of marri dominated communities that occur on the heavy soils on the eastern side of the Swan Coastal Plain (Gibson et al. 1994). Soils on which the community occurs are still relatively wet, however, by comparison with some other communities of the Swan coastal plain, and often become waterlogged in winter. Little information is available on the hydrological features of sites on which this community occurs.
All occurrences of this community occur on the Guildford Unit of the Fluviatile Deposit group (the Guildford clays) or on or near the junction of that Unit with the Ridge Hill Shelf group (Churchward and McArthur 1980). This latter Unit is described as "Flat Plain with medium textured deposits; yellow older duplex soils" (Churchward and McArthur 1980).
Typical and dominant native plant taxa in the community are listed in column 3 of Table 1 below. Community numbers are from Gibson et al. (1994). Although there are some overlaps of typical species with the two other Marri communities with which it is most similar, the differences are clear and consistent. These floristic differences, coupled with measurable differences in rainfall and soil moisture, and with very significant differences in rarer species, make the three communities readily recognisable.
| Marri/Kingia Community (3a) | Marri/Jarrah Community (3b) | Marri/Xanthorrhoea Community (3c) |
|---|---|---|
| Trees | ||
| Corymbia calophylla |
Corymbia calophylla Eucalyptus marginata |
Corymbia calophylla Eucalyptus wandoo (occasional dominant) |
| Shrubs | ||
|
Dryandra nivea Eriostemon spicatus Kingia australis Xanthorrhoea preissii |
Bossiaea eriocarpa Dryandra nivea Hibbertia hypericoides Xanthorrhoea preissii |
Acacia pulchella Dryandra nivea Gompholobium marginatum Hypocalymma angustifolia Xanthorrhoea preissii |
| Herbs | ||
|
Cyathochaeta avenacea Dampiera linearis Haemodorum laxum Loxocarya fasciculata Mesomelaena tetragona Tetraria octandra |
Burchardia umbellata Caesia micrantha Chamaescilla corymbosa Conostylis juncea Drosera erythrorhiza Drosera stolonifera Lepidosperma angustatum Lomandra hermaphrodita Loxocarya fasciculata Mesomelaena tetragona Sowerbaea laxiflora Tetraria octandra |
Burchardia umbellata Cyathochaeta avenacea Neurachne alopecuroidea |
The introduced species, Briza maxima and Romulea rosea are also common, but weed levels in most occurrences are currently quite low. The mean species richness for the ten plots in community 3c is 48 species in 100 square metres (Gibson et al. 1994), which makes it the least diverse of the three Marri dominated communities.
Evidence that the description of the community 'Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain'is conventionally accepted
References and data that support the description and classification of this community are found in the minutes of the WA Threatened Ecological Communities Advisory Committee dealing with the assessment of this community, in the draft interim recovery plan for the community and in the following publications.
Department of Environmental Protection (1994). Threatened or Poorly Reserved Plant Communities Requiring Interim Protection for the Swan Coastal Plain. Preliminary Maps. Environmental Protection Authority, Perth.
Department of Environmental Protection (1996). System 6 update program unpublished site and area records and analysis. EPA, Perth, Western Australia.
Gibson, N., Keighery, B., Keighery, G., Burbidge, A and Lyons, M. (1994). A floristic survey of the Southern Swan Coastal Plain. Unpublished report for the Australian Heritage Commission prepared by the Department of Conservation and Land Management and the Conservation Council of Western Australia (Inc.).
Reasons why the community 'Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain' is considered to be endangered within the meaning of Section 6 of the Act
This community fits criteria 2 (a), (d) and (e) for the following reasons.
- The Community has been reduced by >90%, probably about 97%.
- There are only approximately 41 ha of the community remaining, on seven widely separated remnants, and less than one hectare in a secure conservation reserve.
- Remaining patches are threatened by clearing, weed invasion, hydrological changes due to clearing and draining and too frequent fire.
Past and current distributions of the community 'Corymbia calophylla – Xanthorrhoea preissii woodlands and shrublands of the Swan Coastal Plain'
The series of Marri (Corymbia calophylla), dominated plant communities occurring on heavy soils between Waterloo (near Bunbury) and Bullsbrook are considered to have been some of the most extensive on the eastern side of the Swan Coastal Plain. However they have all suffered extensive clearing and are now rare (Keighery and Trudgen, 1992; Gibson et al. 1994, Department of Environmental Protection (DEP) 1996). The driest sites, dominated by Corymbia calophylla and Xanthorrhoea preissii (this community), occur widely from Bullsbrook north of Perth to Waterloo near Bunbury. This community type has probably been reduced by at least the 97% estimated for vegetation of the eastern side of the Swan coastal plain as a whole.
There are only approximately 41 ha of the community remaining. Of this, about four hectares occur on land vested in the Commonwealth, 27 hectares are on lands vested in Shire Councils, ten hectares are in unvested reserves or vacant Crown land, and about 0.3 hectares occur in a Nature Reserve.
References that support information given in the nomination
Churchward, H.M. and McArthur (1980). Landforms and Soils of the Darling System. In: Atlas of Natural Resources, Darling System, Western Australia. Perth, Pinjarra and Collie Sheets. Department of Conservation and Environment, Western Australia.
Davidson, W.A. (1995). Hydrogeology and Groundwater Resources of the Perth Region, Western Australia. Geological Survey of Western Australia. Bulletin 142.
Department of Conservation and Environment (1985). Conservation reserves for Western Australia; as recommended by the Environmental Protection Authority - 1983. The Darling System - System 6. Report 13, DCE, Perth.
Department of Conservation and Land Management (1988). Policy Statement No. 28 Reporting, Monitoring and Re-evaluation of Ecosystems and Ecosystem Management. Department of Conservation and Land Management, Perth.
Department of Conservation and Land Management (1997). Declared Rare and Priority List for Western Australia. Department of Conservation and Land Management, Perth.
Department of Environmental Protection (1996). System 6 update program unpublished site and area records and analysis. EPA, Perth, Western Australia.
English, V. and Blyth, J. (1997). Identifying and Conserving Threatened Ecological Communities in the South West Botanical Province. Project N702, Final Report to Environment Australia. Department of Conservation and Land Management. Perth, Western Australia.
Gibson, N., Keighery, B., Keighery, G., Burbidge, A and Lyons, M. (1994). A floristic survey of the Southern Swan Coastal Plain. Unpublished report for the Australian Heritage Commission prepared by the Department of Conservation and Land Management and the Conservation Council of Western Australia (Inc.).
Keighery, B. (1996). Flora Information for Roadside Bush Protection Plans in the Shire of Serpentine - Jarrahdale. Report prepared for the Roadside Care Volunteers. Perth, Western Australia.
Keighery, B.J., Keighery, G.J., and Gibson, N. (1997). Floristics of Reserves and Bushland areas of the Perth Region (System 6) Parts XI - XV. Wildflower Society of Western Australia (Inc.), Nedlands.
Keighery, B. and Trudgen, M. (1992). Remnant Vegetation on the Alluvial Soils of the Eastern Side of the Swan Coastal Plain. Unpublished report for Department of Conservation and Land Management, Australian Heritage Commission and Heritage Council of WA.
Keighery, G.J. and Keighery, B.J. (1993). Floristics of Reserves and Bushland Areas of the Perth Region (System 6). Parts V - IX. Wildflower Society of Western Australia (Inc.), Nedlands.