South Olary Plains (Environmental Region 5.1)
This region consists of nine environmental associations. It extends from the Murray River in the south to the low hills and ranges of the Olary Spur in the north. It is bounded to the west by the abruptly rising Flinders Ranges. The region comprises and undulating calcreted plain with shallow soils supporting a low woodland or tall open shrubland with a ground cover of bluebush or saltbush. This plain is overlain in many places by low easterly trending dunes or sand sheets with a cover of degraded mallee over saltbush or porcupine grass. Relict alluvial terraces with low open woodland of black oak form well-defined flat-topped ridges, and rise locally some 5-20 m above the plain. Near the western margin there is a small transition zone with fans shed from the ranges; a very low open shrubland cover of bluebush and saltbush is prominent. nut never extends far into the plain. Some fan streams, however, continue as floodouts well into the plain. The region has a warm climate distinguished by high evaporation an very low unreliable rainfall throughout the year. Temperatures are warm to hot in summer and cool to cold in winter. Mean monthly evaporation exceeds the 90th percentile of monthly rainfall for every month of the year. Mean annual evaporation ranges from around 2100 mm in the south-west to around 2700 mm in the north-west of the region. Mean annual rainfall varies from 350 mm in the extreme south-west of the region to less than 200 mm in the north. Locally these change to middleground or foreground panoramas where dunes or other rises limit the views. In the northern and western border areas of the hills and ranges of the Olary Spur and the northern Mt. Lofty Ranges form backdrop features to the views.
