Australian Natural Resources Atlas

Natural Resource Topics

Rangelands - Overview

Copyright

Location map of Tanami bioregionphotograph

Tanami

Summary

ATSIC Boundaries

Catchment Basins

Statistical Local Areas

Introduction

The Tanami bioregion includes 260,000 sq kms of land within the central area of the Northern Territory and extends into Western Australia. The area is hot and dry and mostly unsuitable for pastoral activity, with only a small proportion of the area covered by pastoral leases. Most of the land is Aboriginal land. Settlements include Wauchope, The Granites mine and Tanami mine and several small Aboriginal settlements and outstations including Lajamanu and Jarra Jarra in the Northern Territory and the Balgo community in Western Australia.

Most of the bioregion is covered by spinifex (hummock grassland) sand plains with sand dunes, rocky outcrops, salt lakes and water courses breaking up the sand plains. The Devils Marbles are a well-known feature.

Natural Environment

Climate

The region is semi arid with monsoonal influences, with 75% - 80% of rainfall occurring in the summer months. Annual rainfall is generally higher in the north of the region. The mean annual rainfall for Tennant Creek is 375 mm. Rainfall is extremely erratic.

The region is north of the frost line, mean temperatures for Rabbit Flat range from 25? style='font-family:Arial'>C-40? style='font-family:Arial'>C in January, and from 8? style='font-family:Arial'>C-23? style='font-family:Arial'>C in July.

Climate averages are available for Balgo Hills (WA):>

www.bom.gov.au/climate/map/climate_avgs/a1.shtml

Temperature and rainfall graphs are available for Rabbit Flat (NT):

www.bom.gov.au/climate/forms/map_forms/new_imagemaps/nt_name.html

Current seasonal conditions and their historical context can be provided by satellite imagery. The Normalised Difference Vegetation Index (NDVI) is a measure of the vegetation 'greenness'. The NDVI for the former (IBRA version 4) Tanami bioregion for this year and previous years can be found at: http://www.ea.gov.au/land/monitoring/ttrace/tan.html

Landforms and hydrology

The Tanami bioregion consists of the mainly red quaternary sand plains overlying the Wiso Basin in the west and the Georgina Basin in the east. The Wiso Basin consists of Early Cambrian to Devonian (354-545 million year old) sedimentary and volcanic rocks. Neoproterozoic to Devonian (354-1,000 million year old) sediments form the Georgina Basin. The basin generally consists of featureless sand plains, alluvial plains with a few low ridges and stony rises.

In the west of the bioregion is the Granites-Tanami Block comprising Palaeoproterozoic (1,600-2,500 million year old) granites, sediments and mafic volcanics. The province is characterised by sandplains and low hills. Gold and silver mineralisation occurs within this province.

For more detailed geological information and map refer to the Australian Geological Survey Organisation website: www.agso.gov.au/map/ and the Northern Territory Geological Survey website: www.dme.nt.gov.au/ntgs/ntgs/geo_overview/geo_over.html

Soils

Soils of the sand plains are predominantly red earthy sands with some red earths and red sandy loams with a gravely or stony crust on lateritic rises.

For more soils information refer to the Digital Atlas of Australian Soils at:

www.brs.gov.au/data/datasets/atlas/index.html

Vegetation

There has been no comprehensive compilation of the plant species known from this bioregion, however Connors, et. al., (1996) have listed 1,073 plant species in the NT portion of this bioregion combined with the Murchison-Davenport bioregion. Species diversity increases to the north due to the presence of species with tropical affinities.

Spinifex (hummock grass) covers most of the Tanami bioregion. The over-storey varies according to variations in topography and substrate.

In the sand plains, soft spinifex (Triodia pungens) or curly spinifex (Plectrachne schinzii) with a tall-sparse shrubland overstorey of acacias is the predominant plant community. Throughout the region snappy gum (E. leucophloia) and scattered shrubs grow with the spinifex (Triodiasp.) on the rocky hills; coolibah (E. microtheca) and tea tree grow along watercourses and floodouts.

River red gum (E. camaldulensis), coolibah (E. microtheca), bloodwoods (Corymbia sp.) and tea tree (Melaleuca sp.) grow along the watercourses with samphire, bluebush and perennial grasslands associated with claypans, salt lakes and floodouts (Kerle, 1996).

Fauna

There has been no comprehensive comprehensive compilation of the animal species known from this bioregion, however Connors, et. al., (1996) listed 394 vertebrate species in the NT portion of this bioregion combined with the Murchison-Davenport bioregion, including 18 rare and threatened bird and mammal species.

Fauna in the bioregion is typical of the arid zone although some species more usually associated with the wet-dry tropics or gulf regions do occur, mainly in the northern fringe. Termite mounds are abundant on the clayey soils of the palaeodrainage channels.

Lake Surprise (NT) is the terminus of the Lander River, and represents an important drought refuge for water birds in a region largely devoid of large water bodies. Lake Gregory in WA retains some surface water permanently. Around 70 waterbird species, including migratory waders have been recorded, sometimes in vast numbers. More than 100,000 birds occur there regularly, and sometimes as many as 600,000 (Morton et. al., 1995).

There has been a substantial rate of regional extinction of small and medium sized mammals including western quoll (Dasyurus geoffroii), golden bandicoot (Isoodon auratus), brush-tailed bettong (Bettongia penicillata) and the central rock rat (Zyzomyspedunculatus). There is also a probable ongoing decline of other species including the greater bilby (Macrotis lagotis), the common brush-tail possum (Trichosurus vupecula) and the black footed rock-wallaby (Petrogale lateralis) (Woinarski, et. al., in prep.).

The night parrot (Pezoporus occidentalis) maybe extinct in this region, and the princess parrot (Polytelis alexandrae) has declined in the region (Woinarski, et. al., in prep.).

Land Tenure & Use

Land tenure

The bioregion comprises Aboriginal freehold, pastoral leases and conservation reserves. Most of the land is under Aboriginal ownership with the remainder being vacant Crown Land or Crown leasehold. The Devil's Marbles Conservation Reserve is within the bioregion.

Land use

Although the region had been extensively explored and assessed for mineral potential from late in the 19th century, the first pastoral leases were not taken up until the 1920's. Mining continues to occur in The Granites and Tanami mines, mostly for gold.

Aboriginal freehold land includes a number of pastoral properties around the periphery of the bioregion, and along the Stuart Highway. The pastoral enterprises are generally of low to moderate viability. Conservation reserves make up a small proportion of the region and are not representative of the range of ecosystems (Connors et. al., 1996).

Tourism is an important industry to the area, the Devil's Marbles and old gold mines are popular attractions.

Condition Of The Landscape

Land degradation

Fire management in the spinifex country is a major issue (Morton et. al., 1995). The fire regime has changed from the intricate mosaic burning practice associated with Aboriginal land management to one of less frequent but more intense and destructive fires (Woinarski, et. al., in prep.). This loss of traditional Aboriginal mosaic burning has had the effect of homogenising the landscape to the disadvantage of some animals (Connors et. al., 1996).

Some of the plant communities with perennial non-spinifex grasses have also been severely degraded by fire and cattle (Morton et. al., 1995). There has been a documented decline in bird species due to land degradation and habitat alteration by exotic herbivores, as well as fire and predators. These changes have particularly affected chenopod shrublands and grassy riparian environments (Connors et. al., 1996).

Pest species

Rabbits have been widespread, although they are absent from the northern Tanami. Foxes and cats are common and are a major threat to at least the small to medium sized mammals. Horses, donkeys and camels do exist but are uncommon or localised (Morton, et. al., 1995). Other pest species include the house sparrows and house mice (Connors et. al., 1996).

Connors et. al., (1996) recorded 21 weed species in this bioregion together with the Davenport Murchison bioregion including buffel grass (Cenchrus ciliaris), couch grass (Cynodon dactylon), bellyache bush (Jatropha gossypifolia), calotrope (Calotropis procera), parkinsonia (Parkinsonia aculeata), and noogoora burr (Xanthium strumarium).

Social & Economic Aspects

People

The region is very sparsely populated. It is predominantly Aboriginal land, and permits are required to access much of the area. The largest permanent population centres are Aboriginal communities such as Lajamanu and Jarra Jarra which are administered by Community Government Councils. There are also a number of small outstations. Aboriginal communities have been moved around the region by Europeans over the past century, and some of the existing communities are not always based on their traditional lands. Lajamanu in the north west of the region for example is on Gurindji land, but includes Walpiri people who were moved there in the 1940's. Lajamanu is an important centre and includes a school, clinic and airstrip.

Other settlements include The Granites and Tanimi mines which consist of a largely fly in fly out work force. There is a road house at Rabbit Flat providing basic supplies. There are several non-Aboriginal owned pastoral properties such as Supplejack, and Aboriginal owned cattle stations such as Tanami Downs.

There is a regional office of the Central Land Council based just outside the bioregion in Tennant Creek, which provides services and support to the various Aboriginal settlements and outstations in the surrounding regions. The bioregion is within the ATSIC regions of Aputula, Kununurra and Warburton and are managed by the Papunya, Wunan and Western Desert regional councils respectively (McLennan, 1997). The bioregion includes the Karlantijpa North, Karlantijpa South, Warrabri Aboriginal lands and most of the Wirliyajarrayi, Tanami Downs, Yiningarra, Central Desert Aboriginal lands in Northern Territory and part of the Balgo and Lake Gregory aboriginal lands in Western Australia. For more information on the Aboriginal people of this region refer to Horton, (1994) and the relevant websites in the reference list.

Resources, References & Contacts

Publications

Connors G., Oliver B., & Woinarski, J. 1996, Bioregions in the Northern Territory: Conservation Values, Reservations Status and Information Gaps. Final report to ANCA National Reserves System Cooperative Program (Project N607), Parks and Wildlife Commission of the Northern Territory, Palmerston, Northern Territory. (www.nt.gov.au/paw/fauna/bau/intro.htm.)

Hema Maps 1997, Australia Touring Atlas, Fergies Colour Printers, Brisbane, Queensland.

Horton, D. R. 1994, The Encyclopaedia of Aboriginal Australia, Aboriginal Studies Press for the Australian Institute of Aboriginal and Torres Strait Islander Studies, Canberra, ACT.

Kerle, J.A. 1996, Bioregions of the Northern Territory. Draft report Conservation Commission of Northern Territory, Palmerston, Northern Territory.

McLennan. W. 1997, 1994 National Aboriginal and Torres Strait Islander Survey: Social Atlas, Australian Bureau of Statistics, Canberra, ACT.

Morton, S.R., Short, J., & Barker, R.D. with an Appendix by Griffin, G.F., & Pearce, G. 1995, Refugia for Biological Diversity in Arid and Semi-arid Australia, Department of the Environment, Sport and Territories, Canberra, ACT.

Thackway, R. & Cresswell I.D. 1995, An Interim Biogeographical Regionalisation for Australia: a Framework for Setting Priorities in the National Reserves System Cooperative Program, Australian Nature Conservation Agency, Canberra.

Woinarski J., Fensham, R., Whitehead, P. & Fisher, A., with map production by Verhagen, C. in prep., Biodiversity in the Australian Rangelands: a Review of Changes in Status and Threatening Processes. Draft report prepared as a resource document for Project 3: Developing an Adaptive Framework for Monitoring Biodiversity in Australia's Rangelands, of the National Land and Water Resources Audit, Theme 4 (Rangelands monitoring) by the Tropical Savannas Cooperative Research Centre, Darwin, Northern Territory.

Websites and contacts

Aboriginal languages of Australia

http://www.dnathan.com/VL/

Aboriginal Studies WWW Virtual Library

http://www.ciolek.com/WWWVL-Aboriginal.html

Australian Torres Strait Islanders Commission (ATSIC)

www.atsic.org.au/about_atsic/board_regional_councillors/regional_information.htm

Australian Geological Survey Organisation, Geology of Australia

www.agso.gov.au/map/

Bureau of Meteorology, Climate averages

http://www.bom.gov.au/climate/map/climate_avgs/a14ga.shtml

http://www.bom.gov.au/climate/map/climate_avgs/a14f.shtml

Bureau of Meteorology, Temperature and Rainfall graphs

www.bom.gov.au/climate/forms/map_forms/new_imagemaps/nt_name.html

Bureau of Rural Sciences, Digital Atlas of Australian Soils

www.brs.gov.au/data/datasets/atlas/index.html

Central Land Council

http://www.clc.org.au

Charles Sturt University: Guide to Australia - NT

http://www.csu.edu.au/australia/nt.html

Connors G., Oliver B., & Woinarski, J. 1996, Bioregions in the Northern Territory: Conservation Values, Reservations Status and Information Gaps. Final report to ANCA National Reserves System Cooperative Program (Project N607), Parks and Wildlife Commission of the Northern Territory, Palmerston, Northern Territory. (www.nt.gov.au/paw/fauna/bau/intro.htm.)

Department of Primary Industries and Fisheries, Rangelands of the Northern Territory

www.nt.gov.au/dpif/rangelands/rl_index.shtml

Environment Australia, Normalized Difference Vegetation Index information including bioregional information

www.ea.gov.au/land/monitoring

Northern Land Council

www.nlc.org.au

Northern Territory Department of Lands, Planning and Environment

www.lpe.nt.gov.au

Northern Territory Geological Survey

www.dme.nt.gov.au/ntgs/ntgs/geo_overview/geo_over.html

Northern Territory Government Tourism www.nt.gov.au/ntg_internet/profile/regions_alice_springs.shtml

and

nttc.com.au/

Tropical Savanna Co-operative Research Centre

www.savanna.ntu.edu.au/information/savannaexplorer.html

Link to the Map Maker to make a map using this information.

Before you download

Most publications are downloadable as PDF files. Adobe Acrobat Reader  is required to view PDF files.

If you are unable to access a publication, please contact us to organise a suitable alternative format.

Key

   Links to an another web site
   Opens a pop-up window