Australian Natural Resources Atlas

Natural Resource Topics

Rangelands - Overview

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Location map of Mount Isa Inlier bioregionphotograph

Mount Isa Inlier

Summary

ATSIC Boundaries

Catchment Basins

Statistical Local Areas

Introduction

The Mount Isa Inlier bioregion includes about 66,600 sq. kms of land. The majority of the bioregion lies within Queensland (99%) with a small area extending into Northern Territory. The bioregion is characterised by rugged hills to mountain ranges and outwash areas. The main towns are Mount Isa, Camooweal and Cloncurry. The bioregion has a semi-arid climate.

Natural Environment

Climate

Climate averages are available for Mount Isa: http://www.bom.gov.au/climate/map/climate_avgs/a27.shtml.

Temperature and rainfall graphs are available for Mount Isa: www.bom.gov.au/climate/forms/map_forms/new_imagemaps/qld_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 Mount Isa Inlier bioregion for this year and previous years can be found at: http://www.environment.gov.au/erin/ndvi/ttrace/mii.html.

For additional climate information the Queensland Department of Natural Resources ‘The Long Paddock’ at: www.dnr.qld.gov.au/longpdk provides seasonal variability information and the latest El Ni?o Southern Oscillation (ENSO) information. ‘Silo’ at: www.dnr.qld.gov.au/resourcenet/climate provides agro meteorological data, such as rainfall, temperature, radiation, climate outlook products. The Queensland Department of Natural Resources’ Patched Point Dataset and Data drill at: www.dnr.qld.gov.au/resourcenet/silo/index.html, provides information on climatic risk management in agriculture, pastoralism, water resources and natural resource management.

Landforms and hydrology

The geology of the bioregion is varied and complex. The Mount Isa Inlier is the main geological province within the bioregion. It consists of Proterozoic sediments (545+ million years ago) and igneous rocks, which are intensely folded. Mesozoic (65-251 millions years ago) sediments of the Carpentaria Basin and Proterozoic marine sediments of the Lawn Hill Platform outcrop mainly in the north and northwest of the bioregion.

The Mount Isa Inlier forms rugged ranges separated by undulating valleys. The Mesozoic sediments generally form remnant undulating plateaux and plains with low hills. The Lawn Hill Platform sediments in the north form low rugged hills.

The Selwyn and Waggaboonyah Ranges form a central northwest to north trending watershed. Streams draining to the north flow into the Gregory, Leichhardt and Cloncurry Rivers and into the Gulf of Carpentaria. Streams to the south flow into the Georgina River into the Lake Eyre Basin.

For more information on the geology see Blake (1987) and refer Australian Geological Survey Organisation. For more detailed geological information and map refer to the Australian Geological Survey Organisation website: www.agso.gov.au/map/ and the Department of Mines and Energy, Queensland: www.dme.qld.gov.au/gsd/index.htm.

Soils

The soils of the bioregion are predominantly shallow red duplexes, red-brown loams and red earths. Areas of clays, alluvial sands and lithosol occur in the north of the bioregion.

For further information on soils refer to Christian et al (1954), Perry et al (1964) and Sattler & Williams (1999) and the Digital Atlas of Australian Soils.

Vegetation

The predominant vegetation is low open woodland of snappy gum (Eucalyptus leucophloia) with bloodwoods (Corymbia spp.) and silver-leaved box (Eucalyptus pruinosa) over open-hummock grassland of soft and curly spinifex (Triodia pungens — Triodia bitextura). Areas of gidgee (Acacia cambagei) and bloodwoods (Corymbia spp.) with Mitchell grasses (Astrebla spp.) and buffel grasses (Cenchrus spp.) occur on sand and alluvial plains (Christian et al 1954, Horton, 1976, Nelder, 1991, and Perry et al 1964).

The vulnerable plant species Ptilotus maconochiei and an undescribed species of Heliotropium have been reported in the Mount Isa highlands. Also recorded from the Mount Isa highlands are Goodenia angustifolia, round-leaved wattle (Acacia strongylophylla) and hill kurrajong (Brachychiton collinus). These plants are all considered to be rare relict populations (Morton, et. al., 1995).

Other significant rare and threatened populations occurring within this bioregion are Amaranthus pallidiflorus, Ptilotus royceanus, Ipomoea antonschmidii, Fimbristylis distincta and Croton tomentellus (Morton, et. al., 1995). For a list of rare and threatened flora and vegetation descriptions of the bioregion refer to Sattler & Williams (1999).

Fauna

Comprehensive surveys of fauna have not been carried out in the bioregion. Common species found within ranges of the bioregion are the common rock-rat (Zyzomys argurus), euro (Macropus robustus) and goannas (Varanus acanthurus & Varanus storri). In the woodland areas common species encountered are cockatiel (Nymphicua hollandicus) and the bearded dragon (Pogona barbartus) (Morton, et. al., 1995).

About 22 fauna species are listed as rare and threatened, of which the western quoll (Dasyurus geoffroii geoffroii) is thought to be extinct. The vulnerable black-footed rock wallaby (Petrogale lateralis) occurs near Mount Isa (particularly in the Selwyn Ranges) and the spectacled hare-wallaby (Lagorchestes conspicillatus) occurs uncommonly across the region. Regionally endemic to the area is a gecko (Gehyra robusta), and a skink, (Ctenotus striaticeps) (Morton, et. al., 1995). For a list of rare and threatened fauna is refer to Sattler & Williams (1999).

Land Tenure & Use

Land tenure

The bioregion includes pastoral leasehold and nature reserves. 5.3% of the bioregion is included within conservation reserves (Woinarski, et. al., in prep.). The conservation reserves within the bioregion are Camooweal Caves National Park, Lawn Hill National Park and part of Lawn Hill Resource Reserves.

The Australian Fossil Mammal Site World Heritage property is located in the north of the bioregion. The Riversleigh site has one of the world’s richest Oligo-Miocene (15-25 millions years ago) mammal records. The fossil record spans at least 20 million years providing records of distinctive groups of living mammals as well as unique and extinct mammals. The site provides information on how the environment changed over time from a rich rainforest to semiarid grassland. For more information refer to the Environment Australia web site: www.environment.gov.au/heritage/awhg/whu/sites/fossil.html.

Land use

The dominant land uses are cattle grazing and mining. The large mines in the region are Mount Isa Copper Mine and Century Lead-Zinc Mine.

Condition Of The Landscape

Land degradation

Most of this bioregion is rugged, grazing levels are usually low. However some land degradation is resulting from over-grazing of many of the alluvial terraces (Sattler & Williams 1999 and is of particular concern (Morton, et. al., 1995).

Mining activities have a relatively localised impact. There are concerns about the impact on biodiversity from the sulphur dioxide emissions from the smelter plant at Mt Isa. Research indicates changes in plant, ant, reptile and bird species composition in the vicinity of the smelter to about 15km away (Woinarski, et. al., in prep.).

Pest species

There are widespread reports of high numbers of feral cats, wild dogs, cane toads and feral pigs. Feral horses and pigs have a major impact on pastoral land and natural ecosystems (Woinarski, et. al., in prep.).

The weed invasion tends to be related to human traffic or the intensity of land use. Noogoora burr (Xanthium pungens) and hyptis (Hyptis sauveolens) are a major threat to native plants and the value of pastoral land. Mesquite (Prosopis spp.) occurs as dense infestation around the Cloncurry area (www.savanna.ntu.edu.au/information/savannaexplorer.html).

Social & Economic Aspects

People

Mount Isa is the major city with a population of 22,866 within the bioregion. It is the mining, industrial and commercial capital of Northwest Queensland. The Barkly Highway is the main transport route through the bioregion, which links the Northern Territory to Northern Queensland and the rest of the eastern Australia. The Inlander railway service operates from Townsville to Mount Isa. The major components of the Mount Isa economy are mining, mineral processing, tourism and pastoralism.

In 1923 a lone prospector, John Campbell Miles stumbled across one of the world’s richest copper, silver, lead and zinc ore bodies. He called the new discovery Mount Isa. The Mt Isa Mines is one of Australia’s major mining companies.

Cloncurry in the east of the bioregion is the birthplace of the Royal Flying Doctor Service in 1867. The town recorded the hottest temperature in Australia, 48.8° C in January 1887 (www.rlq.dcilgp.qld.gov.au).

The Queensland local governments of Mount Isa, Boulia, Cloncurry and Burke are included in the bioregion. The bioregion is within the ATSIC regions of Mount Isa (McLennan, 1997). 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

Blake, D.H. 1987. Geology of the Mt Isa Inlier and Environs, Queensland and Northern Territory. Bureau of Mineral Resources Bulletin 225. Australian Government Publishing Service, Canberra.

Christian, C.S., Noakes, L.C., Perry, R.A., Slatyer, R.O., Stewart, G.A. and Traves, D.M. 1954. Survey of the Barkly Region, Northern Territory and Queensland, 1947-48. Land Research Series No. 3. CSIRO, Melbourne.

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.

Horton, Helen 1976. Around Mt. Isa. Aguide to the Flora and Fauna. University of Queensland Press.

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.

Nelder, V.J. 1991. Vegetation Survey of Queensland - Central Western Queensland. Botany Bulletin No. 9, Queensland Department of Primary Industries, Brisbane.

Perry, R.A., Sleeman, J.R., Tindale, C.R., Prichard, C.E., Slatyer, R.O., Lazarides, M. and Collins, F.H. 1964. General Report on Lands of the Leichhardt-Gilbert Area, Queensland, 1953-54. Land Research Series No. 11. CSIRO, Melbourne.

Sattler, P. & Williams, R. (eds.) 1999, The Conservation Status of Queensland’s Bioregional Ecosystems, Environmental Protection Agency, Brisbane, Queensland.

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, ACT.

Woinarski J., Fensham, R., Whitehead, P. & Fisher, A., with map production by Verhagen, C. in preparation, 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 Landcare Council:

www.affa.gov.au/content/output.cfm?ObjectID=D2C48F86-BA1A-11A1-A2200060B0A04292

Aboriginal Torres Strait Islanders Commission (ATSIC):

www.atsic.gov.au/

Australian Geological Survey Organisation, Geology of Australia:

www.agso.gov.au/map/

Bureau of Meteorology, Climate averages:

www.bom.gov.au/climate/map/climate_avgs/a17.shtml

http://www.bom.gov.au/climate/map/climate_avgs/a37.shtml

Bureau of Meteorology, Temperature and rainfall graphs: www.bom.gov.au/climate/forms/map_forms/new_imagemaps/qld_name.html

Bureau of Rural Sciences, Digital Atlas of Australian Soils:

www.affa.gov.au/content/output.cfm?ObjectID=D2C48F86-BA1A-11A1-A2200060B0A05758

Department of Mines and Energy, Queensland:

www.dme.qld.gov.au/gsd/index.htm

Department of the Environment and Heritage, Australian Fossil Mammal World Heritage Site:

www.environment.gov.au/heritage/worldheritage/sites/fossil/index.html

Department of the Environment and Heritage, Normalized Difference Vegetation Index (NDVI) information including bioregional information:

www.environment.gov.au/erin/ndvi/index.html

National Property Management Planning Campaign, The Future profit program:

www.dpi.qld.gov.au/ruraldev/futureprofit/Welcome.html

Queensland Department of Natural Resources. ‘Long Paddock’:

www.dnr.qld.gov.au/longpdk

Queensland Department of Natural Resources. ‘Silo’:

www.dnr.qld.gov.au/resourcenet/climate/#silo

Queensland Department of Natural Resources. Patched Point Dataset and Data drill:

www.dnr.qld.gov.au/resourcenet/silo/index.html,

Queensland’s Environmental Protection Agency. National Park information, animal and plant species information including rare and threatened species:

www.env.qld.gov.au

Queenslands Parks and Wildlife Service:

www.env.qld.gov.au/environment/park/discover/

Rural Lifestyles Queensland:

www.rlq.dcilgp.qld.gov.au

State-wide Land cover and Tree Study (SLATS) Vegetation cover and cover change information using Landsat Thematic Mapper ™ satellite imagery:

www.dnr.qld.gov.au/resourcenet/veg/slats/index.html

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.

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