Summary - City of Gosnells

Vegetation 522. Shrublands and Woodlands on Muchea Limestone of the Swan Coastal PlainMuchea Limestone (ML), a geological unit also known as Plain Limestone (Gozzard, 1982), occurs on theeastern side of the Swan Coastal Plain. It occurs in a discontinuous distribution from Muchea to Bengeralong the eastern side of the Swan Coastal Plain.The known occurrences of the Muchea Limestone TEC currently include a range of wetland and welldrainedplant habitats, on a variety of landforms. Unlike many other TECs, that are defined primarily on thebasis of floristic composition (e.g. a single Floristic Community Type from Gibson et al.,1994), the MucheaLimestone TEC is defined as a range of relatively heterogeneous assemblages that inhabits a rare geologicalformation. The vegetation that has been recorded on Muchea Limestone includes Melaleuca huegeliishrubland, Eucalyptus decipiens mallee, Casuarina obesa woodland and Melaleuca spp. (M. brevifolia, M.systena, or M. viminea) shrublands (Keighery and Keighery, 1995). Calcicole species such as Eremophilaglabra, Eucalyptus decipiens, Eucalyptus gomphocephala, Gahnia trifida, Grevillea curviloba, Grevilleaevanescens, Melaleuca brevifolia and Thysanotus arenarius can be present (Keighery and Keighery, 1995;English and Blyth, 2000b; B.J. Keighery, pers. comm.). Muchea Limestone vegetation was not sampled byGibson et al, (1994) and/or not identified as a distinct FCT in that study. Floristic analyses of vegetation ofthe eastern SCP that are conducted against the SCP database of Gibson et al, (1994) often group MLvegetation with the FCTs of Tamala Limestone in the Spearwood Dunes or FCT 18 (Shrublands onCalcareous Silts) due to the calicole species common to all of these vegetation types (English and Blyth,200b).The range of flora and vegetation that occurs in Muchea Limestone and the habitats of this TEC are, as yet,poorly documented. In addition to the generally high levels ( >90%) of loss and degradation of nativevegetation on the eastern SCP due to clearing and grazing(Government of Western Australian, 2000a, Table4, Pinjarra Plain), many occurrences of Muchea Limestone on the SCP have been extirpated by mining(Keighery and Keighery, 1995). There is little known about the aquifers that maintain this vegetation and thedevelopment of calcicole vegetation on the eastern SCP. There are no data available about the basiccharacteristics of these aquifers (e.g. fine scale maps of the aquifers or identification of the catchment areasthat maintain them) that could inform in the sustainable management of these ecosystems. The stygofaunathat potentially inhabit these aquifers have also not been investigated. Muchea Limestone and the biotaassociated with it are thus of high scientific and conservation significance.Muchea Limestone TEC occurrences are, as yet, poorly documented, but available data cite only twooccurrences south of the Swan River in the Perth Metropolitan Region. These are in BFS 465, SouthernRiver (Government of Western Australian, 2000) and in Cannington (; B.J. Keighery, pers. comm.).5.1.2 Vegetation of State Conservation SignificanceA search of the Threatened Ecological Communities Database of DEC (2008d) and searches of the literature(including Trudgen and Keighery, 1995 and Government of Western Australian, 2000) showed that, apartfrom the two EPBC listed TECS (as above), occurrences of another seven TECs that are listed by theWestern Australian Department of Environment and Conservation (Table 5.3) have been recorded inCannington, Forrestfield, Kenwick, Maddington, Orange Grove, Queens Park, Southern River, Welshpooland Wattle Grove. There were no Priority Threatened Ecological Communities (PTECs) listed by DEC(2008d) for this area.The seven TECS listed by DEC (2008d) have all been assessed and approved by the Western AustralianThreatened Species Scientific Committee, under the same international criteria that are used to determineTECS under the EPBC Act and thus they are, in a scientific sense, all of national conservation significance.However, these Western Australian-listed TECs are yet to be endorsed by the Federal Department ofEnvironment, Water, Heritage and the Arts for EPBC listing.Tauss, C. and Weston, A.S. (2010). The flora, vegetation and wetlands of the Maddington-Kenwick Strategic Employment Area.A survey of the rural lands in the vicinity of the Greater Brixton Street Wetlands. Report to the City of Gosnells, W.A. Version 18.04.10