Introduction

The sheep rangelands, a subset of the arid and semi-arid lands of Australia, form a broad semi-circular arc from northern Queensland, through New South Wales, South Australia and the southern two-thirds of Western Australia (Fig. 1.5). It covers approximately 1.7 million km2 or 22% of the area of Australia. Climate determines the outer margin of the zone in the southern half of the continent: being the amount and incidence of rain sufficient to cultivate crops, particularly wheat. In southern New South Wales, South Australia and Western Australia this approximates the 260–290 mm isohyet. In southern Queensland the sheep rangelands extend into country receiving nearly 600 mm of rain per annum. The inner margin, where the sheep pastoral zone abuts either cattle rangelands or desert, is at about the 150 mm isohyet in the south and the 300 mm isohyet in the north.

This chapter examines the climate, soils, vegetation and fauna of the sheep rangelands of Australia, focusing on Kinchega National Park and a neighbouring sheep station, Tandou. These are located near the town of Menindee (elevation 61m) at approximately 32 degrees S and 142 degrees E in western New South Wales on the floodplain of the Darling River. Almost all data in succeeding chapters were collected on Kinchega and Tandou. Both were formerly part of a much larger pastoral lease and have been grazed by sheep since 1860. In 1967 Kinchega was declared a national park under the control of the New South Wales National Parks and Wildlife Service.