Nature Notes - Woodland

Open woodlands grow on the sandy soils alongside the rocky ranges of Central Australia. Water and nutrients, running off the ranges, have produced more fertile soils in the woodlands than those areas surrounding them. Well-spaced trees dominate the landscape here: Ghost Gums (Corymbia aparrerinja), Bloodwoods (Corymbia opaca), Ironwoods (Acacia estrophiolata), Whitewoods (Atalaya hemiglauca), Beefwoods (Grevillea striata) and Corkwoods (Hakea species). Underneath them, a variety of grasses and herbs grow, making this prime real estate for herbivorous mammals. 

In the past hundred and thirty years the woodlands have been a site of intense competition for resources between native and introduced species, with the native mammal species losing the battle.

The arrival of cattle in the 1870s and European rabbits around the turn of the century had a significant effect on woodland wildlife. The spread of feral cats and foxes have compounded their problems. Native plant eaters have declined in numbers or disappeared altogether: kangaroos, emus, nailtail wallabies, bettongs, bilbies, sticknest rats and possums. The carnivorous marsupial quolls and phascogales have also gone.

In many localities in the Alice Springs district, the foreign Buffel Grass (Cenchrus ciliaris) is now the dominant grass. Previously Kerosene Grass (Aristida holathera) would have made up 60% of the grass cover. It is an annual or short-lived perennial that’s not favoured by grass-eaters. But a number of more palatable and nutritious grasses grew with it: Woolybutt (Eragrostis eriopoda) (20%); the Oat Grasses (Enneapogon avenaceus) and Enneapogon polyphyllus (10-15%); with tufts of Curly Windmill Grass (Enteropogon acicularis) and Umbrella Grass (Digitaria coenicola) growing under the tree canopies.

A further change to this habitat has been an increase in shrub cover since the reduction of traditional Aboriginal burning practices. Grassland is a fire-made landscape. Regular burning encourages grasses at the expense of shrubs (which are called woody weeds by the pastoral industry). Now that regular burning in some areas has ceased, grassland in Central Australia is being replaced by shrubland.

Compare with a Sonoran Desert habitat.