The Brigalow Belt lies in the sub-humid to semi-arid zone (Cummings and Hardy 2000). The bioregion is split into the Brigalow Belt North (BBN) and Brigalow Belt South (BBS) based primarily on the climatic variation between the north and south. The climate of the BBS is dry in autumn and spring, with wetter conditions during summer and winter. Annual rainfall estimates range between 500 – 750 mm and 449 – 1015 mm per annum for the Queensland and New South Wales sections.
Most brigalow dominated communities occur on gilgaied clay Vertosols. These are shrink-swell soils, which develop deep cracks when dry. Gilgais are a distinctive geomorphic feature of the BBS, comprising a series of alternating mounds and depressions that intermittently fill with water following rainfall events.
(Source: Queensland Herbarium remnant vegetation mapping 2001)
