Eastern Pastoral (Province 5)
This province extends from the plains south and south-east of Lake Frome to the improved pasture lands immediately north of the Murray River. It has a warm dry climate with short cool to cold winters and low, unreliable rainfall showing no distinct seasonal pattern. The highest mean annual rainfalls are found in the south-west of the province, where precipitation varies from around 250 mm to 400 mm. The remainder of the province has a mean annual rainfall of about 200 mm, falling to about 150 mm in the north. Temperatures are generally warm and evaporation is very high. Mean annual evaporation ranges from about 2000 mm in the south-west to about 3200 mm in the north-east.
The calcreted plain north of the Murray is a continuation of that to the south of the river in Province 2. Low dunes or sand sheets of red sands with high susceptibility to wind erosion are widespread in the east of the plain. In the west a narrow belt of fans forms the transition to the Olary upland, which is a broad but relatively low spur striking north-westward from the Mt Lofty and Flinders Ranges. This upland is dominated by low, often densely spaced hogback ridges with gently sloping footslopes and pediments, separated by elongated intramontane basins. Red duplex soils of the footslopes and pediments are very susceptible to erosion and gullying is common on them. In the north, rounded granite hills with extensive pediments are prominent. The Lake Frome is the southern part of a large internal drainage basin of structural origin. The remainder of the basin, including Lake Frome, is situated in Province 8. The provincial boundary follows the southern limit of the lake and the vast areas of parallel dunes east of it.
The whole province is still covered by native vegetation, which has been degraded to varying degrees by continuous extensive grazing for the past 100 years or so. The plains adjacent to the Murray have a vegetative cover of low woodlands in the west, and mallee with a porcupine grass understory in the east. Tall shrublands are common on the Olary spur and low shrubland dominated by bluebush and saltbush which occurs prominently throughout the province, is most significant on the Olary spur. Tall fringing woodlands of river red gums occur throughout the Murray plains and the Olary upland. The sandplains of the Frome basin support a low mulga woodland and, on the northern edge of the province, a sandhill vegetation of wattles, hopbush, ephemeral daisies and other herbs.
Land use is limited to extensive livestock grazing. There are some 70 runs with an average size of about 600 km2, supporting an average livestock population of about 6000 sheep or their equivalent in cattle, on native pastures.
Three regions have been recognized in this province: