Overview
Arid shrublands occur in arid and semi-arid regions of western New South Wales, where limited, sporadic rainfall and low soil moisture are unable to support tree-dominated vegetation.
There are two types of arid shrublands: chenopod shrublands (<1.5m tall) dominated by saltbushes, bluebushes and copperburrs, and acacia shrublands (>2m tall) dominated by various species of
Acacia and other large shrubs.
Plants in the arid zone exploit scarce water resources using one of two contrasting strategies: tolerance or avoidance. Drought tolerators are perennial, long lived, slow growing, tough and frugal in resources, develop deep root systems and have leaves with water-loss reducing features (sunken pores, hairs, thick waxy coating or a narrow or needle-like form). Drought evaders are short-lived and produce seeds that remain buried and dormant, sometimes for many years, until rainfall triggers germination. Rapid maturity and development follows, with many species flowering en masse within weeks of rain, seeding prolifically to replenish the soil seedbank. The amount and timing of rain events determines which species respond: summer rains see a dominance of grasses, while winter rains favour daisies, legumes and other herbs.
Water tanks and bores in desert regions have increased grazing pressures both from domestic stock and feral and native herbivores (pigs, rabbits, goats, kangaroos) and carnivores (foxes and cats). Overgrazing has reduced the environment’s ability to capture and retain water and nutrients, both of which are limiting resources in arid environments. The largest impact has been on native mammal populations, with the loss of 23 species (40%) of the region’s mammal fauna, while many other species are now less common or are restricted in distribution.
Threatened species in this vegetation formation
See a
list of species, populations and ecological communities associated with
the Arid shrublands (Acacia sub-formation) formation.
Find species in a more specific vegetation class
The Arid shrublands (Acacia sub-formation) formation can be divided into the following classes. Select a vegetation class
on the list below to see a list of species associated with it: