Ecological Communities - A Biological Survey of the Gawler Ranges

• Summary
• Full Report

Documents for download from this site are in PDF format and you will need Adobe Acrobat Reader to view them. The reader is free and can be downloaded from the Adobe website.

Summary

The Field Survey

Triodia-covered hills typical of much of the Gawler Ranges (Photo: Tony Robinson)

The Gidgee Skink uses its spiny tail to wedge itself into rock crevices (Photo: Steve Doyle)

The Gawler Ranges Mintbush is confined to the hills of the western Gawler Ranges (Photo: Tony Robinson)

After rain Trilling Frogs emerge from sealed burrows beside creek beds (Photo: Tony Robinson)

The Gawler Ranges are rounded hills of volcanic rock over 1,500 million years old supporting a diverse cover of shrubs and mallee in the west with the eastern hills more dominated by Triodia and other grasslands. The broad valleys between the hills support a mixture of Myall woodland and chenopod shrubland. At the time of the survey the whole area was held under pastoral leases and was used for sheep grazing.

A three-week survey from 6-26 October 1985, sampled the vegetation and vertebrate fauna at quadrats located at sixteen sites across the ranges.

Survey Results

A total of 740 plant species were recorded from the area, and three species are endemic to the Gawler Ranges. Analysis of the quadrat data revealed the following community patterning. Thirteen perennial plant communities and thirteen communities based on the total flora. There was good correspondence between these communities in the tall shrublands, saltmarshes the porphyritic hill and sand dune communities but the total flora analysis revealed an extensive ephemeral herbland/grassland community on the valley loams where extensive sheep grazing has resulted in the establishment of a number of introduced ephemerals and grasses over wide areas.

Thirty-two mammal species (seven introduced) were recorded from the area and these were classified into five small ground mammal communities. There has been total extinction of the medium-sized mammals in the area since European settlement so that these communities would originally have been much more diverse.

The Gawler Ranges is known to have supported 164 bird species and 121 were recorded on the survey. Ten of the original 15 collections of the Night Parrot originated from this area, but this species has not been reliably sighted here since the late 1800s. Of the six passerine bird communities, three were biologically interpretable: one was confined to the southern tall shrublands, another was a geographically widespread group of habitat generalists found in the other treed bird habitats throughout the study area and a third very characteristic group was confined to the treeless chenopod shrublands.

Fifty-nine species of reptiles and three frog species have been recorded including three additions from the survey. Of the six reptile communities, five represented specific habitat preferences for fallen logs, sandy loams with litter, treeless chenopod shrubland, the northern drier and more open chenopod shrublands and the rocky outcrops on the porphyritic hills respectively. An analysis of all the species produced seven well-defined overall communities which were dominated by plant species.

To achieve conservation of all these diverse plant and animal communities in the Gawler Ranges five "Key Biological Areas" and three "Ecologically Valuable Areas" have been defined.

Vegetation Mapping

Vegetation has been mapped over the area surrounding each of the survey sites at a scale of 1:100,000 for the first time.

These vegetation maps are the first step of an ongoing program to ultimately produce vegetation maps at three regional scales to cover the whole State. See also A Vegetation Map of the Western Gawler Ranges, South Australia.

Reference: Robinson, A.C., Casperson, K.D., Canty, P.C. and Macdonald, C.A. (1988). A Biological Survey of the Gawler Ranges, South Australia in October 1985. South Australian National Parks and Wildlife Service and South Australian Museum, Adelaide.

Full Report

A full report of 'A Biological Survey of the Gawler Ranges, South Australia' is available as Acrobat PDF files.

Part 1 - Contents, Acknowledgements, People Involved, Introduction and Methods (2.8Mb PDF)
Part 2 - Results


• 2a - Vegetation, Introduction and Floristic Vegetation Analysis (4.2Mb PDF)
• 2b - Relative Abundance of Plant Species, Mammals, Birds, Reptiles and Biological Patterns in the Gawler Ranges (3.2Mb PDF)
  
Part 3 - Conclusions and Conservation Recommendations and Resource Materials and Bibliography (650Kb PDF)
Part 4 - Appendices

• 4a - Appendix I (6.3Mb PDF)
• 4b - Appendix II, III, IV and V (1.2Mb PDF)

Please note that some of the above files are very large and may take a while to download. To search these files you will need to open the "Bookmarks tag" within each file. If you have any problems please contact Robert Brandle or phone (61 8) 8222 9471.