Banded mosaic (‘tiger bush’) and sheetflow plains: A regional mapping approach

Abstract

Banded mosaic (‘tiger bush’) is characterised on airphotos by a vegetation pattern where bands of relatively dense vegetation alternate with bare interbands. Tiers of bands/interbands cluster together where soil and slope are suitable, forming a swirled pattern like tiger fur. Banded mosaic is a combined soil/sediment and vegetational response to arid climates. As an ecological entity, it allows the maximum plant production for limited water and nutrient resources, by creating efficient micro‐catchments. As a unit of Quaternary geology, banded mosaic poses some problems to the compilers of geological maps. It is clearly different from other Quaternary units (alluvium, sandplains) and often cannot be included within them. However, it is not the business of geologists to map vegetation assemblages or soil types. Examination of Australian and overseas research shows that the banded vegetation pattern is merely the most obvious expression of a discrete Cenozoic unit—sheetflow plains. Mapping this unit may be simple, or may be complicated by gradational or inter‐fingering boundaries. Guidelines are suggested that are analogous to normal practices used in mapping sedimentary and regionally metamorphosed rocks.