Australia’s grassland is different to many grasslands around the world because, at the time of European settlement, it was dominated by warm-season (C4) perennial species that had evolved to grow in hot and dry environments. Over 1100 native grass species grow in Australia, of which, most are warm-season (C4) with only a small proportion of cool-season (C3) perennial grass species that grow in colder months. The dominance of warm-season C4 grass species indicates that Australia’s climate has been hot and dry for an extremely long period.

The growth pattern and co-existence of the two grass types is remarkable because these grassland plants utilise resources separately.  In the hotter months, warm-season C4 grass grows profusely, while cool-season C3 grass becomes dormant to avoid the hot and dry climate. During Australia’s winter months the warm season C4 grass becomes dormant to avoid the cold temperatures and the cool season C3 grass grows. It was this growth pattern and natural dormancy that enabled the development of ‘pasture cropping’.