RUNOFF AND RUNON AREAS IN A PATTERNED CHENOPOD SHRUBLAND, ARID WESTERN NEW-SOUTH-WALES, AUSTRALIA - CHARACTERISTICS AND ORIGIN

Strongly developed vegetation banding in desert chenopod shrubland occurs on hillslopes having gradients of as little as 0.5 degrees and displays a stepped microrelief of about 10 cm. Surface runoff is shed from the bare surfaces in rainstorms of as little as 4-5 mm, and infiltrates readily within the vegetated bands. The banding thus functions as an efficient system for water redistribution, the landscape being divided into multiple bare runoff (water source) and vegetated runon (water sink) zones. Patterns of stone distribution across a study hillslope suggest that the vegetation banding is at least Holocene in age. The patterned shrublands thus represent an enduring component of this arid rangeland environment, and one whose unusual microhydrology should be preserved by informed management.