Southern Wetlands and Dune Ranges (Environmental Region 1.4)
This region consists of 13 environmental associations. It comprises a series of north-north-westerly trending low ridges and intervening plains. the present landscape is a system of parallel coastal dunes stranded during successive phases of retreat of the sea, the dunes becoming progressively older inland. Naracoorte Range, the innermost dune ridge forms the eastern boundary of the region. Locally, the calcarenite dune ridges are overlain by younger sands. Well-drained deep and shallow sands are typical of the dune ridges. The plains contrast markedly with the dune ridges and are characterized by impermeable soils derived from marl, clay and silt. Because of this impermeability and the lack of an organized natural drainage network, seasonal flooding occurs and lakes and swamps are common features. Lunettes (crescent-shaped clay dunes) generally fringe the eastern shorelines of these lakes. Little native vegetation remains. The climate is characterized by a winter rainfall maximum and relatively dry summers. Annual precipitation ranges from 500 mm in the north to 850 mm in the south, and temperatures range from warm to hot in summer to moderate in winter.
