This ecological community was listed under the EPBC Act on 16 July 2000. This Conservation Advice was approved by the Delegate of the Minister on 13 July 2017. Approved Conservation Advice for Corymbia calophylla - Kingia australis woodlands on heavy soils of the Swan Coastal Plain (s266B of the Environment Protection and Biodiversity Conservation Act 1999) This Conservation Advice has been developed based on the best available information at the time this Conservation Advice was approved; this includes existing plans, records or management prescriptions for this ecological community. 1 CONSERVATION OBJECTIVE The objective of this conservation advice is to mitigate the risk of extinction (or collapse) of the Corymbia calophylla - Kingia australis woodlands on heavy soils of the Swan Coastal Plain ecological community, and help recover its biodiversity and function, through: protecting it as a matter of national environmental significance under national environment law, particularly to avoid further loss; and by guiding implementation of management and recovery through the recommended priority conservation and research actions set out in this advice. 2 DESCRIPTION OF THE ECOLOGICAL COMMUNITY The Corymbia calophylla - Kingia australis woodlands on heavy soils of the Swan Coastal Plain ecological community is a woodland community located on heavy soils of the eastern side of the Swan Coastal Plain between Ruabon and Guildford. Typical and common native plant taxa in the community are: Corymbia calophylla (marri); the shrubs Banksia dallanneyi, Philotheca spicata, Kingia australis and Xanthorrhoea preissii; herbs, rushes and sedges, Cyathochaeta avenacea, Dampiera linearis, Haemodorum laxum, Desmocladus fasciculatus, Mesomelaena tetragona and Tetraria octandra (Gibson et al 1994; WA DEC 2011). The introduced grass Briza maxima is also common in the community, although weed cover in most occurrences is currently quite low. A list of taxa that commonly occur in the community is at Appendix 1 of the Western Australia’s Interim Recovery Plan (WA DEC 2011). 3 CONSERVATION STATUS The Corymbia calophylla - Kingia australis woodlands on heavy soils of the Swan Coastal Plain ecological community is listed as Endangered under the EPBC Act. At the time of its assessment, it was listed because of its restricted distribution and extent, and the highly fragmented remaining patches being threatened by clearing, weed invasion and too frequent fire (Endangered Species Scientific Subcommittee 2000). The listing is based on data collected prior to the EPBC Act commencing in July 2000. In Western Australia it is listed as critically endangered, under the name Corymbia calophylla - Kingia australis woodlands on heavy soils, Swan Coastal Plain. No species listed as threatened under the EPBC Act are known to occur in the ecological community, although some threatened fauna such as Calyptorhynchus latirostris (Carnaby's black cockatoo) and Calyptorhynchus banksii naso (forest red-tailed black cockatoo) may utilise remnants, particularly as feeding habitat. Corymbia calophylla - Kingia australis woodlands on heavy soils of the Swan Coastal Plain Approved Conservation Advice – Page 1 of 19 This ecological community was listed under the EPBC Act on 16 July 2000. This Conservation Advice was approved by the Delegate of the Minister on 13 July 2017. 4 DISTRIBUTION AND HABITAT The Corymbia calophylla - Kingia australis woodlands on heavy soils of the Swan Coastal Plain ecological community is one of three Marri (Corymbia calophylla) dominated plant communities, which were historically most likely some of the most common vegetation types on heavy soils on the eastern side of the Swan Coastal Plain. Gibson et al (1994) recognised three distinct communities in this group. The floristic composition of these communities varies with water regime, with the Corymbia calophylla - Kingia australis woodlands on heavy soils occurring on the wettest of the sites and being associated with the median species richness, and lowest level of weed invasion and disturbance. Groundwater is generally within 3m of the natural ground surface in occurrences of this community, and this indicates that these wetlands have a high level of dependence on groundwater (WA DEC 2011). This ecological community aligns with the Gibson et al (1994) vegetation type 3a. As at April 2017, forty one occurrences of this Marri community totalling about 192.5 ha have been located between Ruabon and Guildford and are recorded on Western Australia’s Threatened Ecological Communities Database. The sites were located through extensive survey of the southern Swan Coastal Plain that involved compilation and analysis of data from over 1,500 plots (Keighery & Trudgen 1992; Gibson et al 1994; Government of Western Australia 2000) and additional surveys by consultants and staff from state agencies. As at April 2017, it is known to occur in the following local government areas: Armadale, Capel, Gosnells, Kalamunda, Murray, Serpentine-Jarrahdale, Swan, and Waroona; within the Peel-Harvey and Perth Natural Resource Management (NRM) catchments; and within the Swan Coastal Plain bioregion (Interim Biogeographic Regionalisation for Australia (IBRA) Version 7). The critical habitat for the ecological community is the heavy soils on which it occurs, the fresh superficial groundwater, and/or surface water that helps sustain flora species in this wetland community, and the catchment for this groundwater and surface water (WA DEC 2011). Because of its very restricted distribution, no condition thresholds have been applied to the nationally-listed ecological community and hence all areas meeting the description of the ecological community are habitat areas critical to its survival. 5 THREATS Clearing Clearing for agriculture has been extensive on the heavy soils on the eastern side of the Swan Coastal Plain, with approximately 97% of all vegetation in the area being cleared (Keighery & Trudgen 1992; CALM 1990). The marri dominated types on these heavy soils were probably some of the most common on this portion of the plain but are now very rare and are likely to be at least 90% cleared (Gibson et al 1994). These historical losses propagate significant legacies for the conservation of the community in terms of reduced range of variation, and ongoing threats related to fragmentation and disruption of ecological processes. Pressure for future clearing is accelerating and likely to be associated with developments for road works, housing or industry (Government of Western Australia 2015). Altered fire regimes Mediterranean ecosystems are usually fire prone and may require a particular fire regime to assist regeneration (Abbott and Burrows 2003). If fire is too frequent, however, species that are obligate seeders may not have sufficient time to flower and produce seed. If the time between fires is too long, obligate seeders may senesce and be unable to regenerate. Therefore, wildfires or prescribed burns must occur at appropriate intervals, and possibly at Corymbia calophylla - Kingia australis woodlands on heavy soils of the Swan Coastal Plain Approved Conservation Advice – Page 2 of 19 This ecological community was listed under the EPBC Act on 16 July 2000. This Conservation Advice was approved by the Delegate of the Minister on 13 July 2017. the appropriate season and intensity, to sustain the diversity and integrity of plant communities. Too frequent fire can increase the risk of invasive weeds establishing within small bushland remnants such as this ecological community (Abbott and Burrows 2003). It is likely that the burning regime in the remnants containing the ecological community has been modified to more frequent fires, especially hot burns, since European settlement. The risk of fire is generally increased by the presence of grassy weeds in the understorey, as they are likely to be more flammable than many of the original native species in the herb layer. Many of the occurrences have been burnt recently. Fire regime is a major consideration in Management Plans that have been developed for bushland that contains threatened ecological communities (e.g. Serpentine-Jarrahdale Shire 2009). Burrows (2008) notes that there is no single optimum fire regime that will meet all management objectives, but that there are fire regimes that can be applied based on available evidence. Burrows (2008) recommends fire regimes based on vital attributes, regimes that provide for diversity of frequency, season and intensity, and provide habitat diversity, and a fine-grain mosaic of habitats. Burrows suggests that if these fire regimes are implemented in an adaptive management framework, they provide good data and can lead to better fire management. The juvenile periods of many species that occur in the community are listed in WA DEC (2011). Although the juvenile periods of many taxa are not known, the available data can be used as a guide. In the absence of more detailed demographic data on seedbank accumulation, Burrows et al (2008) recommend a minimum period between fires that are lethal to fire- sensitive plants (obligate seeders with long juvenile periods) of at least twice the juvenile period of the slowest maturing species. That is, the juvenile period of plant taxa that are killed by fire and only reproduce from seed can be used as a guide to determine minimum inter-fire intervals. In fire-sensitive habitats, this may be increased to 3-4 times the juvenile period for fire-sensitive species (Barrett et al 2009). In this case, Hakea