The known distribution of the South East Coastal Plain Grassland is limited to the South East Coastal Plain IBRA bioregion in Victoria. Most occurrences are in the Gippsland Plain subregion (SCP01) with some remnants in the Otway Plain subregion (SCP02). The ecological community occurs as a series of disjunct occurrences across the bioregion, as detailed below (DSE 2004a; DSE 2008):
The region between Yarram and Giffard, south of Traralgon and east of Wilsons Promontory. These remnants represent the easternmost occurrences of the ecological community and have been relatively well surveyed (Frood, 1994; DSE 2004a). Key grassland sites in this region include (DSE, 2004a):
Roadside patches along Stringybark Lane, near Jack Smith Lake.
An occurrence of grassland bordering Jack Smith Lake is now considered to be extinct (DSE, 2004a).
The region at the head of Western Port Bay, around Cranbourne – Pakenham – Koo-Wee-Rup. These occurrences are less well known than the Yarram region grasslands because most remnants are small and surveys have been ad hoc and incomplete (DSE, 2004a). Key grassland sites in this region include (Cook and Yugovic, 2003; DSE, 2004a; Yugovic and Mitchell, 2005; DSE, 2008):
patches beside the disused railway line between Clyde and Tooradin;
Pakenham Grassland Reserve (formerly the Pakenham Airstrip), including a small adjacent patch at the Blue Horizons Retirement Village; and
Gilbert block at Officer.
The ecological community generally is absent from the intervening areas between Yarram and Cranbourne, which comprises elevated and undulating terrain rather than plains. However, very small, isolated patches of native grassland may occur, for instance along Bass Coast roads around Wonthaggi, Kilcunda and Anderson (Dwyer, 2013 & pers. comm., 2013).
The region on the eastern side of Port Phillip Bay. These patches generally are poorly known and have not been thoroughly surveyed or studied, apart from Safety Beach. They exist at fine scales not captured by the broad vegetation mapping used for Ecological Vegetation Classes (EVCs), and may be grouped into non-grassland EVCs, e.g. 175 Grassy Woodland. Known occurrences include (Sinclair, 2007; Sinclair, pers. comm., 2014; Yugovic, pers. comm., 2014):
The region to the west of Port Phillip Bay, on the Otway coastal plain between the Bellarine Peninsula and Portland (Sinclair, 2007 & pers. comm., 2014; Yugovic, pers. comm., 2014). These sites are poorly known but may include damp grasslands along the Lower Barwon River, Painkalac Creek estuary, Curdies Inlet, Belfast Lough and Lake Yambuk (Yugovic, pers. comm., 2014).
Some sites may also contain non-grassland native vegetation on the margins of the grassland or interspersed as pockets within the grassland. These are detailed in Appendix B.
The ecological community generally occurs on fertile clay soils of Quaternary origin, at elevations less than 100 metres above sea level, and in higher rainfall, less drought-prone areas within the region. These South Gippsland sites are wetter than the grasslands and grassy woodlands dominated by Eucalyptus tereticornis (Gippsland red gum) that are typical of the Central Gippsland Plains further to the north and east (DSE, 2008). Gippsland red gum is absent from South Gippsland, being replaced by other canopy species such as E. ovata (swamp gum).
The South East Coastal Plain bioregion has a cool temperate climate. The mean annual rainfall ranges between around 730 mm/year around Yarram; in excess of 780 mm around the Pakenham – Koo-Wee-Rup region (BoM, 2013); around 550 mm on the Bellarine Peninsula; and around 840 mm around Peterborough (Table 1). The mean minimum temperature in winter is 3 to 7 oC and the mean maximum temperature in summer is in the low to mid 20s oC, across the range of the ecological community.
Table 1. Mean Rainfall Data for Locations within the South East Coastal Plain (derived from BoM, 2013)