Farther east, arid desert conditions prevail. Riparian zones in arid and semiarid environments have been called biodiversity hotspots. They inhabit both grassland and arid regions. The desert climate is characterised by hot and very arid conditions. The central plains are characterised by poor, arid and permeable soil. Sorghum is well adapted to growth in hot, arid or semiarid areas. It is a region of barren, arid, frigid and wind-blown wastelands. The allotments were too small to support farming on the arid plains. They also tend to live in arid steppe climates. Sheep can be raised in a range of temperate climates, including arid zones. "Myrmecocystus" nests are found in a variety of arid or semiarid environments. This is especially true of salt lakes in arid climates. Thick sequences of red sedimentary rocks formed in arid climates are called red beds. The regolith profiles of badlands in arid climates are likely to resemble one another. These are smallish birds which inhabit regions of arid scrub.