Biodiversity publications archive

Refugia for biological diversity in arid and semi-arid Australia

Biodiversity Series, Paper No. 4
S.R. Morton, J. Short and R.D. Barker, with an Appendix by G.F. Griffin and G. Pearce
Biodiversity Unit
Department of the Environment, Sport and Territories, 1995

12. Refugia in the Northern Territory (continued)

12.10. Reference number NT10

Refuge area: George Gill Range

Biogeographic region: MacDonnell Ranges

Type of refuge: Gorges/mountain range

Lat./Long. 24°10’ to 24°25’S / 131°30’ to 132°E

Quality of refuge: Extremely significant (7)

Area (km²): <1,000

Chief refuge value

Moist gorges provide habitat for rare and relict species, and the associated mountain range possesses unusual and relictual vegetation.

General description

The George Gill Range is a sandstone block running westward to Kings Canyon for about 60 km from Tempe Downs Station. On its southern face are several gorges containing springs and other moist environments which harbour unique assemblages of moisture-loving species, and the top of the Range supports a rich and unusual flora1, 2.

ANZECC-listed species

The black-footed rock-wallaby Petrogale lateralis (V) occurs1.

Regional endemics and relict species

Among plants, the species list given above under section 12.9 incorporates endemic and relict species from the George Gill Range. This list is compelling evidence of the extent to which the MacDonnell Ranges and the George Gill Range possess an extraordinary flora3. Relict plants recorded for the Range include at least Hydrocotyle larapinta, Ampeara sp., Goodenia sp., Ixiolaena sp., Ricinocarpos sp., Psilotum nudum, Cyclosorus interruptus, Polystichum proliferum, Ottelia ovalifolia, Polygonum salicifolium, Schoenus falcatus, Vallisneria spiralis, Lindsaea ensifolia, and Mirbelia ramulosa1.The dragonfly Hemicordulia flava is confined to the Region4. The camaenid land-snails Sinumelon gillensis and Semotrachia bagoti are confined to the Ranges in tiny pockets5. Relict streams in the George Gill Range represent unique aquatic communities of both ecological and evolutionary importance in the arid zone2. The key factor is the presence of at least six sheltered gorges which contain permanent or near-permanent springs and seepage areas. A small proportion of the fauna appears to be a relictual fauna, as exemplified by the water penny Sclerocyphon fuscus. The conservation status of these streams is extremely high2.

Other significant species

None identified.

Key threats

Exotic vertebrates – horses, rabbits, foxes and cats – and plants – couch grass, buffel grass, and tamarisks. Grazing stock can damage refuge areas. Tourist impacts are likely to increase as visitation escalates. Finally, fire management is essential for relict species.

Land tenure

Watarrka National Park.

Key references

1. Latz et al. (1981)

2. Davis et al. (1993)

3. Latz (1995)

4. Watson et al. (1991)

5. Solem (1993)