Upper Murray Lands (Environmental Region 2.4)
This region consists of 15 environmental associations. It comprises undulating calcreted plains overlain by dunes and extending from the state border in the east to the foothills of the Mt. Lofty Ranges in the west, north of environmental region 2.3. The calcreted ridges here also trend west-north-westerly, and like those of environmental region 2.3 may represent old beach ridge systems. The coastal influence is diminished in this region and the superimposed dunes are of brownish sands with an easterly orientation. They are absent from the vicinity of the Murray River which is incised into the plains by 30-40 m. Terraces are present, with cracking clay soils liable to salinity problems. Mallee is the dominant vegetation type of this region. Its species composition reflects the diminishing coastal influence towards the north, especially in the understory: broombush gives away here to saltbush and blue bush(Atriplex and Marieana spp.) and hummock grass (Trioda irritans). Blue gum (E. leucoxylon) and peppermint box (E. odorata) are characteristic species in the west of the region. Although tracts of mallee still occur, most of the original vegetation has been cleared for agriculture. The region has a climate with a winter rainfall maximum and a somewhat drier summer. Annual rainfall ranges from 300 mm in the south to 250 mm in the north. Temperatures are warm to hot in summer and cool in winter.