winrock.org/factnet-a-lasting...ot-dry-subtropics/
NFTA 89-02, May 1989
A quick guide to useful nitrogen fixing trees from around the world
Of Australia’s tropical area, almost 2 million km2 receives less than 500 mm of rainfall annually. Soils are diverse, but typically low in plant nutrients, with widespread and severe deficiencies in phosphorus and nitrogen and some deficiencies in trace elements. Surface soils are physically poor, and in places may be alkaline/sodic or saline (Brown and Turnbull 1986). Summers are extremely hot and elevated inland areas (e.g. the Pilbara region of northwestern Australia) may receive winter frosts.