1.1.7 Ecology

Summary

The Arckaringa subregion is situated in Australia’s arid zone where highly variable rainfall, low soil fertility and localised soil differentiation are the dominant physical environmental drivers of ecosystem composition. The subregion contains a diverse range of native flora and fauna.

The subregion has become increasingly arid over past millennia, leading to the isolation of aquatic ecosystems. Great Artesian Basin (GAB) springs of the Lake Eyre supergroup are found along the eastern boundary of the Arckaringa subregion and to the south and east. These springs have flowed continuously for at least 465,000 years, providing the only refugia for obligate aquatic species with poor dispersal capabilities. The springs contain a high proportion of endemic species and populations of species that were once widespread. Based on current data, 64 out of the 116 spring complexes in the Lake Eyre supergroup contain endemic or threatened species, and one complex supports a species not found at any other location. However, recent research on invertebrates in springs indicates that it is likely that levels of endemism have been substantially underestimated to date and the true levels of endemism may be higher than is currently understood.

The Neales catchment is the major surface water drainage system within the Arckaringa subregion, draining east into Kati Thanda – Lake Eyre. Ten native fish species occur in the catchment and the hydrology of the catchment is considered largely unaltered. The catchment is highly ephemeral with only one known potentially permanent freshwater waterhole, Algebuckina. Large floods occur infrequently, but drive spectacular booms in biotic production. Clusters of smaller floods prolong waterbody persistence and connectivity between waterbodies and produce a cumulative response from aquatic biota. During extended dry periods, Algebuckina Waterhole has supported the entire diversity of obligate aquatic species in the catchment, although some saline waterholes and low-lying GAB springs provide refuge for a subset of the smaller and hardier species.

To the south of the Neales catchment are the catchments of Stuart, Margaret and Warriner Creeks that flow into Kati Thanda – Lake Eyre South. Very little is known about the ecology or biological composition of these catchments, although two species of fish have been observed in Margaret Creek.

To the west of the Lake Eyre Basin there are dune lakes and depressions in the Great Victoria Desert and minor drainages, gilgais and cracking clay plains in the Stony Plains. These systems are filled very occasionally from local rainfall events and support unique desert biota and nomadic waterbirds. These systems are very poorly studied.

Last updated:
5 January 2018
Thumbnail of the Arckaringa subregion

Product Finalisation date

2015